determination of steroidogenic potential of ovarian cells of the brushtail possum (trichosurus vulpecula).the ovary of the brushtail possum (trichosurus vulpecula) secretes steroids; however, little is known about the identity of the steroidogenic cells in the ovary. the aim of the present study was to determine the identity of the ovarian cell types expressing mrnas encoding proteins important for steroidogenesis and determine at what stage of follicular development they are expressed. the genes examined were those for steroidogenic factor-1 (sf-1), steroidogenic acute regulatory protein (star), cy ...200312773431
effect of oestradiol treatment on mast cell populations and microflora in the vaginal cul-de-sac of seasonally anoestrous brushtail possums (trichosurus vulpecula).mast cell populations in the vaginal cul-de-sac of female brushtail possums do not appear to be related to microbial invasion but changes in their density occur at oestrus, indicating a hormonal influence. the present study examined the effect of treatment with oestradiol on microflora and on mast cell numbers and their spatial location in cul-de-sac tissue of seasonally anoestrous brushtail possums. tissue was collected from seasonally anoestrous brushtail possums (n = 6 per group) that were ei ...200312713436
cloning and expression of a novel cdna encoding shell coat protein, cp4, from the brushtail possum (trichosurus vulpecula).the marsupial conceptus is enclosed by several egg coats of evolutionary significance and unknown composition, of which the shell coat in mammals occurs only in marsupials and monotremes. intact coats are vital to marsupial embryonic development. towards a better understanding of the marsupial coat proteins, a cdna sequence (cp4) encoding a shell coat protein was cloned from the brushtail possum. a cdna library of a zygote stage uterus was screened using a deduced oligonucleotide sequence based ...200312704724
the lymphoid and immunohaematopoietic tissues of the embryonic brushtail possum ( trichosurus vulpecula).the lymphoid and immunohaematopoietic tissues of the embryonic and full-term brushtail possums was investigated histologically and immunohistochemically using antibodies to the t- and b-cell markers, cd3, cd5, cd79a and cd79b. no clearly defined thymus, bone marrow, spleen, lymph nodes, gut-associated lymphoid tissues or bronchus-associated lymphoid tissues were observed histologically. the liver was haematopoietic and contained erythrocytic and granulocytic precursors. no mature lymphocytes wer ...200312592570
the gh/igf-i axis in the brushtail possum (trichosurus vulpecula) pouch young.plasma and pituitary gh concentrations and liver gh receptor (ghr), igf-i and igf-binding protein-3 (igfbp-3) mrna expression were determined in brushtail possum (trichosurus vulpecula) pouch young aged 12-150 days post-partum and in adults. mean plasma gh concentrations were highest, measuring around 150 ng/ml, from 12 to 100 days post-partum, and thereafter declined so that by 150 days post-partum levels were not significantly different from those in adults (10.8+/-1.8 ng/ml (s.e.m.)). in cont ...200312553870
expression of the fcrn receptor (alpha and beta) gene homologues in the intestine of suckling brushtail possum (trichosurus vulpecula) pouch young.the neonatal igg transporter fcrn consists of two chains, fcrn alpha and beta (also known as beta(2) microglobulin), and is involved in transferring igg molecules across both mammary and intestinal epithelial cells. developmental changes in fcrn igg alpha and beta chain mrna levels were investigated in the gut of brushtail possum (trichosurus vulpecula) pouch young (py) using northern hybridisation. fcrn alpha transcripts were detected in the py proximal intestine at all times examined, between ...200312531282
expression of anti-müllerian hormone mrna during gonadal and follicular development in the brushtail possum (trichosurus vulpecula).the ontogeny of anti-müllerian hormone (amh) gene expression in the brushtail possum during formation of the ovary and growth of follicles was examined using in situ hybridization. for comparative purposes, the expression pattern of amh was also examined in the developing testis. in the female, amh mrna was observed in the ovary of 50% (3/6) of pouch young collected around the time of sexual differentiation of the gonad (days 1-5): the signal was predominately localized to the inner-cortical and ...200212467360
application of solid-phase microextraction to the quantitative analysis of 1,8-cineole in blood and expired air in a eucalyptus herbivore, the brushtail possum (trichosurus vulpecula).we have developed two solid-phase microextraction (spme) methods, coupled with gas chromatography, for quantitatively analysing the major eucalyptus leaf terpene, 1,8-cineole, in both expired air and blood from the common brushtail possum (trichosurus vulpecula). in-line spme sampling (5 min at 20 degrees c room temperature) of excurrent air from an expiratory chamber containing a possum dosed orally with 1,8-cineole (50 mg/kg) allowed real-time semi-quantitative measurements reflecting 1,8-cine ...200212401367
characterisation of echidna igm provides insights into the time of divergence of extant mammals.the immunobiology of monotremes is poorly understood. in this paper, we describe the characterisation of the heavy chain of igm from tachyglossus aculeatus, the short-beaked echidna. the echidna heavy chain constant region of igm (cmu)was isolated from a spleen cdna library using a trichosurus vulpecula probe. it has approximately 46.5% amino acid identity to marsupial and eutherian cmus, and approximately 30% amino acid identity with cmu from birds and reptiles. phylogenetic analysis of mammali ...200212377222
the effect of excesses and deficiencies in amino acids on the feeding behaviour of the common brushtail possum (trichosurus vulpecula).in this study of the amino acid nutrition of a marsupial we tested three hypotheses: (a) that brushtail possums eat less when diets contain excesses or deficiencies in essential amino acids, (b) that brushtail possums choose diets that do not contain amino acid excesses, and (c) that amino acid consumption is mediated partly by the 5ht3 receptor. possums ate less when 0.2-1.0% methionine (wet matter) was added to the diet, but similar concentrations of lysine and threonine had little effect. how ...200212355229
quantification of mast cells and microflora in the vaginal cul-de-sac of the brushtail possum (trichosurus vulpecula).mast cells are typically associated with biological responses to intracellular parasitic or bacterial invasion in gut and pulmonary tissues. large numbers of these cells are present in the vaginal cul-de-sac, a component of the reproductive tract in female brushtail possums (trichosurus vulpecula). the presence of mast cells in this area may reflect microbial presence or indicate a role for mast cells in reproductive function in this marsupial. in this study, the number and spatial location of m ...200212201813
aldosterone does not regulate amiloride-sensitive na(+) transport in the colon of the australian common brushtail possum, trichosurus vulpecula.plasma aldosterone concentrations and the magnitude of amiloride-sensitive na(+) transport in the proximal and distal colon of newly caught wild possums, and of possums maintained on either low or high na(+) diets, were determined to evaluate their role in the regulation of salt content of faeces in common brushtail possums. wild animals had a plasma aldosterone concentration of 439+/-115 pmol l(-1) and high levels of amiloride-sensitive na(+) transport in both the proximal and distal colon. ani ...200212192514
