| adrenocortical function in a prototherian mammal, tachyglossus aculeatus (shaw). | the peripheral plasma concentrations and production rates of corticosterone and cortisol were measured in the conscious, unrestrained echidna (tachyglossus aculeatus) under basal conditions and during maximal acth stimulation. using sephadex lh-20 column chromatography and radioligand assay, only cortisol and corticosterone could be detected in the peripheral blood plasma at very low concentrations of 0-07 +/- 0-03 (s.e.m.) mug/100 ml and 0-14 +/- 0-07 mug/100 ml respectively. two-hourly samplin ... | 1977 | 188965 |
| immunoglobulin gamma chains of a monotreme mammal, the echidna (tachyglossus aculeatus): amino acid composition and partial amino acid sequence. | the echidna represents the lowest stage in phylogeny at which molecules clearly homologous to igg antibodies appear to occur. we provide evidence that a fraction of gamma chains possess an unblocked n terminal sequence comparable to the vhiii sub-group of human gamma chains and that glycine is the c-terminal residue. statistical comparison of amino acid composition of the component chains with other immunoglobulin heavy chains suggests that echidna gamma chains are more closely related to euther ... | 1977 | 406331 |
| synthesis of steroids by echidna (tachyglossus aculeatus) testis and the effects of gonadotrophin administration. | after administration of hcg and pmsg to male echidnas (in non-breeding state) the testis to body weight ratio increased 3-fold and the diameter of the seminiferous tubules doubled, but spermatogenesis was not induced. the major conversion product of testicular homogenate with [4-14c]progesterone as substrate was 17 alpha-hydroxyprogesterone (4% in untreated and 29% in treated echidnas). testosterone (5%), androstenedione (16%) and 17 alpha,20 beta-dihydroxypregn-4-en-3-one (7%) were also obtaine ... | 1979 | 480305 |
| 7s immunoglobulins of a monotreme, the echidna tachyglossus aculeatus: two distinct isotypes which bind a protein of staphylococcus aureus. | | 1978 | 624566 |
| glycoproteins secreted by sublingual glands of the echidna (tachyglossus aculeatus). | the portion of echnida sublingual glycoproteins which could be solubilized was fractionated by electrophoresis in polyacrylamide gel and by filtration on a column of sephadex g-100. analyses for carbohydrate and amino acid are given and are compared with those of the submaxillary mucins of cattle, dog, pig and sheep. the molar ratio of galactosamine to sialic acid was roughly 1:1 in the echidna fractions, the sialic acid was n-acetyl-neuraminic acid, and there was very little neutral sugar. prol ... | 1975 | 810442 |
| antigenic cross-reactions among immunoglobulin of diverse vertebrates (elasmobranchs to man) detected using xenoantisera. | 1. antisera raised in rabbits and goats against intact immunoglobulins or their constituent light and heavy chains from man, mouse and the galapagos shark (carcharhinus galapagenesis) were tested for their reactivity with immunoglobulins of elasmobranchs, other lower vertebrates and eutherian and prototherian mammals. 2. xenoantisera directed against human heavy chain isotypes allowed the serological identification of igm and igg immunoglobulins in the echidna (tachyglossus aculeatus), a monotre ... | 1992 | 1351441 |
| a light-microscopic immunocytochemical study of the endocrine pancreas in the australian fat-tailed dunnart (sminthopsis crassicaudata). | the endocrine pancreas of the australian fat-tailed dunnart (sminthopsis crassicaudata) was investigated by means of immunocytochemistry using the avidin-biotin-peroxidase technique. this was a light microscopic study using this established technique and has not been previously investigated. serial paraffin sections were stained individually with primary antibodies for anti-porcine glucagon, anti-beef pork insulin, anti-human somatostatin, and anti-avian pancreatic polypeptide (app), anti-bovine ... | 1992 | 1352914 |
| sparganosis in the monotremes tachyglossus aculeatus and ornithorhynchus anatinus in australia. | sparganosis in the echidna, tachyglossus aculeatus, is characterized by large subcutaneous masses that may be confused with neoplasms. plerocercoids, believed to be spirometra erinacei, were found in the ventral or lateral subcutaneous tissues of three echidnas. in each case there was a prominent fibrous mass < or = 12 cm in diameter enclosing plerocercoids, which were surrounded by an intense inflammatory infiltrate dominated by plasma cells and lymphocytes, with focal suppuration. multiple, sm ... | 1992 | 1474663 |
| a survey of endocrine cells in the pancreas of the echidna (tachyglossus aculeatus) with special reference to pancreatic motilin cells. | pancreatic endocrine cells were examined in a primitive egg-laying mammal, the echidna, using immunohistochemistry. immunoreactive endocrine cells were observed using antisera to insulin, glucagon, somatostatin, avian pancreatic polypeptide and bovine pancreatic polypeptide. in addition, motilin-immunoreactive cells were identified in both the endocrine and exocrine pancreas of pouch-young and adult echidnas using three types of motilin antisera. since the motilin-immunoreactive cells did not cr ... | 1990 | 1981999 |
| cartilaginous bone extremities of growing monotremes appear unique. | cartilage canals are present in the epiphyseal cartilage of most mammals and birds. they are considered necessary for the maintenance of chondrocytes and for the formation of epiphyseal ossification centers. the epiphyseal cartilage of marsupials was recently shown not to contain cartilage canals, and placental rats appear not to have cartilage canals, although some confusion exists in the literature. the present study examines the cartilaginous epiphyses and physes from the knee and hip of the ... | 1991 | 2048749 |
| ventilatory responses of the ground squirrel, spermophilus tridecemlineatus, to various levels of hypoxia. | 1. minute ventilation (ve) in the semifossorial ground squirrel (spermophilus tridecemlineatus) increased with increased levels of hypoxia. 2. the increase in ve was brought about primarily by an increase in breathing frequency (f). there was no significant change in tidal volume (vt). 3. the pio2 threshold for the ventilatory response to hypoxia and position of the ventilatory response curve in the ground squirrel were closer to the semifossorial echidna (tachyglossus aculeatus) than the comple ... | 1989 | 2566413 |
