Publications

essential fatty acid nutrition of the american alligator (alligator mississippiensis).	the essential fatty acid (efa) nutrition of young american alligators (alligator mississippiensis) was examined by feeding a variety of fats/oils with potential efa activity. over a 12-wk period, alligators fed diets containing 2.5 or 5.0% chicken liver oil grew longer and heavier and converted feed to body mass more efficiently than alligators fed other fat/oil combinations that lacked or contained only trace amounts of arachidonic acid [20:4(n-6)]. alligators fed an efa-deficient diet (contain ...	1990	2114472
microsomal activation of benzo[a]pyrene by alligator mississippiensis: mechanisms, mutagenicity and induction.		1991	1783208
primary structure of two forms of gonadotropin-releasing hormone from brains of the american alligator (alligator mississippiensis).	two forms of gonadotropin-releasing hormone (gnrh) have been purified from brains of the american alligator, alligator mississippiensis, using reverse-phase high-pressure liquid chromatography (hplc). the concentration of total gnrh was 8.8 ng/g of frozen brain tissue or 21.1 ng per brain. the amino acid sequence of each form of gnrh was determined using automated edman degradation. the presence of the n-terminal pglu residue was established by digestion studies with bovine pyroglutamyl aminopep ...	1991	1882082
inositol phosphate formation in uterine tissue from two species of reptiles is stimulated by arginine vasotocin and influenced by stage of reproduction.	phosphoinositide hydrolysis, resulting in inositol trisphosphate (ip3) and diacylglycerol (dg) formation, has been implicated in oxytocin-stimulated pulsatile secretion of prostaglandin f2 alpha (pgf2 alpha) from uterine endometrium of sheep and other mammals. in reptiles, arginine vasotocin (avt) stimulates uterine secretion of pgf2 alpha. these studies investigated the ability of avt to stimulate incorporation of [3h]inositol into inositol mono-, bis-, and trisphosphates in two reptilian speci ...	1991	1936930
contaminants in american alligator eggs from lake apopka, lake griffin, and lake okeechobee, florida.	residues of organochlorine pesticides, polychlorinated biphenyls (pcbs), and 16 elements were measured in american alligator (alligator mississippiensis) eggs collected in 1984 from lakes apopka, griffin, and okeechobee in central and south florida. organochlorine pesticides were highest in eggs from lake apopka. none of the elements appeared to be present at harmful concentrations in eggs from any of the lakes. a larger sample of eggs was collected in 1985, but only from lakes griffin, a lake w ...	1991	24241940
time course of temperature effects on arterial acid-base status in alligator mississippiensis.	temperature effects on extracellular acid-base status in terrestrial poikilotherms are well known. comparatively less is known concerning the time course of acid-base responses to prolonged changes in temperature. in this study, two questions were addressed: (1) what is the time course of acid-base responses to a temperature change of 5 days duration in alligator mississippiensis?; and (2) what are the relative contributions of respiratory vs metabolic (strong ion) processes to the acid-base res ...	1991	1902966
the effects of norethindrone on the mullerian ducts of the american alligator.	norethindrone, a reported aromatase inhibitor, has been used to examine the role of estrogens in the unilateral regression of the mullerian ducts that occurs in female chick embryos. the mullerian ducts are embryonic oviducts that regress in most male vertebrates under the influence of the testicular hormone, mullerian inhibiting substance (mis). the ovaries of the chick also produce mis during early development, but only the right duct regresses. based on the finding that the left duct contains ...	1991	1783275
a new method for obtaining electrocardiograms in unrestrained crocodilian reptiles.	a new procedure is described for acquiring measurements of electrocardiographic parameters in unrestrained crocodilians. these measurements are difficult to obtain in freely moving animals; hence, electrocardiographic activity under natural conditions has not been previously quantified. in this investigation, twelve american alligators were equipped with subcutaneous electrodes. the lead wires were sutured to each animal's skin and the extracutaneous wires coiled and held in place against the an ...	1992	1316516
alligators provide evidence for the evolution of an archosaurian mode of oviparity.	the female reproductive tract of birds is different from that of other oviparous amniotes in that the eggshell membranes and calcareous layer are formed in separate regions of the uterus; the isthmus and shell gland, respectively. phylogenetically, birds are included among the archosaurs, along with crocodilians and dinosaurs. many dinosaurs were oviparous, producing hard-shelled eggs, yet the reproductive system of dinosaurs has proven difficult to investigate, due to poor preservation of soft ...	1992	1547315
actin filaments associated with the basal sertoli cell surface in the alligator and turtle.	we have studied, using electron microscopy, the basal cytoplasm of sertoli cells in the alligator (alligator mississippiensis) and the turtle (pseudemys scripta). filament bundles occur immediately adjacent to the basal plasma membrane. the diameter of these filaments is smaller than that of perinuclear intermediate filaments, but is similar to that of filaments present in peritubular cells. in the alligator, the filament bundles appear to form a branching network over the base of the cell and a ...	1992	18621219
effects of vagotomy on ventilatory responses to co2 in alligators.	reptiles increase ventilation during hypercapnia at a constant temperature. in this study, the contributions of vagal vs non-vagal receptors to co2 ventilatory responses were investigated in 16 sedated alligator mississippiensis (25 mg/kg pentobarbital; 3 days prior to data collection). four animals served as controls to assess the effects of time and/or anesthetic drift on ventilation and blood gases; significant ventilatory drift was not detected during the observation period. the effects of b ...	1992	1313182
purification and biological activity of alligator bradykinin.	incubation of plasma form the alligator (alligator mississipiensis) with glass beads in the presence of a kininase inhibitor resulted in the activation of the kallikrein-kinin system and generation of bradykinin-like immunoreactivity. the kinin peptides were purified to homogeneity and were shown to comprise [thr6]-bradykinin and des-arg9[thr6]bradykinin in the molar ratio of approximately 10:1. bolus injections of synthetic [thr6]bradykinin into the jugular vein of the anesthetized alligator re ...	1992	1510179
the pressor response to exogenous angiotensin i and its blockade by angiotensin ii analogues in the american alligator.	we examined the pressor response to exogenous, nonnative angiotensin i (ang i; bullfrog, turtle, and fowl) in the conscious american alligator, alligator mississippiensis. in addition, the inhibitory effects of three ang ii analogues ([sar1, ala8], [sar1, thr8], and [sar1, ile8]ang ii) on the pressor responses to angiotensin i (fowl ang i, [asp1, val5, ser9]) were also examined. intravenous administration of bullfrog, turtle, and fowl ang i at 0.1, 0.5, and 1.0 micrograms/kg produced dose-depend ...	1992	1624094