electrogenic ion transport in the intestine of the australian common brushtail possum, trichosurus vulpecula: indications of novel transport patterns in a this study, electrogenic ion transport in the intestine of the australian common brushtail possum, trichosurus vulpecula was investigated. in the ileum, a na(+)-dependent, phloridzin- and amiloride-insensitive short-circuit current ( isc) was present. mucosal glucose stimulated a further phloridzin-sensitive, dose-dependent increase in isc. a na(+)-dependent, ouabain-sensitive isc was also present in the caecum and colon. in the proximal and distal colon, amiloride (100 micro mol l(-1), mucos ...200212192511
in vitro and in vivo maturation of oocytes from gonadotrophin-treated brushtail possums.the time course of nuclear maturation of oocytes was examined in brushtail possums, trichosurus vulpecula. oocytes were recovered from ovarian follicles > 2 mm in diameter after pregnant mares' serum gonadotrophin/porcine luteinizing hormone (pmsg/lh) treatment (in vivo matured) or 72 hr after pmsg treatment (in vitro matured). oocytes recovered from small (< 2 mm) and large (> 2 mm) follicles were also assessed for their ability to mature in vitro. staining with the dna-specific dye hoechst 333 ...200212112584
the effects of hypoosmotic infusion on the composition of renal tissue of the australian brush-tailed possum trichosurus vulpecula.although the occurrence of organic osmolytes in the inner medulla of the marsupial kidney has been recently reported [comp. biochem. physiol. (2002) 132b 635-644], changes in these substances, in response to water loading in vivo, has not been studied. adult trichosurus vulpecula, the australian brush-tailed possum, were subjected to water deprivation for 48 h. following anaesthesia and unilateral nephrectomy, the animals were perfused with hypo-osmotic saline (80 mmol l(-1); 1.5 ml min(-1)) for ...200212091110
ontogeny of immunoglobulin expression in the brushtail possum (trichosurus vulpecula).marsupials, unlike eutherians, are born immunologically immature, without circulating lymphocytes or organised lymphoid tissue. their immune response develops while they are in the pouch not in the uterus. in this study, the onset time of immunoglobulin expression in trichosurus vulpecula pouch young was estimated by reverse transcription polymerase chain reaction. as in eutherian species, igm heavy chain transcripts were detected first, at day 10 post partum. the first switched transcript, dete ...200212074924
the corpus luteum and interstitial tissue in a marsupial, the brushtail possum (trichosurus vulpecula).the australian brushtail possum (trichosurus vulpecula) is a nocturnal, arboreal marsupial. it has become a pest of significant ecological and economic importance in new zealand, and thus a renewed interest in understanding the reproductive biology of this species has been generated. the corpus luteum (cl) in possums is a largely autonomous gland in that it does not rely on pituitary hormones to function and is not responsive to luteolytic agents for its demise. its importance in regulating the ...200212044921
ovarian expression of messenger rna encoding the receptors for luteinizing hormone and follicle-stimulating hormone in a marsupial, the brushtail possum (trichosurus vulpecula).both lh and fsh play a central role in controlling ovarian function in mammals. however, little is known about the type of ovarian cells that are responsive to lh and fsh in marsupials. we determined, using in situ hybridization, the localization of mrna encoding the receptors (r) for lh and fsh in ovaries of brushtail possums. the mrna encoding fsh-r was observed in granulosa cells of healthy follicles containing at least two complete layers of cells. the mrna encoding lh-r was first observed i ...200211967192
molecular cloning of four lambda light chain cdnas from the australian brushtail possum trichosurus vulpecula.a brushtail possum mesenteric lymph node cdna library was screened with a grey short-tail opossum clambda probe and four immunoglobulin lambda cdnas were isolated. two of the isolated clones (l5 and l10) contained identical framework 4 regions and constant regions (but different variable regions), suggesting that the possum lambda locus is organized as multiple j-c pairs--a feature seen in the opossum and placental mammals. the cloning of the lambda light chain cdnas signifies the completion of ...200211918633
development of the lung of the brushtail possum, trichosurus vulpecula.the developing lung of the brushtail possum, trichosurus vulpecula, was studied by light microscopy, and transmission electron microscopy was used to study the morphology of the conducting airways in the adult. bronchi did not extend beyond the hilus of each of the six lobes of the lung, and lobules were supplied by major bronchioles. by 105 days post partum, bronchi and bronchioles were fully formed, coinciding with the emergence of mucosal associated lymphoid tissue (malt), which preceded alve ...200211895109
gene expression of the tyrosine kinase receptor c-kit during ovarian development in the brushtail possum (trichosurus vulpecula).ovarian development and function have been extensively studied in eutherian species, with stem cell factor and its receptor, c-kit, having been shown to play key roles at various stages of these processes. in contrast, relatively little is known regarding ovarian development in marsupials. the aims of this study were, first, to establish the timing of key events during germ cell maturation and follicular development and, second, to determine the timing and cellular localization of gene expressio ...200211804947
inhibitory motor innervation of the gall bladder musculature by intrinsic neurones containing nitric oxide in the australian brush-tailed possum (trichosurus vulpecula).gall bladder functions are modulated by neurones intrinsic to the organ. data are available on the neurochemical composition of intrinsic and extrinsic nerves innervating the gall bladder but are lacking on specific functional classes of gall bladder neurones.200111600474
adjustment of offspring sex ratios in relation to the availability of resources for philopatric offspring in the common brushtail possum.the local-resource-competition hypothesis predicts that where philopatric offspring compete for resources with their mothers, offspring sex ratios will be biased in favour of the dispersing sex. this should produce variation in sex ratios between populations in relation to differences in the availability of resources for philopatric offspring. however, previous tests of local resource competition in mammals have used indirect measures of resource availability and have focused on sex-ratio variat ...200111571046
does excretion of secondary metabolites always involve a measurable metabolic cost? fate of plant antifeedant salicin in common brushtail possum, trichosurus vulpecula.salicin was administered orally to six brushtail possums by incorporation in food for six days at three dose levels (0.05, 0.5, and 1.5% wet weight), giving mean +/- sd daily intakes of 0.31 +/- 0.09, 2.76 +/- 0.75, and 6.04 +/- 1.12 mmol salicin. metabolites were identified by mass spectrometry and assayed by hplc. salicyl alcohol glucuronide accounted for 56-64% of urinary metabolites over the three doses, salicyluric acid 15-26%, salicin 10-18%, and there were smaller amounts of free (2-4%) a ...200111504015