| hibernation in a monotreme, the echidna (tachyglossus aculeatus). | the body temperatures of five echidnas in australia's southern alps were monitored by radio telemetry from february to december 1987. all five hibernated throughout the winter, showing very low body temperatures (4-9 degrees c, close to ambient) when torpid, compared with 28-33 degrees c in a typical day during the active season. spontaneous arousals from hibernation occurred every 2-3 weeks, during which body temperatures rose rapidly to over 30 degrees c for several hours before dropping to be ... | 1989 | 2566425 |
| responses of electroreceptors in the snout of the echidna. | 1. this is a report of experiments which provide evidence in support of the existence of an electric sense in the echidna, or spiny anteater tachyglossus aculeatus. it is the first known example of electroreception in a terrestrial animal. 2. in each of four animals anaesthetized with alpha-chloralose, afferent responses were recorded in dissected filaments of the infraorbital branch of the trigeminal nerve which supplies skin of the upper jaw. recordings were obtained from a total of forty-seve ... | 1989 | 2607440 |
| efferent connections of the prefrontal cortex of echidna (tachyglossus aculeatus). | in two echidnas injections of radioactively labeled amino acids were made into the cortical area which has been shown to receive afferents from the anteromediodorsal region of the thalamus and which is therefore tentatively identified as the prefrontal cortex. efferents were found in the symmetrical area of the contralateral cortex, in the paleocortex and neostriatum bilaterally, the ipsilateral anteromediodorsal region of the thalamus, the hypothalamus, the ventral tegmental area, and the pons. ... | 1987 | 3427410 |
| architectonics of the thalamus in the echidna (tachyglossus aculeatus): search for the mediodorsal nucleus. | architectural characteristics of the thalamus in echidnas and rats were compared in sections stained to reveal cell bodies, myelin, acetylcholinesterase, succinate dehydrogenase and cytochrome oxidase. numerous species differences were noticed: in general, the thalamus is architecturally more homogeneous in echidnas than in rats, especially anteriorly. in this report we emphasize the presence of a relatively large structure localized in the anteromediodorsal part of the thalamus in echidnas. thi ... | 1987 | 3427411 |
| morbidity and mortality of free-living and captive echidnas, tachyglossus aculeatus (shaw), in australia. | between 1976 and 1985 necropsies were conducted on 55 free-living and 18 captive echidnas originating from several localities in victoria, australia. injuries arising from motor vehicle accidents were the most common cause of death (24 of 55; 47%). an additional nine live echidnas were presented for clinical examination for dog or fox wounds (eight), or wire snare wounds (one). incidental infestations with ticks (aponomma concolor) on the skin or in the ear canal (eight of 82; 10%), and infectio ... | 1986 | 3735583 |
| phylogenetic studies on the immune response. ii. the immune response of the australian echidna tachyglossus aculeatus. | | 1967 | 4168093 |
| renin secretion in a monotreme (tachyglossus aculeatus). | | 1971 | 4401098 |
| haemoglobin polymorphisms in the echidna, tachyglossus aculeatus. | | 1973 | 4741125 |
| major immunoglobulin classes of the echidna (tachyglossus aculeatus). | | 1973 | 4761634 |
| thermoregulatory responses to the injection of monoamines, acetylcholine and prostaglandins into a lateral cerebral ventricle of the echidna. | 1. the putative neurotransmitter substances 5-hydroxytryptamine (5-ht), noradrenaline (na), acetylcholine (ach) and prostaglandins e(1) (pge(1)) and e(2) (pge(2)) have been injected into a lateral cerebral ventricle of the conscious echidna (tachyglossus aculeatus); thermoregulatory responses in thermoneutral (ambient dry bulb temperature, t(db), of approximately 22 degrees c), cool (t(db) of approximately 14 degrees c) and warm (t(db) of approximately 26 degrees c) environments were determined. ... | 1974 | 4822575 |
| electrophysiological studies of the echidna, tachyglossus aculeatus. 3. sensory and interhemispheric evoked responses. | | 1972 | 5074167 |
| intestinal and cloacal lymphoepithelial glands in the australian echidna: a possible homologue of the bursa of fabricius. | | 1969 | 5350494 |
| lymphoepithelial glands in the intestines and cloaca of the australian echidna (tachyglossus aculeatus). | | 1969 | 5786100 |
| phylogenetic studies on the immune response. 3. autoradiographic studies on the lymphoid system of the australian echidna tachyglossus aculeatus. | | 1967 | 6055752 |
| active cation transport and na+k+mg atpase of the monotreme erythrocytes. | the erythrocytes of the echidna (tachyglossus aculeatus) and platypus (ornithorhynchus anatinus), which are practically devoid of intracellular atp content (1), were examined for active rb86 influx and for the presence of na+k+mg atpase. we found that intact erythrocytes of both species possess the ability to actively transport cations. ouabain sensitive rb86 influx in the echidna was approximately 0.17 mumoles/ml cells x hr, whereas the platypus exhibited a higher value of 0.43 mumoles/ml cells ... | 1984 | 6143557 |
| thalamic projections to the somatosensory cortex of the echidna, tachyglossus aculeatus. | evoked potential studies (lende, '64) suggest that echidnas have a single, topographically organized somatosensory area (smi) that spans a mediolaterally oriented sulcus called sulcus alpha. a motor area (mi) is situated on the prealpha gyrus. this study examines the cytoarchitecture and thalamic afferents of smi in the echidna, tachyglossus aculeatus. smi contains two cytoarchitectonic fields. a caudal field extends across the postalpha gyrus and onto the floor of sulcus alpha. it has a well-de ... | 1984 | 6438189 |
| the prevalence of anti-leptospiral agglutinins in sera of wildlife in southeastern australia. | anti-leptospiral agglutinins were found in the serum from 18 (7 species) of 419 (25 species) animals sampled from various areas of southeastern australia. positive serologic reactions were observed in 5 of 25 (20%) brush-tailed possum (trichosurus vulpecula), 1 of 26 (3.8%) tammar wallaby (macropus eugenii), 2 of 12 (16.7%) swamp wallaby (wallabia bicolor), 1 of 3 (33.3%) koala (phascolarctos cinereus), 3 of 41 (7.3%) common wombat (vombatus ursinus), 2 of 100 (2%) bush rat (rattus fuscipes) and ... | 1981 | 7241704 |
| adenosine triphosphate-deficient erythrocytes of the egg-laying mammal, echidna (tachyglossus aculeatus). | the erythrocytes of the short-beaked echidna (tachyglossus aculeatus), an egg-laying mammal, were examined for the presence of phosphorylated compounds. the erythrocytes contained only 0.03 +/- 0.01 micromoles of adenosine 5'-triphosphate per milliliter of cells. this amount is two orders of magnitude less than that in human cells. although the echidna erythrocytes had an abundance of 2,3-diphosphoglycerate and other glycolytic intermediates, no other energy-rich pyridine and purine compounds we ... | 1981 | 7280672 |