effects of converting enzyme inhibition and alpha receptor blockade on the angiotensin pressor response in the american alligator.	this study examines the effects of two converting enzyme inhibitors (captopril and enalaprilat) and two alpha-adrenergic receptor antagonists (phentolamine and phenoxybenzamine) on the pressor response produced by exogenous angiotensin i ([asp1, val5, ser9] ang i, fowl) and [val5] angiotensin ii (ang ii) in the american alligator (alligator mississippiensis). bolus administration of ang i at 0.1, 0.5, and 1.0 micrograms/kg; ang ii at 0.05, 0.1, and 0.5 micrograms/kg; or norepinephrine (ne) at 2 ...	1992	1352511
structural characterization of tachykinins (neuropeptide gamma, neurokinin a, and substance p) from a reptile, alligator mississipiensis.	an extract of the whole brain of the alligator (alligator mississipiensis) contained very high concentrations of substance p-like immunoreactivity (405 pmol/g wet tissue) and neurokinin a-like immunoreactivity (514 pmol/g), as measured with antisera raised against the mammalian peptides. the primary structure of alligator substance p was established as: arg-pro-arg-pro-gln-gln-phe-phe-gly-leu-met-nh2. this sequence is the same as that of chicken substance p and shows one substitution (arg for ly ...	1992	1282482
cloning and expression analysis of two zfy-related zinc finger genes from alligator mississippiensis, a species with temperature-dependent sex determination.	in order to investigate the molecular mechanism of temperature-dependent sex determination, a human zinc finger gene (zfy), known to be highly conserved amongst other species, was used to isolate homologues from the genome of the american alligator, alligator mississippiensis. zfy was originally a candidate for the primary testis-determining gene in man, but is now thought to function further down the sex-determining cascade. two alligator genes are described, zfc and znc6. both code for zinc fi ...	1992	1398103
synthesis of 3 alpha, 7 alpha-dihydroxy-5 beta-cholestan-26-oic acid from 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestan-26-oic acid: configuration in the bile of alligator mississippiensis.	synthesis of 25r- and 25s-diastereoisomers of 3 alpha,7 alpha-dihydroxy-5 beta-cholestan-26-oic acid from 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestan-26-oic acid is described. the 25s-diastereoisomer of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestan- 26-oic acid was obtained by vigorous hydrolysis of the bile of alligator mississippiensis followed by repeated crystallization of the hydrolysate, and the 25r-diastereoisomer was isolated by hydrolysis of the bile salts in bile of a m ...	1992	1519259
neuroendocrine peptides (npy, grp, vip, somatostatin) from the brain and stomach of the alligator.	despite the important position of the reptiles in phylogeny, relatively few regulatory peptides from reptilian species have been characterized structurally. neuropeptide y was isolated from the brain of the alligator, alligator mississippiensis, and vasoactive intestinal polypeptide (vip), gastrin-releasing peptide (grp), its cooh-terminal decapeptide (grp-10), and somatostatin-14 were isolated from the alligator stomach. the primary structures of npy and somatostatin-14 are the same as the corr ...	1993	8101369
purification and primary structure of alligator neurotensin.	the gastrointestinal neurohormones of reptiles have been poorly characterized structurally. neurotensin has been purified to apparent homogeneity from an extract of the small intestine of the alligator, alligator mississipiensis. the primary structure of the peptide (pglu-leu-his-val-asn-lys-ala-arg-arg-pro-tyr-ile-leu) is identical to that of chicken neurotensin. the data provide further evidence for a close phylogenetic relationship between crocodilians and birds.	1993	8284256
new angiotensin i isolated from a reptile, alligator mississippiensis.	angiotensin i (ang i) of the american alligator alligator mississippiensis was isolated from incubates of homologous plasma and kidney extract, and its amino acid sequence was determined as h-asp-arg-val-tyr-val-his-pro-phe-ala-leu-oh. the presence of strongly hydrophobic alanine at position 9 is unusual among angs i sequenced to date. since alanine can be converted to serine by a one-point mutation of the triplet nucleotides, the phylogenetic proximity of the alligator to birds, whose ang i has ...	1993	8319878
primary structure of neuropeptide y from brains of the american alligator (alligator mississippiensis).	the purification of npy from brains of the american alligator (alligator mississippiensis) was achieved using reverse-phase high performance liquid chromatography (hplc). the amino acid sequence was determined using automated edman degradation as tyr-pro-ser-lys-pro-asp-asn-pro-gly-glu- asp-ala-pro-ala-glu-asp-met-ala-arg-tyr-tyr-ser-ala-leu-arg-his-tyr-ile- asn-leu - ile-thr-arg-gln-arg-tyr. alligator npy is the first non-mammalian vertebrate to have 100% sequence identity to human npy. the con ...	1993	8351403
localization of insulin-like growth factor-i-like immunoreactivity in the reproductive tract of the vitellogenic female american alligator, alligator mississippiensis.	insulin-like growth factor i (igf-i) is a 70 amino acid, mitogenic polypeptide, which, in mammals, acts through an endocrine, paracrine, and/or autocrine pathway to regulate growth and development. the primary goal of this study was to determine whether or not igf-i-like immunoreactivity is present in the oviduct of the vitellogenic american alligator, alligator mississippiensis, and if immunoreactivity patterns vary among the three functional oviducal regions: the albumen-secreting tube region, ...	1993	8379588
purification and properties of alligator mississipiensis cytochrome c.	cytochrome c has been purified to homogeneity from alligator liver (alligator mississipiensis) using aluminum sulfate precipitation, cm-cellulose and gel-filtration chromatography, and reverse-phase hplc. the protein exhibited a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an approximate molecular weight of 12,000 da. oxidized and reduced visible spectra yielded maxima at 408 (tau) nm and 315 (delta), 415 (tau), 520 (beta), and 550 (alpha) nm, respectively, while ...	1993	8384830
fibrous trabeculae in the liver of alligator (alligator mississippiensis).	in the mature alligator, fibrous trabeculae run from the portal areas and capsule through the hepatic parenchyma. the extent of these trabeculae becomes clear only after staining for collagen with, for example, fast green or picrosirius red. the trabeculae are less well developed in young caiman. the alligator's liver might use the trabeculae to withstand thrashing of the body.	1993	8363042
effect of temperature on central chemical control of ventilation in the alligator alligator mississippiensis.	central chemoreceptor function was assessed in unanesthetized alligators, alligator mississippiensis, at body temperatures of 15, 25 and 35 degrees c. two experiments were performed. in the first experiment, the fourth ventricle was perfused with mock cerebrospinal fluid (csf) solutions of different ph values (7.1-7.9). changes in pulmonary ventilation were evaluated with a pneumotachograph and arterial ph (pha) was measured. perfusion with low-ph solutions increased ventilation and arterial ph. ...	1993	8340730
chemoreception in crocodilians: anatomy, natural history, and empirical results.	anatomical and behavioral aspects of chemoreception in crocodilians are reviewed. extant crocodilians possess valvular nostrils regulated by smooth muscles; paired nasal cavities, each with three conchae; and flaps closing the rear of the buccopharyngeal passage to channel inspired air through the nasopharyngeal duct. olfaction is enhanced by gular pumping, whereby the floor of the pharynx is alternately lowered and raised to pulse air through the nasal cavity. taste buds occur on the tongue, pa ...	1993	8477347
