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Sample records for monotreme ornithorhynchus anatinus

  1. The mitochondrial genome of a monotreme--the platypus (Ornithorhynchus anatinus).

    Science.gov (United States)

    Janke, A; Gemmell, N J; Feldmaier-Fuchs, G; von Haeseler, A; Pääbo, S

    1996-02-01

    The complete nucleotide sequence of the mitochondrial genome of a platypus (Ornithorhynchus anatinus) was determined. Its overall genomic organization is similar to that of placental mammals, Xenopus laevis, and fishes. However, it contains an apparently noncoding sequence of 88 base pairs located between the genes for tRNA(Leu)(UUR) and ND1. The base composition of this sequence and its conservation among monotremes, as well as the existence of a transcript from one of the strands, indicate that it may have a hitherto-unknown function. When the protein-coding sequences are used to reconstruct a phylogeny of mammals, the data suggest that monotremes and marsupials are sister groups and thus that placental mammals represent the most ancient divergence among mammals.

  2. Spermiogenesis and spermiation in a monotreme mammal, the platypus, Ornithorhynchus anatinus.

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    Lin, M; Jones, R C

    2000-02-01

    Spermatogenesis in the platypus (Ornithorhynchus anatinus) is of considerable biological interest as the structure of its gametes more closely resemble that of reptiles and birds than marsupial or eutherian mammals. The ultrastructure of 16 steps of spermatid development is described and provides a basis for determining the kinetics of spermatogenesis. Steps 1-3 correspond to the Golgi phase of spermatid development, steps 4-8 correspond to the cap phase, steps 9-12 are the acrosomal phase, and steps 13-16 are the maturation phase. Acrosomal development follows the reptilian model and no acrosomal granule is formed. Most other features of spermiogenesis are similar to processes in reptiles and birds. However, some are unique to mammals. For example, a thin, lateral margin of the acrosome of platypus sperm expands over the nucleus as in other mammals, and more than in reptiles and birds. Also, a tubulobulbar complex develops around the spermatid head, a feature which appears to be unique to mammals. Further, during spermiation the residual body is released from the caudal end of the nucleus of platypus sperm leaving a cytoplasmic droplet located at the proximal end of the middle piece as in marsupial and eutherian mammals. Other features of spermiogenesis in platypus appear to be unique to monotremes. For example, nuclear condensation involves the formation of a layer of chromatin granules under the nucleolemma, and development of the fibrous sheath of the principal piece starts much later in the platypus than in birds or eutherian mammals.

  3. The pretectal nuclei in two monotremes: the short-beaked echidna (Tachyglossus aculeatus) and the platypus (Ornithorhynchus anatinus).

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    Ashwell, K W S; Paxinos, G

    2007-12-01

    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, medial, posterior (now called tectal gray) and olivary pretectal nuclei as well as a nucleus of the optic tract, all with largely similar topographical and chemoarchitectonic features to the homologous regions in therian mammals. The positions of these pretectal nuclei correspond to the distributions of retinofugal terminals identified by other authors. The overall size of the pretectum in both monotremes was found to be at least comparable in size, if not larger than, the pretectum of representative therian mammals of similar brain and body size. Our findings suggest that the pretectum of these two monotreme species is comparable in both size and organization to that of eutherian mammals, and is more than just an undifferentiated area pretectalis. The presence of a differentiated pretectum with similar chemoarchitecture to therians in both living monotremes lends support to the idea that the stem mammal for both prototherian and therian lineages also had a differentiated pretectum. This in turn indicates that a differentiated pretectum appeared at least 125 million years ago in the mammalian lineage and that the stem mammal for proto- and eutherian lineages probably had similar pretectal nuclei to those identified in its descendants.

  4. Novel genotypes of Trypanosoma binneyi from wild platypuses (Ornithorhynchus anatinus) and identification of a leech as a potential vector.

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    Paparini, Andrea; Macgregor, James; Irwin, Peter J; Warren, Kristin; Ryan, Una M

    2014-10-01

    Little is known about the prevalence and pathogenesis of trypanosomes in Australian monotremes, and few genetic characterisation studies have been conducted with these haemoparasites. During the present investigation, molecular and microscopic methods were used to screen peripheral blood (n=28) and ectoparasites (n=10 adult ticks; n=5 tick nymphs; n=1 leech; and n>500 tick eggs) collected from wild Tasmanian platypuses (Ornithorhynchus anatinus), for the presence of trypanosomatid-specific DNA and/or trypomastigotes. The genes for the small ribosomal subunit RNA (18S rDNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) were amplified and sequenced, prior to conducting phylogenetic analyses. The detection rate of the parasite-specific 18S rDNA in platypus blood was 85.7% (n=24/28), and the leech was also positive at both loci. Microscopically, high parasitaemia and the presence of abundant trypomastigotes, morphologically consistent with Trypanosoma binneyi Mackerras (1959), were observed in the blood films. Phylogenetic analyses at the 18S locus revealed the existence of four trypanosomatid-like genotypes, with variable similarity to two previously-described genotypes of T. binneyi (range of genetic p-distance: 0.0-0.5%). For the gGAPDH locus, for which only one T. binneyi sequence is available in GenBank, three genotypes closely related T. binneyi were identified (range of genetic p-distance: 0.1-0.4%). The leech-derived trypanosome isolate was virtually identical (at the two loci studied) to the other parasites sequenced from infected platypuses; however, the molecular or morphological identification of the leech species was not possible. Although further studies are required, the molecular detection of trypanosomes in an aquatic leech removed from a platypus, suggests the possibility that these haematophagous hirudineans may be a vector for T. binneyi (and closely related genotypes).

  5. Small population size and extremely low levels of genetic diversity in island populations of the platypus, Ornithorhynchus anatinus.

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    Furlan, Elise; Stoklosa, J; Griffiths, J; Gust, N; Ellis, R; Huggins, R M; Weeks, A R

    2012-04-01

    Genetic diversity generally underpins population resilience and persistence. Reductions in population size and absence of gene flow can lead to reductions in genetic diversity, reproductive fitness, and a limited ability to adapt to environmental change increasing the risk of extinction. Island populations are typically small and isolated, and as a result, inbreeding and reduced genetic diversity elevate their extinction risk. Two island populations of the platypus, Ornithorhynchus anatinus, exist; a naturally occurring population on King Island in Bass Strait and a recently introduced population on Kangaroo Island off the coast of South Australia. Here we assessed the genetic diversity within these two island populations and contrasted these patterns with genetic diversity estimates in areas from which the populations are likely to have been founded. On Kangaroo Island, we also modeled live capture data to determine estimates of population size. Levels of genetic diversity in King Island platypuses are perilously low, with eight of 13 microsatellite loci fixed, likely reflecting their small population size and prolonged isolation. Estimates of heterozygosity detected by microsatellites (H(E)= 0.032) are among the lowest level of genetic diversity recorded by this method in a naturally outbreeding vertebrate population. In contrast, estimates of genetic diversity on Kangaroo Island are somewhat higher. However, estimates of small population size and the limited founders combined with genetic isolation are likely to lead to further losses of genetic diversity through time for the Kangaroo Island platypus population. Implications for the future of these and similarly isolated or genetically depauperate populations are discussed.

  6. On the morphology of the brachial plexus of the platypus (Ornithorhynchus anatinus) and the echidna (Tachyglossus aculeatus).

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    Koizumi, M; Sakai, T

    1997-04-01

    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) and dorsal bundle (axillary nerve) is clear, as in other mammals. However, for monotremes, in the caudal half of the plexus from C7 and T1 (+T2) and the nerves arising from the caudal plexus there is no definite division into the ventral and dorsal bundles, which distribute to the flexor and extensor parts of the forelimbs, respectively. The lower trunk of the monotreme brachial plexus forms a cord which contains both ventral and dorsal components. This characteristic diverges from the generally accepted idea that the tetrapod limb plexus is divided clearly into 2 layers: a dorsal layer for extensors and a ventral layer for flexors of the limb. Considering the incomplete dorsoventral division of forelimb nerves in some reptiles and urodeles, the caudal half of the monotreme brachial plexus has characteristics in common with those of lower tetrapods.

  7. Development of the hypothalamus and pituitary in platypus (Ornithorhynchus anatinus) and short-beaked echidna (Tachyglossus aculeatus)

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    Ashwell, Ken W S

    2012-01-01

    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 development of the monotreme hypothalamus and its connections with the pituitary gland both in the period leading up to hatching and during the lactational phase of development, and to relate this structural maturation to behavioural development. In the incubation phase, development of the hypothalamus proceeds from closure of the anterior neuropore to formation of the lateral hypothalamic zone and putative medial forebrain bundle. Some medial zone hypothalamic nuclei are emerging at the time of hatching, but these are poorly differentiated and periventricular zone nuclei do not appear until the first week of post-hatching life. Differentiation of the pituitary is also incomplete at hatching, epithelial cords do not develop in the pars anterior until the first week, and the hypothalamo-neurohypophyseal tract does not appear until the second week of post-hatching life. In many respects, the structure of the hypothalamus and pituitary of the newly hatched monotreme is similar to that seen in newborn marsupials, suggesting that both groups rely solely on lateral hypothalamic zone nuclei for whatever homeostatic mechanisms they are capable of at birth/hatching. PMID:22512474

  8. Distinct development of peripheral trigeminal pathways in the platypus (Ornithorhynchus anatinus) and short-beaked echidna (Tachyglossus aculeatus).

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    Ashwell, Ken W S; Hardman, Craig D; Giere, Peter

    2012-01-01

    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 the trigeminal pathways to be similar in the early stages of platypus and short-beaked echidna development, with structural divergence occurring later. We examined the development of the peripheral trigeminal pathway from snout skin to trigeminal ganglion in sectioned material in the Hill and Hubrecht collections to test for similarities and differences between the two during the development from egg to adulthood. Each monotreme showed a characteristic and different pattern of distribution of developing epidermal sensory gland specializations (electroreceptor primordia) from the time of hatching. The cross-sectional areas of the trigeminal divisions and the volume of the trigeminal ganglion itself were also very different between the two species at embryonic ages, and remained consistently different throughout post-hatching development. Our findings indicate that the trigeminal pathways in the short-beaked echidna and the platypus follow very different developmental trajectories from the earliest ages. These findings are more consistent with the notion that the platypus and echidna have both diverged from an ancestor with rudimentary electroreception and/or trigeminal specialization, rather than the contention that the echidna is derived from a platypus-like ancestor. Copyright © 2011 S. Karger AG, Basel.

  9. Development of the dorsal and ventral thalamus in platypus (Ornithorhynchus anatinus) and short-beaked echidna (Tachyglossus aculeatus).

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    Ashwell, Ken W S

    2012-04-01

    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. Prosomeric organization of the forebrain emerged at 6 mm crown-rump length (CRL), but thalamic neurogenesis did not commence until about 8-9 mm CRL. Distinctive features of the dorsal thalamus in the two species began to emerge after hatching (about 14-15 mm CRL). During the first post-hatching week, dense clusters of granular cells aggregated to form the VP of the platypus, whereas the VP complex of the echidna remained smaller and divided into distinct medial and lateral divisions. At the end of the first post-hatching week, the thalamocortical tract was much larger in the platypus than the echidna. The dorsal thalamus of the platypus is essentially adult-like by the sixth week of post-hatching life. The similar appearance of the dorsal thalamus in the two species until the time of hatching, followed by the rapid expansion of the VP in the platypus, is most consistent with ancestral platypuses having undergone changes in the genetic control of thalamic neurogenesis to produce a large VP for trigeminal electroreception after the divergence of the two lineages of monotreme.

  10. Lung development of monotremes: evidence for the mammalian morphotype.

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    Ferner, Kirsten; Zeller, Ulrich; Renfree, Marilyn B

    2009-02-01

    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 structure is thus a reflection of the metabolic capacity of neonates. The lung development in monotremes (Ornithorhynchus anatinus, Tachyglossus aculeatus), in one marsupial (Monodelphis domestica), and one altricial eutherian (Suncus murinus) species was examined. The results and additional data from the literature were integrated into a morphotype reconstruction of the lung structure of the mammalian neonate. The lung parenchyma of monotremes and marsupials was at the early terminal air sac stage at birth, with large terminal air sacs. The lung developed slowly. In contrast, altricial eutherian neonates had more advanced lungs at the late terminal air sac stage and postnatally, lung maturation proceeded rapidly. The mammalian lung is highly conserved in many respects between monotreme, marsupial, and eutherian species and the structural differences in the neonatal lungs can be explained mainly by different developmental rates. The lung structure of newborn marsupials and monotremes thus resembles the ancestral condition of the mammalian lung at birth, whereas the eutherian newborns have a more mature lung structure.

  11. Sensory receptors in monotremes.

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    Proske, U; Gregory, J E; Iggo, A

    1998-01-01

    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 expanded epidermal portion that is innervated by large-diameter nerve fibres. Afferent recordings have shown that in both platypuses and echidnas the receptors excited by cathodal (negative) pulses and inhibited by anodal (positive) pulses. Estimates give a total of 40,000 mucous sensory glands in the upper and lower bill of the platypus, whereas there are only about 100 in the tip of the echidna snout. Recording of electroreceptor-evoked activity from the brain of the platypus have shown that the largest area dedicated to somatosensory input from the bill, S1, shows alternating rows of mechanosensory and bimodal neurons. The bimodal neurons respond to both electrosensory and mechanical inputs. In skin of the platypus bill and echidna snout, apart from the electroreceptors, there are structures called push rods, which consist of a column of compacted cells that is able to move relatively independently of adjacent regions of skin. At the base of the column are Merkel cell complexes, known to be type I slowly adapting mechanoreceptors, and lamellated corpuscles, probably vibration receptors. It has been speculated that the platypus uses its electric sense to detect the electromyographic activity from moving prey in the water and for obstacle avoidance. Mechanoreceptors signal contact with the prey. For the echidna, a role for the electrosensory system has not yet been established during normal foraging behaviour, although it has been shown that it is able to detect the presence

  12. The claustrum is not missing from all monotreme brains.

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    Ashwell, Ken W S; Hardman, Craig; Paxinos, George

    2004-01-01

    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 although the insular claustrum is a small structure in the echidna brain, it is nevertheless clearly present as loosely clustered neurons embedded in the white matter ventrolateral to the putamen and deep to the piriform and entorhinal cortices. Neurons in this region share the chemical features of the adjacent cortex (presence of a similar proportion of parvalbumin immunoreactive neurons and minimal activity for acetylcholinesterase and tyrosine hydroxylase), unlike the adjacent putamen and ventral pallidum. A putative endopiriform nucleus can be identified in the interior of the piriform lobe of the echidna as calretinin immunoreactive neurons embedded within the white matter. The situation is much less clear in the platypus, but our data suggest that there may be an insular claustrum deep to frontal cortex, separated from layer VI by only a thin layer of white matter. We could not identify an endopiriform nucleus in our platypus material. Our findings indicate that presence of the claustrum cannot be considered a feature confined to therian mammals and lend weight to arguments that this structure was present in the ancestral mammalian brain.

  13. The lamina cribrosa of Ornithorhynchus (Monotremata, Mammalia).

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    Zeller, U

    1988-01-01

    A vestigial and transitory lamina cribrosa was found in nestling platypus (Ornithorhynchus anatinus). The heads of two nest-young (180 and 333 mm length), one subadult and one adult Ornithorhynchus were serially sectioned and studied with special reference to the development of the nasal region. In nest-young Ornithorhynchus an irregularly shaped bar of cartilage develops at the foramen olfactorium advehens. In the subadult it is largely resorbed, and in the osseous skull of the adult it is completely lacking. Ontogeny and topographical relationships of this bar of cartilage indicate that it is part of a lamina cribrosa. It embraces the ramus medialis of the nervus ethmoidalis and the arteria ethmoidalis, as do the corresponding parts of the lamina cribrosa of Tachyglossus. Compared to other parts of the chondrocranium this bar develops late in ontogeny, as does the lamina cribrosa of other mammals. Therefore, it can be concluded that part of the lamina cribrosa is present for a short period during the ontogeny of Ornithorhynchus, contrary to earlier reports. As in many other water-adapted mammals, the olfactory system of Ornithorhynchus is reduced. This suggests that the rest of the lamina cribrosa of Ornithorhynchus is secondarily reduced. The common ancestor of Ornithorhynchus and Tachyglossidae most probably possessed a lamina cribrosa which can be traced back to the common mammalian stock. The lamina cribrosa developed only once in the phylogeny of mammals. Its lack in the adult Ornithorhynchus is not a "reptilian" character.

  14. Energetics of foraging and locomotion in the platypus Ornithorhynchus anatinus.

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    Bethge, P; Munks, S; Nicol, S

    2001-08-01

    We measured the energy requirements of platypuses foraging, diving and resting in a swim tank using flow-through respirometry. Also, walking metabolic rates were obtained from platypuses walking on a conventional treadmill. Energy requirements while foraging were found to depend on water temperature, body weight and dive duration and averaged 8.48 W kg(-1). Rates for subsurface swimming averaged 6.71 W kg(-1). Minimal cost of transport for subsurface swimming platypuses was 1.85 J N(-1)m(-1) at a speed of 0.4 m s(-1). Aerobic dive limit of the platypus amounted to 59 s. Metabolic rate of platypuses resting on the water surface was minimal with 3.91 W kg(-1) while minimal RMR on land was 2.08 W kg(-1). The metabolic rate for walking was 8.80 W kg(-1) and 10.56 W kg(-1) at speeds of 0.2 m s(-1) and 0.3 m s(-1), respectively. A formula was derived, which allows prediction of power requirements of platypuses in the wild from measurements of body weight, dive duration and water temperature. Platypuses were found to expend energy at only half the rate of semiaquatic eutherians of comparable body sizes during both walking and diving. However, costs of transport at optimal speed were in line with findings for eutherians. These patterns suggest that underwater locomotion of semiaquatic mammals have converged on very similar efficiencies despite differences in phylogeny and locomotor mode.