| echidnotaenia tachyglossi (johnston) gen. et comb. nov. (anoplocephalata: linstowiidae) from the monotreme tachyglossus aculeatus shaw in australia. | echidnotaenia gen. nov. (anoplocephalata: linstowiidae) is proposed for cittotaenia tachyglossi johnston, 1913 from the monotreme tachyglossus acuteatus shaw, 1792. the new genus is distinguished from other genera of the linstowiidae by its paired genitalia and aporally extended vitellaria. | 1980 | 7410808 |
| comparative erythrocyte metabolism in marsupials and monotremes. | concentrations of atp and dpg, activities of 10 enzymes and the glycolytic rates were measured in the erythrocytes of 11 species of marsupials and two species of monotremes. mean dpg concentrations were greater in the erythrocytes of marsupials than those of eutherian mammals. the opposite is true of atp. significant findings from the results of enzyme activities were: high activity of hexokinase (7.39 +/- 0.82 eu/g hb) in the short-beaked echidna, pyruvate kinase (37.49 +/- 1.0 eu/g) hb in brid ... | 1995 | 7599974 |
| disseminated coccidiosis in short-beaked echidnas (tachyglossus aculeatus) from australia. | | 1993 | 8373870 |
| sequences homologous to the human x- and y-borne zinc finger protein genes (zfx/y) are autosomal in monotreme mammals. | the human zinc finger protein genes (zfx/y) were identified as a result of a systematic search for the testis-determining factor gene on the human y chromosome. although they play no direct role in sex determination, they are of particular interest because they are highly conserved among mammals, birds, and amphibians and because, in eutherian mammals at least, they have active alleles on both the x and the y chromosomes outside the pseudoautosomal region. we used in situ hybridization to locali ... | 1993 | 8449497 |
| the echidna tachyglossus aculeatus combines rem and non-rem aspects in a single sleep state: implications for the evolution of sleep. | placental and marsupial mammals exist in three states of consciousness: waking, non-rem sleep, and rem sleep. we now report that the echidna tachyglossus aculeatus, a representative of the earliest branch of mammalian evolution (the monotremes), does not have the pattern of neuronal activity of either of the sleep states seen in nonmonotreme mammals. echidna sleep was characterized by increased brainstem unit discharge variability, as in rem sleep. however, the discharge rate decreased and the e ... | 1996 | 8627382 |
| cyto- and myeloarchitectonic organisation of the spinal cord of an echidna (tachyglossus aculeatus). | we have studied the cyto- and myeloarchitectural organisation of the spinal cord of an echidna (tachyglossus aculeatus) with the aid of nisst staining, darkfield examination and p-phenylenediamine staining. we have also examined the distribution of unmyelinated afferents by labelling with a peroxidase-conjugated lectin derived from griffonia simplicifolia (b1 isolectin). the cytoarchitectural features characterising the laminar organisation of the spinal cord in eutherian mammals were broadly ap ... | 1997 | 9150897 |
| lactose synthesis in a monotreme, the echidna (tachyglossus aculeatus): isolation and amino acid sequence of echidna alpha-lactalbumin. | alpha-lactalbumin and lysozyme were each isolated from echidna (tachyglossus aculeatus) milk by gel permeation and ion exchange chromatography. the alpha-lactalbumin modified the action of echidna milk galactosyltransferase to promote the synthesis of lactose but had very little effect on bovine galactosyltransferase. echidna alpha-lactalbumin is a glycosylated protein with an apparent molecular weight of 20,000 (sds-page) whose concentration in the milk is very low compared with the concentrati ... | 1997 | 9440233 |
| evolution and molecular characterization of a beta-globin gene from the australian echidna tachyglossus aculeatus (monotremata). | coinciding with a period in evolution when monotremes, marsupials, and eutherians diverged from a common ancestor, a proto-beta-globin gene duplicated, producing the progenitors of mammalian embryonic and adult beta-like globin genes. to determine whether monotremes contain orthologues of these genes and to further investigate the evolutionary relationships of monotremes, marsupials, and eutherians, we have determined the complete dna sequence of an echidna (tachyglossus aculeatus) beta-like glo ... | 1999 | 10381323 |
| structure, sequence and function of a marsupial lif gene: conservation of il-6 family cytokines. | leukaemia inhibitory factor (lif) is a multifunctional cytokine with an obligate role in the mouse in embryonic implantation. in this paper we demonstrate the existence of a functional lif gene in the marsupial sminthopsis crassicaudata, and the presence of lif-related sequences in the monotreme tachyglossus aculeatus (australian echidna). isolation of genomic and cdna clones from s. crassicaudata, indicated that the lif gene is highly conserved between marsupials and monotremes in terms of sequ ... | 2001 | 11435700 |
| distortion product otoacoustic emission and auditory brainstem responses in the echidna (tachyglossus aculeatus). | the auditory function of four wild-caught echidnas was measured using distortion product otoacoustic emissions (dpoaes) and auditory brainstem responses (abrs). emission audiograms were constructed by finding the stimulus levels required to produce a criterion emission amplitude at a given stimulus frequency. for an emission amplitude of -10 db spl, the median "best threshold" was 28 db spl, and this minimum threshold occurred between 4 and 8 khz for all animals. the relative effective range of ... | 2001 | 11550523 |
| phylogenetic analysis of 18s rrna and the mitochondrial genomes of the wombat, vombatus ursinus, and the spiny anteater, tachyglossus aculeatus: increased support for the marsupionta hypothesis. | the monotremes, the duck-billed platypus and the echidnas, are characterized by a number of unique morphological characteristics, which have led to the common belief that they represent the living survivors of an ancestral stock of mammals. analysis of new data from the complete mitochondrial (mt) genomes of a second monotreme, the spiny anteater, and another marsupial, the wombat, yielded clear support for the marsupionta hypothesis. according to this hypothesis marsupials are more closely rela ... | 2002 | 11734900 |