an mhc class i gene in the australian brushtail possum (trichosurus vulpecula). 200111486282
glycoconjugates on the surface of epididymal spermatozoa in a marsupial, the brushtail possum, trichosurus vulpecula.variation in localization and distribution of saccharides on the sperm surface of a marsupial, the brushtail possum, trichosurus vulpecula, was compared between spermatozoa from the caput and cauda epididymides. spermatozoa were subjected to the following treatments: (i) unfixed and fixed spermatozoa were stained with fluorescein-labelled lectins; (ii) unfixed spermatozoa were incubated with lectins for determination of agglutination; and (iii) spermatozoa were incubated with detergent to remove ...200111425341
determination of auditory thresholds in the brushtail possum (trichosurus vulpecula).the auditory abilities of the brushtail possum (trichosurus vulpecula) have been measured by cochlear potential readings, but no behavioural determinations of their auditory abilities have been published. six experimentally naive possums were trained to perform a two-response conditional discrimination between the presence and absence of an 880-hz tone (at 80 db). all six possums readily learned this task. the behavioural threshold for this tone was determined using a modified tracking procedure ...200111399311
ultrastructure of oogenesis in the brushtail possum.marsupial ova are slightly larger on average than those of eutherians. they have often been described as "yolky", although the nature and roles of their contents in later development are poorly understood. in the ova of all marsupial species studied, large quantities of electron-lucent vesicles are present. this study describes the ultrastructure of oogenesis in the brushtail possum, trichosurus vulpecula. oocytes of primordial follicles contain a variety of organelles of unknown function, some ...200111170271
social interactions among captive brushtail possums (trichosurus vulpecula).a biological control strategy relying on a self-disseminating agent may provide the only affordable long-term technique for reducing brushtail possum (trichosurus vulpecula) numbers throughout new zealand. the objective of this study was to determine the frequency and patterns of social interactions in single and mixed-sex groups of possums, in order to identify interactions that may assist in the dissemination of biocontrol agents. thirty-two sexually mature wild-caught possums (16 female, 16 m ...200011080558
biotransformation of 1,8-cineole in the brushtail possum (trichosurus vulpecula).1. the metabolic fate of 1,8-cineole was investigated in the brushtail possum. six possums were fed an artificial diet to which 0.5% 1,8-cineole (wet weight) was added for 2 days. urine and faeces were collected after the second day. a sample of each was extracted into ethyl acetate and analysed for metabolites. both free and total levels of metabolites were identified by gc-ms and lc-ms and quantified by gc-ms. 2. the pattern of metabolite excretion was very complex in the brushtail possum. nin ...200011055269
secretory proteins from the female reproductive tract of the brushtail possum (trichosurus vulpecula): binding to sperm and effects on sperm survival in vitro.previous studies have demonstrated that co-culture of brushtail possum epididymal spermatozoa with oviduct epithelial cell monolayers prolongs sperm survival and results in the re-orientation of the sperm head and tail to the t-shape (thumbtack) configuration. transformation of sperm to thumbtack orientation is believed to be associated with marsupial sperm capacitation. here we report that incubation in oviduct-conditioned media also significantly prolongs sperm survival and results in the tran ...199910972301
a new papillomavirus of possums (trichosurus vulpecula) associated with typical wart-like papillomas.a previously unknown, cutaneous papillomavirus (papovaviridae) in a brushtail possum (trichosurus vulpecula) was demonstrated. this represents one of the first viruses reported in this species. possum papillomas were identified by typical wart-like appearance and histology. papillomavirus particles were detected by electron microscopy in tissue homogenates following purification and negative staining. the polymerase chain reaction amplified a conserved portion of the l1 gene which was purified a ...200010948997
in vitro culture of brushtail possum (trichosurus vulpecula) epididymal epithelium and induction of epididymal sperm maturation in co-culture.a medium modified from eutherian systems was used to culture epididymal epithelial cells of the brushtail possum (trichosurus vulpecula) for more than 2 months. epididymal tubule fragments from the caput, corpus and cauda epididymides were used to generate cell monolayers. all three epididymal cell culture systems supported maturational changes in marsupial spermatozoa and enabled immature possum spermatozoa to differentiate from a t-shape to a streamlined shape, accompanied by the development o ...200010864808
how well can common brushtail possums regulate their intake of eucalyptus toxins?we studied factors affecting the ability of common brushtail possums (trichosurus vulpecula) to regulate their intake of a dietary toxin, jensenone, extracted from eucalyptus leaves. increasing concentrations of jensenone in the diet led to a dose-dependent decrease in food intake best described as an exponential decay. animals that had not previously been exposed to jensenone ate significantly more when first offered food containing the compound than on subsequent days. however, when offered th ...200010841261
sperm transport in the female reproductive tract of the brushtail possum, trichosurus vulpecula, following superovulation and artificial insemination.this study investigated sperm transport following superovulation and artificial insemination (ai) in the common brushtail possum, trichosurus vulpecula. females were superovulated by treatment with 15 iu pregnant mare serum gonadotrophin (pmsg) then 4 mg luteinizing hormone (lh) 78 h later. inseminations were performed 27 h after lh (4 million motile spermatozoa/uterus). at 1.5, 3, 6, 9 and 12 h after ai (n=5 per group), females were euthanised and reproductive tracts removed for examination and ...200010837981
immunological protection of the vulnerable marsupial pouch young: two periods of immune transfer during lactation in trichosurus vulpecula (brushtail possum).marsupial young are born with an underdeveloped immune system and are dependent upon passively acquired immune protection provided by the mother's milk. colostrum and milk samples were collected from the brushtail possum throughout lactation and the concentration of secretory iga (siga), igg and transferrin was determined by western blotting. two periods of immune transfer were identified. the first, a colostral phase, occurs immediately after birth and involves siga, igg and transferrin. during ...200010785274
effect of jaw shape in kill-traps on time to loss of palpebral reflexes in brushtail possums.the effect of three configurations of the jaw of kill-traps on time to loss of palpebral reflex of brushtail possums (trichosurus vulpecula) was assessed. traps were standard, with an offset rotating jaw closing past a pear-shaped constriction, offset, with a rotating jaw closing past a straight edge, and opposing, with a rotating jaw closing directly onto a static bar. possums captured in the standard and offset traps had significantly lower times to loss of palpebral reflexes (42 and 50 sec re ...200010682749