extended production of the müllerian duct regressor in the american alligator.	regression of the müllerian ducts in mammals and birds is caused by the testicular hormone, müllerian inhibiting substance (mis), which is produced for an extended period of time after testicular differentiation. because it is present long after the ducts regress, it has been proposed to have additional effects other than inducing mullerian duct regression. a testicular substance also appears to be responsible for müllerian duct regression in the alligator based on studies in which testicular gr ...	1994	7843560
ontogeny and regional distribution of hormone-producing cells in the embryonic pancreas of alligator mississippiensis.	the hormones of the endocrine pancreas are believed to play an important role in early development. the development of the pancreas and the appearance of hormone-producing cells during embryogenesis have been extensively studied in mammals and birds. relatively little work has been done in other vertebrates, and there are no published studies regarding the order crocodilia. given the pivotal phylogenetic position of crocodilians, alligator mississippiensis provides an interesting species in whic ...	1994	7926634
glutamic acid decarboxylase immunoreactivity in some dorsal thalamic nuclei in crocodilia.	glutamic acid decarboxylase (gad) immunocytochemical properties of thalamic nuclei known to project to the telencephalon were investigated in reptiles, caiman crocodilus and alligator mississippiensis, by monoclonal antibodies to gad epitopes designated as gad-1, gad-2 and gad-5. gad-immunoreactive puncta were observed with all three monoclonal antibodies in the following dorsal thalamic nuclei by avidin-biotin complex methodology: dorsolateralis anterior, dorsomedialis anterior, diagonalis, rot ...	1994	7517022
chloride-dependent organic phosphate sensitivity of the oxygenation reaction in crocodilian hemoglobins	we show that crocodilian hemoglobins (hbs), which previously have been considered to be model pigments lacking allosteric interaction with organic phosphate esters, do exhibit oxylabile atp and 2,3-diphosphoglycerate (dpg) binding that decreases o2 affinity and increases ph sensitivity (bohr effect), in the absence of cl- and at the low cl- concentrations that may occur in crocodilian plasma during 'post-ingestive alkaline tides'. hbs from different species vary in their phosphate sensitivities. ...	1994	9317219
purification and primary structure of galanin from the alligator stomach.	galanin-like immunoreactivity (6 pmol/g tissue) was detected by radioimmunoassay in an extract of the stomach of the alligator, alligator mississipiensis, but the peptide was present only in low concentration (< 0.5 pmol/g) in extracts of the brain and small intestine. alligator galanin comprises 29 amino acid residues and contains an alpha-amidated c-terminal residue. residues 1-22 of alligator galanin are identical to the corresponding sequence in pig/sheep/rat galanins, demonstrating that str ...	1994	7524049
the karyotype of alligator mississippiensis, and chromosomal mapping of the zfy/x homologue, zfc.	comparative mapping studies of x-linked genes in mammals have provided insights into the evolution of the x chromosome. many reptiles including the american alligator, alligator mississippiensis, do not appear to possess heteromorphic sex chromosomes, and sex is determined by the incubation temperature of the egg during embryonic development. mapping of homologues of mammalian x-linked genes in reptiles could lead to a greater understanding of the evolution of vertebrate sex chromosomes. one of ...	1994	7720416
chromosomal and temperature-dependent sex determination: the search for a conserved mechanism.	to test the hypothesis that the same (or similar) genes may be involved in chromosomal sex determination and temperature dependent sex determination we investigated the expression of the mammalian testis determining gene sry in the american alligator (alligator mississippiensis), a species with temperature dependent sex. we have cloned alligator sry-related genes (a-srys) which constitute three major gene classes with high degrees of sequence homology (45-87%) to mammalian sry and related genes. ...	1994	7931128
molecular mechanisms of tsd in reptiles: a search for the magic bullet.	significant progress has been made in understanding mechanisms of genetic sex determination. the zfy gene encodes a zinc finger protein but is not the primary signal in sex determination. the sry gene is the testis determining gene in man, mouse, rabbit, and probably marsupial mouse and wallaby. temperature dependent sex determination probably involves a modification of development of the indifferent gonad due to differential expression of one or more specific dna sequences whose behavior is con ...	1994	7931129
dynamics of mhc evolution in birds and crocodilians: amplification of class ii genes with degenerate primers.	genes of the major histocompatibility complex (mhc) are the most polymorphic functional loci in mammalian populations, but little is known of mhc variability in natural populations of nonmammalian vertebrates. to help extend such studies to birds and relatives, we present a pair of degenerate primers that amplify polymorphic segments of one chain (the beta chain) of the class ii genes from the major histocompatibility complex (mhc) of archosaurs (birds+crocodilians). the primers target two conse ...	1995	8564010
central vascular flow patterns in the alligator alligator mississipiensis.	many different flow patterns have been described through the central circulation of crocodilian reptiles. we tested the hypothesis that the vagus nerve stimulation promotes right-to-left (r-l) shunting in the alligator. flow patterns were investigated before and during stimulation of the intact left vagus nerve using three methods. 1) atrial and aortic po2 were measured simultaneously and continuously by gas probes. 2) atrial outflows were tracked with a blood tracer (helium). 3) flows were asse ...	1995	7503302
intraocular pressure variation associated with body length in young american alligators (alligator mississippiensis).	using an applanation tonometer, 5 replicate intraocular pressure (iop) measurements were obtained from each eye of 12 young clinically normal, american alligators. alligator length ranged from 46 to 117 cm, measured from snout to tail tip. all iop were recorded by a single observer at an ambient temperature of approximately 25 c, and ranged from 5 to 35 mm of hg. observer reliability was excellent (intraclass r = 0.93), and iop did not change over the ordered sequence of 5 replicate measurements ...	1995	8928958
mathematical models for growth in alligator (alligator mississippiensis) embryos developing at different incubation temperatures.	a variety of model-based (growth models) and model-free (cubic splines, exponentials) equations were fitted using weighted-nonlinear least squares regression to embryonic growth data from alligator mississippiensis eggs incubated at 30 and 33 degrees c. goodness of fit was estimated using a chi 2 on the sum of squared, weighted residuals, and run and sign tests on the residuals. one of the growth models used (preece & baines, 1978) was found to be superior to the classical growth models (exponen ...	1995	7591979