| win-shift and win-stay learning in the short-beaked echidna (tachyglossus aculeatus). | numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. in three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). this is a species and a foraging situation that have not been examined in this way before. echidnas we ... | 2002 | 12150039 |
| the major histocompatibility complex in monotremes: an analysis of the evolution of mhc class i genes across all three mammalian subclasses. | we report the isolation and characterization of cdna clones of expressed, functional major histocompatibility complex class-i ( mhc-i) genes from two species of monotremes: the duck-billed platypus and the short-beaked echidna. the cdna clones were isolated from libraries constructed from spleen rna, clearly establishing their expression in at least this one peripheral lymphoid organ. from the presence of conserved amino acid residues, it appears the expressed sequences encode molecules that lik ... | 2002 | 12242589 |
| neuronal classes in the isocortex of a monotreme, the australian echidna (tachyglossus aculeatus). | we have used valverde-golgi and golgi-colonnier techniques to analyze cortical neuronal morphology in four regions (frontal cortex, primary motor cortex, primary somatosensory cortex, primary visual cortex) of the isocortex of the echidna (tachyglossus aculeatus). eight classes of neurons could be identified--pyramidal, spinous bipolar, aspinous bipolar, spinous bitufted, aspinous bitufted, spinous multipolar, aspinous multipolar and neurogliaform. all except the pyramidal neurons were morpholog ... | 2003 | 12626859 |
| the anatomy of the cerebral cortex of the echidna (tachyglossus aculeatus). | the cerebral cortex of the echidna is notable for its extensive folding and the positioning of major functional areas towards its caudal extremity. the gyrification of the echidna cortex is comparable in magnitude to prosimians and cortical thickness and neuronal density are similar to that seen in rodents and carnivores. on the other hand, many pyramidal neurons in the cerebral cortex of the echidna are atypical with inverted somata and short or branching apical dendrites. all other broad class ... | 2003 | 14667848 |
| review of the monotreme fossil record and comparison of palaeontological and molecular data. | monotremes have traditionally been considered a remnant group of mammals descended from archaic mesozoic stock, surviving to the present day on the relatively isolated australian continent. challenges to this orthodoxy have been spurred by discoveries of 'advanced' cretaceous monotremes (steropodon galmani, archer, m., et al., 1985. first mesozoic mammal from australia-an early cretaceous monotreme, nature. 318, 363-366) as well as by results from molecular data linking monotremes to therian mam ... | 2003 | 14667856 |
| isolation of monotreme t-cell receptor alpha and beta chains. | monotremes are an ancient mammalian lineage that last shared a common ancestor with the marsupial and eutherian (placental) mammals about 170 million years ago. characterization of their immune genes is allowing us to gain insights into the evolutionary processes that lead to the 'mammalian' immune response. here we describe the characterization of the first cdna clones encoding t-cell receptors from a monotreme. two tcr alpha-chain cdnas ( tcra) from the short-beaked echidna, tachyglossus acule ... | 2004 | 15133646 |
| structure of the calcium-binding echidna milk lysozyme at 1.9 a resolution. | a lysozyme isolated from the milk of a monotreme, the echidna, tachyglossus aculeatus multiaculeatus, has been crystallized (space group p2(1), with unit-cell dimensions a = 37.1, b = 42.0, c = 38.1 a, beta = 91 degrees and z = 2) and the structure refined to an r value of 0.167 for all measured data in the resolution range 7.0-1.9 a. it had previously been inferred from sequence homology with alpha-lactalbumins that echidna milk lysozyme (eml) would bind one calcium ion per molecule. this has b ... | 1997 | 15299900 |
| cyto- and chemoarchitecture of the cerebral cortex of an echidna (tachyglossus aculeatus). ii. laminar organization and synaptic density. | we have examined the distribution and morphology of neurons immunoreactive for nonphosphorylated neurofilament protein (smi-32 antibody), calcium-binding proteins (parvalbumin, calbindin, calretinin), and neuropeptide y as well as neurons reactive for nadph diaphorase in the cerebral cortex of the australian short-beaked echidna (tachyglossus aculeatus). we have also studied synaptic morphology and density in s1 somatosensory cortex and assessed parameters associated with metabolic activity of t ... | 2005 | 15612022 |
| high variability in complementarity-determining regions compensates for a low number of v gene families in the lambda light chain locus of the platypus. | based on the analysis of a panel of variable (v) region sequences from the australian duck-billed platypus and the australian short beaked echidna, the monotremes were found to express a highly diversified vlambda repertoire. high variability was observed both in sequence and in length of all three cdr regions. however, all monotreme sequences were found to form a separate branch on a distance tree, and the monotremes appear to express only two vlambda gene families. the appearance of all vlambd ... | 2005 | 16143985 |
| body temperature-related structural transitions of monotremal and human hemoglobin. | in this study, temperature-related structural changes were investigated in human, duck-billed platypus (ornithorhynchus anatinus, body temperature t(b) = 31-33 degrees c), and echidna (tachyglossus aculeatus, body temperature t(b) = 32-33 degrees c) hemoglobin using circular dichroism spectroscopy and dynamic light scattering. the average hydrodynamic radius (r(h)) and fractional (normalized) change in the ellipticity (f(obs)) at 222 +/- 2 nm of hemoglobin were measured. the temperature was vari ... | 2006 | 16844747 |
| the unique paired retinal vascular pattern in marsupials: structural, functional and evolutionary perspectives based on observations in a range of species. | in the few marsupial species studied to date that possess a retinal vasculature, the arterial and venous segments, down to the smallest calibre capillaries, have been shown to occur in pairs. it is a pattern seen in the marsupial central nervous system (cns) but not in other tissues in this group or in any tissues in eutherian mammals. the aim of the present study was to investigate the presence of retinal vessels in a range of non-eutherian mammalian species (marsupials and monotremes) and to d ... | 2007 | 17475712 |