cdna cloning, characterization, expression and recombinant protein production of leukemia inhibitory factor (lif) from the marsupial, the brushtail possum (trichosurus vulpecula).a reverse transcription technique using rna templates combined with polymerase chain reaction (rt-pcr) was used to clone the cdna fragment encoding the amino acid sequence of mature lif protein of the marsupial, the brushtail possum, trichosurus vulpecula. a pcr product with expected size, of 546bp, and termed tvlif, was obtained using cdna reverse-transcribed from total rna isolated from possum uterus. a genomic dna fragment (about 650bp) between the specified primers was also amplified, indica ...200010675625
extratesticular sperm maturation in the brush-tail possum, trichosurus vulpecula.the changes in distribution of protein and sugar components in, and on, the plasmalemma of the spermatozoon during epididymal transit of a marsupial, the brush-tail possum, trichosurus vulpecula, are described. freeze-fracture studies indicate a change in organization of plasmalemma intramembranous particles of both the head and midpiece of the tail as the spermatozoa pass from the caput to cauda epididymides. staining with fluorescein isothiocyanate (fitc)-lectins shows, that heads of caput spe ...199810645281
reproductive capability of brushtail possums (trichosurus vulpecula) transferred from the wilds of brisbane, adelaide, and armidale into captivity in brisbane.the transfer of animals from the wild into captivity is an important strategy for the conservation of species that are under threat of extinction. to determine the reproductive capability of animals following transfer from the wild, brushtail possums relocated from brisbane, adelaide, and armidale into captivity in brisbane were monitored. seventy five percent of the brisbane possums (n = 80) gave birth during the months from march to may following transfer from the suburbs of brisbane and 75% o ...199910620769
follicle development in cyclic, anoestrous and fsh-treated brushtail possums (trichosurus vulpecula).the common brushtail possum (trichosurus vulpecula) is a pest of considerable economic importance in new zealand. attempts to develop methods of suppressing reproduction in this species are currently hampered by the lack of reliable methods to synchronise oestrus and ovulation in this species. the objective of this study was to compare antral follicle populations in anoestrous and cyclic brushtail possums and to assess the efficacy of exogenous fsh to induce follicle development in anoestrous an ...199910610040
ontogeny of the immune system of the brushtail possum, trichosurus vulpecula.the numbers and distribution of t and b cells in the thoracic thymus, spleen and intestinal tissue and the proliferation of t lymphocytes were examined during pouch life and in the adult to determine when the developing brushtail possum reaches immunological maturity. cd3-positive cells were observed in the thoracic thymus at day 2 post-partum indicating that the thymus produces t lymphocytes at or soon after birth. by day 25 the thymus was fully populated with cd3-positive t lymphocytes and the ...199910589022
cytochemical staining characteristics of leukocytes of the common brushtail possum (trichosurus vulpecula). 199910561797
induction of thumbtack sperm during coculture with oviduct epithelial cell monolayers in a marsupial, the brushtail possum (trichosurus vulpecula).a reorientation of the sperm head so that it is perpendicular to the sperm tail (i.e., t-shape or thumbtack) is considered an indicator of sperm capacitation in the australian marsupial the brushtail possum (trichosurus vulpecula). this study describes a method of oviduct epithelial cell monolayer and sperm coculture in the brushtail possum to obtain a high percentage of thumbtack sperm. the oviduct epithelial cell (oec) monolayers were prepared in vitro from the isthmal and ampullary segments o ...199910529285
plasma gonadotropin concentrations in the cyclic female brushtail possum (trichosurus vulpecula).changes in plasma concentrations of follicle-stimulating hormone (fsh) and luteinizing hormone (lh), and their relationship to antral follicle development and ovulation, were determined in female brushtail possums (trichosurus vulpecula) in experiments in which pouch young were removed (rpy) from lactating females to promote ovarian activity. in experiment 1 (n = 8), the development of preovulatory follicles and ovulation was monitored by laparoscopy. in experiment 2 (n = 15) estrus and mating w ...199910525363
isolation and sequence of a cdna coding for the heavy chain constant region of igg from the australian brushtail possum, trichosurus vulpecula.a brushtail possum (trichosurus vulpecula) mesenteric lymph node cdna library was screened with a south american short-tailed opossum (monodlelphis domestica) immunoglobulin gamma heavy chain constant region (cgamma) probe, resulting in the isolation of a 1518 nucleotide cdna clone. the sequence corresponds to exons 1-3 of cgamma. the australian marsupial (t. vulpeculla) sequence is 70% identical at the amino acid level with the american marsupial (m. domestica) sequence, but less similar to the ...199910475608
physiological changes in the brushtail possum (trichosurus vulpecula) following relocation from armidale to brisbane, determine the effect of relocation on the health of possums the body weights and hormone and immune responses of six male and nine female brushtail possums were monitored for 20 weeks following transfer from the environs of armidale into enclosures in brisbane. over the first 6 weeks of captivity, male possums lost 11.0% of their original body weight and females lost 16.8%. the mean concentrations of plasma cortisol in the male and female possums were 14.5 and 29.4 ng/ml, respectively, and di ...199910368933
pharmacokinetics of antipyrine, warfarin and paracetamol in the brushtail possum.the plasma pharmacokinetics of antipyrine, warfarin and paracetamol have been studied in the australian brushtail possum (trichosurus vulpecula). the plasma elimination half-lives (t1/2) were 1.2 h for antipyrine, 11.9 h for warfarin and 5.2-12.9 h for paracetamol. our data indicate that the clearance of these three xenobiotics in the possum is similar to that reported in eutherian mammals. there was no dose-dependent increase in paracetamol plasma t1/2 over the dose range 100-1000 mg kg(-1), in ...201310362265
two stages of increased iga transfer during lactation in the marsupial, trichosurus vulpecula (brushtail possum).the polymeric ig receptor (pigr) and j chain molecules are involved in the transfer of iga across the mammary gland epithelia into milk. the j chain binds two iga molecules to form dimeric iga, and the pigr transports this complex through epithelial cells. we report here the cloning of the first marsupial homologues for the pigr and j chain from the brushtail possum. marsupial young are born after a short gestation and are less developed than eutherian newborn. the pouch young is completely depe ...199910229840