gonadal steroidogenesis in vitro from juvenile alligators obtained from contaminated or control lakes.	the ubiquitous distribution of many contaminants and the nonlethal, multigenerational effects of such contaminants on reproductive, endocrine, and immune systems have led to concerns that wildlife worldwide are affected. although the causal agents and effects are known for some species, the underlying physiological mechanisms associated with contaminant-induced reproductive modifications are still poorly understood and require extensive research. we describe a study examining the steroidogenic a ...	1995	7556021
insulin-like growth factor-i in the plasma of two reptiles: assay development and validations.	radioimmunoassays (rias) of insulin-like growth factor-i (igf-i) in nonmammals are complicated by two problems: decreased specificity due to heterologous assays and assay interference from igf binding proteins. we have developed and validated an ria for the detection of igf-i in reptilian plasma that circumvents these problems. biochemical validations show parallelism between standard curves, plasma dilutions, and internal standards. further, biological validations indicate that (1) plasma igf-i ...	1995	7781962
breathing pattern and cost of ventilation in the american alligator.	the energetic cost of pulmonary ventilation is termed the "cost of breathing" and is commonly determined from the change in oxygen uptake with altered ventilation. previous analyses of lung mechanics predicts increased tidal volume would be more expensive than increased breathing frequency. existing studies on the oxidative cost of breathing have, however, not addressed breathing pattern. we stimulated ventilation in juvenile alligators by either hypoxia or hypercapnia. both hypoxia and hypercap ...	1995	8610206
interaction of environmental chemicals with the estrogen and progesterone receptors from the oviduct of the american alligator.	reports of reproductive abnormalities in the american alligator from lake apopka, florida, have been linked to a spill of ddt and other pesticides suspected of having hormonelike activity. to determine whether environmental chemicals had the potential to function as exogenous hormones in the american alligator, we examined the ability of chemicals to bind the estrogen receptor (aer) and progesterone receptor (apr) in a protein extract prepared from the oviduct of the alligator. in competition bi ...	1996	9118873
plasma insulin-like growth factor-i concentration during the reproductive cycle of the american alligator (alligator mississippiensis).	insulin-like growth factor i (igf-i) is involved in the growth, reproduction, and development of vertebrates. in this study, we report plasma igf-i concentrations throughout the reproductive cycle of the american alligator (alligator mississippiensis) and consider these concentrations with respect to several reproductive steroid hormones and ions involved in reptilian reproduction. mean plasma igf-i concentrations were significantly different among reproductive stages. maximal plasma concentrati ...	1996	8921362
protamines of reptiles.	we have characterized for the first time the complete primary structure of the main protamine components of the sperm from four reptiles: chrysemys picta (turtle), elaphe obsoleta (snake), anolis carolinensis (lizard), and alligator mississipiensis (crocodilian). these species were chosen to represent one of each of the main phylogenetic branches of this taxonomic group. comparison of these protamine sequences with those already available from other vertebrate groups allows us to define properly ...	1996	8798564
the complete mitochondrial genome of alligator mississippiensis and the separation between recent archosauria (birds and crocodiles).	the complete mitochondrial genome of the alligator, alligator mississippiensis, was sequenced. the size of the molecule is 16,642 nucleotides. previously reported rearrangements of trnas in crocodile mitochondrial genomes were confirmed and, relative to mammals, no other deviations of gene order were observed. the analysis of protein-coding genes of the alligator showed an evolutionary rate that is roughly the same as in mammals. thus, the evolutionary rate in the alligator is faster than that i ...	1997	9402737
a study on biliary ductal system and bile fistula in the american alligator, alligator mississippiensis.	the anomalous arrangement of bile ducts in the crocodylia has not been fully appreciated. a clear understanding of biliary anatomy is necessary in order to create complete bile drainage in these reptiles. the object of this study was to clarify the anatomy of the bile ductal system and to establish total bile fistulas in the american alligator, alligator mississippiensis. bile duct anatomy was studied in 104 juvenile alligators, and bile fistulas were constructed in seven alligators. in 93 out o ...	1997	9399428
the reproductive cycle of the female american alligator (alligator mississippiensis).	we examined ovarian and oviducal gross morphology and collected blood samples from wild female alligators in central florida during most of the year. females with vitellogenic follicles were observed throughout the year, although ovaries containing follicles larger than 15 mm were seen only during the spring and early summer (march-june). we detected a poor relationship between female body size and the number of vitellogenic follicles whereas body size was significantly correlated with clutch si ...	1997	9378277
effects of long-term corticosterone implants on growth and immune function in juvenile alligators, alligator mississippiensis.	sixty juvenile alligators were implanted subcutaneously with slow release pellets of corticosterone or placebo. alligators were divided into five different groups such that each group received a different dose. a blood sample was taken prior to and 4 days after the implants were in place to measure hormone levels. additional blood samples were collected at 1 month and 3 months. at 4 days corticosterone levels ranged from 3,400 ng/ml in the group treated with the high dose to 40 ng/ml in the grou ...	1997	9293640
yolk steroids decline during sexual differentiation in the alligator.	the leading explanation of temperature-dependent sex determination (tsd) in reptiles postulates that (1) ovarian differentiation is directed by estrogen and that (2) estrogen is synthesized in the developing gonad following induction of aromatase expression. however, the source of steroid substrate for aromatization has not yet been identified. in addition, sex ratios vary as a function of clutch, but such biases are as yet unexplained. to address these issues, we measured estradiol, testosteron ...	1997	9245527
alterations in steroidogenesis in alligators (alligator mississippiensis) exposed naturally and experimentally to environmental contaminants.	many environmental contaminants alter the reproduction of animals by altering the development and function of the endocrine system. the ability of environmental contaminants to alter the endocrine system of alligators was studied both in a descriptive study in which juvenile alligators from a historically contaminated lake were compared to animals from a control lake and in an experimental study in which hatchling control alligators were exposed in ovo to several endocrine-disrupting standards a ...	1997	9222139
the isolation of parvalbumin isoforms from the tail muscle of the american alligator (alligator mississipiensis).	multiple parvalbumin isoforms have been detected in the tail (skeletal) muscle of the american alligator (alligator mississipiensis). one of these isoforms (apv-1) has been highly purified and partially characterized. protein purification involved mainly gel filtration and anion exchange chromatography, and characterization included gel electrophoresis, amino acid composition analysis, metal ion analysis, maldi-tof and esi mass spectrometry, ultraviolet and fluorescence spectroscopy, and one- an ...	1997	9076974