| the pretectal nuclei in two monotremes: the short-beaked echidna (tachyglossus aculeatus) and the platypus (ornithorhynchus anatinus). | we have examined the organization of the pretectal area in two monotremes (the short beaked echidna-tachyglossus aculeatus, and the platypus-ornithorhynchus anatinus) and compared it to that in the wistar strain rat, using nissl staining in conjunction with enzyme histochemistry (acetylcholinesterase and nadph diaphorase) and immunohistochemistry for parvalbumin, calbindin, calretinin and non-phosphorylated neurofilament protein (smi-32 antibody). we were able to identify distinct anterior, medi ... | 2007 | 17717686 |
| disruption and pseudoautosomal localization of the major histocompatibility complex in monotremes. | the monotremes, represented by the duck-billed platypus and the echidnas, are the most divergent species within mammals, featuring a flamboyant mix of reptilian, mammalian and specialized characteristics. to understand the evolution of the mammalian major histocompatibility complex (mhc), the analysis of the monotreme genome is vital. | 2007 | 17727704 |
| hepatozoon tachyglossi in the short-beaked echidna (tachyglossus aculeatus). | | 2008 | 18454841 |
| the exceptional longevity of an egg-laying mammal, the short-beaked echidna (tachyglossus aculeatus) is associated with peroxidation-resistant membrane composition. | the echidna tachyglossus aculeatus is a monotreme mammal from australia that is exceptionally long-living. its documented maximum lifespan of 50 years is 3.7 times that predicted from its body mass. other exceptionally long-living mammals (naked mole-rats and humans) are known to have peroxidation-resistant membrane composition, raising the question about echidnas. phospholipids were extracted from skeletal muscle, liver and liver mitochondria of echidnas and fatty acid composition measured. as ... | 2008 | 18586080 |
| cone visual pigments of monotremes: filling the phylogenetic gap. | we have determined the sequence and genomic organization of the genes encoding the cone visual pigment of the platypus (ornithorhynchus anatinus) and the echidna (tachyglossus aculeatus), and inferred their spectral properties and evolutionary pathways. we prepared platypus and echidna retinal rna and used primers of the middle-wave-sensitive (mws), long-wave-sensitive (lws), and short-wave sensitive (sws1) pigments corresponding to coding sequences that are highly conserved among mammals; to pc ... | 2008 | 18598396 |
| expanded hoxa13 polyalanine tracts in a monotreme. | the n-terminal region of human hoxa13 has seven discrete polyalanine tracts. our previous analysis of these tracts in multiple major vertebrate clades suggested that three are mammal-specific. we now report the n-terminal hoxa13 repetitive tract structures in the monotreme tachyglossus aculeatus (echidna). contrary to our expectations, echidna hoxa13 possesses a unique set of polyalanine tracts and an unprecedented polyglycine tract. the data support the conclusion that the emergence of expanded ... | 2008 | 18638320 |
| reproductive biology in egg-laying mammals. | the duck-billed platypus and short-beaked echidna are iconic species in australia. their morphology and physiology have puzzled scientists all over the world for more than 200 years. recent genetic studies, particularly the platypus whole-genome sequencing project, have revealed the molecular basis of some of the extraordinary characteristics of monotremes. this and other works demonstrate the great value of research on our most distantly related mammalian relatives for comparative genomics and ... | 2008 | 18769071 |
| paneth cells of the echidna (tachyglossus aculeatus). | | 2014 | 4109671 |
| an ultrastructural and immunocytochemical study on endocrine cells in the proximal duodenum of the echidna (tachyglossus aculeatus). | | 2013 | 3913187 |
| studies on monotreme proteins. i. amino acid sequence of the -chain of haemoglobin from the echidna, tachyglossus aculeatus aculeatus. | | 2015 | 4663350 |
| an evolutionary view of the male reproductive tract and sperm maturation in a monotreme mammal--the echidna, tachyglossus aculeatus. | in exploring the evolution and adaptive significance of epididymal function, we have studied the male excurrent duct and spermatozoa of a monotreme mammal--the echidna. sperm maturation in the echidna excurrent duct appears simpler than that in most therians examined. furthermore, neither the duct nor the spermatozoa of the echidna display specific therian characteristics; they bear a much closer resemblance to those of non-passerine birds. the echidna spermatozoon is filiform, the sperm tail ha ... | 2004 | 506951 |
| electrophysiological studies of the echidna, tachyglossus aculeatus. i. waking and sleep. | | 2014 | 4342268 |
| histochemical, ultrastructural and hormonal studies on the pars distalis of the echidna (tachyglossus aculeatus). | there were no consistent significant differences between the concentrations of luteinizing hormone (lh) and adrenocorticotrophin (acth) in the rostral compared with the caudal zone of the echidna pars distalis. this suggests that lh is secreted by cells containing s-type granules (probably corresponding to secretory vesicles 200-300 nm diameter) which are distributed throughout the gland. some of the cells containing vesicles 100-200 nm diameter, seen in small numbers in both zones of the gland, ... | 1996 | 167975 |
| novel borrelia species detected in echidna ticks, bothriocroton concolor, in australia. | to date, little has been documented about microorganisms harboured within australian native ticks or their pathogenic potential. recently, a borrelia sp. related to the relapsing fever (rf) group was identified in a single tick removed from a wild echidna (tachyglossus aculeatus). the present study investigated the presence of borrelia in 97 bothriocroton concolor ticks parasitizing echidnas in queensland, new south wales, and victoria, australia, using nested pcr with borrelia-specific primers ... | 2016 | 27301754 |
| monotreme lactation protein is highly expressed in monotreme milk and provides antimicrobial protection. | monotremes (platypus and echidna) are the descendants of the oldest ancestor of all extant mammals distinguished from other mammals by mode of reproduction. monotremes lay eggs following a short gestation period and after an even briefer incubation period, altricial hatchlings are nourished over a long lactation period with milk secreted by nipple-less mammary patches located on the female's abdomen. milk is the sole source of nutrition and immune protection for the developing young until weanin ... | 2014 | 25245409 |