  15. Electroreception in monotremes.

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    Pettigrew, J D

    1999-05-01

    I will briefly review the history of the bill sense of the platypus, a sophisticated combination of electroreception and mechanoreception that coordinates information about aquatic prey provided from the bill skin mechanoreceptors and electroreceptors, and provide an evolutionary account of electroreception in the three extant species of monotreme (and what can be inferred of their ancestors). Electroreception in monotremes is compared and contrasted with the extensive body of work on electric fish, and an account of the central processing of mechanoreceptive and electroreceptive input in the somatosensory neocortex of the platypus, where sophisticated calculations seem to enable a complete three-dimensional fix on prey, is given.

  16. Energy Homeostasis in Monotremes

    Directory of Open Access Journals (Sweden)

    Stewart C. Nicol

    2017-04-01

    Full Text Available In 1803, the French anatomist Étienne Geoffroy Saint-Hilaire decided that the newly described echidna and platypus should be placed in a separate order, the monotremes, intermediate between reptiles and mammals. The first physiological observations showed monotremes had low body temperatures and metabolic rates, and the consensus was that they were at a stage of physiological development intermediate between “higher mammals” and “lower vertebrates.” Subsequent studies demonstrated that platypuses and echidnas are capable of close thermoregulation in the cold although less so under hot conditions. Because the short-beaked echidna Tachyglossus aculeatus, may show very large daily variations in body temperature, as well as seasonal hibernation, it has been suggested that it may provide a useful model of protoendotherm physiology. Such analysis is complicated by the very significant differences in thermal relations between echidnas from different climates. In all areas female echidnas regulate Tb within 1°C during egg incubation. The lactation period is considered to be the most energetically expensive time for most female mammals but lactating echidnas showed no measurable difference in field metabolic rate from non-lactating females, while the lactation period is more than 200 days for Kangaroo Island echidnas but only 150 days in Tasmania. In areas with mild winters echidnas show reduced activity and shallow torpor in autumn and early winter, but in areas with cold winters echidnas enter true hibernation with Tb falling as low as 4.5°C. Monotremes do not possess brown adipose tissue and maximum rates of rewarming from hibernation in echidnas were only half those of marmots of the same mass. Although echidnas show very large seasonal variations in fat stores associated with hibernation there is no relationship between plasma leptin and adiposity. Leptin levels are lowest during post-reproductive fattening, supporting suggestions that in

  17. Lactate dehydrogenase A as a highly abundant eye lens protein in platypus (Ornithorhynchus anatinus): upsilon (upsilon)-crystallin.

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    van Rheede, Teun; Amons, Reinout; Stewart, Niall; de Jong, Wilfried W

    2003-06-01

    Vertebrate eye lenses mostly contain two abundant types of proteins, the alpha-crystallins and the beta/gamma-crystallins. In addition, certain housekeeping enzymes are highly expressed as crystallins in various taxa. We now observed an unusual approximately 41-kd protein that makes up 16% to 18% of the total protein in the platypus eye lens. Its cDNA sequence was determined, which identified the protein as muscle-type lactate dehydrogenase A (LDH-A). It is the first observation of LDH-A as a crystallin, and we designate it upsilon (upsilon)-crystallin. Interestingly, the related heart-type LDH-B occurs as an abundant lens protein, known as epsilon-crystallin, in many birds and crocodiles. Thus, two members of the ldh gene family have independently been recruited as crystallins in different higher vertebrate lineages, suggesting that they are particularly suited for this purpose in terms of gene regulatory or protein structural properties. To establish whether platypus LDH-A/upsilon-crystallin has been under different selective constraints as compared with other vertebrate LDH-A sequences, we reconstructed the vertebrate ldh-a gene phylogeny. No conspicuous rate deviations or amino acid replacements were observed.

  18. Taxonomy Icon Data: platypus [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available us_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Ornithorhynchus+anatinus&t=L http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Ornithorhynchus+anatinus&t=NL http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Ornithorhynchus+anatinus&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Ornithorhynchus+anatinus&t=NS ...

  19. Gene : CBRC-OPRI-01-0143 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ICTED: hypothetical protein [Ornithorhynchus anatinus] 4e-19 28% MQSLLCTPVYALSLLCTPVYALSLLCTPVYAESAVHSCICRVCCALLYMQSLLCTPVYAESAVHCCI...LYIQSLLCTPVYAHGLLCTPVYALSLLCTAVYAESAVHSCICTWSALHCCIYIRCLMELCSLCTPLYTGYYLIFLCPPYTTLSSMLPCHILRKLACPMS ...

  20. Comparative cranial morphology in living and extinct platypuses: Feeding behavior, electroreception, and loss of teeth.

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    Asahara, Masakazu; Koizumi, Masahiro; Macrini, Thomas E; Hand, Suzanne J; Archer, Michael

    2016-10-01

    The modern platypus, Ornithorhynchus anatinus, has an eye structure similar to aquatic mammals; however, platypuses also have a "sixth sense" associated with the bill electro- and mechanoreception that they use without opening their eyes underwater. We hypothesize that Ornithorhynchus and the Miocene taxon Obdurodon have different sensory capacities, which may have resulted from differences in foraging behavior. To estimate differences in foraging, sensory systems, and anatomical divergence between these monotremes, we compared their skull morphologies. Results indicate that the bill of Obdurodon is more dorsally deflected than that of Ornithorhynchus, suggesting a pelagic foraging behavior in Obdurodon compared to the bottom-feeding behavior in Ornithorhynchus. The infraorbital foramen of Obdurodon, through which the maxillary nerve passes sensory data from the bill to the brain, is relatively less developed than that of Ornithorhynchus. Whereas bill-focused sensory perception was likely shared among Mesozoic monotremes, the highly developed electrosensory system of Ornithorhynchus may represent an adaptation to foraging in cloudy water. Computed tomography imagery indicates that the enlarged infraorbital canal of Ornithorhynchus restricts the space available for maxillary tooth roots. Hence, loss of functional teeth in Ornithorhynchus may possibly have resulted from a shift in foraging behavior and coordinate elaboration of the electroreceptive sensory system. Well-developed electroreceptivity in monotremes is known at least as far back as the early Cretaceous; however, there are differences in the extent of elaboration of the feature among members of the ornithorhynchid lineage.

  1. Monotreme lactation protein is highly expressed in monotreme milk and provides antimicrobial protection.

    Science.gov (United States)

    Enjapoori, Ashwantha Kumar; Grant, Tom R; Nicol, Stewart C; Lefèvre, Christophe M; Nicholas, Kevin R; Sharp, Julie A

    2014-09-22

    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 weaning. Using transcriptome and mass spectrometry analysis of milk cells and milk proteins, respectively, a novel Monotreme Lactation Protein (MLP) was identified as a major secreted protein in milk. We show that platypus and short-beaked echidna MLP genes show significant homology and are unique to monotremes. The MLP transcript was shown to be expressed in a variety of tissues; however, highest expression was observed in milk cells and was expressed constitutively from early to late lactation. Analysis of recombinant MLP showed that it is an N-linked glycosylated protein and biophysical studies predicted that MLP is an amphipathic, α-helical protein, a typical feature of antimicrobial proteins. Functional analysis revealed MLP antibacterial activity against both opportunistic pathogenic Staphylococcus aureus and commensal Enterococcus faecalis bacteria but showed no effect on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Salmonella enterica. Our data suggest that MLP is an evolutionarily ancient component of milk-mediated innate immunity absent in other mammals. We propose that MLP evolved specifically in the monotreme lineage supporting the evolution of lactation in these species to provide bacterial protection, at a time when mammals lacked nipples.

  2. Monotreme Lactation Protein Is Highly Expressed in Monotreme Milk and Provides Antimicrobial Protection

    Science.gov (United States)

    Enjapoori, Ashwantha Kumar; Grant, Tom R.; Nicol, Stewart C.; Lefèvre, Christophe M.; Nicholas, Kevin R.; Sharp, Julie A.

    2014-01-01

    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 weaning. Using transcriptome and mass spectrometry analysis of milk cells and milk proteins, respectively, a novel Monotreme Lactation Protein (MLP) was identified as a major secreted protein in milk. We show that platypus and short-beaked echidna MLP genes show significant homology and are unique to monotremes. The MLP transcript was shown to be expressed in a variety of tissues; however, highest expression was observed in milk cells and was expressed constitutively from early to late lactation. Analysis of recombinant MLP showed that it is an N-linked glycosylated protein and biophysical studies predicted that MLP is an amphipathic, α-helical protein, a typical feature of antimicrobial proteins. Functional analysis revealed MLP antibacterial activity against both opportunistic pathogenic Staphylococcus aureus and commensal Enterococcus faecalis bacteria but showed no effect on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Salmonella enterica. Our data suggest that MLP is an evolutionarily ancient component of milk-mediated innate immunity absent in other mammals. We propose that MLP evolved specifically in the monotreme lineage supporting the evolution of lactation in these species to provide bacterial protection, at a time when mammals lacked nipples. PMID:25245409

  3. Tracing Monotreme Venom Evolution in the Genomics Era

    Science.gov (United States)

    Whittington, Camilla M.; Belov, Katherine

    2014-01-01

    The monotremes (platypuses and echidnas) represent one of only four extant venomous mammalian lineages. Until recently, monotreme venom was poorly understood. However, the availability of the platypus genome and increasingly sophisticated genomic tools has allowed us to characterize platypus toxins, and provides a means of reconstructing the evolutionary history of monotreme venom. Here we review the physiology of platypus and echidna crural (venom) systems as well as pharmacological and genomic studies of monotreme toxins. Further, we synthesize current ideas about the evolution of the venom system, which in the platypus is likely to have been retained from a venomous ancestor, whilst being lost in the echidnas. We also outline several research directions and outstanding questions that would be productive to address in future research. An improved characterization of mammalian venoms will not only yield new toxins with potential therapeutic uses, but will also aid in our understanding of the way that this unusual trait evolves. PMID:24699339

  4. Dicty_cDB: Contig-U01438-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available telium discoideum slug cDNA, clone SLJ658. 258 6e-65 1 ( AC147587 ) Ornithorhynchus anatinus clone OA_Bb-560F18, WORK...... 36 0.005 2 ( AC198836 ) Ornithorhynchus anatinus clone OA_Bb-498J4, WORK...rhynchus anatinus MHC class I antigen (Ora... 38 0.018 2 ( AC186714 ) Ornithorhynchus anatinus clone OA_Bb-315P16, WORK...... 36 0.018 2 ( AC186258 ) Ornithorhynchus anatinus clone OA_Bb-278I11, WORK...... 36 0.018 2 ( AC163382 ) Ornithorhynchus anatinus clone OA_Bb-516D17, WORK... 38 0.018 2 ( AC19968

  5. Gene : CBRC-PHAM-01-0819 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ICTED: hypothetical protein [Ornithorhynchus anatinus] 2e-35 36% MESRACGQEGLLLLPSALKKQGHVRVPVCTGEMCVPVCAGEVCVPVC...TGERCVYPCVQVRCACPCVQVRVVYPVCTGEVCVPVCTGEVRVPVCTGEVCMPVCTGQVCVLLCTGEVCVPVCTGEVCVPVCTGEECMPVCAGEVCVPVCTGEECMPVCAGEVCVPVC...TGEVCVLLCAGEVCVPVCTGEVCVPVCTGEVCVPVCAGEVCVPVCTGEVCVPVCTGEMCVPVCTGEVCMPVCTVQVCVLLCTGEECMPVC...TGQGCIPRVYRRGVRARVQVRCVCPCAQVRCACPCVQVRVVYPVCTGEVRVPVCTGEVCVPVYR ...

  6. Gene : CBRC-SARA-01-1535 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CTED: hypothetical protein [Ornithorhynchus anatinus] 6e-26 39% MLKDYSWECSGTMGVLRIEPSWHLKRLVPGTIAPGCQIILLLLLFLLLRLLLLLFLLLPLLHLPLLPLL...PPLLLPFPLLLPLLPLPLLPLPPLLPLPHLPPPLFLPPLLLLPLILPLPLLPLLLPFPLLLPLPPLLPLPPRPPPPLPPPPLFLPPLLLLPLLLPLLFLPLPPLL...PPLLPLLLPLLPLFFFLFGSHPAMLRGYSWLCTQELLLAVLGGPYGMPGIEPGSAACKA...NALPAMLSLWPLFYLFLIFLLFLLFLSPSPLPPLPPYLPPPSLPLPSPLPPLLPLLLLLLLLLLLLYPSPSSPLAVYTQQCSGIIPGDVFRNHSWLCSGTIWDIWDQTCMCVQHLYPACYNVGARRES ...

  7. Formation and Dissociation of Sperm Bundles in Monotremes.

    Science.gov (United States)

    Nixon, Brett; Ecroyd, Heath; Dacheux, Jean-Louis; Dacheux, Francoise; Labas, Valerie; Johnston, Steve D; Jones, Russell C

    2016-10-01

    Because monotremes are the earliest offshoot of the mammalian lineage, the platypus and short-beaked echidna were studied as model animals to assess the origin and biological significance of adaptations considered unique to therian mammals: epididymal sperm maturation and subsequent capacitation. We show that spermatozoa from both species assemble into bundles of approximately 100 cells during passage through the epididymis and that an epididymal protein-secreted protein, acidic, cysteine-rich (osteonectin; SPARC)-is involved in bundle formation. The bundles persisted during incubation in vitro for at least 1 h under conditions that capacitate therian spermatozoa, and then underwent a time-dependent dissociation to release spermatozoa capable of fertilization. Only after this dissociation could the spermatozoa bind to the perivitelline membrane of a hen's egg, display an altered form of motility reminiscent of hyperactivation, and be induced to undergo an acrosome reaction. It is concluded that the development of sperm bundles in the monotreme epididymis mandates that they require a time-dependent process to be capable of fertilizing an ovum. However, because this functional end point was achieved without overt changes in protein tyrosine phosphorylation (a hallmark of capacitation in therians), it is concluded that the process in monotremes is distinctly different from capacitation in therian mammals. © 2016 by the Society for the Study of Reproduction, Inc.

  8. Genome analysis of the platypus reveals unique signatures of evolution.

    Science.gov (United States)

    Warren, Wesley C; Hillier, LaDeana W; Marshall Graves, Jennifer A; Birney, Ewan; Ponting, Chris P; Grützner, Frank; Belov, Katherine; Miller, Webb; Clarke, Laura; Chinwalla, Asif T; Yang, Shiaw-Pyng; Heger, Andreas; Locke, Devin P; Miethke, Pat; Waters, Paul D; Veyrunes, Frédéric; Fulton, Lucinda; Fulton, Bob; Graves, Tina; Wallis, John; Puente, Xose S; López-Otín, Carlos; Ordóñez, Gonzalo R; Eichler, Evan E; Chen, Lin; Cheng, Ze; Deakin, Janine E; Alsop, Amber; Thompson, Katherine; Kirby, Patrick; Papenfuss, Anthony T; Wakefield, Matthew J; Olender, Tsviya; Lancet, Doron; Huttley, Gavin A; Smit, Arian F A; Pask, Andrew; Temple-Smith, Peter; Batzer, Mark A; Walker, Jerilyn A; Konkel, Miriam K; Harris, Robert S; Whittington, Camilla M; Wong, Emily S W; Gemmell, Neil J; Buschiazzo, Emmanuel; Vargas Jentzsch, Iris M; Merkel, Angelika; Schmitz, Juergen; Zemann, Anja; Churakov, Gennady; Kriegs, Jan Ole; Brosius, Juergen; Murchison, Elizabeth P; Sachidanandam, Ravi; Smith, Carly; Hannon, Gregory J; Tsend-Ayush, Enkhjargal; McMillan, Daniel; Attenborough, Rosalind; Rens, Willem; Ferguson-Smith, Malcolm; Lefèvre, Christophe M; Sharp, Julie A; Nicholas, Kevin R; Ray, David A; Kube, Michael; Reinhardt, Richard; Pringle, Thomas H; Taylor, James; Jones, Russell C; Nixon, Brett; Dacheux, Jean-Louis; Niwa, Hitoshi; Sekita, Yoko; Huang, Xiaoqiu; Stark, Alexander; Kheradpour, Pouya; Kellis, Manolis; Flicek, Paul; Chen, Yuan; Webber, Caleb; Hardison, Ross; Nelson, Joanne; Hallsworth-Pepin, Kym; Delehaunty, Kim; Markovic, Chris; Minx, Pat; Feng, Yucheng; Kremitzki, Colin; Mitreva, Makedonka; Glasscock, Jarret; Wylie, Todd; Wohldmann, Patricia; Thiru, Prathapan; Nhan, Michael N; Pohl, Craig S; Smith, Scott M; Hou, Shunfeng; Nefedov, Mikhail; de Jong, Pieter J; Renfree, Marilyn B; Mardis, Elaine R; Wilson, Richard K

    2008-05-08

    We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles. Analysis of the first monotreme genome aligned these features with genetic innovations. We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology. Expansions of protein, non-protein-coding RNA and microRNA families, as well as repeat elements, are identified. Sequencing of this genome now provides a valuable resource for deep mammalian comparative analyses, as well as for monotreme biology and conservation.