identification and characterization of estrogen and progesterone receptors from the oviduct of the american alligator (alligator mississippiensis).	a protein extract prepared from the egg shell fiber-secreting region of the oviduct of alligator mississippiensis was assayed for the presence of receptors for estrogen and progesterone. in the presence of [3h]-estradiol-17 beta, the extract contained an estrogen-binding activity which reached equilibrium at 25 degrees c in 1 h. scatchard analysis demonstrated that a single estrogen-binding activity was present in the extract with a kd of 0.5 nm for [3h]estradiol-17 beta. a steroid specificity c ...	1997	9125170
cck-a- and cck-b-like receptors in the gallbladder and stomach of the alligator (alligator mississippiensis).	autoradiographic analysis of radioligand binding was used to localize and characterize cholecystokinin (cck) receptors expressed in the stomach and gallbladder of the american alligator (alligator mississippiensis). alligator gallbladder smooth muscle expresses a cck-a receptor subtype, and stomach oxyntic mucosa expresses a distinct receptor subtype, termed cck-b/x because of its similarities to both cck-b and cck-x receptors. both the gallbladder and the stomach binding sites have very low aff ...	1997	9000471
tissue mercury concentrations in alligators (alligator mississippiensis) from the florida everglades and the savannah river site, south carolina.	mercury pollution is a serious problem in some areas of the southeastern united states. due to biomagnification, long-lived predators should have high hg concentrations in affected areas. american alligators(alligator mississippiensis) are important predators in many southwestern wetlands, but little information is available on hg concentrations in this species. we collected tissues from alligators inhabiting two sites in the everglades, florida (n = 18) and a manmade reservoir in south carolina ...	1997	9096083
assessment of transmyocardial perfusion in alligator hearts.	techniques for achieving myocardial perfusion directly from the left ventricular chamber are currently under investigation. although originally based on the anatomy of reptilian hearts, which are rich in transmural channels and reported to have a poorly developed coronary vasculature, the blood flow capacity of a transmyocardial blood supply has not been studied in these hearts. with the ultimate goal of providing insight into the potential for achieving transmyocardial perfusion in human hearts ...	1997	9118529
in vitro synergistic interaction of alligator and human estrogen receptors with combinations of environmental chemicals.	the effect of mixtures of environmental chemicals with hormonal activity has not been well studied. to investigate this phenomenon, the estrogen receptor (er) from the american alligator (aer) or human (her) was incubated with [3h]17beta-estradiol in the presence of selected environmental chemicals individually or in combination. the environmental chemicals included the insecticide chlordane, which has no estrogenic activity, and the pesticides dieldrin and toxaphene, which have very weak estrog ...	1997	9168004
mercury distribution in american alligators (alligator mississippiensis) in florida.	thirty american alligators (alligator mississippiensis), including 24 wild-caught and six control captive farm-raised alligators, were analyzed for whole body mercury contamination. wild-caught animals were collected from water conservation area 3 in the everglades ecosystem (n = 12) and from alachua, brevard, and collier counties outside the everglades (n = 12). using cold-vapor atomic absorption spectrophotometry, samples of brain, cervical spinal cord, liver, paired kidneys, paired testes, pa ...	1997	9226618
guanylyl cyclase receptors and guanylin-like peptides in reptilian intestine.	receptors for guanylin and uroguanylin were identified on the mucosal surface of enterocytes lining the intestine of the bobtail skink (tiliqua rugosa), king's skink (egernia kingii), and knight anole (anolis equestris) by receptor autoradiography using 125i-st (escherichia coli heat-stable enterotoxin) as the radioligand. specific, high-affinity binding of 125i-st to receptors was found on the microvillus border of enterocytes and little or no specific binding of 125i-st was observed in other s ...	1997	9245531
purification, amino acid sequence, synthesis, and receptor selectivity of alligator gastrin.	gastrin-like immunoreactive peptides were extracted from the gastric antrum of the american alligator (alligator mississippiensis) and purified by fractionation using c18 sep-paks, sephadex g-50, ph stable c8 reversed-phase hplc, and c18 reversed-phase hplc. three major immunoreactive peaks were purified and found to correspond to 49, 45, and 34 residue peptides by microsequence analysis. the amino acid sequence of the largest peptide was dwlaslsqdq khliskflph iygelan qen ywqeddalhd hdypgwmdf-am ...	1997	9356227
cellular bioavailability of natural hormones and environmental contaminants as a function of serum and cytosolic binding factors.	environmental contaminants have been reported to function as hormone mimics in various wildlife species. to investigate a potential mechanism for the interaction of contaminants with the endocrine system, we evaluated the cellular bioavailability of numerous chemicals. hormone binding proteins from oviductal cytosol of the american alligator (alligator mississippiensis) and yellow-bellied turtle (trachemys scripta) were used in competitive binding assays with [3h] 17 beta-estradiol. most of the ...	1998	9460179
antibiotic effects on cytochromes p450 content and mixed-function oxygenase (mfo) activities in the american alligator, alligator mississippiensis.	there are no food and drug administration (fda)-approved antimicrobial agents for use in cultured american alligators (alligator mississippiensis) destined for human consumption yet some producers administer antibiotics for prophylaxis. the cytochromes p450-dependent mixed-function oxygenases (mfo) catalyze the oxidation of xenobiotic compounds such as drugs, pesticides and polycyclic aromatic hydrocarbons. herein, we describe the effects of oxytetracycline, ceftazidime and enrofloxacin on the m ...	1998	9731949
origin of enamel prisms and hunter-schreger bands in reptilian enamel.	enamel prisms in mammalian enamel structure including human are considered to have originated in the reptilian enamel. the author has reported the original pattern of enamel prisms and of hunter-schreger bands in fossil reptiles of mosasaurus sp. and phytosaurus sp. the origin of the patterns of crystallite groups appear to arise in the fossil reptiles. mosasaurus sp. had an island pattern and phytosaurus sp. had a slender pattern. these two types are of various sizes, and are formed by variable ...	1998	11063014
induction time course of cytochromes p450 by phenobarbital and 3-methylcholanthrene pretreatment in liver microsomes of alligator mississippiensis.	alligator mississippiensis has at least two classes of inducible hepatic microsomal cytochromes p450 (cyp): (1) those induced by 3-methylcholanthrene (3mc), and (2) those induced by phenobarbital (pb). the rates of induction by these xenobiotic compounds are significantly slower than those reported for mammals. carbon monoxide binding, western blots, and enzymatic activity measurements indicated that at least 48-72 hr are required to reach full induction. a methoxy-, ethoxy-, pentoxy, and benzyl ...	1998	10076545