| functional characterization of the rod visual pigment of the echidna (tachyglossus aculeatus), a basal mammal. | monotremes are the most basal egg-laying mammals comprised of two extant genera, which are largely nocturnal. visual pigments, the first step in the sensory transduction cascade in photoreceptors of the eye, have been examined in a variety of vertebrates, but little work has been done to study the rhodopsin of monotremes. we isolated the rhodopsin gene of the nocturnal short-beaked echidna (tachyglossus aculeatus) and expressed and functionally characterized the protein in vitro. three mutants w ... | 2012 | 22874131 |
| dietary fats and body lipid composition in relation to hibernation in free-ranging echidnas. | laboratory studies have shown that high levels of dietary unsaturated fatty acids prolong torpor and lower body temperatures in hibernating herbivorous rodents, which may in turn improve winter survival. the importance of nutritional ecology in relation to hibernation in insectivorous hibernators is unknown. we therefore studied fatty acid composition of dietary insects and the depot fat of echidnas tachyglossus aculeatus (monotremata) during the pre-hibernation season and compared depot fat fat ... | 2001 | 11352101 |
| a molecular survey of tick-borne pathogens from ticks collected in central queensland, australia. | central queensland (cq) is a large and isolated, low population density, remote tropical region of australia with a varied environment. the region has a diverse fauna and several species of ticks that feed upon that fauna. this study examined 518 individual ticks: 177 rhipicephalus sanguineus (brown dog tick), 123 haemaphysalis bancrofti (wallaby tick), 102 rhipicephalus australis (australian cattle tick), 47 amblyomma triguttatum (ornate kangaroo tick), 57 ixodes holocyclus (paralysis tick), 9 ... | 2018 | 29336689 |
| australian penguin ticks screened for novel borrelia species. | lyme borreliosis (or lyme disease) is an emerging threat to human health in the northern hemisphere caused by tick-borne bacteria from the borrelia burgdorferi sensu lato (bbsl) complex. seabirds are important reservoir hosts of some members of the bbsl complex in the northern hemisphere, and some evidence suggests this may be true of penguins in the southern hemisphere. while the bbsl complex has not been detected in australia, a novel borrelia species ('candidatus borrelia tachyglossi') was re ... | 2017 | 29275874 |
| deep-sequencing to resolve complex diversity of apicomplexan parasites in platypuses and echidnas: proof of principle for wildlife disease investigation. | the short-beaked echidna (tachyglossus aculeatus) and the platypus (ornithorhynchus anatinus) are iconic egg-laying monotremes (mammalia: monotremata) from australasia. the aim of this study was to demonstrate the utility of diversity profiles in disease investigations of monotremes. using small subunit (18s) rdna amplicon deep-sequencing we demonstrated the presence of apicomplexan parasites and confirmed by direct and cloned amplicon gene sequencing theileria ornithorhynchi, theileria tachyglo ... | 2017 | 28919547 |
| molecular evolution of monotreme and marsupial whey acidic protein genes. | whey acidic protein (wap), a major whey protein present in milk of a number of mammalian species has characteristic cysteine-rich domains known as four-disulfide cores (4-dsc). eutherian wap, expressed in the mammary gland throughout lactation, has two 4-dsc domains, (di-dii) whereas marsupial wap, expressed only during mid-late lactation, contains an additional 4-dsc (diii), and has a diii-d1-dii configuration. we report the expression and evolution of echidna (tachyglossus aculeatus) and platy ... | 2007 | 17651362 |
| a survey of type i interferons from a marsupial and monotreme: implications for the evolution of the type i interferon gene family in mammals. | sequence data for type i interferons (ifns) have previously only been available for birds and eutherian ('placental') mammals, but not for the other two groups of extant mammals, the marsupials and monotremes. this has left a large gap in our knowledge of the evolutionary and functional relationships of what is a complex gene family in eutherians. in this study, a pcr-based survey of type i ifn genes from a marsupial, the tammar wallaby (macropus eugenii), and a monotreme, the short-beaked echid ... | 2003 | 12697149 |
| lung development of monotremes: evidence for the mammalian morphotype. | the reproductive strategies and the extent of development of neonates differ markedly between the three extant mammalian groups: the monotremata, marsupialia, and eutheria. monotremes and marsupials produce highly altricial offspring whereas the neonates of eutherian mammals range from altricial to precocial. the ability of the newborn mammal to leave the environment in which it developed depends highly on the degree of maturation of the cardio-respiratory system at the time of birth. the lung s ... | 2009 | 19051249 |
| assessment of oxidant susceptibility of red blood cells in various species based on cell deformability. | the present study was designed to investigate the oxidant susceptibility of red blood cells (rbc) from four species (echidna, human, koala, tasmanian devil) based on changes in cellular deformability. these species were specifically chosen based on differences in lifestyle and/or biology associated with varied levels of oxidative stress. the major focus was the influence of superoxide radicals generated within the cell (phenazine methosulfate, pms, 50 μm) or in the extracellular medium (xanthine ... | 2011 | 22433570 |
| development of the spinal cord and peripheral nervous system in platypus (ornithorhynchus anatinus) and short-beaked echidna (tachyglossus aculeatus). | the modern monotremes (platypus and echidnas) are characterized by development of their young in a leathery egg that is laid into a nest or abdominal pouch. at hatching, the young are externally immature, with forelimbs capable of digitopalmar prehension, but hindlimbs little advanced beyond limb buds. the embryological collections at the museum für naturkunde in berlin were used to examine the development of the spinal cord and early peripheral nervous system in developing monotremes and to cor ... | 2012 | 22401666 |
| 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 ... | 2002 | 12377222 |
| type i interferon genes from the egg-laying mammal, tachyglossus aculeatus (short-beaked echidna). | the type i ifn are an important group of multifunctional cytokines that have, for whatever reason, evolved to a high level of complexity in eutherian mammals such as humans and mice. however, until recently, little was known about the type i ifn systems of the other two groups of extant mammals, the marsupials and the egg-laying monotremes. preliminary partial type i ifn sequences from the short-beaked echidna were previously found to cluster only with the ifn-beta subtype in phylogenetic analys ... | 2004 | 15061761 |