  9. Genome analysis of the platypus reveals unique signatures of evolution

    Science.gov (United States)

    Warren, Wesley C.; Hillier, LaDeana W.; Marshall Graves, Jennifer A.; Birney, Ewan; Ponting, Chris P.; Grützner, Frank; Belov, Katherine; Miller, Webb; Clarke, Laura; Chinwalla, Asif T.; Yang, Shiaw-Pyng; Heger, Andreas; Locke, Devin P.; Miethke, Pat; Waters, Paul D.; Veyrunes, Frédéric; Fulton, Lucinda; Fulton, Bob; Graves, Tina; Wallis, John; Puente, Xose S.; López-Otín, Carlos; Ordóñez, Gonzalo R.; Eichler, Evan E.; Chen, Lin; Cheng, Ze; Deakin, Janine E.; Alsop, Amber; Thompson, Katherine; Kirby, Patrick; Papenfuss, Anthony T.; Wakefield, Matthew J.; Olender, Tsviya; Lancet, Doron; Huttley, Gavin A.; Smit, Arian F. A.; Pask, Andrew; Temple-Smith, Peter; Batzer, Mark A.; Walker, Jerilyn A.; Konkel, Miriam K.; Harris, Robert S.; Whittington, Camilla M.; Wong, Emily S. W.; Gemmell, Neil J.; Buschiazzo, Emmanuel; Vargas Jentzsch, Iris M.; Merkel, Angelika; Schmitz, Juergen; Zemann, Anja; Churakov, Gennady; Kriegs, Jan Ole; Brosius, Juergen; Murchison, Elizabeth P.; Sachidanandam, Ravi; Smith, Carly; Hannon, Gregory J.; Tsend-Ayush, Enkhjargal; McMillan, Daniel; Attenborough, Rosalind; Rens, Willem; Ferguson-Smith, Malcolm; Lefèvre, Christophe M.; Sharp, Julie A.; Nicholas, Kevin R.; Ray, David A.; Kube, Michael; Reinhardt, Richard; Pringle, Thomas H.; Taylor, James; Jones, Russell C.; Nixon, Brett; Dacheux, Jean-Louis; Niwa, Hitoshi; Sekita, Yoko; Huang, Xiaoqiu; Stark, Alexander; Kheradpour, Pouya; Kellis, Manolis; Flicek, Paul; Chen, Yuan; Webber, Caleb; Hardison, Ross; Nelson, Joanne; Hallsworth-Pepin, Kym; Delehaunty, Kim; Markovic, Chris; Minx, Pat; Feng, Yucheng; Kremitzki, Colin; Mitreva, Makedonka; Glasscock, Jarret; Wylie, Todd; Wohldmann, Patricia; Thiru, Prathapan; Nhan, Michael N.; Pohl, Craig S.; Smith, Scott M.; Hou, Shunfeng; Renfree, Marilyn B.; Mardis, Elaine R.; Wilson, Richard K.

    2009-01-01

    We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles. Analysis of the first monotreme genome aligned these features with genetic innovations. We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology. Expansions of protein, non-protein-coding RNA and microRNA families, as well as repeat elements, are identified. Sequencing of this genome now provides a valuable resource for deep mammalian comparative analyses, as well as for monotreme biology and conservation. PMID:18464734

  10. Identification and functional characterization of a novel monotreme- specific antibacterial protein expressed during lactation.

    Directory of Open Access Journals (Sweden)

    Swathi Bisana

    Full Text Available Monotremes are the only oviparous mammals and exhibit a fascinating combination of reptilian and mammalian characters. They represent a component of synapsidal reproduction by laying shelled eggs which are incubated outside the mother's body. This is accompanied by a prototherian lactation process, marking them as representatives of early mammals. The only extant monotremes are the platypus, and the short- and long- beaked echidnas, and their distributions are limited to Australia and New Guinea. Apart for a short weaning period, milk is the sole source of nutrition and protection for the hatchlings which are altricial and immunologically naive. The duration of lactation in these mammals is prolonged relative to the gestational length and period of incubation of eggs. Much of the development of monotreme young occurs in the non-sterile ex-utero environment. Therefore the role of milk in the growth, development and disease protection of the young is of significant interest. By sequencing the cDNA of cells harvested from monotreme milk, we have identified a novel monotreme- specific transcript, and the corresponding gene was designated as the EchAMP. The expression profile of this gene in various tissues revealed that it is highly expressed in milk cells. The peptides corresponding to the EchAMP protein have been identified in a sample of echidna milk In silico analysis indicated putative antimicrobial potential for the cognate protein of EchAMP. This was further confirmed by in vitro assays using a host of bacteria. Interestingly, EchAMP did not display any activity against a commensal gut floral species. These results support the hypothesis of enhancement of survival of the young by antimicrobial bioactives of mammary gland origin and thus emphasize the protective, non- nutritional role of milk in mammals.

  11. Gene : CBRC-OANA-01-1685 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available | PREDICTED: similar to vomeronasal V1r-type receptor V1rg7 [Ornithorhynchus anatinus] 1e-148 100% gnl|UG|Oa...LSIFQAITISPSTSWWAGRKTKLPKCILPSFVIFWILNMLIDFHTLIVVTGPHNARIHQDMKYCSLGNASARATLIFSVVLSLRDLFFVGLMSVASVYMVFVLYSHHR

  12. The X factor: X chromosome dosage compensation in the evolutionarily divergent monotremes and marsupials.

    Science.gov (United States)

    Whitworth, Deanne J; Pask, Andrew J

    2016-08-01

    Marsupials and monotremes represent evolutionarily divergent lineages from the majority of extant mammals which are eutherian, or placental, mammals. Monotremes possess multiple X and Y chromosomes that appear to have arisen independently of eutherian and marsupial sex chromosomes. Dosage compensation of X-linked genes occurs in monotremes on a gene-by-gene basis, rather than through chromosome-wide silencing, as is the case in eutherians and marsupials. Specifically, studies in the platypus have shown that for any given X-linked gene, a specific proportion of nuclei within a cell population will silence one locus, with the percentage of cells undergoing inactivation at that locus being highly gene-specific. Hence, it is perhaps not surprising that the expression level of X-linked genes in female platypus is almost double that in males. This is in contrast to the situation in marsupials where one of the two X chromosomes is inactivated in females by the long non-coding RNA RSX, a functional analogue of the eutherian XIST. However, marsupial X chromosome inactivation differs from that seen in eutherians in that it is exclusively the paternal X chromosome that is silenced. In addition, marsupials appear to have globally upregulated X-linked gene expression in both sexes, thus balancing their expression levels with those of the autosomes, a process initially proposed by Ohno in 1967 as being a fundamental component of the X chromosome dosage compensation mechanism but which may not have evolved in eutherians.

  13. NCBI nr-aa BLAST: CBRC-ACAR-01-0716 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-ACAR-01-0716 ref|XP_001508572.1| PREDICTED: similar to long wavelength sensiti...ve [Ornithorhynchus anatinus] gb|ABN43076.1| long wavelength sensitive [Ornithorhynchus anatinus] XP_001508572.1 0.0 87% ...

  14. NCBI nr-aa BLAST: CBRC-OANA-01-1895 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-1895 ref|XP_001508636.1| PREDICTED: similar to short wavelength sensit...ive 2 [Ornithorhynchus anatinus] gb|ABN43075.1| short wavelength sensitive 2 [Ornithorhynchus anatinus] XP_001508636.1 0.0 100% ...

  15. NCBI nr-aa BLAST: CBRC-OANA-01-1880 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-1880 ref|XP_001508572.1| PREDICTED: similar to long wavelength sensiti...ve [Ornithorhynchus anatinus] gb|ABN43076.1| long wavelength sensitive [Ornithorhynchus anatinus] XP_001508572.1 0.0 100% ...

  16. NCBI nr-aa BLAST: CBRC-XTRO-01-1883 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-1883 ref|XP_001508636.1| PREDICTED: similar to short wavelength sensit...ive 2 [Ornithorhynchus anatinus] gb|ABN43075.1| short wavelength sensitive 2 [Ornithorhynchus anatinus] XP_001508636.1 1e-166 75% ...

  17. NCBI nr-aa BLAST: CBRC-ACAR-01-0704 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-ACAR-01-0704 ref|XP_001508636.1| PREDICTED: similar to short wavelength sensit...ive 2 [Ornithorhynchus anatinus] gb|ABN43075.1| short wavelength sensitive 2 [Ornithorhynchus anatinus] XP_001508636.1 0.0 84% ...

  18. The hypothalamic supraoptic and paraventricular nuclei of the echidna and platypus.

    Science.gov (United States)

    Ashwell, Ken W S; Lajevardi, Shahab-Eddin; Cheng, Gang; Paxinos, George

    2006-01-01

    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, calbindin, oxytocin, neurophysin and non-phosphorylated neurofilament protein, and carbocyanine dye tracing techniques to examine the supraoptic and paraventricular nuclei and the course of the hypothalamo-neurohypophysial tract in two monotremes: the short-beaked echidna (Tachyglossus aculeatus) and the platypus (Ornithorhynchus anatinus). In both monotremes, the supraoptic nucleus consisted of loosely packed neurons, mainly in the retrochiasmatic position. In the echidna, the paraventricular nucleus was quite small, but had similar chemoarchitectural features to therians. In the platypus, the paraventricular nucleus was larger and appeared to be part of a stream of magnocellular neurons extending from the paraventricular nucleus to the retrochiasmatic supraoptic nucleus. Immunohistochemistry for non-phosphorylated neurofilament protein and carbocyanine dye tracing suggested that hypothalamo-neurohypophysial tract neurons in the echidna lie mainly in the retrochiasmatic supraoptic and lateral hypothalamic regions, but most neurophysin and oxytocin immunoreactive neurons in the echidna were found in the paraventricular, lateral hypothalamus and supraoptic nuclei and most oxytocinergic neurons in the platypus were distributed in a band from the paraventricular nucleus to the retrochiasmatic supraoptic nucleus. The small size of the supraoptic nucleus in the two monotremes might reflect functional aspects of monotreme lactation.

  19. Echidna venom gland transcriptome provides insights into the evolution of monotreme venom.

    Directory of Open Access Journals (Sweden)

    Emily S W Wong

    Full Text Available Monotremes (echidna and platypus are egg-laying mammals. One of their most unique characteristic is that males have venom/crural glands that are seasonally active. Male platypuses produce venom during the breeding season, delivered via spurs, to aid in competition against other males. Echidnas are not able to erect their spurs, but a milky secretion is produced by the gland during the breeding season. The function and molecular composition of echidna venom is as yet unknown. Hence, we compared the deeply sequenced transcriptome of an in-season echidna crural gland to that of a platypus and searched for putative venom genes to provide clues into the function of echidna venom and the evolutionary history of monotreme venom. We found that the echidna venom gland transcriptome was markedly different from the platypus with no correlation between the top 50 most highly expressed genes. Four peptides found in the venom of the platypus were detected in the echidna transcriptome. However, these genes were not highly expressed in echidna, suggesting that they are the remnants of the evolutionary history of the ancestral venom gland. Gene ontology terms associated with the top 100 most highly expressed genes in echidna, showed functional terms associated with steroidal and fatty acid production, suggesting that echidna "venom" may play a role in scent communication during the breeding season. The loss of the ability to erect the spur and other unknown evolutionary forces acting in the echidna lineage resulted in the gradual decay of venom components and the evolution of a new role for the crural gland.

  20. Echidna venom gland transcriptome provides insights into the evolution of monotreme venom.

    Science.gov (United States)

    Wong, Emily S W; Nicol, Stewart; Warren, Wesley C; Belov, Katherine

    2013-01-01

    Monotremes (echidna and platypus) are egg-laying mammals. One of their most unique characteristic is that males have venom/crural glands that are seasonally active. Male platypuses produce venom during the breeding season, delivered via spurs, to aid in competition against other males. Echidnas are not able to erect their spurs, but a milky secretion is produced by the gland during the breeding season. The function and molecular composition of echidna venom is as yet unknown. Hence, we compared the deeply sequenced transcriptome of an in-season echidna crural gland to that of a platypus and searched for putative venom genes to provide clues into the function of echidna venom and the evolutionary history of monotreme venom. We found that the echidna venom gland transcriptome was markedly different from the platypus with no correlation between the top 50 most highly expressed genes. Four peptides found in the venom of the platypus were detected in the echidna transcriptome. However, these genes were not highly expressed in echidna, suggesting that they are the remnants of the evolutionary history of the ancestral venom gland. Gene ontology terms associated with the top 100 most highly expressed genes in echidna, showed functional terms associated with steroidal and fatty acid production, suggesting that echidna "venom" may play a role in scent communication during the breeding season. The loss of the ability to erect the spur and other unknown evolutionary forces acting in the echidna lineage resulted in the gradual decay of venom components and the evolution of a new role for the crural gland.

  1. The platypus in Edinburgh: Robert Jameson, Robert Knox and the place of the Ornithorhynchus in nature, 1821-24.

    Science.gov (United States)

    Jenkins, Bill

    2016-10-01

    The duck-billed platypus, or Ornithorhynchus, was the subject of an intense debate among natural historians in the late eighteenth and early nineteenth centuries. Its paradoxical mixture of mammalian, avian and reptilian characteristics made it something of a taxonomic conundrum. In the early 1820s Robert Jameson (1774-1854), the professor of natural history at the University of Edinburgh and the curator of the University's natural history museum, was able to acquire three valuable specimens of this species. He passed one of these on to the anatomist Robert Knox (1791-1862), who dissected the animal and presented his results in a series of papers to the Wernerian Natural History Society, which later published them in its Memoirs. This paper takes Jameson's platypus as a case study on how natural history specimens were used to create and contest knowledge of the natural world in the early nineteenth century, at a time when interpretations of the relationships between animal taxa were in a state of flux. It shows how Jameson used his possession of this interesting specimen to provide a valuable opportunity for his protégé Knox while also helping to consolidate his own position as a key figure in early nineteenth-century natural history.

  2. The platypus in Edinburgh: Robert Jameson, Robert Knox and the place of the Ornithorhynchus in nature, 1821–24

    Science.gov (United States)

    Jenkins, Bill

    2016-01-01

    SUMMARY The duck-billed platypus, or Ornithorhynchus, was the subject of an intense debate among natural historians in the late eighteenth and early nineteenth centuries. Its paradoxical mixture of mammalian, avian and reptilian characteristics made it something of a taxonomic conundrum. In the early 1820s Robert Jameson (1774–1854), the professor of natural history at the University of Edinburgh and the curator of the University's natural history museum, was able to acquire three valuable specimens of this species. He passed one of these on to the anatomist Robert Knox (1791–1862), who dissected the animal and presented his results in a series of papers to the Wernerian Natural History Society, which later published them in its Memoirs. This paper takes Jameson's platypus as a case study on how natural history specimens were used to create and contest knowledge of the natural world in the early nineteenth century, at a time when interpretations of the relationships between animal taxa were in a state of flux. It shows how Jameson used his possession of this interesting specimen to provide a valuable opportunity for his protégé Knox while also helping to consolidate his own position as a key figure in early nineteenth-century natural history. PMID:27671001

  3. Cyto- and chemoarchitecture of the amygdala of a monotreme, Tachyglossus aculeatus (the short-beaked echidna).

    Science.gov (United States)

    Ashwell, Ken W S; Hardman, Craig D; Paxinos, George

    2005-10-01

    We have examined the cyto- and chemoarchitecture of the temporal and extended amygdala in the brain of a monotreme (the short-beaked echidna Tachyglossus aculeatus) using Nissl and myelin staining, enzyme histochemistry for acetylcholine esterase and NADPH diaphorase, immunohistochemistry for calcium binding proteins (parvalbumin, calbindin and calretinin) and tyrosine hydroxylase. While the broad subdivisions of the eutherian temporal amygdala were present in the echidna brain, there were some noticeable differences. No immunoreactivity for parvalbumin or calretinin for somata was found in the temporal amygdala of the echidna. The nucleus of the lateral olfactory tract could not be definitively identified and the medial nucleus of amygdala appeared to be very small in the echidna. Calbindin immunoreactive neurons were most frequently found in the ventrolateral part of the lateral nucleus, intraamygdaloid parts of the bed nucleus of the stria terminalis and the lateral part of the central nucleus. Neurons strongly reactive for NADPH diaphorase with filling of the dendritic tree were found mainly scattered through the cortical, central and lateral subnuclei, while neurons showing only somata reactivity for NADPH diaphorase were concentrated in the basomedial and basolateral subnuclei. Most of the components of the extended amygdala of eutherians could also be identified in the echidna. Volumetric analysis indicated that the temporal amygdala in both the platypus and echidna is small compared to the same structure in both insectivores and primates, with the central and medial components of the temporal amygdala being particularly small.

  4. Cyto- and chemoarchitecture of the dorsal thalamus of the monotreme Tachyglossus aculeatus, the short beaked echidna.

    Science.gov (United States)

    Ashwell, Ken W S; Paxinos, George

    2005-12-01

    We have examined the cyto- and chemoarchitecture of the dorsal thalamus of the short beaked echidna (Tachyglossus aculeatus), using Nissl and myelin staining, immunoreactivity for parvalbumin, calbindin, calretinin and non-phosphorylated neurofilament protein (SMI-32 antibody), and histochemistry for acetylcholinesterase and NADPH diaphorase. Immunohistochemical methods revealed many nuclear boundaries, which were difficult to discern with Nissl staining. Parvalbumin immunoreactive somata were concentrated in the ventral posterior, reticular, posterior, lateral and medial geniculate nuclei, while parvalbumin immunoreactivity of the neuropil was present throughout all but the midline nuclei. Large numbers of calbindin immunoreactive somata were also found within the midline thalamic nuclei, and thalamic sensory relay nuclei. Immunoreactivity for calretinin was found in many small somata within the lateral geniculate "a" nucleus, with other labelled somata found in the lateral geniculate "b" nucleus, ventral posterior medial and ventral posterior lateral nuclei. Immunoreactivity with the SMI-32 antibody was largely confined to somata and neuropil within the thalamocortical relay nuclei (ventral posterior medial and lateral nuclei, lateral and medial geniculate nuclei and the posterior thalamic nucleus). In broad terms there were many similarities between the thalamus of this monotreme and that of eutheria (e.g. disposition of somatosensory thalamus, complementarity of parvalbumin and calbindin immunoreactive structures), but there were some unique features of the thalamus of the echidna. These include the relatively small size of the thalamic reticular nucleus and the preponderance of calbindin immunoreactive neurons over parvalbumin immunoreactive neurons in the ventral posterior nucleus.