locomotion in alligator mississippiensis: kinematic effects of speed and posture and their relevance to the sprawling-to-erect paradigm	in terms of locomotory posture, amphibians and lizards are considered to be sprawlers, mammals and dinosaurs are considered to be erect, and extant crocodilians are considered to be intermediate because they use the 'high walk', a semi-erect posture where the body is held half-way between the sprawling and erect grades during locomotion. in addition, crocodilians occasionally use a sprawling posture. extant crocodilians, therefore, provide an interesting model in which to investigate the sprawli ...	1998	9716509
mercury in alligators (alligator mississippiensis) in the southeastern united states.	mercury methylation may be enhanced in wetlands and humic-rich, blackwater systems that crocodiles and alligators typically inhabit. given their high trophic level and long life-spans, crocodilians could accumulate significant burdens of hg. our objectives were to survey hg concentrations in alligators from several areas in the southeastern united states to test their utility as sentinels of hg contamination, to examine relationships among hg concentrations in various tissues and to look for any ...	1998	9652131
rapid hydrolysis of bile acid conjugates using microwaves: retention of absolute stereochemistry in the hydrolysis of (25r) 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestan-26-oyltaurine.	in recent years, defects of bile acid synthesis caused by disorders of peroxisome biogenesis have led to increased interest in c27 bile acids. in humans, while the majority of bile acids are c24 carboxylic acids, the presence of increased concentrations of c27 bile acids and their metabolites in hereditary diseases associated with peroxisomal dysfunction can serve as a useful marker for the intensity of the metabolic disorder. our present studies describe an efficient method for the rapid hydrol ...	1998	9560809
relative distribution of polychlorinated biphenyls among tissues of neonatal american alligators (alligator mississippiensis).	recent papers have investigated the utility of chemical analysis of the chorioallantoic membrane (cam) as a nonlethal indicator of avian and reptilian exposure to persistent environmental contaminants. this study was undertaken to evaluate the chemical distribution among fat, cam, and residual yolk tissues of live neonatal american alligators (alligator mississippiensis) to investigate the potential utility of cam use as a nonlethal indicator of exposure to polychlorinated biphenyls (pcbs). cams ...	1999	10473793
rhombomere development in a reptilian embryo.	rhombomere development was investigated in a reptile, alligator mississippiensis, using a variety of methodologies: cytoarchitecture (cresyl violet), histochemistry (peanut agglutinin), immunocytochemistry (antibodies to acetylated tubulin, vimentin, calretinin, and acetylcholinesterase), and external and internal morphology of wholemount embryos. rhombomere boundaries form sequentially until 8 rhombomeres are present at stage 8. from stage 11 onwards, rhombomere borders fade. when present, boun ...	1999	10404256
in vivo locomotor strain in the hindlimb bones of alligator mississippiensis and iguana iguana: implications for the evolution of limb bone safety factor and non-sprawling limb posture	limb postures of terrestrial tetrapods span a continuum from sprawling to fully upright; however, most experimental investigations of locomotor mechanics have focused on mammals and ground-dwelling birds that employ parasagittal limb kinematics, leaving much of the diversity of tetrapod locomotor mechanics unexplored. this study reports measurements of in vivo locomotor strain from the limb bones of lizard (iguana iguana) and crocodilian (alligator mississippiensis) species, animals from previou ...	1999	10101104
serum concentrations of various environmental contaminants and their relationship to sex steroid concentrations and phallus size in juvenile american alligators.	recent studies have reported a number of abnormalities in the hatchling and juvenile alligators of lake apopka, fl (usa). these abnormalities include modifications of plasma concentrations of sex steroids in males and females as well as abnormalities in gonadal morphology, gonadal enzyme activity, and steroidogenesis. embryonic exposure to environmental contaminants in the eggs has been hypothesized to be the causal agent for these changes. however, posthatchling exposure can also contribute to ...	1999	10227864
liver microsomal cytochromes p450-dependent alkoxyphenoxazone o-dealkylation in vitro by alligator and rat: activities, inhibition, substrate preference, and discrimination factors.	six substituted alkoxyphenoxazones (resorufins) and four inhibitors of p450-dependent mixed-function oxygenases (mfo) were used to probe the breadth and extent of p450 metabolism induced by pretreatment with five xenobiotic chemicals in liver microsomes of the american alligator, alligator mississippiensis. phenobarbital (pb), 3-methylcholanthrene (3mc), and pb-3mc co-pretreatment elicited major induction of alligator mfo activity measured by alkoxyresorufin o-dealkylation (arod). the induced le ...	1999	9890444
temperature-dependent sex determination: upregulation of sox9 expression after commitment to male development.	in mammals, birds and reptiles the morphological development of the gonads appear to be conserved. this conservation is evident despite the different sex determining switches employed by these vertebrate groups. mammals exhibit chromosomal sex determination (csd) where the key sex determining switch is the y-linked gene, sry. although sry is the trigger for testis determination in mammals, it is not conserved in other vertebrate groups. however, a gene closely related to sry, the highly conserve ...	1999	10090144
immunochemical analysis of liver microsomal cytochromes p450 of the american alligator, alligator mississippiensis.	ten antibodies raised against various mammalian and fish cytochromes p450 (cyp) enzymes were used to probe the effects of xenobiotic pretreatment on liver microsomes of the american alligator, alligator mississippiensis. pretreatment with phenobarbital (pb), 3-methylcholanthrene (3mc), and pb plus 3mc elicited significant induction of multiple cyp enzymes in alligator, as detected by antibodies to cyp1a, cyp2b, cyp2c, cyp2e, cyp2k, and cyp3a. in contrast to the rat, 3mc treatment induced alligat ...	1999	10373399
identification and characterization of proteins synthesized de novo and secreted by the reproductive tract of the american alligator, alligator mississippiensis.	the objectives of this study were to identify, characterize and examine differences in proteins synthesized de novo and secreted by different regions of the reproductive tract of the american alligator, alligator mississippiensis, during three reproductive (vitellogenic, gravid, post-clutch) and one non-reproductive state. after capture, alligators from lakes in north central florida were anaesthetized, the reproductive tract excised aseptically, the size of any follicle determined, and differen ...	1999	10434925