cloning and expression of the transferrin and ferritin genes in a marsupial, the brushtail possum (trichosurus vulpecula).transferrin and ferritin cdnas have been isolated and characterised from the common brushtail possum (trichosurus vulpecula), the first marsupial examples of these genes. the transferrin cdna encodes a 711 amino acid pre-protein which shows high levels of amino acid identity with eutherian transferrins (58-60%) and lactoferrins (54-56%). phylogenetic analysis suggests that the possum transferrin has evolved independently along a pathway distinct from that of the eutherian transferrins and lactof ...199910209259
cyclical changes in epithelial cells of the vaginal cul-de-sac of brushtail possums (trichosurus vulpecula).the aim of this study was to describe and quantify the changes that occur in cul-de-sac tissue, in particular to epithelial cells and their constituents, at specific stages of the estrous cycle in the brushtail possum. stereological techniques were used to quantify changes in cul-de-sac epithelial cells collected at four stages of the estrous cycle; the time of removal of pouch young (rpy; n = 5), of initial follicle development (n = 5), of preovulatory follicle formation (n = 5), of midluteal s ...199910096662
cdna sequence analysis, gene expression and protein localisation of the inhibin alpha-subunit of australian brushtail possum (trichosurus vulpecula).an inhibin alpha-subunit cdna sequence from the australian brushtail possum (trichosurus vulpecula) has been identified and analysed. the cdna includes an open reading frame encoding a predicted precursor protein of 361 amino acids. the predicted protein sequence includes four possible proteolytic cleavage sites, 12 evolutionarily conserved cysteine residues and three potential n-linked glycosylation sites. the mature alpha-subunit is the carboxyl terminal fragment (alphac) consisting of 131 ami ...19989801457
response of the parotid gland of the brushtail possum, trichosurus vulpecula, to adrenergic stimulation.adrenergic stimulation of parotid secretion was investigated in anaesthetised brushtail possums to ascertain fluid secretion rates and salivary composition. because neither alpha- nor beta-adrenergic stimulation evoked saliva output, infusion of the adrenergic agonists was superimposed on a pre-existing bethanechol-stimulated flow. isoprenaline infusion (2.4 nmol min-1) increased salivary amylase activity, [protein]; [hco3]; [po4] and [ca], and amylase/ca and protein/ca ratios; reduced [cl]; [k] ...19989773509
presence of males affects the incidence of ovulation after pouch young removal in brushtail possums (trichosurus vulpecula).the traditional method for inducing and synchronising oestrus in the brushtail possum (trichosurus vulpecula) is by removal of their suckling pouch young (rpy). however, our studies have recently shown that, in addition to wide variation between animals in the time of ovulation after rpy, a proportion of animals failed to ovulate. evidence from several mammalian species indicates that the presence of males can stimulate ovarian activity and synchronise oestrus in females. the aim of this study w ...19989672669
an ultrastructural study of the role of an extracellular matrix during normal cleavage in a marsupial, the brushtail marsupials, the mechanisms of lineage allocation into pluriblast and trophoblast are related to conceptus polarity and polarized discharge of extracellular matrix (ecm). the brushtail possum, trichosurus vulpecula, a major pest species in new zealand, is being intensively studied to develop an immunocontraceptive control method. of 23 specimens examined, 11 were examined by electron microscopy to study the presence and role of the ecm in lineage allocation in the possum. a number of polarized ...19989669526
fertility of brushtail possums (trichosurus vulpecula) immunised against sperm.the brushtail possum (trichosurus vulpecula) is a major pest species in new zealand. research to develop a possum-specific method of immunologically-based fertility control (immunocontraception) has begun. this study examined the effect of immunization against sperm on the fertility of possums. possums were assigned to 16 mating groups (two females and one male per group) before the start of the breeding season. one female in each group and eight males were injected subcutaneously with 5 x 10(7) ...19989571567
differential expression of milk protein genes during lactation in the common brushtail possum (trichosurus vulpecula).in the common brushtail possum (trichosurus vulpecula) lactation lasts for 200 days and consists of two distinct phases. milk composition changes dramatically between phase 2 and 3, which correspond to early and late lactation respectively (phase 1 corresponds to pregnancy). rna expression patterns have been established for eight major milk protein genes throughout lactation in possum mammary glands. the levels of mrna expressed from two genes, encoding the early and late lactation proteins, wer ...19989513080
physiological changes in brushtail possums, trichosurus vulpecula, transferred from the wild to determine the effect of relocation on the health of possums, the body weights and hormone and immune responses of 11 male and 9 female brushtail possums were monitored following transfer from the environs of brisbane into an established breeding colony in brisbane. the possums were monitored weekly for the first 20 weeks of captivity, and their immune responses assessed again 12 months after capture. over the first 5 weeks of captivity, male possums lost a mean of 8.8% of their original body ...19989472479
ontogenic expression of detoxication enzymes in an australian marsupial, the brushtail possum (trichosurus vulpecula).marsupials and eutherians display vastly different reproductive strategies. marsupials are characterised by the production of altricial neonates with little functional capacity. an investigation of the ontogenic expression of phase i (mixed function oxidase) and phase ii (glutathione transferase) enzyme systems in the marsupial, the brushtail possum was undertaken. enzyme expression in the youngest age group studied (60 days old) was between 5% and 10% of the adult level. a gradual increase in e ...19979418014
preovulatory follicle development and ovulation in the brushtail possum (trichosurus vulpecula) monitored by repeated laparoscopy.the common method for synchronizing oestrus in brushtail possums is by removal of their pouch young (rpy). however, there is little information on the ovarian response to this treatment, the timing and incidence of ovulation is poorly defined, and methods of identifying oestrus are unreliable. in this study, the development of preovulatory follicles, ovulation and reproductive tract changes following rpy were monitored by repeated laparoscopic observation. a total of 120 adult female possums und ...19979306991
mixed function oxidases in an australian marsupial, the brushtail possum (trichosurus vulpecula).investigation of the mixed function oxidase system of the brushtail possum was undertaken to provide fundamental information about this detoxication enzyme system in a marsupial. brushtail possum hepatic cytochrome p450, cytochrome b5 and nadph-cytochrome c reductase levels, 7-ethoxyresorufin o-deethylase and (erod) 7-ethoxycoumarin o-deethylase (ecod) activities were in the range of values reported for eutherian mammals. hepatic cyrochrome p450 content was significantly greater (p < 0.01) in br ...19979216875