  5. Gene : CBRC-OANA-01-0477 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available |Oan#S38831641 PREDICTED: Ornithorhynchus anatinus similar to serpin peptidase inhibitor, clade G (C1 inhibitor), member 1, (angioede...ma, hereditary), (LOC100079402), partial mRNA /cds=p(1,9

  6. Gene : CBRC-OANA-01-1559 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available |Oan#S38831641 PREDICTED: Ornithorhynchus anatinus similar to serpin peptidase inhibitor, clade G (C1 inhibitor), member 1, (angioede...ma, hereditary), (LOC100079402), partial mRNA /cds=p(1,9

  7. NCBI nr-aa BLAST: CBRC-ETEL-01-0879 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available trophy 2 (Best disease, bestrophin), partial [Ornithorhynchus anatinus] XP_001517466.1 0.57 32% ... ...CBRC-ETEL-01-0879 ref|XP_001517466.1| PREDICTED: similar to vitelliform macular dys

  8. Unigene BLAST: CBRC-OANA-01-1871 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-1871 gnl|UG|Oan#S38868957 PREDICTED: Ornithorhynchus anatinus similar to Tena...scin precursor (TN) (Tenascin-C) (TN-C) (Hexabrachion) (Cytotactin) (Neuronectin) (GMEM) (JI) (Myoten

  9. Unigene BLAST: CBRC-OANA-01-0666 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-0666 gnl|UG|Oan#S38868957 PREDICTED: Ornithorhynchus anatinus similar to Tena...scin precursor (TN) (Tenascin-C) (TN-C) (Hexabrachion) (Cytotactin) (Neuronectin) (GMEM) (JI) (Myoten

  10. Unigene BLAST: CBRC-OANA-01-0916 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-0916 gnl|UG|Oan#S38868957 PREDICTED: Ornithorhynchus anatinus similar to Tena...scin precursor (TN) (Tenascin-C) (TN-C) (Hexabrachion) (Cytotactin) (Neuronectin) (GMEM) (JI) (Myoten

  11. Unigene BLAST: CBRC-OANA-01-2075 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-2075 gnl|UG|Oan#S38868957 PREDICTED: Ornithorhynchus anatinus similar to Tena...scin precursor (TN) (Tenascin-C) (TN-C) (Hexabrachion) (Cytotactin) (Neuronectin) (GMEM) (JI) (Myoten

  12. Unigene BLAST: CBRC-OANA-01-1589 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-1589 gnl|UG|Oan#S38868957 PREDICTED: Ornithorhynchus anatinus similar to Tena...scin precursor (TN) (Tenascin-C) (TN-C) (Hexabrachion) (Cytotactin) (Neuronectin) (GMEM) (JI) (Myoten

  13. The evolution of imprinting: chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals

    Directory of Open Access Journals (Sweden)

    Dunham Ian

    2007-09-01

    Full Text Available Abstract Background The evolution of genomic imprinting, the parental-origin specific expression of genes, is the subject of much debate. There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome. Results Here we demonstrate that mammalian orthologues of imprinted genes are dispersed amongst autosomes in both monotreme and marsupial karyotypes. Conclusion These data, along with the similar distribution seen in birds, suggest that imprinted genes were not located on an ancestrally imprinted chromosome or associated with a sex chromosome. Our results suggest imprinting evolution was a stepwise, adaptive process, with each gene/cluster independently becoming imprinted as the need arose.

  14. Passive electroreception in aquatic mammals.

    Science.gov (United States)

    Czech-Damal, Nicole U; Dehnhardt, Guido; Manger, Paul; Hanke, Wolf

    2013-06-01

    Passive electroreception is a sensory modality in many aquatic vertebrates, predominantly fishes. Using passive electroreception, the animal can detect and analyze electric fields in its environment. Most electric fields in the environment are of biogenic origin, often produced by prey items. These electric fields can be relatively strong and can be a highly valuable source of information for a predator, as underlined by the fact that electroreception has evolved multiple times independently. The only mammals that possess electroreception are the platypus (Ornithorhynchus anatinus) and the echidnas (Tachyglossidae) from the monotreme order, and, recently discovered, the Guiana dolphin (Sotalia guianensis) from the cetacean order. Here we review the morphology, function and origin of the electroreceptors in the two aquatic species, the platypus and the Guiana dolphin. The morphology shows certain similarities, also similar to ampullary electroreceptors in fishes, that provide cues for the search for electroreceptors in more vertebrate and invertebrate species. The function of these organs appears to be very similar. Both species search for prey animals in low-visibility conditions or while digging in the substrate, and sensory thresholds are within one order of magnitude. The electroreceptors in both species are innervated by the trigeminal nerve. The origin of the accessory structures, however, is completely different; electroreceptors in the platypus have developed from skin glands, in the Guiana dolphin, from the vibrissal system.

  15. First Molecular Characterization of Theileria ornithorhynchi Mackerras, 1959: yet Another Challenge to the Systematics of the Piroplasms.

    Science.gov (United States)

    Paparini, Andrea; Macgregor, James; Ryan, Una M; Irwin, Peter J

    2015-12-01

    Piroplasms, tick-transmitted Apicomplexa of the genera Theileria, Babesia and Cytauxzoon, are blood-borne parasites of clinical and veterinary importance. The order Piroplasmida shows a puzzling systematics characterized by multiple clades, soft polytomies and paraphyletic/polyphyletic genera. In the present study, screening of platypuses (Ornithorhynchus anatinus), was performed to infer the parasite molecular phylogeny. DNA was extracted from blood, ectoparasites and tick eggs and the 18S rRNA- hsp70-genes were used for the phylogenetic reconstructions. Microscopic analyses detected pleomorphic intra-erythrocytic organisms and tetrads consistent with previous descriptions of Theileria ornithorhynchi Mackerras, 1959, but observation of possible schizonts could not be confirmed. DNA sequences obtained from blood and ticks allowed resolving the systematics of the first piroplasm infecting a monotreme host. Molecularly, T. ornithorhynchi formed a novel monophyletic group, basal to most known piroplasms' clades. The ancestral position of this clade, isolated from an ancient lineage of mammalian host appears particularly fascinating. The present paper discusses the inadequacies of the current molecular systematics for the Piroplasmida and the consequences of incomplete sampling, morphology-based classification and ambiguous microscopic identifications. Likely when the current sampling bias is rectified and more sequence data is made available, the phylogenetic position of T. ornithorhynchi will be further contextualized without ambiguity. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. Gene : CBRC-MMUS-13-0121 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available mordial protein), complete cds /cds=p(442,1194) /gb=D00570 /gi=220577 /ug=Mm.464374...CTED: hypothetical protein, partial [Ornithorhynchus anatinus] 9e-16 45% gnl|UG|Mm#S11121997 Mus musculus mRNA for ORFs (putative pri

  17. Unigene BLAST: CBRC-OANA-01-1553 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 3.2 36% ...

  18. Unigene BLAST: CBRC-OANA-01-0332 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 0.033 29% ...

  19. Unigene BLAST: CBRC-OANA-01-1975 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 2.5 45% ...

  20. Unigene BLAST: CBRC-OANA-01-0333 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 0.50 37% ...

  1. Unigene BLAST: CBRC-OANA-01-1180 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 0.074 28% ...

  2. Unigene BLAST: CBRC-OANA-01-2135 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 2.1 37% ...

  3. Unigene BLAST: CBRC-OANA-01-2158 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to sp|P11499|HS9B_MOUSE Heat shock protein HSP 90-beta (HSP 84) (Tumor specific transplan...tation 84 kDa antigen) (TSTA), mRNA sequence /gb=EH004654 /gi=118081083 /ug=Oan.2501 /len=662 0.19 32% ...

  4. NCBI nr-aa BLAST: CBRC-CJAC-01-1179 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CJAC-01-1179 ref|XP_001517394.1| PREDICTED: similar to Multiple epidermal grow...th factor-like domains 6 precursor (EGF-like domain-containing protein 3) (Multiple EGF-like domain protein 3), partial [Ornithorhynchus anatinus] XP_001517394.1 1e-09 30% ...

  5. NCBI nr-aa BLAST: CBRC-EEUR-01-0273 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-EEUR-01-0273 ref|XP_001517394.1| PREDICTED: similar to Multiple epidermal grow...th factor-like domains 6 precursor (EGF-like domain-containing protein 3) (Multiple EGF-like domain protein 3), partial [Ornithorhynchus anatinus] XP_001517394.1 3e-14 28% ...

  6. NCBI nr-aa BLAST: CBRC-TTRU-01-0608 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ceptual translation supplied by author [Ornithorhynchus anatinus] XP_001519860.1 1e-07 31% ... ...CBRC-TTRU-01-0608 ref|XP_001519860.1| PREDICTED: similar to putative G-protein-coupled receptor; Method: con

  7. NCBI nr-aa BLAST: CBRC-OANA-01-0213 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ceptual translation supplied by author [Ornithorhynchus anatinus] XP_001519860.1 0.0 100% ... ...CBRC-OANA-01-0213 ref|XP_001519860.1| PREDICTED: similar to putative G-protein-coupled receptor; Method: con

  8. Gene : CBRC-OANA-01-2144 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available protein [Magnetospirillum gryphiswaldense MSR-1] 1e-10 45% gnl|UG|Oan#S38869732 PREDICTED: Ornithorhynchus anatinus similar to repul...sive guidance molecule C, RgmC protein (LOC100074217), mRNA /cds=p(1,3762) /gb=XM_0

  9. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals.

    Science.gov (United States)

    Patel, Vidushi S; Cooper, Steven J B; Deakin, Janine E; Fulton, Bob; Graves, Tina; Warren, Wesley C; Wilson, Richard K; Graves, Jennifer A M

    2008-07-25

    Vertebrate alpha (alpha)- and beta (beta)-globin gene families exemplify the way in which genomes evolve to produce functional complexity. From tandem duplication of a single globin locus, the alpha- and beta-globin clusters expanded, and then were separated onto different chromosomes. The previous finding of a fossil beta-globin gene (omega) in the marsupial alpha-cluster, however, suggested that duplication of the alpha-beta cluster onto two chromosomes, followed by lineage-specific gene loss and duplication, produced paralogous alpha- and beta-globin clusters in birds and mammals. Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus), to explore haemoglobin evolution at the stem of the mammalian radiation. The platypus alpha-globin cluster (chromosome 21) contains embryonic and adult alpha- globin genes, a beta-like omega-globin gene, and the GBY globin gene with homology to cytoglobin, arranged as 5'-zeta-zeta'-alphaD-alpha3-alpha2-alpha1-omega-GBY-3'. The platypus beta-globin cluster (chromosome 2) contains single embryonic and adult globin genes arranged as 5'-epsilon-beta-3'. Surprisingly, all of these globin genes were expressed in some adult tissues. Comparison of flanking sequences revealed that all jawed vertebrate alpha-globin clusters are flanked by MPG-C16orf35 and LUC7L, whereas all bird and mammal beta-globin clusters are embedded in olfactory genes. Thus, the mammalian alpha- and beta-globin clusters are orthologous to the bird alpha- and beta-globin clusters respectively. We propose that alpha- and beta-globin clusters evolved from an ancient MPG-C16orf35-alpha-beta-GBY-LUC7L arrangement 410 million years ago. A copy of the original beta (represented by omega in marsupials and monotremes) was inserted into an array of olfactory genes before the amniote radiation (>315 million years ago), then duplicated and diverged to form orthologous clusters of beta-globin genes with different expression

  10. Receptors in the bill of the platypus.

    Science.gov (United States)

    Gregory, J E; Iggo, A; McIntyre, A K; Proske, U

    1988-01-01

    1. Afferent responses were recorded from filaments of the trigeminal nerve in each of two platypuses (Ornithorhynchus anatinus) anaesthetized with alpha-chloralose. All receptive fields were located along the lateral border of the upper bill. Discrete receptive fields could be identified as belonging to two distinct classes of sensory receptor. 2. The most prominent response was an irregular resting discharge which could be increased or decreased by weak electric pulses. These receptors were insensitive to moderately strong mechanical stimulation, and it was concluded that they were electroreceptors. 3. Each electroreceptor had a single spot of maximum sensitivity on the bill surface. When the stimulating electrode over this spot was the cathode it excited the receptor for the duration of the stimulating pulse, using stimulus strengths as low as 20 mV. When it was the anode, it inhibited the discharge. Cathodal excitation was followed by rebound inhibition and anodal inhibition by rebound excitation. 4. Receptors responded to cathodal steps with an initial high-frequency burst of impulses, followed by a lower maintained rate of discharge. Rapidly changing pulses were similarly effective in exciting receptors, adding support to the claim that platypuses are able to detect moving prey by the electrical activity associated with muscle contraction. 5. The centres of the receptive fields of two electroreceptors were marked by the insertion of fine entomological pins. Histological examination established the presence of a large mucus-secreting gland at the marked spot. The epidermal duct of the gland contained an elaborate myelinated innervation, with morphologically distinct axon terminals that we identify as the electroreceptors. 6. As well as electroreceptors, the skin of the bill contained three kinds of mechanoreceptors: slow-adapting receptors, rapidly adapting, vibration-sensitive receptors and receptors with an intermediate adaptation rate. The slowly adapting

  11. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals

    Directory of Open Access Journals (Sweden)

    Warren Wesley C

    2008-07-01

    Full Text Available Abstract Background Vertebrate alpha (α- and beta (β-globin gene families exemplify the way in which genomes evolve to produce functional complexity. From tandem duplication of a single globin locus, the α- and β-globin clusters expanded, and then were separated onto different chromosomes. The previous finding of a fossil β-globin gene (ω in the marsupial α-cluster, however, suggested that duplication of the α-β cluster onto two chromosomes, followed by lineage-specific gene loss and duplication, produced paralogous α- and β-globin clusters in birds and mammals. Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus, to explore haemoglobin evolution at the stem of the mammalian radiation. Results The platypus α-globin cluster (chromosome 21 contains embryonic and adult α- globin genes, a β-like ω-globin gene, and the GBY globin gene with homology to cytoglobin, arranged as 5'-ζ-ζ'-αD-α3-α2-α1-ω-GBY-3'. The platypus β-globin cluster (chromosome 2 contains single embryonic and adult globin genes arranged as 5'-ε-β-3'. Surprisingly, all of these globin genes were expressed in some adult tissues. Comparison of flanking sequences revealed that all jawed vertebrate α-globin clusters are flanked by MPG-C16orf35 and LUC7L, whereas all bird and mammal β-globin clusters are embedded in olfactory genes. Thus, the mammalian α- and β-globin clusters are orthologous to the bird α- and β-globin clusters respectively. Conclusion We propose that α- and β-globin clusters evolved from an ancient MPG-C16orf35-α-β-GBY-LUC7L arrangement 410 million years ago. A copy of the original β (represented by ω in marsupials and monotremes was inserted into an array of olfactory genes before the amniote radiation (>315 million years ago, then duplicated and diverged to form orthologous clusters of β-globin genes with different expression profiles in different lineages.

  12. Did sex chromosome turnover promote divergence of the major mammal groups?: De novo sex chromosomes and drastic rearrangements may have posed reproductive barriers between monotremes, marsupials and placental mammals.

    Science.gov (United States)

    Graves, Jennifer A M

    2016-08-01

    Comparative mapping and sequencing show that turnover of sex determining genes and chromosomes, and sex chromosome rearrangements, accompany speciation in many vertebrates. Here I review the evidence and propose that the evolution of therian mammals was precipitated by evolution of the male-determining SRY gene, defining a novel XY sex chromosome pair, and interposing a reproductive barrier with the ancestral population of synapsid reptiles 190 million years ago (MYA). Divergence was reinforced by multiple translocations in monotreme sex chromosomes, the first of which supplied a novel sex determining gene. A sex chromosome-autosome fusion may have separated eutherians (placental mammals) from marsupials 160 MYA. Another burst of sex chromosome change and speciation is occurring in rodents, precipitated by the degradation of the Y. And although primates have a more stable Y chromosome, it may be just a matter of time before the same fate overtakes our own lineage. Also watch the video abstract. © 2016 The Authors. BioEssays Published by WILEY Periodicals, Inc.

  13. Unigene BLAST: CBRC-OANA-01-1664 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_000691.1| annexin I; annexin I (lipocortin I); lipocor...tin I [Homo sapiens] sp|P04083|ANX1_HUMAN Annexin A1 (Annexin I) (Lipocortin I) (Calpactin II) (Chro> /gb=EH003108 /gi=118079537 /ug=Oan.3951 /len=644 5.5 38% ...

  14. Unigene BLAST: CBRC-OANA-01-1724 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 9.2 50% ...

  15. Unigene BLAST: CBRC-OANA-01-1009 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 1.1 32% ...

  16. Unigene BLAST: CBRC-OANA-01-1042 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 8.9 50% ...

  17. Unigene BLAST: CBRC-OANA-01-1034 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 4.7 45% ...

  18. Unigene BLAST: CBRC-OANA-01-0513 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 2.5 55% ...

  19. Unigene BLAST: CBRC-OANA-01-1930 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_000691.1| annexin I; annexin I (lipocortin I); lipocor...tin I [Homo sapiens] sp|P04083|ANX1_HUMAN Annexin A1 (Annexin I) (Lipocortin I) (Calpactin II) (Chro> /gb=EH003108 /gi=118079537 /ug=Oan.3951 /len=644 7.7 37% ...

  20. Unigene BLAST: CBRC-OANA-01-1101 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 9.3 50% ...

  1. Unigene BLAST: CBRC-OANA-01-0341 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 3.2 45% ...

  2. Unigene BLAST: CBRC-OANA-01-2161 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_001147.1| annexin VII isoform 1; annexin VII (synexin)...; synexin [Homo sapiens] sp|P20073|ANX7_HUMAN Annexin A7 (Annexin VII) (Synexin) gb|AAA36616.1| syne> /gb=EH000738 /gi=118077167 /ug=Oan.4494 /len=665 0.74 46% ...

  3. Gene : CBRC-OANA-01-0309 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available Oan#S36547943 KAAN-aaa52f02.b1 Platypus_EST_Cell_line_1.0-4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| dow...ame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /u

  4. Unigene BLAST: CBRC-OANA-01-0309 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| downstream neighbor of SON isoform a; chromo...some 21 open reading frame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /ug=Oan.4604 /len=713 0.78 36% ...

  5. Unigene BLAST: CBRC-OANA-01-0766 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| downstream neighbor of SON isoform a; chromo...some 21 open reading frame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /ug=Oan.4604 /len=713 6.2 36% ...

  6. Unigene BLAST: CBRC-OANA-01-0192 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| downstream neighbor of SON isoform a; chromo...some 21 open reading frame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /ug=Oan.4604 /len=713 9.3 64% ...