neuroendocrine peptides (insulin, pancreatic polypeptide, neuropeptide y, galanin, somatostatin, substance p, and neuropeptide gamma) from the desert tortoise, gopherus agassizii.	the traditional view that testudines (tortoises and turtles) should be regarded as the surviving clade of the anapsid reptiles rather than classified with the diapsid reptiles (snakes, lizards, and crocodiles) has recently been challenged. neuropeptide y, neuropeptide gamma, and somatostatin-14 were isolated from an extract of the brain, substance p and galanin from an extract of the intestine, and insulin and pancreatic polypeptide from an extract of the pancreas of the desert tortoise, gopheru ...	1999	10477126
modulation of endocrine pathways by 4,4'-dde in the deer mouse peromyscus maniculatus.	4,4'-ddt and 4,4'-dde are widespread environmental contaminants that cause eggshell thinning in birds, altered sex ratios in the american alligator, and changes in the anal-genital distance in rodents. these contaminants are known to cause some of their toxicity by altering steroid receptor-mediated mechanisms. however, chemical-specific alterations in the expression of hormone-metabolizing enzymes may also be a mechanism for endocrine disruption, by altering the half-life of hormones in critica ...	1999	10492900
temperature-dependent sex determination in the american alligator: amh precedes sox9 expression.	gonadal morphogenesis is very similar among mammals, birds, and reptiles. despite this similarity, each group utilises quite different genetic triggers for sex determination. in mammals, testis development is initiated by action of the y-chromosome gene sry. current evidence suggests that sry may act together with a related gene, sox9, to activate another gene(s) in the pathway of testicular differentiation. a downstream candidate for regulation by sry and sox9 is amh. in mouse, sox9 is expresse ...	1999	10633860
treatment of traumatic perforative fractures of the nasal cavities and paranasal sinus in an american alligator.		1999	93825
temperature-dependent sex determination in the american alligator: expression of sf1, wt1 and dax1 during gonadogenesis.	sex determination in mammals and birds is chromosomal, while in many reptiles sex determination is temperature dependent. morphological development of the gonads in these systems is conserved, suggesting that many of the genes involved in gonad development are also conserved. the genes sf1, wt1 and dax1 play various roles in the mammalian testis-determining pathway. sf1 and wt1 are thought to interact to cause male-specific gene expression during testis development, while dax1 is believed to inh ...	2000	10675033
regional hypoxia elicits regional changes in chorioallantoic membrane vascular density in alligator but not chicken embryos.	hypoxic incubation increases vascularization in the chick chorioallantoic membrane (cam). the effect of regional hypoxia on the vascular density of american alligator (alligator mississippiensis) and chicken (gallus gallus) cams was studied to determine if hypoxic proliferation of blood vessels is localized or global across the cam. eggs were incubated under normoxic conditions with a portion of the eggshell covered with non-toxic beeswax to induce external regional hypoxia. cams were examined u ...	2000	10779731
morbidity and mortality associated with a new mycoplasma species from captive american alligators (alligator mississippiensis).	nine of 74 american alligators (alligator mississippiensis) from a captive florida herd of 3-4-m-long, 200-350-kg, adult males greater than 30 yr of age died within a 10-day period during 1995. nonspecific clinical signs included anorexia, lethargy, muscle weakness, paraparesis, bilateral white ocular discharge, and various degrees of periocular, facial, cervical, and limb edema. pneumonia, pericarditis, and arthritis were found on postmortem evaluation of the spontaneously dead and euthanatized ...	2000	11237136
respiration and gas exchange during recovery from exercise in the american alligator.	low respiratory exchange ratios (r) occur in reptiles. in crocodilians they have been attributed to the loss of respiratory co2 into the urine and to the immediate exercise-history of an animal. in this study, expired ventilation (v(e)), oxygen consumption (v(o2)), and carbon dioxide excretion (v(co2)) were measured during recovery from treadmill-exercise in the american alligator. both v(o2) and v(co2) decreased exponentially during recovery, but the decrease of v(co2) was greater than that of ...	2000	10786647
a screening level probabilistic risk assessment of mercury in florida everglades food webs.	a screening level probabilistic assessment of risks was performed on three species of piscivorous wildlife at the top of everglades aquatic food webs: the american alligator (alligator mississippiensis), the great egret (egretta alba), and the raccoon (procyon lotor varius). ranges of dietary exposure concentrations (and probability distribution functions) were derived for two general areas of the everglades: shark slough and the southcentral everglades (highly contaminated with hg), and the nor ...	2000	11139184
effects of feeding on arterial blood gases in the american alligator alligator mississippiensis.	reptiles habitually ingest large meals at infrequent intervals, leading to changes in acid-base status as the net secretion of acid to the stomach causes a metabolic alkalosis (the alkaline tide). in chronically cannulated and undisturbed amphibians and reptiles, the ph changes in arterial blood are, nevertheless, reduced by a concomitant respiratory acidosis (increased p(co2) caused by a relative hypoventilation). alligators (alligator mississippiensis) have been reported to exhibit exceptional ...	2000	11003822
mercury bioconcentration factors in american alligators (alligator mississippiensis) in the florida everglades.	alligators inhabiting the florida everglades contain elevated levels of mercury within their tissues due to accumulation of mercury in the sediments. the objective of this study was to determine the mercury bioconcentration factors (bcfs) in the alligators based on mercury concentrations in the alligator tissues and mercury levels in the water column. data from studies on mercury concentrations in the everglades alligator tissues and water quality were used to determine the mercury bioconcentrat ...	2000	10993703
oogenesis and ovarian histology of the american alligator alligator mississippiensis.	although folliculogenesis and oogenesis have been observed in numerous reptiles, these phenomena have not been described in detail in a crocodilian. oogenesis and histological features of the adult ovary of alligator mississippiensis are described. using a complex process, the ovary develops telolecithal oocytes that attain a diameter of 38.8 +/- 2.4 mm. the morphology of yolk platelets shows gradual changes throughout the oogenic process. initially, yolk platelets are seen surrounded by a vesic ...	2000	10972971
pelvic aspiration in the american alligator (alligator mississippiensis).	the pelvis of crocodilians is highly derived in that the pubic bones are isolated from the acetabulum and are attached to the ischia via moveable joints. we examined the possible role of this unusual morphology in lung ventilation by measuring ventilation, abdominal pressure and the electrical activity of several abdominal and pelvic muscles in the american alligator (alligator mississippiensis). we found that the activity of two pelvic muscles, the ischiopubis and ischiotruncus muscles, was cor ...	2000	10804158
ventilation and gas exchange during treadmill locomotion in the american alligator (alligator mississippiensis).	a number of anatomical characters of crocodilians appear to be inconsistent with their lifestyle as sit-and-wait predators. to address this paradoxical association of characters further, we measured lung ventilation and respiratory gas exchange during walking in american alligators (alligator mississippiensis). during exercise, ventilation consisted of low-frequency, large-volume breaths. the alligators hyperventilated severely during walking with respect to their metabolic demands. air convecti ...	2000	10804157