| afferents of the frontal cortex in the echidna (tachyglossus aculeatus). indication of an outstandingly large prefrontal area. | afferents of the large, electrically 'silent' frontal cortex in an egg-laying mammal, the echidna, were studied with the somatopetal axonal transport technique. this cortical area receives thalamic projections only from the anterior part of the anteromediodorsal region. the medial parts of the cortex receive afferents from more medial neurons, whereas the lateral area is innervated from the laterally placed perikarya of this thalamic region. the nonthalamic afferents to the frontal cortex are, w ... | 1987 | 3427409 |
| mammalian engineers drive soil microbial communities and ecosystem functions across a disturbance gradient. | the effects of mammalian ecosystem engineers on soil microbial communities and ecosystem functions in terrestrial ecosystems are poorly known. disturbance from livestock has been widely reported to reduce soil function, but disturbance by animals that forage in the soil may partially offset these negative effects of livestock, directly and/or indirectly by shifting the composition and diversity of soil microbial communities. understanding the role of disturbance from livestock and ecosystem engi ... | 2016 | 27426226 |
| morbidity and mortality of monotremes admitted to the australian wildlife health centre, healesville sanctuary, australia, 2000-2014. | the medical records of individual monotremes admitted to the australian wildlife health centre from 2000 to 2014 were reviewed to determine the causes of morbidity and mortality. | 2016 | 27021894 |
| inner ear labyrinth anatomy of monotremes and implications for mammalian inner ear evolution. | the monophyletic clade monotremata branches early from the rest of the mammalian crown group in the jurassic and members of this clade retain many ancestral mammalian traits. thus, accurate and detailed anatomical descriptions of this group can offer unique insight into the early evolutionary history of mammalia. in this study, we examine the inner ear anatomy of two extant monotremes, ornithorhynchus anatinus and tachyglossus aculeatus, with the primary goals of elucidating the ancestral mammal ... | 2017 | 27889918 |
| a spur to atavism: placing platypus poison. | for over two centuries, the platypus (ornithorhynchus anatinus) has been constructed and categorized in multiple ways. an unprecedented mélange of anatomical features and physiological functions, it long remained a systematic quandary. nevertheless, since 1797, naturalists and biologists have pursued two recurring obsessions. investigations into platypus reproduction and lactation have focused attention largely upon females of the species. despite its apparent admixture of avian, reptilian and m ... | 2015 | 25964144 |
| immunohistochemical analysis of pancreatic islets of platypus (ornithorhynchus anatinus) and echidna (tachyglossus aculeatus ssp.). | monotremes have undergone remarkable changes to their digestive and metabolic control system; however, the monotreme pancreas remains poorly characterized. previous work in echidna demonstrated the presence of pancreatic islets, but no information is available for platypus and the fine structure has not been described for either monotreme. based on our recent finding that monotremes lack the ghrelin gene, which is expressed in mouse and human pancreatic islets, we investigated the structure of m ... | 2015 | 25682842 |
| development of the cerebellum in the platypus (ornithorhynchus anatinus) and short-beaked echidna (tachyglossus aculeatus). | the monotremes are a unique group of mammals whose young are incubated in a leathery-shelled egg and fed with milk from teatless areolae after hatching. as soon as they hatch, monotreme young must be able to maneuver around the nest or maternal pouch to locate the areolae and stimulate milk ejection. in the present study, the embryological collections at the museum für naturkunde, berlin, have been used to follow the development of the monotreme cerebellum through incubation and lactational phas ... | 2012 | 22572119 |
| development of the hypothalamus and pituitary in platypus (ornithorhynchus anatinus) and short-beaked echidna (tachyglossus aculeatus). | the living monotremes (platypus and echidnas) are distinguished by the development of their young in a leathery-shelled egg, a low and variable body temperature and a primitive teat-less mammary gland. their young are hatched in an immature state and must deal with the external environment, with all its challenges of hypothermia and stress, as well as sourcing nutrients from the maternal mammary gland. the hill and hubrecht embryological collections have been used to follow the structural develo ... | 2012 | 22512474 |
| distinct development of peripheral trigeminal pathways in the platypus (ornithorhynchus anatinus) and short-beaked echidna (tachyglossus aculeatus). | the extant monotremes (platypus and echidnas) are believed to all be capable of electroreception in the trigeminal pathways, although they differ significantly in the number and distribution of electroreceptors. it has been argued by some authors that electroreception was first developed in an aquatic environment and that echidnas are descended from a platypus-like ancestor that invaded an available terrestrial habitat. if this were the case, one would expect the developmental trajectories of th ... | 2012 | 22179203 |
| development of the dorsal and ventral thalamus in platypus (ornithorhynchus anatinus) and short-beaked echidna (tachyglossus aculeatus). | the living monotremes (platypus and echidnas) are distinguished from therians as well as each other in part by the unusual structure of the thalamus in each. in particular, the platypus has an enlarged ventral posterior (vp) nucleus reflecting the great behavioural importance of trigeminosensation and electroreception. the embryological collections of the museum für naturkunde in berlin were used to analyse the development of the dorsal thalamus and ventral thalamus (prethalamus) in both species ... | 2012 | 22113857 |
| characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals. | using a milk-cell cdna sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (ornithorhynchus anatinus) and echidna (tachyglossus aculeatus) and found a full set of caseins and casein variants. the genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we conf ... | 2009 | 19874726 |