  7. Unigene BLAST: CBRC-OANA-01-1884 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| downstream neighbor of SON isoform a; chromo...some 21 open reading frame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /ug=Oan.4604 /len=713 1.0 36% ...

  8. Unigene BLAST: CBRC-OANA-01-1283 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| downstream neighbor of SON isoform a; chromo...some 21 open reading frame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /ug=Oan.4604 /len=713 8.0 38% ...

  9. Unigene BLAST: CBRC-OANA-01-0851 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_060083.1| downstream neighbor of SON isoform a; chromo...some 21 open reading frame 60 [Homo sapiens] sp|Q9NYP3|DONS_HUMAN Downstream of son gene protein (Pr> /gb=EH001541 /gi=118077970 /ug=Oan.4604 /len=713 1.0 36% ...

  10. Unigene BLAST: CBRC-OANA-01-0889 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 5.4 58% ...

  11. Unigene BLAST: CBRC-OANA-01-1887 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 1.0 91% ...

  12. Unigene BLAST: CBRC-OANA-01-0960 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.46 51% ...

  13. Unigene BLAST: CBRC-OANA-01-1282 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.078 56% ...

  14. Unigene BLAST: CBRC-OANA-01-0028 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.016 60% ...

  15. Unigene BLAST: CBRC-OANA-01-1584 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2e-05 56% ...

  16. Unigene BLAST: CBRC-OANA-01-0223 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.001 36% ...

  17. Unigene BLAST: CBRC-OANA-01-1451 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.82 40% ...

  18. Unigene BLAST: CBRC-OANA-01-1036 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 4.9 57% ...

  19. Unigene BLAST: CBRC-OANA-01-0600 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 8e-07 77% ...

  20. Unigene BLAST: CBRC-OANA-01-0189 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.002 60% ...

  1. Unigene BLAST: CBRC-OANA-01-1731 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.83 35% ...

  2. Unigene BLAST: CBRC-OANA-01-1611 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2.4 35% ...

  3. Unigene BLAST: CBRC-OANA-01-0067 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 3e-05 76% ...

  4. Unigene BLAST: CBRC-OANA-01-2183 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 8.1 29% ...

  5. Unigene BLAST: CBRC-OANA-01-1313 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.006 41% ...

  6. Unigene BLAST: CBRC-OANA-01-0704 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.23 50% ...

  7. Unigene BLAST: CBRC-OANA-01-1244 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2e-04 85% ...

  8. Unigene BLAST: CBRC-OANA-01-1022 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.023 61% ...

  9. Unigene BLAST: CBRC-OANA-01-0589 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 4.1 73% ...

  10. Unigene BLAST: CBRC-OANA-01-1936 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.002 58% ...

  11. Unigene BLAST: CBRC-OANA-01-0376 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 3.4 41% ...

  12. Unigene BLAST: CBRC-OANA-01-1804 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.095 92% ...

  13. Unigene BLAST: CBRC-OANA-01-1908 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.011 60% ...

  14. Unigene BLAST: CBRC-OANA-01-2049 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.81 45% ...

  15. Unigene BLAST: CBRC-OANA-01-0030 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 3e-05 49% ...

  16. Unigene BLAST: CBRC-OANA-01-0037 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.018 75% ...

  17. Unigene BLAST: CBRC-OANA-01-0921 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 1.2 76% ...

  18. Unigene BLAST: CBRC-OANA-01-2210 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 3e-11 90% ...

  19. Unigene BLAST: CBRC-OANA-01-0659 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2.3 66% ...

  20. Unigene BLAST: CBRC-OANA-01-1002 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.23 50% ...

  1. Unigene BLAST: CBRC-OANA-01-1479 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.21 86% ...

  2. Unigene BLAST: CBRC-OANA-01-0647 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.002 58% ...

  3. Unigene BLAST: CBRC-OANA-01-1841 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.001 50% ...

  4. Unigene BLAST: CBRC-OANA-01-2061 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2e-07 54% ...

  5. Unigene BLAST: CBRC-OANA-01-1434 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.039 55% ...

  6. Unigene BLAST: CBRC-OANA-01-0688 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2e-07 66% ...

  7. Unigene BLAST: CBRC-OANA-01-1227 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.005 33% ...

  8. Unigene BLAST: CBRC-OANA-01-0526 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 5e-05 70% ...

  9. Unigene BLAST: CBRC-OANA-01-0778 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 6.2 81% ...

  10. Unigene BLAST: CBRC-OANA-01-0687 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.046 66% ...

  11. Unigene BLAST: CBRC-OANA-01-0287 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 2e-09 80% ...

  12. Unigene BLAST: CBRC-OANA-01-0361 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.022 40% ...

  13. Unigene BLAST: CBRC-OANA-01-0741 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 1e-04 58% ...

  14. Unigene BLAST: CBRC-OANA-01-0232 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 3e-05 64% ...

  15. Unigene BLAST: CBRC-OANA-01-1628 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.001 68% ...

  16. Unigene BLAST: CBRC-OANA-01-0549 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 3e-08 75% ...

  17. Unigene BLAST: CBRC-OANA-01-1901 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 1e-06 75% ...

  18. Unigene BLAST: CBRC-OANA-01-2204 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 8e-08 62% ...

  19. Unigene BLAST: CBRC-OANA-01-2064 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 4.0kb Ornithorhynchus anatinus cDNA similar to ref|NP_444392.1| mitochondrial ribosomal protein L34; DNA seg...ment, Chr 8, Brigham & Women's Genetics 1484 expressed [Mus musculus] sp|Q99N91|RM34_MOUSE 60S ribos> /gb=EH000574 /gi=118077003 /ug=Oan.4473 /len=654 0.023 75% ...

  20. Mammalian peptide isomerase: platypus-type activity is present in mouse heart.

    Science.gov (United States)

    Koh, Jennifer M S; Chow, Stephanie J P; Crossett, Ben; Kuchel, Philip W

    2010-06-01

    Male platypus (Ornithorhynchus anatinus) venom has a peptidyl aminoacyl L/D-isomerase (hereafter called peptide isomerase) that converts the second amino acid residue in from the N-terminus from the L- to the D-form, and vice versa. A reversed-phase high-performance liquid chromatography (RP-HPLC) assay has been developed to monitor the interconversion using synthetic hexapeptides derived from defensin-like peptide-2 (DLP-2) and DLP-4 as substrates. It was hypothesised that animals other than the platypus would have peptide isomerase with the same substrate specificity. Accordingly, eight mouse tissues were tested and heart was shown to have the activity. This is notable for being the first evidence of a peptide isomerase being present in a higher mammal and heralds finding the activity in man.

  1. Defensins and the convergent evolution of platypus and reptile venom genes.

    Science.gov (United States)

    Whittington, Camilla M; Papenfuss, Anthony T; Bansal, Paramjit; Torres, Allan M; Wong, Emily S W; Deakin, Janine E; Graves, Tina; Alsop, Amber; Schatzkamer, Kyriena; Kremitzki, Colin; Ponting, Chris P; Temple-Smith, Peter; Warren, Wesley C; Kuchel, Philip W; Belov, Katherine

    2008-06-01

    When the platypus (Ornithorhynchus anatinus) was first discovered, it was thought to be a taxidermist's hoax, as it has a blend of mammalian and reptilian features. It is a most remarkable mammal, not only because it lays eggs but also because it is venomous. Rather than delivering venom through a bite, as do snakes and shrews, male platypuses have venomous spurs on each hind leg. The platypus genome sequence provides a unique opportunity to unravel the evolutionary history of many of these interesting features. While searching the platypus genome for the sequences of antimicrobial defensin genes, we identified three Ornithorhynchus venom defensin-like peptide (OvDLP) genes, which produce the major components of platypus venom. We show that gene duplication and subsequent functional diversification of beta-defensins gave rise to these platypus OvDLPs. The OvDLP genes are located adjacent to the beta-defensins and share similar gene organization and peptide structures. Intriguingly, some species of snakes and lizards also produce venoms containing similar molecules called crotamines and crotamine-like peptides. This led us to trace the evolutionary origins of other components of platypus and reptile venom. Here we show that several venom components have evolved separately in the platypus and reptiles. Convergent evolution has repeatedly selected genes coding for proteins containing specific structural motifs as templates for venom molecules.

  2. Phylogeny of Tec family kinases identification of a premetazoan origin of Btk, Bmx, Itk, Tec, Txk, and the Btk regulator SH3BP5.

    Science.gov (United States)

    Ortutay, Csaba; Nore, Beston F; Vihinen, Mauno; Smith, C I Edvard

    2008-01-01

    It is generally considered mammals and birds have five Tec family kinases (TFKs): Btk, Bmx (also known as Etk), Itk, Tec, and Txk (also known as Rlk). Here, we discuss the domains and their functions and regulation in TFKs. Over the last few years, a large number of genomes from various phyla have been sequenced making it possible to study evolutionary relationships at the molecular and sequence level. Using bioinformatics tools, we for the first time demonstrate that a TFK ancestor exists in the unicellular choanoflagellate Monosiga brevicollis, which is the closest known relative to metazoans with a sequenced genome. The analysis of the genomes for sponges, insects, hagfish, and frogs suggests that these species encode a single TFK. The insect form has a divergent and unique N-terminal region. Duplications generating the five members took place prior to the emergence of vertebrates. Fishes have two or three forms and the platypus, Ornithorhynchus anatinus, has four (lacks Txk). Thus, not all mammals have all five TFKs. The single identified TFK in frogs is an ortholog of Tec. Bmx seems to be unique to mammals and birds. SH3BP5 is a negative regulator of Btk. It is conserved in choanoflagellates and interestingly exists also in nematodes, which do not express TFKs, suggesting a broader function in addition to Btk regulation. The related SH3BP5-like protein is not found in Nematodes.

  3. Marsupial and monotreme serum immunoglobulin binding by proteins A, G and L and anti-kangaroo antibody.

    Science.gov (United States)

    Vaz, Paola K; Hartley, Carol A; Browning, Glenn F; Devlin, Joanne M

    2015-12-01

    Serological studies are often conducted to examine exposure to infectious agents in wildlife populations. However, specific immunological reagents for wildlife species are seldom available and can limit the study of infectious diseases in these animals. This study examined the ability of four commercially available immunoglobulin-binding reagents to bind serum immunoglobulins from 17 species within the Marsupialia and Monotremata. Serum samples were assessed for binding, using immunoblots and ELISAs (Enzyme-linked immunosorbent assays), to three microbially-derived proteins - staphylococcal protein A, streptococcal protein G and peptostreptococcal protein L. Additionally, an anti-kangaroo antibody was included for comparison. The inter- and intra-familial binding patterns of the reagents to serum immunoglobulins varied and evolutionary distance between animal species was not an accurate predictor of the ability of reagents to bind immunoglobulins. Results from this study can be used to inform the selection of appropriate immunological reagents in future serological studies in these clades.

  4. Controlling wildlife fungal disease spread: in vitro efficacy of disinfectants against Batrachochytrium dendrobatidis and Mucor amphibiorum.

    Science.gov (United States)

    Webb, Rebecca; Philips, Annie; Speare, Rick; Connolly, Joanne; Berger, Lee

    2012-06-13

    Chytridiomycosis in amphibians, and mucormycosis in the platypus Ornithorhynchus anatinus and amphibians, are serious fungal diseases affecting these aquatic taxa. In Tasmania, Australia, the fungi that cause these diseases overlap in range along with Phytophthora cinnamomi (Pc), an invasive fungal plant pathogen. To identify disinfectants that may be useful to reduce anthropogenic spread of these fungi to uninfected wilderness areas, for example by bush walkers and forestry or fire-fighting operations, we tested 3 disinfectants and a fire-fighting foam against Mucor amphibiorum (Ma) and tested 1 disinfectant and the foam against Batrachochytrium dendrobatidis (Bd). Combining the present study with previous work we found Bd was more susceptible to all 4 chemicals than Ma. Phytoclean, a disinfectant used at 2 to 10% for 30 s to control Pc, killed cultures of Bd at 0.075% and Ma at 5%, when also applied for 30 s. The disinfectant F10sc was not effective against Ma at standard exposures, but previous work shows Bd is killed at 0.03% with a 1 min exposure. Path-X is effective against Bd at 0.001% with a 30 s exposure and killed Ma at 1% with a 5 min exposure. Forexpan S, a foam added to water at 0.1 to 1% to control forest fires, killed Bd but not Ma when used at 1% for 2 min. Therefore, Phytoclean and Path-X have broader efficacy, although Path-X has not been trialled against Pc. Interestingly a positive mating strain of Ma (from a platypus) was more resistant to disinfectants than a negative strain (from a frog). Current protocols against Pc that involve high concentrations (10%) of Phytoclean are likely to reduce spread of pathogenic wildlife fungi, which is important for protecting biodiversity.

  5. Conservation of a vitellogenin gene cluster in oviparous vertebrates and identification of its traces in the platypus genome.

    Science.gov (United States)

    Babin, Patrick J

    2008-04-30

    Vitellogenin (Vtg) derivatives are the main egg-yolk proteins in most oviparous animal species, and are, therefore, key players in reproduction and embryo development. Conserved synteny and phylogeny were used to identify a Vtg gene cluster (VGC) that had been evolutionarily conserved in most oviparous vertebrates, encompassing the three linked Vtgs on chicken (Gallus gallus) chromosome 8. Tandem arranged homologs to chicken VtgII and VtgIII were retrieved in similar locations in Xenopus (Xenopus tropicalis) and homologous transcribed inverted genes were found in medaka (Oryzias latipes), stickleback (Gasterosteus aculeatus), pufferfish (Takifugu rubripes), and Tetrahodon (Tetraodon nigroviridis), while zebrafish (Danio rerio) Vtg3 may represent a residual trace of VGC in this genome. Vtgs were not conserved in the paralogous chromosomal segment attributed to a whole-genome duplication event in the ancestor of teleosts, while tandem duplicated forms have survived the recent African clawed frog (Xenopus laevis) tetraploidization. Orthologs to chicken VtgI were found in similar locations in teleost fish, as well as in the platypus (Ornithorhynchus anatinus). Additional Vtg fragments found suggested that VGC had been conserved in this egg-laying mammal. A low ratio of nonsynonymous-to-synonymous substitution values and the paucity of pseudogene features suggest functional platypus Vtg products. Genomic identification of Vtgs, Apob, and Mtp in this genome, together with maximum likelihood and Bayesian inference phylogenetic analyses, support the existence of these three large lipid transfer protein superfamily members at the base of the mammalian lineage. In conclusion, the establishment of a VGC in the vertebrate lineage predates the divergence of ray-finned fish and tetrapods and the shift in reproductive and developmental strategy observed between prototherians and therians may be associated with its loss, as shown by its absence from the genomic resources currently

  6. Pharmacological action of Australian animal venoms.

    Science.gov (United States)

    Hodgson, W C

    1997-01-01

    1. Australia has some of the most venomous fauna in the world. Although humans are not usually perceived as being predators against these animals they are often envenomated, accidentally or otherwise. This has led to the development of antivenoms against some of the potentially lethal venoms. However, further understanding of the mechanism(s) of action of these and other venoms is important, not only for developing new treatment strategies but also in the search for novel research tools. 2. The present review discusses the pharmacology of some of the components found in venoms and outlines the research undertaken on some of Australia's venomous animals, with the exception of snakes. 3. Biogenic amines, peptides and enzymes are common venom components and produce a wide range of effects in envenomated humans. For example, respiratory failure observed after envenomation by the box jellyfish (Chirnex fleckeri) and Sydney funnel-web spider (Atrax robustus) is most likely due to potent neurotoxins in the venoms. Stonefish (Synanceja trachynis) and platypus (Ornithorhynchus anatinus) venoms, although not considered lethal, cause severe pain. However, the components responsible for these effects have not been isolated. Venom components, as yet unidentified, may be responsible for the cutaneous necrotic lesions that have been reported after some spider bites (e.g. Lampona cylindrata). Other venoms, such as those of the jumper ant (Myrmecia pilosula) and bull ant (M. pyriformis), may produce only mild skin irritation to the majority of humans but a severe anaphylactic response in sensitized victims. 4. While there has been a renewed interest in toxinology, further research is required to fully elucidate the pharmacological action of many of these venoms.

  7. Evolution of the Antisense Overlap between Genes for Thyroid Hormone Receptor and Rev-erbα and Characterization of an Exonic G-Rich Element That Regulates Splicing of TRα2 mRNA.

    Directory of Open Access Journals (Sweden)

    Stephen H Munroe

    Full Text Available The α-thyroid hormone receptor gene (TRα codes for two functionally distinct proteins: TRα1, the α-thyroid hormone receptor; and TRα2, a non-hormone-binding variant. The final exon of TRα2 mRNA overlaps the 3' end of Rev-erbα mRNA, which encodes another nuclear receptor on the opposite strand of DNA. To understand the evolution of this antisense overlap, we sequenced these genes and mRNAs in the platypus Orthorhynchus anatinus. Despite its strong homology with other mammals, the platypus TRα/Rev-erbα locus lacks elements essential for expression of TRα2. Comparative analysis suggests that alternative splicing of TRα2 mRNA expression evolved in a stepwise fashion before the divergence of eutherian and marsupial mammals. A short G-rich element (G30 located downstream of the alternative 3'splice site of TRα2 mRNA and antisense to the 3'UTR of Rev-erbα plays an important role in regulating TRα2 splicing. G30 is tightly conserved in eutherian mammals, but is absent in marsupials and monotremes. Systematic deletions and substitutions within G30 have dramatically different effects on TRα2 splicing, leading to either its inhibition or its enhancement. Mutations that disrupt one or more clusters of G residues enhance splicing two- to three-fold. These results suggest the G30 sequence can adopt a highly structured conformation, possibly a G-quadruplex, and that it is part of a complex splicing regulatory element which exerts both positive and negative effects on TRα2 expression. Since mutations that strongly enhance splicing in vivo have no effect on splicing in vitro, it is likely that the regulatory role of G30 is mediated through linkage of transcription and splicing.