neurogenesis in septum, amygdala and hippocampus in the marsupial brushtailed possum (trichosurus vulpecula).the times of origin of neurons in the septum, amygdala and hippocampus of the marsupial brushtailed possum, trichosurus vulpecula, were determined with 3h thymidine autoradiography. the long time period for neurogenesis in the brushtailed possum facilitated analysis of neurogenetic gradients in the brain. a series of 20 possums were injected with 3h thymidine from postnatal (p) days 5-95 and were allowed to survive until brain cytoarchitecture was mature. our results indicate that septal neuroge ...19979646648
titration of heparinase for removal of the pcr-inhibitory effect of heparin in dna samples.heparin is a naturally occurring polysaccharide found primarily in the liver, lung and artery walls (white et al. 1968), which is commonly used as an anticoagulant for venal blood samples. although the inhibitory effect of heparin on the polymerase chain reaction (pcr) and other enzyme-mediated reactions has been noted (beutler et al. 1990; izraeli et al. 1991), this is not widely known to field biologists collecting samples which are subsequently used for genetic analysis. the enzyme heparinase ...19979131813
the follicle-stimulating hormone beta-subunit gene of the common brushtail possum (trichosurus vulpecula): analysis of cdna sequence and expression.reverse transcription-pcr has been used to obtain a cdna sequence from the follicle-stimulating hormone (fsh) beta-subunit gene of the australian brushtail possum (trichosurus vulpecula). comparisons of the possum fshbeta-mrna coding region nucleotide sequence with that of six eutherian mammal homologues reveals a mean percent identity of 77.3% and 76.8% at the nucleotide and predicted amino acid-sequence levels respectively. furthermore, the predicted amino acid sequence of the possum fshbeta m ...19979733063
development of lung, kidney and skin in the brushtail possum, trichosurus vulpecula.the thyroid gland is not present at birth in marsupials and thyroid function begins during the latter half of pouch life. the hormonal output of the thyroid gland is important for normal development. in this study the structure of the lung, kidney and skin of the developing possum was examined and the structural development of these three organs was described. the lung of the newborn brushtail possum was functional and continued to develop during pouch life, alveolar formation beginning at day 3 ...19979522893
ontogeny of thyroid hormone receptors in the brushtail possum (trichosurus vulpecula).newborn marsupials do not have a thyroid gland at birth. the gland develops while the young marsupial is in the mother's pouch. the young brushtail possum initiates secretion of thyroid hormones from its own thyroid at about day 65 post partum. however, during the first three weeks of pouch life thyroxine is passed from the mother to the young via the milk. to determine if this maternal thyroxine can effect organ development in the young possum before it initiates secretion of thyroxine from its ...19979418977
development of the ovary in the brushtail possum trichosurus vulpecula (marsupialia).the urogenital region of 25 fetuses and 75 pouch young, ranging in age from newborn to 103 days (d) in development, was examined in serial histological sections. the rete ridges formed the anterior extensions of the gonadal ridges and gave rise to the rete system and gonads respectively. sexual differentiation of the ovary commenced 2.5 d after birth, when 2 cell types appeared: the larger of these then clumped together to form the medullary cords, while the smaller cells gave rise to the stroma ...19968982841
a morphometric study of early ovarian development in pouch young of the brushtail possum (trichosurus vulpecula).although the pattern of gonadal differentiation in marsupials is well documented, there is little information available on germ cell initiation and development. furthermore, neither parameter has been well described for the brushtail possum (trichosurus vulpecula).19968888964
the effect of methimazole on the growth of the developing brushtail possum, trichosurus vulpecula.the brushtail possum, trichosurus vulpecula, produces a single offspring 200 mg in body weight. the young grow slowly during the first half of pouch of life at approximately 1g/day. at day 96 post partum the growth rate increases dramatically and it has been suggested that this change in growth rate may result from the initiation of thyroid function in the young possum. to determine the role of the thyroid gland of the possum on growth, the production of hormones from the thyroid was inhibited b ...20139007567
cloning, sequencing and expression of stem cell factor (c-kit ligand) cdna of brushtail possum (trichosurus vulpecula).by means of reverse transcription polymerase chain reaction (rt-pcr), three stem cell factor (scf) cdnas (822-738 bp in size) were amplified from brushtail possum ovarian poly (a)+ rna. the largest and smallest of these cdnas were cloned and sequenced. characterization of these cdnas has revealed that possum scf has approximately 75% and 66% homology to scf of eutherian mammals at the nucleotide level and the predicted amino acid level respectively. nucleotide sequencing shows that the 738-bp cd ...19968870099
a light microscopic study of oogenesis in the brushtail possum trichosurus vulpecula.ovaries from young of the brushtail possum, trichosurus vulpecula, were examined histologically and histochemically to determine stages of oogenesis. groups of dividing oogonia were first present in a 13-day-old pouch young, with extensive oogonial proliferation after about 23 days of age. meiosis was initiated in some oogonia by 48 days of age, and by 88 days numerous early primordial follicles were present. the first primary follicles had formed by 103 days of age. in oocytes of quiescent prim ...19968870079
effect of changing from a short-day to long-day photoperiod on the breeding season of the brushtail possum (trichosurus vulpecula).in queensland, possums (trichosurus vulpecula) in the wild and in captivity first give birth during march and april and continue to give birth throughout the year until november. the possum has a gestation length of 17.5 days, gives birth to one young, and lactation continues for approximately 180 days. if the newborn possum is removed during the breeding season, the possum will ovulate approximately 9 days later and give birth approximately 26 days after removal of the pouch young (rpy). repeat ...19957595285
thyroid gland development in the brushtail possum, trichosurus vulpecula. 19958554181
parathyroid morphology of the brush-tail possum, trichosurus of the comparative anatomy of the parathyroid glands contain very little or no information on this endocrine gland in marsupials. this paper is the initial report of a broader investigation of the parathyroid glands in marsupials and monotremes.19957755180
the anticoagulant pindone causes liver damage in the brushtail possum (trichosurus vulpecula). 19947945103
lipopigments in the brushtail possum, trichosurus vulpecula.two lipopigments have been found in the hepatic and lymphoid tissues of the brushtail possum, trichosurus vulpecula. one pigment was present in hepatocytes of five out of 15 (33%) possums from a site in the wairarapa region in the north island of new zealand, but was absent from the livers of 34 possums from a site in the manawatu. the pigment is possibly of dietary origin. an extra-hepatic lipopigment was found within macrophages in the lymph nodes of three out of 12 (25%) possums from the wair ...199416031749