| the hypothalamic supraoptic and paraventricular nuclei of the echidna and platypus. | the monotremes are an intriguing group of mammals that have major differences in their reproductive physiology and lactation from therian mammals. monotreme young hatch from leathery skinned eggs and are nourished by milk secreted onto areolae rather than through nipples. parturition and lactation are in part controlled through the paraventricular and supraoptic nuclei of the hypothalamus. we have used nissl staining, enzyme histochemistry, immunohistochemistry for tyrosine hydroxylase, calbindi ... | 2006 | 16809908 |
| the complexity of expressed kappa light chains in egg-laying mammals. | complementary dnas encoding immunoglobulin light chains were isolated from two monotreme species, ornithorhynchus anatinus (duckbill platypus) and tachyglossus aculeatus (echidna). the sequences of both the variable and constant regions of these clones had greater similarity to igk than to other light chain classes and phylogenetic analyses place them squarely within the mammalian igk group, establishing them as monotreme igk homologues. the constant region sequences of all clones were essential ... | 2004 | 15448942 |
| the claustrum is not missing from all monotreme brains. | many authors have reported that the claustrum, which comprises the insular claustrum and the endopiriform nucleus, is missing from the monotreme forebrain. we used nissl and myelin staining in conjunction with enzyme histochemistry for acetylcholinesterase and immunohistochemistry for parvalbumin, calbindin, calretinin and tyrosine hydroxylase to examine the brains of two monotremes, the short-beaked echidna (tachyglossus aculeatus) and the platypus (ornithorhynchus anatinus). we found that alth ... | 2004 | 15319553 |
| tactile neural mechanisms in monotremes. | monotremes, perhaps more than any other order of mammals, display an enormous behavioural reliance upon the tactile senses. in the platypus, ornithorhynchus anatinus, this is manifest most strikingly in the special importance of the bill as a peripheral sensory organ, an importance confirmed by electrophysiological mapping that reveals a vast area of the cerebral cortex allocated to the processing of tactile inputs from the bill. although behavioural evidence in the echidna, tachyglossus aculeat ... | 2003 | 14667851 |
| immunoglobulin genetics of ornithorhynchus anatinus (platypus) and tachyglossus aculeatus (short-beaked echidna). | in this paper, we review data on the monotreme immune system focusing on the characterisation of lymphoid tissue and of antibody responses, as well the recent cloning of immunoglobulin genes. it is now known that monotremes utilise immunoglobulin isotypes that are structurally identical to those found in marsupials and eutherians, but which differ to those found in birds and reptiles. monotremes utilise igm, igg, iga and ige. they do not use igy. their igg and iga constant regions contain three ... | 2003 | 14667846 |
| characterization of beta(2)-microglobulin coding sequence from three non-placental mammals: the duckbill platypus, the short-beaked echidna, and the grey short-tailed opossum. | to further characterize genes of immunological importance from non-placental mammals, cdnas encoding beta(2)-microglobulin (beta(2)m) were isolated from two prototherians, the platypus and an echidna, and one metatherian, a grey short-tailed opossum. in addition, a second allele of beta(2)m was identified in another metatherian species, the brushtail possum. analysis of the deduced translations revealed conservation of key residues in these molecules over a long evolutionary history. the types o ... | 2003 | 12590975 |
| the distribution and morphological characteristics of catecholaminergic cells in the brain of monotremes as revealed by tyrosine hydroxylase immunohistochemistry. | the present study describes the distribution and cellular morphology of catecholaminergic neurons in the cns of two species of monotreme, the platypus (ornithorhynchus anatinus) and the short-beaked echidna (tachyglossus aculeatus). tyrosine hydroxylase immunohistochemistry was used to visualize these neurons. the standard a1-a17, c1-c3 nomenclature was used for expediency, but the neuroanatomical names of the various nuclei have also been given. monotremes exhibit catecholaminergic neurons in t ... | 2002 | 12476055 |
| the distribution and morphological characteristics of cholinergic cells in the brain of monotremes as revealed by chat immunohistochemistry. | the present study employs choline acetyltransferase (chat) immunohistochemistry to identify the cholinergic neuronal population in the central nervous system of the monotremes. two of the three extant species of monotreme were studied: the platypus (ornithorhynchus anatinus) and the short-beaked echidna (tachyglossus aculeatus). the distribution of cholinergic cells in the brain of these two species was virtually identical. distinct groups of cholinergic cells were observed in the striatum, basa ... | 2002 | 12476054 |
| parathyroids and ultimobranchial bodies in monotremes. | only scant information is available in the scientific literature on the parathyroids and ultimobranchial bodies in the primitive mammals, the echidna (tachyglossus aculeatus) and platypus (ornithorhynchus anatinus). the major aim of this paper is to describe the morphology of the monotreme parathyroid gland and to compare it with parathyroids in mammals and reptiles. the gross anatomy and light microscopic structure of the ultimobranchial body, thymus, and thyroid are also given. animals were di ... | 1999 | 9972812 |
| sensory receptors in monotremes. | this is a summary of the current knowledge of sensory receptors in skin of the bill of the platypus, ornithorhynchus anatinus, and the snout of the echidna, tachyglossus aculeatus. brief mention is also made of the third living member of the monotremes, the long-nosed echidna, zaglossus bruijnii. the monotremes are the only group of mammals known to have evolved electroreception. the structures in the skin responsible for the electric sense have been identified as sensory mucous glands with an e ... | 1998 | 9720114 |
| on the morphology of the brachial plexus of the platypus (ornithorhynchus anatinus) and the echidna (tachyglossus aculeatus). | four forelimbs of 3 platypuses and 3 forelimbs of 2 echidnas were examined to study the precise form of the brachial plexus and to clarify the structural characteristics of the brachial plexus in phylogeny. the spinal components contributing to the plexus (c4-t2) and the formation patterns of the 3 trunks of the plexus were the same as those generally observed in mammals. in the cranial half of the brachial plexus from c4, 5 and 6 in monotremes, division into the ventral bundle (lateral cord) an ... | 1997 | 9147230 |