  8. Sex determination in mammals--before and after the evolution of SRY.

    Science.gov (United States)

    Wallis, M C; Waters, P D; Graves, J A M

    2008-10-01

    Therian mammals (marsupials and placentals) have an XX female: XY male sex chromosome system, which is homologous to autosomes in other vertebrates. The testis-determining gene, SRY, is conserved on the Y throughout therians, but is absent in other vertebrates, suggesting that the mammal system evolved about 310 million years ago (MYA). However, recent work on the basal monotreme mammals has completely changed our conception of how and when this change occurred. Platypus and echidna lack SRY, and the therian X and Y are represented by autosomes, implying that SRY evolved in therians after their divergence from monotremes only 166 MYA. Clues to the ancestral mechanism usurped by SRY in therians are provided by the monotremes, whose sex chromosomes are homologous to the ZW of birds. This suggests that the therian X and Y, and the SRY gene, evolved from an ancient bird-like sex chromosome system which predates the divergence of mammals and reptiles 310 MYA.

  9. Histological observations on presumed electroreceptors and mechanoreceptors in the beak skin of the long-beaked echidna, Zaglossus bruijnii.

    Science.gov (United States)

    Manger, P. R.; Collins, R.; Pettigrew, J. D.

    1997-01-01

    Sensory receptors in the rostral portion of the beak skin of a single specimen of the rare long-beaked echidna, Zaglossus bruijnii, are described. Mucous glands which have been modified to accommodate sensory innervation, similar to those seen in Ornithorhynchus, are found in the rostral 2 cm of the beak skin, anterior to the maxillofacial foramen, at a density of approximately 12/mm2. The papillary epidermal portion of the gland ducts are walled by concentric layers of keratinocytes, and each duct is innervated by 10–15 myelinated nerve terminals. The mucous gland receptors in Zaglossus are intermediate in structure between those of Ornithorhynchus and Tachyglossus, but are similar enough to the former to suggest that electroreception may play a major role in the sensory experience of Zaglossus. Push-rod mechanoreceptors also occur throughout the same region of beak skin, and appear similar to those described for Tachyglossus.

  10. Comparative aspects of the inner root sheath in adult and developing hairs of mammals in relation to the evolution of hairs.

    Science.gov (United States)

    Alibardi, Lorenzo

    2004-09-01

    The inner root sheath (IRS) allows the exit of hairs through the epidermal surface. The fine structure of monotreme and marsupial IRS and trichohyalin is not known. Using electron microscopy and immunocytochemistry, the localization of trichohyalin and transglutaminase have been studied in monotreme and marsupial hairs, and compared with trichohyalin localization in placental hairs. Trichohyalin in all mammalian species studied here is recognized by a polyclonal antibody against sheep trichohyalin. This generalized immunoreactivity suggests that common epitopes are present in trichohyalin across mammals. In differentiating IRS cells, trichohyalin granules of variable dimensions are composed of an immunolabelled amorphous matrix associated with a network of 10-12-nm-thick keratin filaments. Transglutaminase labelling is present among keratin bundles and trichohyalin granules, and in condensed nuclei of terminally differentiating cells of the inner root sheath. The IRS in monotreme hairs is multistratified but lacks a distinguishable Henle layer. Cornification of IRS determines the sculpturing of the fibre cuticle and later shedding from the follicle for the exit of the hair fibre on the epidermal surface. It is hypothesized that the stratification of IRS in Henle, Huxley and IRS cuticle layers is derived from a simpler organization, like that present in the IRS of monotremes. The IRS is regarded as a localized shedding/sloughing layer needed for the exit of hairs without injury to the epidermis. The formation of the IRS during the evolution of mammalian epidermis allowed the physiological exit of hairs produced inside the skin. The peculiar morphogenesis of hairs in possible primitive skins, such as those of the monotremes (mammals with some reptilian characteristics) or the tails of some rodents (a scaled skin), may elucidate the evolution of hairs. In monotreme and rodent tail skin, the dermal papilla remains localized on the proximal side of the hair peg and

  11. [Evolution of genomic imprinting in mammals: what a zoo!].

    Science.gov (United States)

    Proudhon, Charlotte; Bourc'his, Déborah

    2010-05-01

    Genomic imprinting imposes an obligate mode of biparental reproduction in mammals. This phenomenon results from the monoparental expression of a subset of genes. This specific gene regulation mechanism affects viviparous mammals, especially eutherians, but also marsupials to a lesser extent. Oviparous mammals, or monotremes, do not seem to demonstrate monoparental allele expression. This phylogenic confinement suggests that the evolution of the placenta imposed a selective pressure for the emergence of genomic imprinting. This physiological argument is now complemented by recent genomic evidence facilitated by the sequencing of the platypus genome, a rare modern day case of a monotreme. Analysis of the platypus genome in comparison to eutherian genomes shows a chronological and functional coincidence between the appearance of genomic imprinting and transposable element accumulation. The systematic comparative analyses of genomic sequences in different species is essential for the further understanding of genomic imprinting emergence and divergent evolution along mammalian speciation.

  12. The evolution of gene expression levels in mammalian organs

    DEFF Research Database (Denmark)

    Brawand, David; Soumillon, Magali; Necsulea, Anamaria

    2011-01-01

    and chromosomes, owing to differences in selective pressures: transcriptome change was slow in nervous tissues and rapid in testes, slower in rodents than in apes and monotremes, and rapid for the X chromosome right after its formation. Although gene expression evolution in mammals was strongly shaped......Changes in gene expression are thought to underlie many of the phenotypic differences between species. However, large-scale analyses of gene expression evolution were until recently prevented by technological limitations. Here we report the sequencing of polyadenylated RNA from six organs across...... ten species that represent all major mammalian lineages (placentals, marsupials and monotremes) and birds (the evolutionary outgroup), with the goal of understanding the dynamics of mammalian transcriptome evolution. We show that the rate of gene expression evolution varies among organs, lineages...

  13. Cyto- and chemoarchitecture of the sensory trigeminal nuclei of the echidna, platypus and rat.

    Science.gov (United States)

    Ashwell, Ken W S; Hardman, Craig D; Paxinos, George

    2006-02-01

    We have examined the cyto- and chemoarchitecture of the trigeminal nuclei of two monotremes using Nissl staining, enzyme reactivity for cytochrome oxidase, immunoreactivity for calcium binding proteins and non-phosphorylated neurofilament (SMI-32 antibody) and lectin histochemistry (Griffonia simplicifolia isolectin B4). The principal trigeminal nucleus and the oralis and interpolaris spinal trigeminal nuclei were substantially larger in the platypus than in either the echidna or rat, but the caudalis subnucleus was similar in size in both monotremes and the rat. The numerical density of Nissl stained neurons was higher in the principal, oralis and interpolaris nuclei of the platypus relative to the echidna, but similar to that in the rat. Neuropil immunoreactivity for parvalbumin was particularly intense in the principal trigeminal, oralis and interpolaris subnuclei of the platypus, but the numerical density of parvalbumin immunoreactive neurons was not particularly high in these nuclei of the platypus. Neuropil immunoreactivity for calbindin and calretinin was relatively weak in both monotremes, although calretinin immunoreactive somata made up a large proportion of neurons in the principal, oralis and interpolaris subnuclei of the echidna. Distribution of calretinin immunoreactivity and Griffonia simplicifolia B4 isolectin reactivity suggested that the caudalis subnucleus of the echidna does not have a clearly defined gelatinosus region. Our findings indicate that the trigeminal nuclei of the echidna do not appear to be highly specialized, but that the principal, oralis and interpolaris subnuclei of the platypus trigeminal complex are highly differentiated, presumably for processing of tactile and electrosensory information from the bill.

  14. Electroreception in the Guiana dolphin (Sotalia guianensis).

    Science.gov (United States)

    Czech-Damal, Nicole U; Liebschner, Alexander; Miersch, Lars; Klauer, Gertrud; Hanke, Frederike D; Marshall, Christopher; Dehnhardt, Guido; Hanke, Wolf

    2012-02-22

    Passive electroreception is a widespread sense in fishes and amphibians, but in mammals this sensory ability has previously only been shown in monotremes. While the electroreceptors in fish and amphibians evolved from mechanosensory lateral line organs, those of monotremes are based on cutaneous glands innervated by trigeminal nerves. Electroreceptors evolved from other structures or in other taxa were unknown to date. Here we show that the hairless vibrissal crypts on the rostrum of the Guiana dolphin (Sotalia guianensis), structures originally associated with the mammalian whiskers, serve as electroreceptors. Histological investigations revealed that the vibrissal crypts possess a well-innervated ampullary structure reminiscent of ampullary electroreceptors in other species. Psychophysical experiments with a male Guiana dolphin determined a sensory detection threshold for weak electric fields of 4.6 µV cm(-1), which is comparable to the sensitivity of electroreceptors in platypuses. Our results show that electroreceptors can evolve from a mechanosensory organ that nearly all mammals possess and suggest the discovery of this kind of electroreception in more species, especially those with an aquatic or semi-aquatic lifestyle.

  15. Electroreception and electrolocation in platypus.

    Science.gov (United States)

    Scheich, H; Langner, G; Tidemann, C; Coles, R B; Guppy, A

    Electroreceptors with sensitivity in the microvolt range, which mainly function to detect live prey, are well known in phylogenetically old fishes and some amphibians. In African mormyriform and South American gymnotiform fishes this sense has evolved to an active system using an electric organ as a source for impedance measurement of the environment and for communication. Electroreception in higher vertebrates has not previously been reported. Here we establish that the platypus, the Australian nocturnal diving monotreme, can locate and avoid objects on the basis of d.c. fields. High-frequency sensitivity to a.c. could allow the detection of muscle activity of animals, such as crustaceans, which are preyed on by the platypus. Recordings of cortical evoked potentials showed that the bill of the platypus, previously considered to be exclusively mechanoreceptive, is also an electroreceptive organ with behavioural and electrophysiological sensitivity of approximately 50 microV cm-1. Several lines of evidence suggest that electroreception has evolved independently in this monotreme.

  16. Myoglobin of the shark Heterodontus portusjacksoni: isolation and amino acid sequence.

    Science.gov (United States)

    Fisher, W K; Thompson, E O

    1979-06-01

    Myoglobin isolated from red muscle of the shark H. portusjacksoni was purified by ion-exchange chromatography on sulfopropyl-Sephadex and gel-filtration. Amino acid analysis and sequence determination showed 148 amino acid residues. The amino terminal residue is acetylated as shown by mass spectrographic analysis of N-terminal peptides. There is a deletion of four residues at the amino terminal end as well as one residue in the CD interhelical area relative to other myoglobins. The complete amino acid sequence has been determined following digestion with trypsin, chymotrypsin, pepsin and staphylococcal protease. Sequences of the purified peptides were determined by the dansyl-Edman procedure. The amino acid sequence showed approximately 85 differences from mammalian, monotreme and bird myoglobins. The date of divergence of the shark H. portusjacksoni from these other orders was estimated at 450 +/- 16 million years, based on the number of amino acid differences between species and allowing for multiple mutations during the evolutionary period. This estimate agrees well with similar estimates made using alpha- and beta-globin sequences, in contrast to widely differing estimates of dates of divergence for monotremes using the same three globin chains. Compared with myoglobins from species previously studied, there are many more differences in amino acid sequences, and in many positions residues are found that are more characteristic of alpha- and beta-globins, suggesting a conservation of residues over a long period of evolutionary time. There are fewer stabilizing hydrogen bonds and salt-linkages than in other myoglobins.

  17. Role of the epididymis in sperm competition

    Institute of Scientific and Technical Information of China (English)

    Russell C. Jones; Jean-Louis Dacheux; Brett Nixon; Heath W. Ecroyd

    2007-01-01

    Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the context of the evolution of the mammalian epididymis, this report provides evidence that a major role of the epididymis is to enhance a male's chance of achieving paternity in a competitive mating system. A unique example of sperm cooperation in monotremes is used as evidence that the epididymis produces sperm competition proteins to form groups of 100 sperm into bundles that have a forward motility nearly thrice that of individual spermatozoa. As it required 3-h incubation in vitro under capacitation conditions to release motile sperm from the bundles, it is suggested that the monotremes provide an example of capacitation that is quite different from capacitation in higher mammals. It is Suggested that variation between species in the intensity of sperm competition could explain the variation that occurs between species in the amount of post-testicular sperm maturation and storage in the epididymis, an explanation of why the human epididymis does not play as important a role in reproduction as the epididymis of most mammals.

  18. Evolution of the turtle bauplan: the topological relationship of the scapula relative to the ribcage.

    Science.gov (United States)

    Lyson, Tyler R; Joyce, Walter G

    2012-12-23

    The turtle shell and the relationship of the shoulder girdle inside or 'deep' to the ribcage have puzzled neontologists and developmental biologists for more than a century. Recent developmental and fossil data indicate that the shoulder girdle indeed lies inside the shell, but anterior to the ribcage. Developmental biologists compare this orientation to that found in the model organisms mice and chickens, whose scapula lies laterally on top of the ribcage. We analyse the topological relationship of the shoulder girdle relative to the ribcage within a broader phylogenetic context and determine that the condition found in turtles is also found in amphibians, monotreme mammals and lepidosaurs. A vertical scapula anterior to the thoracic ribcage is therefore inferred to be the basal amniote condition and indicates that the condition found in therian mammals and archosaurs (which includes both developmental model organisms: chickens and mice) is derived and not appropriate for studying the developmental origin of the turtle shell. Instead, among amniotes, either monotreme mammals or lepidosaurs should be used.

  19. Variability and constraint in the mammalian vertebral column.

    Science.gov (United States)

    Asher, R J; Lin, K H; Kardjilov, N; Hautier, L

    2011-05-01

    Patterns of vertebral variation across mammals have seldom been quantified, making it difficult to test hypotheses of covariation within the axial skeleton and mechanisms behind the high level of vertebral conservatism among mammals. We examined variation in vertebral counts within 42 species of mammals, representing monotremes, marsupials and major clades of placentals. These data show that xenarthrans and afrotherians have, on average, a high proportion of individuals with meristic deviations from species' median series counts. Monotremes, xenarthrans, afrotherians and primates show relatively high variation in thoracolumbar vertebral count. Among the clades sampled in our dataset, rodents are the least variable, with several species not showing any deviations from median vertebral counts, or vertebral anomalies such as asymmetric ribs or transitional vertebrae. Most mammals show significant correlations between sacral position and length of the rib cage; only a few show a correlation between sacral position and number of sternebrae. The former result is consistent with the hypothesis that adult axial skeletal structures patterned by distinct mesodermal tissues are modular and covary; the latter is not. Variable levels of correlation among these structures may indicate that the boundaries of prim/abaxial mesodermal precursors of the axial skeleton are not uniform across species. We do not find evidence for a higher frequency of vertebral anomalies in our sample of embryos or neonates than in post-natal individuals of any species, contrary to the hypothesis that stabilizing selection plays a major role in vertebral patterning.

  20. Mammalian development does not recapitulate suspected key transformations in the evolutionary detachment of the mammalian middle ear.

    Science.gov (United States)

    Ramírez-Chaves, Héctor E; Wroe, Stephen W; Selwood, Lynne; Hinds, Lyn A; Leigh, Chris; Koyabu, Daisuke; Kardjilov, Nikolay; Weisbecker, Vera

    2016-01-13

    The ectotympanic, malleus and incus of the developing mammalian middle ear (ME) are initially attached to the dentary via Meckel's cartilage, betraying their origins from the primary jaw joint of land vertebrates. This recapitulation has prompted mostly unquantified suggestions that several suspected--but similarly unquantified--key evolutionary transformations leading to the mammalian ME are recapitulated in development, through negative allometry and posterior/medial displacement of ME bones relative to the jaw joint. Here we show, using µCT reconstructions, that neither allometric nor topological change is quantifiable in the pre-detachment ME development of six marsupials and two monotremes. Also, differential ME positioning in the two monotreme species is not recapitulated. This challenges the developmental prerequisites of widely cited evolutionary scenarios of definitive mammalian middle ear (DMME) evolution, highlighting the requirement for further fossil evidence to test these hypotheses. Possible association between rear molar eruption, full ME ossification and ME detachment in marsupials suggests functional divergence between dentary and ME as a trigger for developmental, and possibly also evolutionary, ME detachment. The stable positioning of the dentary and ME supports suggestions that a 'partial mammalian middle ear' as found in many mammaliaforms--probably with a cartilaginous Meckel's cartilage--represents the only developmentally plausible evolutionary DMME precursor.