metals and metalloids in tissues of american alligators in three florida lakes.	concentrations of metals and selenium were examined in tissues of american alligators (alligator mississippiensis) from three lakes in central florida, in one of which alligators have exhibited reproductive or developmental defects. our overall objective was to determine whether the levels of metals were sufficiently high to confound the association between chlorinated hydrocarbons, which are elevated in eggs and juvenile plasma, and reproductive impairment. the concentrations of all metals were ...	2000	10787102
alligator aromatase cdna sequence and its expression in embryos at male and female incubation temperatures.	in all species of crocodilians, sex is determined not by genetic mechanisms, but by the temperature at which the egg is incubated. in the american alligator (alligator mississippiensis) the thermosensitive period (tsp) for sex determination is a 7- to 10-day window within stages 21-24 of development, around the middle third of the incubation period. treating embryos with estrogen during the tsp produces female offspring, even at male incubation temperatures. conversely, blocking embryonic estrog ...	2001	11555851
postparietal and prehatching ontogeny of the supraoccipital in alligator mississippiensis (archosauria, crocodylia).	the first record of the postparietal bone of alligator mississippiensis, documented by transverse histological sections, is presented. it is the first evidence of the presence of this bone within recent reptiles. the postparietal is present in a specimen with a head length of 32.3 mm. the bone is a small dermal plate lying ventrally and posteriorly to the posterior margin of the parietal and dorsally to the trabecular bone, forming a dorsal surface of the supraoccipital portion of the neural end ...	2001	11466742
multiple paternity and mating patterns in the american alligator, alligator mississippiensis.	eggs were sampled from 22 wild american alligator nests from the rockefeller wildlife refuge in south-west louisiana, along with the females guarding the nests. three nests were sampled in 1995 and 19 were sampled in 1997. females and offspring from all clutches were genotyped using five polymorphic microsatellite loci and the three nests from 1995 were also genotyped using one allozyme locus. genotypes of the hatchlings were consistent with the guarding females being the mothers of their respec ...	2001	11348507
fine structure of the developing epidermis in the embryo of the american alligator (alligator mississippiensis, crocodilia, reptilia).	the morphological transition from the simple epidermis that contacts the amniotic fluid of embryonic crocodilians to the adult epidermis required in a terrestrial environment has never been described. we used light and electron microscopy to study the development, differentiation and keratinisation of the epidermis of the american alligator, alligator mississippiensis, between early and late stages of embryonic skin formation. in early embryonic development, the epidermis consists of a flat bila ...	2001	11322720
mechanics of limb bone loading during terrestrial locomotion in the green iguana (iguana iguana) and american alligator (alligator mississippiensis).	in vivo measurements of strain in the femur and tibia of iguana iguana (linnaeus) and alligator mississippiensis (daudin) have indicated three ways in which limb bone loading in these species differs from patterns observed in most birds and mammals: (i) the limb bones of i. iguana and a. mississippiensis experience substantial torsion, (ii) the limb bones of i. iguana and a. mississippiensis have higher safety factors than those of birds or mammals, and (iii) load magnitudes in the limb bones of ...	2001	11222128
oxygen isotope variability in bones of wild caught and constant temperature reared sub-adult american alligators.	(1) the mean delta18o(bp) ( per thousandsmow) for any given bone sampled from captive alligators maintained at high constant temperature was lower (indicative of higher temperatures of bone deposition) than that of the same bone from wild alligators caught in northern florida, but these differences were only greater than two standard deviations from the mean for the thoracic vertebrae and metatarsal bones. (2) inter-bone variability of delta18o(bp) ( per thousandsmow) was similar for captive all ...	2001	11240224
mycoplasma alligatoris sp. nov., from american alligators.	mycoplasmas were isolated from multiple tissues of diseased american alligators (alligator mississippiensis). this paper presents biochemical, serological and molecular genetic characterizations of a lethal pathogen of alligators for which the name mycoplasma alligatoris sp. nov. is proposed. the type strain is a21jp2t (atcc 700619t).	2001	11321088
expression of dax-1 during gonadal development of the frog.	dax-1, a member of the nuclear hormone receptor superfamily of transcription factors, is known to be involved in gonadal development in mammals. to date, dax-1 has only been isolated in reptiles, birds and mammals. the expression of dax-1 is down-regulated in the developing testis, but persists in the ovary of mice (swain et al., nat. genet. 12 (1996) 404) and chicken (smith et al., j. mol. endocrinol. 24 (2000) 23). curiously, there is no sex difference in the expression patterns of dax-1 in th ...	2001	11738819
alterations in sexually dimorphic biotransformation of testosterone in juvenile american alligators (alligator mississippiensis) from contaminated lakes.	the goal of this study was to determine whether hepatic biotransformation of testosterone is normally sexually dimorphic in juvenile alligators and whether living in a contaminated environment affects hepatic dimorphism. lake woodruff served as our reference site. moonshine bay, located on the west side of lake okeechobee, served as an intermediate site. lake apopka, the belle glade area located at the south end of lake okeechobee, and water conservation area 3a, in the northern everglades, serv ...	2001	11748033
pathology of experimental mycoplasmosis in american alligators.	mycoplasma alligatoris was the suspected etiology of an epidemic of acute multisystemic inflammatory disease which emerged in captive american alligators (alligator mississippiensis) in florida (usa) in 1995. in an experimental inoculation study conducted from april through october 1999, 18 alligators were inoculated with 10(2), 10(4), or 10(6) colony forming units (cfu) of m. alligatoris by instillation into the glottis. as early as 1 wk post-inoculation (pi), mycoplasma were cultured from bloo ...	2001	11763730
detection of antibodies to a pathogenic mycoplasma in american alligators (alligator mississippiensis), broad-nosed caimans (caiman latirostris), and siamese crocodiles (crocodylus siamensis).	an epidemic of pneumonia with fibrinous polyserositis and multifocal arthritis emerged in captive american alligators (alligator mississippiensis) in florida, united states, in 1995. mycoplasma alligatoris sp. nov. was cultured from multiple organs, peripheral blood, synovial fluid, and cerebrospinal fluid of affected alligators. in a subsequent experimental inoculation study, the henle-koch-evans postulates were fulfilled for m. alligatoris as the etiological agent of fatal mycoplasmosis of all ...	2001	11136785