effects of cholinergic stimulation and aldosterone administration on salivary parotid secretion in the brushtail possum, trichosurus vulpecula.parotid salivation was stimulated by infusion of bethanechol chloride into anaesthetized brushtail possums to ascertain maximal flow rates, salivary composition and dietary adaptations of salivary function. secretion rates for one gland ranged from 5.3 +/- 0.16 to 84.3 +/- 3.20 microliters/min (2.4 +/- 0.07 to 37.8 +/- 1.43 microliters/min per kg body weight). salivary osmolality (160.8 +/- 15.39 to 248.2 +/- 8.70 mosmol/kg) and the concentrations of na (63.1 +/- 10.93 to 124.1 +/- 5.52 mmol/l) ...19948024500
mesotocin and arginine-vasopressin in the corpus luteum of an australian marsupial, the brushtail possum (trichosurus vulpecula).the neuropeptide hormones arginine-vasopressin (avp) and oxytocin (ot) have been found in the ovarian follicles and corpora lutea (cl) of many eutherian mammals. in ruminants, there is persuasive evidence that luteal ot is involved in luteolysis via stimulation of uterine prostaglandins. however, based on scant evidence, the marsupial ovary has been viewed as being devoid of ot-like and avp-like peptides. in this study, corpora lutea from the brushtail possum were examined for ot, avp, and mesot ...19948174926
nitric oxide mediates nonadrenergic, noncholinergic neural relaxation in the australian possum.nitric oxide has been shown to play an important role in neurally mediated relaxations of gastrointestinal smooth muscle. the aim of this study was to determine whether no may be the inhibitory transmitter to circular smooth muscle from the sphincter of oddi of the australian brush-tailed possum (trichosurus vulpecula).19937902822
smi cortical barrels in an australian marsupial, trichosurus vulpecula (brush-tailed possum): structural organization, patterned distribution, and somatotopic relationships.this study reports on the cerebral cortex of an australian marsupial, trichosurus vulpecula (brush-tailed possum). it consists of an analysis of layer iv of somatosensory cortex in tangential sections of flattened specimens and in oblique radial sections stained to show nissl substance or myelin, or tested for succinic dehydrogenase. it includes results of electrophysiological mapping experiments that ascertained the somatotopic significance of the cytoarchitecture of this cortical region. layer ...19938282853
posterior pituitary of the newborn marsupial possum, trichosurus vulpecula.the fetal anterior pituitary-adrenal axis is thought to be involved in the initiation of birth in both eutherian and marsupial mammals. little is known about the structure and function of the posterior pituitary at birth in the marsupial. immunocytochemistry, high pressure liquid chromatography, and radioimmunoassay were used to identify vasopressin and mesotocin in the posterior pituitary of a newborn marsupial, the brushtail possum, trichosurus vulpecula. the concentrations of vasopressin and ...19938238974
the development of thermoregulation in the marsupial brushtail possum trichosurus vulpecula.1. the adult possums showed a circadian rhythm of body temperature with a peak in temperature around midnight and a nadir at noon. 2. the young possum within the pouch displayed a circadian rhythm with the highest temperatures during the day and the lowest in the early evening. 3. although the body temperature of the young possum exceeded that of the mother occassionally, for the major part of the 24 hr the body temperature of the young was lower than that of the mother. 4. the young possum coul ...19937902793
effect of photoperiod on the breeding season of the marsupial possum trichosurus vulpecula.the production of young by three groups of eight possums, housed in a natural, a short-day (10 h light:14 h dark) and a long-day (14 h light:10 h dark) photoperiod was monitored for 24 months to determine the role of photoperiod on the occurrence and duration of the breeding season. possums were housed in each of the three light regimens on 22 november. the possum has a gestation duration of 17.5 days. removal of the newborn young leads to ovulation approximately 9 days later and birth 26 days l ...19938410819
effects of halothane anesthesia on the motility of the sphincter of oddi and transsphincteric flow in australian brush-tailed possums.we evaluated the effect of halothane anesthesia on the motility of the sphincter of oddi and simultaneous transsphincteric flow in australian brush-tailed possums (trichosurus vulpecula). halothane levels in the range of 0.25 to 2% were administered and decreased transsphincteric flow in a dose-dependent manner. sphincter of oddi basal pressure was higher than normal, but not in a dose-dependent manner. additionally, halothane anesthesia influenced the sphincter of oddi motility by decreasing th ...19938355483
inhibition of cardiac vagal action by galanin but not neuropeptide y in the brush-tailed possum trichosurus vulpecula.1. stimulation of the right cardiac sympathetic nerve for 2 min at 16 hz in the presence of either beta- or alpha- and beta-adrenoceptor blockade evoked attenuation of cardiac vagal action in eight possums: 31.3 +/- 10.3% maximum inhibition of cardiac vagal action on prolonging pulse interval, with a time to half-recovery of 4.9 +/- 1.1 min. 2. intravenous injection of galanin (2-3.5 nmol kg-1) evoked similar inhibition of cardiac vagal action: 41.3 +/- 4.1% maximum inhibition of cardiac vagal a ...19937688807
structure and innervation of the extrahepatic biliary system in the australian possum, trichosurus vulpecula.the morphology, microanatomy and innervation of the biliary tree of the australian possum, trichosurus vulpecula, was examined. the gross morphology of the gallbladder, hepatic and cystic ducts, and the course of the common bile duct, conforms to those of other species. the sphincter of oddi has an extraduodenal segment that extends 15mm from the duodenal wall; within this segment the pancreatic and common bile ducts are ensheathed together by sphincter muscle. their lumens unite to form a commo ...19938268104
influence of stress of capture on haematological values and cellular immune responses in the australian brushtail possum (trichosurus vulpecula).possums (trichosurus vulpecula) captured for the first time (single-capture) had significantly lower blood lymphocyte and eosinophil counts, but higher neutrophil counts than possums which had been captured frequently. single-capture possums also had depressed lymphocyte responses to concanavalin a (males and females) and pokeweed mitogen (males only). the haematological changes and the depressed lymphocyte reactivity to the t-cell mitogens were consistent with the animals being in a stressed st ...199216031681
erythromycin and motilin stimulate sphincter of oddi motility and inhibit trans-sphincteric flow in the australian possum.the actions of erythromycin lactobionate and porcine motilin on trans-sphincteric flow and simultaneous sphincter of oddi motility were studied in 15 anaesthetized australian brush-tailed possums (trichosurus vulpecula). erythromycin (25-200 micrograms/kg) and motilin (25-200 ng/kg) were administered as graded doses by close intraarterial injection. trans-sphincteric flow was measured as inflow and outflow. both motilin and erythromycin decreased trans-sphincteric inflow (both p < 0.0001) and ou ...19921484568