  1. The genome sequence of taurine cattle: a window to ruminant biology and evolution.

    Science.gov (United States)

    Elsik, Christine G; Tellam, Ross L; Worley, Kim C; Gibbs, Richard A; Muzny, Donna M; Weinstock, George M; Adelson, David L; Eichler, Evan E; Elnitski, Laura; Guigó, Roderic; Hamernik, Debora L; Kappes, Steve M; Lewin, Harris A; Lynn, David J; Nicholas, Frank W; Reymond, Alexandre; Rijnkels, Monique; Skow, Loren C; Zdobnov, Evgeny M; Schook, Lawrence; Womack, James; Alioto, Tyler; Antonarakis, Stylianos E; Astashyn, Alex; Chapple, Charles E; Chen, Hsiu-Chuan; Chrast, Jacqueline; Câmara, Francisco; Ermolaeva, Olga; Henrichsen, Charlotte N; Hlavina, Wratko; Kapustin, Yuri; Kiryutin, Boris; Kitts, Paul; Kokocinski, Felix; Landrum, Melissa; Maglott, Donna; Pruitt, Kim; Sapojnikov, Victor; Searle, Stephen M; Solovyev, Victor; Souvorov, Alexandre; Ucla, Catherine; Wyss, Carine; Anzola, Juan M; Gerlach, Daniel; Elhaik, Eran; Graur, Dan; Reese, Justin T; Edgar, Robert C; McEwan, John C; Payne, Gemma M; Raison, Joy M; Junier, Thomas; Kriventseva, Evgenia V; Eyras, Eduardo; Plass, Mireya; Donthu, Ravikiran; Larkin, Denis M; Reecy, James; Yang, Mary Q; Chen, Lin; Cheng, Ze; Chitko-McKown, Carol G; Liu, George E; Matukumalli, Lakshmi K; Song, Jiuzhou; Zhu, Bin; Bradley, Daniel G; Brinkman, Fiona S L; Lau, Lilian P L; Whiteside, Matthew D; Walker, Angela; Wheeler, Thomas T; Casey, Theresa; German, J Bruce; Lemay, Danielle G; Maqbool, Nauman J; Molenaar, Adrian J; Seo, Seongwon; Stothard, Paul; Baldwin, Cynthia L; Baxter, Rebecca; Brinkmeyer-Langford, Candice L; Brown, Wendy C; Childers, Christopher P; Connelley, Timothy; Ellis, Shirley A; Fritz, Krista; Glass, Elizabeth J; Herzig, Carolyn T A; Iivanainen, Antti; Lahmers, Kevin K; Bennett, Anna K; Dickens, C Michael; Gilbert, James G R; Hagen, Darren E; Salih, Hanni; Aerts, Jan; Caetano, Alexandre R; Dalrymple, Brian; Garcia, Jose Fernando; Gill, Clare A; Hiendleder, Stefan G; Memili, Erdogan; Spurlock, Diane; Williams, John L; Alexander, Lee; Brownstein, Michael J; Guan, Leluo; Holt, Robert A; Jones, Steven J M; Marra, Marco A; Moore, Richard; Moore, Stephen S; Roberts, Andy; Taniguchi, Masaaki; Waterman, Richard C; Chacko, Joseph; Chandrabose, Mimi M; Cree, Andy; Dao, Marvin Diep; Dinh, Huyen H; Gabisi, Ramatu Ayiesha; Hines, Sandra; Hume, Jennifer; Jhangiani, Shalini N; Joshi, Vandita; Kovar, Christie L; Lewis, Lora R; Liu, Yih-Shin; Lopez, John; Morgan, Margaret B; Nguyen, Ngoc Bich; Okwuonu, Geoffrey O; Ruiz, San Juana; Santibanez, Jireh; Wright, Rita A; Buhay, Christian; Ding, Yan; Dugan-Rocha, Shannon; Herdandez, Judith; Holder, Michael; Sabo, Aniko; Egan, Amy; Goodell, Jason; Wilczek-Boney, Katarzyna; Fowler, Gerald R; Hitchens, Matthew Edward; Lozado, Ryan J; Moen, Charles; Steffen, David; Warren, James T; Zhang, Jingkun; Chiu, Readman; Schein, Jacqueline E; Durbin, K James; Havlak, Paul; Jiang, Huaiyang; Liu, Yue; Qin, Xiang; Ren, Yanru; Shen, Yufeng; Song, Henry; Bell, Stephanie Nicole; Davis, Clay; Johnson, Angela Jolivet; Lee, Sandra; Nazareth, Lynne V; Patel, Bella Mayurkumar; Pu, Ling-Ling; Vattathil, Selina; Williams, Rex Lee; Curry, Stacey; Hamilton, Cerissa; Sodergren, Erica; Wheeler, David A; Barris, Wes; Bennett, Gary L; Eggen, André; Green, Ronnie D; Harhay, Gregory P; Hobbs, Matthew; Jann, Oliver; Keele, John W; Kent, Matthew P; Lien, Sigbjørn; McKay, Stephanie D; McWilliam, Sean; Ratnakumar, Abhirami; Schnabel, Robert D; Smith, Timothy; Snelling, Warren M; Sonstegard, Tad S; Stone, Roger T; Sugimoto, Yoshikazu; Takasuga, Akiko; Taylor, Jeremy F; Van Tassell, Curtis P; Macneil, Michael D; Abatepaulo, Antonio R R; Abbey, Colette A; Ahola, Virpi; Almeida, Iassudara G; Amadio, Ariel F; Anatriello, Elen; Bahadue, Suria M; Biase, Fernando H; Boldt, Clayton R; Carroll, Jeffery A; Carvalho, Wanessa A; Cervelatti, Eliane P; Chacko, Elsa; Chapin, Jennifer E; Cheng, Ye; Choi, Jungwoo; Colley, Adam J; de Campos, Tatiana A; De Donato, Marcos; Santos, Isabel K F de Miranda; de Oliveira, Carlo J F; Deobald, Heather; Devinoy, Eve; Donohue, Kaitlin E; Dovc, Peter; Eberlein, Annett; Fitzsimmons, Carolyn J; Franzin, Alessandra M; Garcia, Gustavo R; Genini, Sem; Gladney, Cody J; Grant, Jason R; Greaser, Marion L; Green, Jonathan A; Hadsell, Darryl L; Hakimov, Hatam A; Halgren, Rob; Harrow, Jennifer L; Hart, Elizabeth A; Hastings, Nicola; Hernandez, Marta; Hu, Zhi-Liang; Ingham, Aaron; Iso-Touru, Terhi; Jamis, Catherine; Jensen, Kirsty; Kapetis, Dimos; Kerr, Tovah; Khalil, Sari S; Khatib, Hasan; Kolbehdari, Davood; Kumar, Charu G; Kumar, Dinesh; Leach, Richard; Lee, Justin C-M; Li, Changxi; Logan, Krystin M; Malinverni, Roberto; Marques, Elisa; Martin, William F; Martins, Natalia F; Maruyama, Sandra R; Mazza, Raffaele; McLean, Kim L; Medrano, Juan F; Moreno, Barbara T; Moré, Daniela D; Muntean, Carl T; Nandakumar, Hari P; Nogueira, Marcelo F G; Olsaker, Ingrid; Pant, Sameer D; Panzitta, Francesca; Pastor, Rosemeire C P; Poli, Mario A; Poslusny, Nathan; Rachagani, Satyanarayana; Ranganathan, Shoba; Razpet, Andrej; Riggs, Penny K; Rincon, Gonzalo; Rodriguez-Osorio, Nelida; Rodriguez-Zas, Sandra L; Romero, Natasha E; Rosenwald, Anne; Sando, Lillian; Schmutz, Sheila M; Shen, Libing; Sherman, Laura; Southey, Bruce R; Lutzow, Ylva Strandberg; Sweedler, Jonathan V; Tammen, Imke; Telugu, Bhanu Prakash V L; Urbanski, Jennifer M; Utsunomiya, Yuri T; Verschoor, Chris P; Waardenberg, Ashley J; Wang, Zhiquan; Ward, Robert; Weikard, Rosemarie; Welsh, Thomas H; White, Stephen N; Wilming, Laurens G; Wunderlich, Kris R; Yang, Jianqi; Zhao, Feng-Qi

    2009-04-24

    To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

  2. Metabolism of dinosaurs as determined from their growth

    Science.gov (United States)

    Lee, Scott A.

    2015-09-01

    A model based on cellular properties is used to analyze the mass growth curves of 20 dinosaurs. This analysis yields the first measurement of the average cellular metabolism of dinosaurs. The organismal metabolism is also determined. The cellular metabolism of dinosaurs is found to decrease with mass at a slower rate than is observed in extant animals. The organismal metabolism increases with the mass of the dinosaur. These results come from both the Saurischia and Ornithischia branches of Dinosauria, suggesting that the observed metabolic features were common to all dinosaurs. The results from dinosaurs are compared to data from extant placental and marsupial mammals, a monotreme, and altricial and precocial birds, reptiles, and fish. Dinosaurs had cellular and organismal metabolisms in the range observed in extant mesotherms.

  3. Sir William Turner and his studies on the mammalian placenta.

    Science.gov (United States)

    Magee, Reginald

    2003-06-01

    William Turner was appointed Professor of Anatomy at the University of Edinburgh in 1867, and from 1903 until his death in 1916, he was Principal and Vice-Chancellor. He was an outstanding teacher and many of those he taught went on to occupy chairs of anatomy. He published widely on anatomical subjects and one of his interests was comparative anatomy and physiology of the placenta. This paper takes a brief look at Turner's studies on the anatomical structure of the placenta, its comparative anatomy, his thoughts about its physiology and its place in the evolutionary process. At the time, these lectures constituted an anatomical and physiological classic. At the time Turner prepared his lectures, which were delivered in 1875 and 1876, little was known about the gestatory process in marsupials or monotremes. These mammals have a very brief period of intrauterine gestation and placentation and mention is made of studies that have been done in recent times on this subject.

  4. New gliding mammaliaforms from the Jurassic

    Science.gov (United States)

    Meng, Qing-Jin; Grossnickle, David M.; Liu, Di; Zhang, Yu-Guang; Neander, April I.; Ji, Qiang; Luo, Zhe-Xi

    2017-08-01

    Stem mammaliaforms are Mesozoic forerunners to mammals, and they offer critical evidence for the anatomical evolution and ecological diversification during the earliest mammalian history. Two new eleutherodonts from the Late Jurassic period have skin membranes and skeletal features that are adapted for gliding. Characteristics of their digits provide evidence of roosting behaviour, as in dermopterans and bats, and their feet have a calcaneal calcar to support the uropagatium as in bats. The new volant taxa are phylogenetically nested with arboreal eleutherodonts. Together, they show an evolutionary experimentation similar to the iterative evolutions of gliders within arboreal groups of marsupial and placental mammals. However, gliding eleutherodonts possess rigid interclavicle-clavicle structures, convergent to the avian furculum, and they retain shoulder girdle plesiomorphies of mammaliaforms and monotremes. Forelimb mobility required by gliding occurs at the acromion-clavicle and glenohumeral joints, is different from and convergent to the shoulder mobility at the pivotal clavicle-sternal joint in marsupial and placental gliders.

  5. Ancient antimicrobial peptides kill antibiotic-resistant pathogens: Australian mammals provide new options.

    Science.gov (United States)

    Wang, Jianghui; Wong, Emily S W; Whitley, Jane C; Li, Jian; Stringer, Jessica M; Short, Kirsty R; Renfree, Marilyn B; Belov, Katherine; Cocks, Benjamin G

    2011-01-01

    To overcome the increasing resistance of pathogens to existing antibiotics the 10×'20 Initiative declared the urgent need for a global commitment to develop 10 new antimicrobial drugs by the year 2020. Naturally occurring animal antibiotics are an obvious place to start. The recently sequenced genomes of mammals that are divergent from human and mouse, including the tammar wallaby and the platypus, provide an opportunity to discover novel antimicrobials. Marsupials and monotremes are ideal potential sources of new antimicrobials because they give birth to underdeveloped immunologically naïve young that develop outside the sterile confines of a uterus in harsh pathogen-laden environments. While their adaptive immune system develops innate immune factors produced either by the mother or by the young must play a key role in protecting the immune-compromised young. In this study we focus on the cathelicidins, a key family of antimicrobial peptide genes. We identified 14 cathelicidin genes in the tammar wallaby genome and 8 in the platypus genome. The tammar genes were expressed in the mammary gland during early lactation before the adaptive immune system of the young develops, as well as in the skin of the pouch young. Both platypus and tammar peptides were effective in killing a broad range of bacterial pathogens. One potent peptide, expressed in the early stages of tammar lactation, effectively killed multidrug-resistant clinical isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii. Marsupial and monotreme young are protected by antimicrobial peptides that are potent, broad spectrum and salt resistant. The genomes of our distant relatives may hold the key for the development of novel drugs to combat multidrug-resistant pathogens.

  6. Distinct development of the trigeminal sensory nuclei in platypus and echidna.

    Science.gov (United States)

    Ashwell, Ken W S; Hardman, Craig D

    2012-01-01

    Both lineages of the modern monotremes have been reported to be capable of electroreception using the trigeminal pathways and it has been argued that electroreception arose in an aquatic platypus-like ancestor of both modern monotreme groups. On the other hand, the trigeminal sensory nuclear complex of the platypus is highly modified for processing tactile and electrosensory information from the bill, whereas the trigeminal sensory nuclear complex of the short-beaked echidna (Tachyglossus aculeatus) is not particularly specialized. If the common ancestor for both platypus and echidna were an electroreceptively and trigeminally specialized aquatic feeder, one would expect the early stages of development of the trigeminal sensory nuclei in both species to show evidence of structural specialization from the outset. To determine whether this is the case, we examined the development of the trigeminal sensory nuclei in the platypus and short-beaked echidna using the Hill and Hubrecht embryological collections. We found that the highly specialized features of the platypus trigeminal sensory nuclei (i.e. the large size of the principal nucleus and oral part of the spinal trigeminal nuclear complex, and the presence of a dorsolateral parvicellular segment in the principal nucleus) appear around the time of hatching in the platypus, but are never seen at any stage in the echidna. Our findings support the proposition that the modern echidna and platypus are derived from a common ancestor with only minimal trigeminal specialization and that the peculiar anatomy of the trigeminal sensory nuclei in the modern platypus emerged in the ornithorhynchids after divergence from the tachyglossids. Copyright © 2012 S. Karger AG, Basel.

  7. Evolution of the patellar sesamoid bone in mammals

    Science.gov (United States)

    Samuels, Mark E.; Regnault, Sophie

    2017-01-01

    The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition) and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution

  8. Evolution of the patellar sesamoid bone in mammals

    Directory of Open Access Journals (Sweden)

    Mark E. Samuels

    2017-03-01

    Full Text Available The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa. Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across

  9. Substrate specificity of platypus venom L-to-D-peptide isomerase.

    Science.gov (United States)

    Bansal, Paramjit S; Torres, Allan M; Crossett, Ben; Wong, Karen K Y; Koh, Jennifer M S; Geraghty, Dominic P; Vandenberg, Jamie I; Kuchel, Philip W

    2008-04-04

    The L-to-D-peptide isomerase from the venom of the platypus (Ornithorhyncus anatinus) is the first such enzyme to be reported for a mammal. In delineating its catalytic mechanism and broader roles in the animal, its substrate specificity was explored. We used N-terminal segments of defensin-like peptides DLP-2 and DLP-4 and natriuretic peptide OvCNP from the venom as substrates. The DLP analogues IMFsrs and ImFsrs (srs is a solubilizing chain; lowercase letters denote D-amino acid) were effective substrates for the isomerase; it appears to recognize the N-terminal tripeptide sequence Ile-Xaa-Phe-. A suite of 26 mutants of these hexapeptides was synthesized by replacing the second residue (Met) with another amino acid, viz. Ala, alpha-aminobutyric acid, Ile, Leu, Lys, norleucine, Phe, Tyr, and Val. It was shown that mutant peptides incorporating norleucine and Phe are substrates and exhibit L- or D-amino acid isomerization, but mutant peptides that contain residues with shorter, beta-branched or long side chains with polar terminal groups, viz. Ala, alpha-aminobutyric acid, Ile, Val, Leu, Lys, and Tyr, respectively, are not substrates. It was demonstrated that at least three N-terminal amino acid residues are absolutely essential for L-to-D-isomerization; furthermore, the third amino acid must be a Phe residue. None of the hexapeptides based on LLH, the first three residues of OvCNP, were substrates. A consistent 2-base mechanism is proposed for the isomerization; abstraction of a proton by 1 base is concomitant with delivery of a proton by the conjugate acid of a second base.

  10. The Molecular Architecture for the Intermediate Filaments of Hard [alpha]-Keratin Based on the Superlattice Data Obtained from a Study ofMammals Using Synchrotron Fibre Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    James, Veronica (ANU)

    2014-09-24

    High- and low-angle X-ray diffraction studies of hard {alpha}-keratin have been studied, and various models have been proposed over the last 70 years. Most of these studies have been confined to one or two forms of alpha keratin. This high- and low-angle synchrotron fibre diffraction study extends the study to cover all available data for all known forms of hard {alpha}-keratin including hairs, fingernails, hooves, horn, and quills from mammals, marsupials, and a monotreme, and it confirms that the model proposed is universally acceptable for all mammals. A complete Bragg analysis of the meridional diffraction patterns, including multiple-time exposures to verify any weak reflections, verified the existence of a superlattice consisting of two infinite lattices and three finite lattices. An analysis of the equatorial patterns establishes the radii of the oligomeric levels of dimers, tetramers, and intermediate filaments (IFs) together with the centre to centre distance for the IFs, thus confirming the proposed helices within helices molecular architecture for hard {alpha}-keratin. The results verify that the structure proposed by Feughelman and James meets the criteria for a valid {alpha}-keratin structure.

  11. Widespread horizontal transfer of retrotransposons.

    Science.gov (United States)

    Walsh, Ali Morton; Kortschak, R Daniel; Gardner, Michael G; Bertozzi, Terry; Adelson, David L

    2013-01-15

    In higher organisms such as vertebrates, it is generally believed that lateral transfer of genetic information does not readily occur, with the exception of retroviral infection. However, horizontal transfer (HT) of protein coding repetitive elements is the simplest way to explain the patchy distribution of BovB, a long interspersed element (LINE) about 3.2 kb long, that has been found in ruminants, marsupials, squamates, monotremes, and African mammals. BovB sequences are a major component of some of these genomes. Here we show that HT of BovB is significantly more widespread than believed, and we demonstrate the existence of two plausible arthropod vectors, specifically reptile ticks. A phylogenetic tree built from BovB sequences from species in all of these groups does not conform to expected evolutionary relationships of the species, and our analysis indicates that at least nine HT events are required to explain the observed topology. Our results provide compelling evidence for HT of genetic material that has transformed vertebrate genomes.

  12. The head and neck muscles of the serval and tiger: homologies, evolution, and proposal of a mammalian and a veterinary muscle ontology.

    Science.gov (United States)

    Diogo, Rui; Pastor, Francisco; De Paz, Felix; Potau, Josep M; Bello-Hellegouarch, Gaëlle; Ferrero, Eva M; Fisher, Rebecca E

    2012-12-01

    Here we describe the head and neck muscles of members of the two extant felid subfamilies (Leptailurus serval: Felinae; Panthera tigris: Pantherinae) and compare these muscles with those of other felids, other carnivorans (e.g., domestic dogs), other eutherian mammals (e.g., rats, tree-shrews and modern humans), and noneutherian mammals including monotremes. Another major goal of the article is to discuss and help clarify nomenclatural discrepancies found in the Nomina Anatomica Veterinaria and in veterinary atlases and textbooks that use cats and dogs as models to understand the anatomy of domestic mammals and to stress differences with modern humans. We propose a unifying nomenclature that is expanded to all the head and neck muscles and to all mammalian taxa in order to help build veterinary and mammalian muscle ontologies. Our observations and comparisons and the specific use of this nomenclature point out that felids such as tigers and servals and other carnivorans such as dogs have more facial muscle structures related to the mobility of both the auricular and orbital regions than numerous other mammals, including modern humans, which might be the result of an ancient adaptation related to the remarkable predatory capacities of carnivorans. Interestingly, the skeletal differences, mainly concerning the hyoid apparatus, pharynx, and larynx, that are likely associated with the different types of vocalizations seen in the Felinae (mainly purring) and Pantherinae (mainly roaring) are not accompanied by clear differences in the musculature connected to these structures in the feline L. serval and the pantherine P. tigris.