brain content and plasma concentrations of arginine vasopressin in an australian marsupial, the brushtail possum trichosurus vulpecula.arginine vasopressin (avp) has been identified and quantified in the brain and plasma of the possum using a highly specific radioimmunoassay and high-performance liquid chromatography. large amounts of avp were found in the pituitary (16.3 +/- 0.56 micrograms/pituitary, n = 5) and hypothalamus (398 +/- 82.5 ng/hypothalamus), and significant amounts of avp were also present in the cerebral cortex (26.8 +/- 11.5 ng/cortex). plasma avp concentrations were significantly lower (2.2 +/- 0.45 pg/ml, n ...19921478438
the role of photoperiod on the initiation of the breeding season of the brushtail possum (trichosurus vulpecula).the role of photoperiod on the initiation of the breeding season of brushtail possums was investigated in possums housed in three light regimens: a short-day, a natural and a long-day photoperiod. seven possums were housed in a natural photoperiod. four possums were transferred to a short-day photoperiod (10 h light, 14 h dark) and eight possums to a long-day photoperiod (14 h light, 10 h dark) on 22 november, when the daylength was 13.34 h. the first rises in plasma progesterone concentrations ...19921404087
galanin is more common than npy in vascular sympathetic neurons of the brush-tailed possum.the distribution of galanin (gal) in sympathetic vascular neurons of adult and juvenile brush-tailed possums (trichosurus vulpecula), was examined using double-labelling immunohistochemistry. this was compared with the distribution of neuropeptide y (npy) in the same tissues. immunoreactivity (ir) to galanin was present in the majority (64-99%) of nerve cell bodies in paravertebral sympathetic ganglia, where it mostly co-existed with ir to the catecholamine-synthesizing enzyme, tyrosine hydroxyl ...19921371612
carcass composition and meat quality of brush-tail possums (trichosurus vulpecula).one-hundred-and-thirty-nine possums, balanced as far as possible for sex (68 male, 71 female) and age (1 year, 42; 2-4 years, 61; 5+ years, 36), were slaughtered and the dissected carcass composition, muscle, and cooked meat composition measured. possums were slaughtered at time in captivity tic 0 (n = 58), tic 14 days (n = 20) and tic 28 days (n = 61). compared with the 5+ years (mature) age group the 1 year olds (juveniles) were 67% and the 2-4 year olds (immature) 96% of the live weight of th ...199222059633
oxytocin receptors in the mammary gland and reproductive tract of a marsupial, the brushtail possum (trichosurus vulpecula).previous studies of marsupial lactation have shown that the milk-ejection reflex changes in sensitivity, being greater in small mammary glands sucked by small pouch young and lesser in larger glands supplying milk to larger young. the involvement of oxytocin receptors in these changes was examined in the brushtail possum trichosurus vulpecula. oxytocin receptors were measured in the mammary glands, uterus, and medial vaginal sacs by radioreceptor assay, using [3h]oxytocin as radioligand. in the ...19911661615
bile acids of marsupials. 2. hepatic formation of vulpecholic acid (1 alpha,3 alpha,7 alpha-trihydroxy-5 beta-cholan-24-oic acid) from chenodeoxycholic acid in a marsupial, trichosurus vulpecula (lesson).free vulpecholic acid (1 alpha,3 alpha,7 alpha-trihydroxy-5 beta-cholan-24-oic) is the major biliary component of the australian opossum (trichosurus vulpecula), accompanied only by a few percent of its taurine conjugate. in order to exclude a microbial involvement in its formation (i.e., secondary origin) four sets of experiments were performed. it was found that a) the level of vulpecholic acid remained unchanged in the bile of opossums fed with neomycin and kanamycin for 7 days prior to bile ...19911753212
spontaneous or experimentally induced formation of a special zone in the adrenal cortex of the adult brush-tailed possum (trichosurus vulpecula).the cytology and ultrastructure of the hypertrophied special zone, which is formed spontaneously in the adrenal cortex of adult female brush-tailed possums (trichosurus vulpecula), was compared to the adrenocortical tissue in adult males in which the special zone, normally absent, was induced following castration alone or by additional treatment with follicle-stimulating hormone (fsh). the special zone in females was situated between the zona fasciculata and the zona reticularis, the latter bein ...19911901439
retinal epithelial fine structure in the brush-tailed possum (trichosurus vulpecula).as part of a comparative morphological study, the fine structure of the retinal pigment epithelium (rpe), the choriocapillaris and bruch's membrane (complexus basalis) has been studied by electron microscopy in the brush-tailed possum (trichosurus vulpecula), an australian marsupial. in this species, the rpe consists of a single layer of squamous cells which show numerous shallow basal (scleral) infoldings as well as extensive apical (vitreal) processes enclosing rod outer segments. the epitheli ...19912048742
a simple glycerol-based freezing protocol for the semen of a marsupial trichosurus vulpecula, the common brushtail possum.frozen storage of semen and embryos is now a well established part of the breeding of many eutherian mammals but it has not been applied to marsupials. this paper reports the first successful technique for the frozen preservation of marsupial spermatozoa. semen was collected by electroejaculation under anaesthesia from a pool of five brushtail possums. the ejaculated semen was diluted 1:1 with krebs henseleit ringer, centrifuged at 800 g for 5 min, resuspended in the test cryoprotectant media at ...19911947217
whey proteins of the common brushtail possum (trichosurus vulpecula): isolation, characterization and changes in concentration in milk during lactation of transferrin, alpha-lactalbumin and serum albumin.1. transferrin and serum albumin were purified from both whey and serum and alpha-lactalbumin was purified from whey from the common brushtail possum (trichosurus vulpecula). 2. the n-terminal amino acid sequences for transferrin and serum albumin were identical for the proteins from both whey and serum and showed homologies with transferrin or serum albumin from other species. 3. n- and c-terminal regions of possum alpha-lactalbumin were also sequenced and have been compared with wallaby alpha- ...19911868684
mesotocin in the brain and plasma of an australian marsupial, the brushtail possum (trichosurus vulpecula).oxytocic peptides extracted from the brain and plasma of the brushtail possum, trichosurus vulpecula, were separated by reverse-phase high pressure lipid chromatography (hplc) and quantified by specific radioimmunoassays for oxytocin (ot) and mesotocin (mt). the pituitary, hypothalamus and cerebral cortex were found to contain mt only in quantities of 3.9 +/- 0.2 (se) ug, 17.6 +/- 0.6 ng and 21.0 +/- 2.6 ng respectively. the plasma concentration of mt varied according to the degree of stress of ...19902082200
influence of daylength on the initiation of the breeding season of the marsupial possum, trichosurus queensland, possums in the wild and in captivity first give birth during march and continue to give birth throughout the year until november. in this study the effect of short daylengths on the initiation of breeding activity was examined. one male and 4 female possums were transferred from an outside enclosure into a light control room (10 h light, 14 h dark) on 22 november. a control group of possums was housed in outside enclosures. the possums held in the light room gave birth 81.2 +/- 14 ...19902325020
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