  13. The evolutionary history of testicular externalization and the origin of the scrotum

    Indian Academy of Sciences (India)

    Karel Kleisner; Richard Ivell; Jaroslav Flegr

    2010-03-01

    This paper re-examines the evolution of the scrotum and testicular descent in the context of the recent phylogeny of mammals. The adaptive significance of testicular descent and scrotality is briefly discussed. We mapped four character states reflecting the position of testes and presence of scrotum onto recent mammalian phylogeny. Our results are interpreted as follows: as to the presence of testicondy in Monotremata and most of Atlantogenata, which represent the basal group of all eutherians, we argue that primary testicondy represents a plesiomorphic condition for Eutheria as well as for all mammals. This is in opposition to the previous hypothesis of Werdelin and Nilsonne that the scrotum may have evolved before the origin of mammals and then repeatedly disappeared in many groups including monotremes. We suggest that the scrotum evolved at least twice during the evolutionary history of mammals, within Marsupialia and Boreoeutheria, and has subsequently been lost by many groups; this trend is especially strong in Laurasiatheria. We suggest that the recent diversity in testicular position within mammals is the result of multiple selection pressures stemming from the need to provide conditions suitable for sperm development and storage, or to protect the male gonads from excessive physical and physiological disturbance.

  14. Origin of INSL3-mediated testicular descent in therian mammals.

    Science.gov (United States)

    Park, Jae-Il; Semyonov, Jenia; Chang, Chia Lin; Yi, Wei; Warren, Wesley; Hsu, Sheau Yu Teddy

    2008-06-01

    Testicular descent is a unique physiological adaptation found in therian mammals allowing optimal spermatogenesis below core body temperature. Recent studies show that INSL3, produced by Leydig cells, and its receptor LGR8 (RXFP2) are essential for mediating the transabdominal phase of testicular descent during early development. However, the origin and genetic basis for this physiological adaptation is not clear. Using syntenic mapping and the functional characterization of contemporary and resurrected relaxin family hormones, we show that derivation of INSL3-mediated testicular descent involved the duplication of an ancestral RLN3-like gene that encodes an indiscriminate ligand for LGR7 (RXFP1) and LGR8. This event was followed by acquisition of the LGR7-selective characteristics by a daughter gene (RLN3) prior to the evolution of the common ancestor of monotremes, marsupials, and placentals. A subsequent mutation of the other daughter gene (INSL3) occurred before the emergence of therian mammals, which then led to the derivation of the reciprocal LGR8-specific characteristics of INSL3. The stepwise evolution of these independent signaling pathways through gene duplication and subsequent divergence is consistent with Darwinian theory of selection and adaptation, and the temporal proximity suggests an association between these genetic events and the concurrent evolution of testicular descent in ancestral therian mammals.

  15. Brain and behaviour of living and extinct echidnas.

    Science.gov (United States)

    Ashwell, Ken W S; Hardman, Craig D; Musser, Anne M

    2014-10-01

    The Tachyglossidae (long- and short-beaked echidnas) are a family of monotremes, confined to Australia and New Guinea, that exhibit striking trigeminal, olfactory and cortical specialisations. Several species of long-beaked echidna (Zaglossus robusta, Zaglossus hacketti, Megalibgwilia ramsayi) were part of the large-bodied (10 kg or more) fauna of Pleistocene Australasia, but only the diminutive (2-7 kg) Tachyglossus aculeatus is widespread today on the Australian mainland. We used high-resolution CT scanning and other osteological techniques to determine whether the remarkable neurological specialisations of modern echidnas were also present in Pleistocene forms or have undergone modification as the Australian climate changed in the transition from the Pleistocene to the Holocene. All the living and extinct echidnas studied have a similar pattern of cortical gyrification that suggests comparable functional topography to the modern short-beaked form. Osteological features related to olfactory, trigeminal, auditory and vestibular specialisation (e.g., foramina and cribriform plate area, osseous labyrinth topography) are also similar in living and extinct species. Our findings indicate that despite differences in diet, habitat and body size, the suite of neurological specialisations in the Tachyglossidae has been remarkably constant: encephalisation, sensory anatomy and specialisation (olfactory, trigeminal, auditory and vestibular), hypoglossal nerve size and cortical topography have all been stable neurological features of the group for at least 300,000 years. Crown Copyright © 2014. Published by Elsevier GmbH. All rights reserved.

  16. Vascularization of the gray whale palate (Cetacea, Mysticeti, Eschrichtius robustus): soft tissue evidence for an alveolar source of blood to baleen.

    Science.gov (United States)

    Ekdale, Eric G; Deméré, Thomas A; Berta, Annalisa

    2015-04-01

    The origin of baleen in mysticetes heralded a major transition during cetacean evolution. Extant mysticetes are edentulous in adulthood, but rudimentary teeth develop in utero within open maxillary and mandibular alveolar grooves. The teeth are resorbed prenatally and the alveolar grooves close as baleen germ develops. Arteries supplying blood to highly vascularized epithelial tissue from which baleen develops pass through lateral nutrient foramina in the area of the embryonic alveolar grooves and rudimentary teeth. Those vessels are hypothesized to be branches of the superior alveolar artery, but branches of the greater palatine arteries may play a role in the baleen vascularization. Through a combination of latex injection, CT, and traditional dissection of the palate of a neonatal gray whale (Eschrichtius robustus), we confirm that the baleen receives blood from vessels within the superior alveolar canal via the lateral foramina. The greater palatine artery is restricted to its own passage with no connections to the baleen. This study has implications for the presence of baleen in extinct taxa by identifying the vessels and bony canals that supply blood to the epithelium from which baleen develops. The results indicate that the lateral foramina in edentulous mysticete fossils are bony correlates for the presence of baleen, and the results can be used to help identify bony canals and foramina that have been used to reconstruct baleen in extinct mysticetes that retained teeth in adulthood. Further comparisons are made with mammals that also possess oral keratin structures, including ruminants, ornithorhynchid monotremes, and sirenians.

  17. The nocturnal bottleneck and the evolution of activity patterns in mammals

    Science.gov (United States)

    Gerkema, Menno P.; Davies, Wayne I. L.; Foster, Russell G.; Menaker, Michael; Hut, Roelof A.

    2013-01-01

    In 1942, Walls described the concept of a ‘nocturnal bottleneck’ in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail. PMID:23825205

  18. Identification of a novel PNMA-MS1 gene in marsupials suggests the LTR retrotransposon-derived PNMA genes evolved differently in marsupials and eutherians.

    Science.gov (United States)

    Iwasaki, Sawa; Suzuki, Shunsuke; Pelekanos, Matthew; Clark, Helen; Ono, Ryuichi; Shaw, Geoff; Renfree, Marilyn B; Kaneko-Ishino, Tomoko; Ishino, Fumitoshi

    2013-10-01

    Two major gene families derived from Ty3/Gypsy long terminal repeat (LTR) retrotransposons were recently identified in mammals. The sushi-ichi retrotransposon homologue (SIRH) family comprises 12 genes: 11 in eutherians including Peg10 and Peg11/Rtl1 that have essential roles in the eutherian placenta and 1 that is marsupial specific. Fifteen and 12 genes were reported in the second gene family, para-neoplastic antigen MA (PNMA), in humans and mice, respectively, although their biological functions and evolutionary history remain largely unknown. Here, we identified two novel candidate PNMA genes, PNMA-MS1 and -MS2 in marsupials. Like all eutherian-specific PNMA genes, they exhibit the highest homology to a Gypsy12_DR (DR, Danio rerio) Gag protein. PNMA-MS1 is conserved in both Australian and South American marsupial species, the tammar wallaby and grey short-tailed opossum. However, no PNMA-MS1 orthologue was found in eutherians, monotremes or non-mammalian vertebrates. PNMA-MS1 was expressed in the ovary, mammary gland and brain during development and growth in the tammar, suggesting that PNMA-MS1 may have acquired a marsupial-specific function. However, PNMA-MS2 seems to be a pseudogene. The absence of marsupial orthologues of eutherian PNMA genes suggests that the retrotransposition events of the Gypsy12_DR-related retrotransposons that gave rise to the PNMA family occurred after the divergence of marsupials and eutherians.

  19. Morphological and molecular evolution of the ultimobranchial gland of nonmammalian vertebrates, with special reference to the chicken C cells.

    Science.gov (United States)

    Kameda, Yoko

    2017-10-01

    This review summarizes the current understanding of the nonmammalian ultimobranchial gland from morphological and molecular perspectives. Ultimobranchial anlage of all animal species develops from the last pharyngeal pouch. The genes involved in the development of pharyngeal pouches are well conserved across vertebrates. The ultimobranchial anlage of nonmammalian vertebrates and monotremes does not merge with the thyroid, remaining as an independent organ throughout adulthood. Although C cells of all animal species secrete calcitonin, the shape, cellular components and location of the ultimobranchial gland vary from species to species. Avian ultimobranchial gland is unique in several phylogenic aspects; the organ is located between the vagus and recurrent laryngeal nerves at the upper thorax and is densely innervated by branches emanating from them. In chick embryos, TuJ1-, HNK-1-, and PGP 9.5-immunoreactive cells that originate from the distal vagal (nodose) ganglion, colonize the ultimobranchial anlage and differentiate into C cells; neuronal cells give rise to C cells. Like C cells of mammals, the cells of fishes, amphibians, reptiles, and also a subset of C cells of birds, appear to be derived from the endodermal epithelium forming ultimobranchial anlage. Thus, the avian ultimobranchial C cells may have dual origins, neural progenitors and endodermal epithelium. Developmental Dynamics 246:719-739, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. A comparative approach to understanding tissue-specific expression of uncoupling protein 1 expression in adipose tissue

    Directory of Open Access Journals (Sweden)

    Andrew eShore

    2013-01-01

    Full Text Available The thermoregulatory function of brown adipose tissue (BAT is due to the tissue-specific expression of uncoupling protein 1 (UCP1 which is thought to have evolved in early mammals. We report that a CpG island close to the UCP1 transcription start site is highly conserved in all 29 vertebrates examined apart from the mouse and xenopus. Using methylation sensitive restriction digest and bisulphite mapping we show that the CpG island in both the bovine and human is largely un-methylated and is not related to differences in UCP1 expression between white and brown adipose tissue. Tissue-specific expression of UCP1 has been proposed to be regulated by a conserved 5’ distal enhancer which has been reported to be absent in marsupials. We demonstrate that the enhancer, is also absent in 5 eutherians as well as marsupials, monotremes, amphibians and fish, is present in pigs despite UCP1 having become a pseudogene, and that absence of the enhancer element does not relate to brown adipose tissue-specific UCP1 expression. We identify an additional putative 5’ regulatory unit which is conserved in 14 eutherian species but absent in other eutherians and vertebrates, but again unrelated to UCP1 expression. We conclude that despite clear evidence of conservation of regulatory elements in the UCP1 5’ untranslated region, this does not appear to be related to species or tissues-specific expression of UCP1.

  1. Weird mammals provide insights into the evolution of mammalian sex chromosomes and dosage compensation

    Indian Academy of Sciences (India)

    Jennifer A. Marshall Graves

    2015-12-01

    The deep divergence of mammalian groups 166 and 190 million years ago (MYA) provide genetic variation to explore the evolution of DNA sequence, gene arrangement and regulation of gene expression in mammals. With encouragement from the founder of the field, Mary Lyon, techniques in cytogenetics and molecular biology were progressively adapted to characterize the sex chromosomes of kangaroos and other marsupials, platypus and echidna—and weird rodent species. Comparative gene mapping reveals the process of sex chromosome evolution from their inception 190 MYA (they are autosomal in platypus) to their inevitable end (the Y has disappeared in two rodent lineages). Our X and Y are relatively young, getting their start with the evolution of the sex-determining gene, which triggered progressive degradation of the Y chromosome. Even more recently, sex chromosomes of placental mammals fused with an autosomal region which now makes up most of the Y. Exploration of gene activity patterns over four decades showed that dosage compensation via X-chromosome inactivation is unique to therian mammals, and that this whole chromosome control process is different in marsupials and absent in monotremes and reptiles, and birds. These differences can be exploited to deduce how mammalian sex chromosomes and epigenetic silencing evolved.

  2. Phylogenetic origins of early alterations in brain region proportions.

    Science.gov (United States)

    Charvet, Christine J; Sandoval, Alexis L; Striedter, Georg F

    2010-01-01

    Adult galliform birds (e.g. chickens) exhibit a relatively small telencephalon and a proportionately large optic tectum compared with parrots and songbirds. We previously examined the embryonic origins of these adult species differences and found that the optic tectum is larger in quail than in parakeets and songbirds at early stages of development, prior to tectal neurogenesis onset. The aim of this study was to determine whether a proportionately large presumptive tectum is a primitive condition within birds or a derived feature of quail and other galliform birds. To this end, we examined embryonic brains of several avian species (emus, parrots, songbirds, waterfowl, galliform birds), reptiles (3 lizard species, alligators, turtles) and a monotreme (platypuses). Brain region volumes were estimated from serial Nissl-stained sections. We found that the embryos of galliform birds and lizards exhibit a proportionally larger presumptive tectum than all the other examined species. The presumptive tectum of the platypus is unusually small. The most parsimonious interpretation of these data is that the expanded embryonic tectum of lizards and galliform birds is a derived feature in both of these taxonomic groups.

  3. Evolution and survival on eutherian sex chromosomes.

    Directory of Open Access Journals (Sweden)

    Melissa A Wilson

    2009-07-01

    Full Text Available Since the two eutherian sex chromosomes diverged from an ancestral autosomal pair, the X has remained relatively gene-rich, while the Y has lost most of its genes through the accumulation of deleterious mutations in nonrecombining regions. Presently, it is unclear what is distinctive about genes that remain on the Y chromosome, when the sex chromosomes acquired their unique evolutionary rates, and whether X-Y gene divergence paralleled that of paralogs located on autosomes. To tackle these questions, here we juxtaposed the evolution of X and Y homologous genes (gametologs in eutherian mammals with their autosomal orthologs in marsupial and monotreme mammals. We discovered that genes on the X and Y acquired distinct evolutionary rates immediately following the suppression of recombination between the two sex chromosomes. The Y-linked genes evolved at higher rates, while the X-linked genes maintained the lower evolutionary rates of the ancestral autosomal genes. These distinct rates have been maintained throughout the evolution of X and Y. Specifically, in humans, most X gametologs and, curiously, also most Y gametologs evolved under stronger purifying selection than similarly aged autosomal paralogs. Finally, after evaluating the current experimental data from the literature, we concluded that unique mRNA/protein expression patterns and functions acquired by Y (versus X gametologs likely contributed to their retention. Our results also suggest that either the boundary between sex chromosome strata 3 and 4 should be shifted or that stratum 3 should be divided into two strata.

  4. Physical mapping of the elephant X chromosome: conservation of gene order over 105 million years.

    Science.gov (United States)

    Delgado, Claudia Leticia Rodríguez; Waters, Paul D; Gilbert, Clément; Robinson, Terence J; Graves, Jennifer A Marshall

    2009-01-01

    All therian mammals (eutherians and marsupials) have an XX female/XY male sex chromosome system or some variant of it. The X and Y evolved from a homologous pair of autosomes over the 166 million years since therian mammals diverged from monotremes. Comparing the sex chromosomes of eutherians and marsupials defined an ancient X conserved region that is shared between species of these mammalian clades. However, the eutherian X (and the Y) was augmented by a recent addition (XAR) that is autosomal in marsupials. XAR is part of the X in primates, rodents, and artiodactyls (which belong to the eutherian clade Boreoeutheria), but it is uncertain whether XAR is part of the X chromosome in more distantly related eutherian mammals. Here we report on the gene content and order on the X of the elephant (Loxodonta africana)-a representative of Afrotheria, a basal endemic clade of African mammals-and compare these findings to those of other documented eutherian species. A total of 17 genes were mapped to the elephant X chromosome. Our results support the hypothesis that the eutherian X and Y chromosomes were augmented by the addition of autosomal material prior to eutherian radiation. Not only does the elephant X bear the same suite of genes as other eutherian X chromosomes, but gene order appears to have been maintained across 105 million years of evolution, perhaps reflecting strong constraints posed by the eutherian X inactivation system.

  5. Reassessing the relationship between brain size, life history, and metabolism at the marsupial/placental dichotomy.

    Science.gov (United States)

    Weisbecker, Vera; Goswami, Anjali

    2014-09-01

    A vigorous discussion surrounds the question as to what enables some mammals--including primates and cetaceans--to evolve large brains. We recently published a study suggesting that the radiation of marsupial mammals is highly relevant to this question because of the unique reproductive and metabolic traits within this clade. In particular, we controversially suggested that marsupial brain sizes are not systematically smaller than those of placentals, and that elevated basal metabolic rates (BMR) are not linked to larger marsupial brains. As our dataset was found to contain some erroneous body size data, derived from a published source, we here use an updated and corrected dataset and employ standard as well as phylogenetically corrected analyses to re-assess and elaborate on our original conclusions. Our proposal that marsupials are not systematically smaller-brained than placentals remains supported, particularly when the unusually large-brained placental clade, Primates, is excluded. Use of the new dataset not only confirms that high metabolic rates are not associated with larger brain size in marsupials, but we additionally find some support for a striking negative correlation between BMR and brain size. The best supported correlates of large brain size remain the reproductive traits of weaning age and litter size. These results support our suggestion that mammalian brain sizes (including, by inference, those of monotremes) are predominantly constrained by the ability of females to fuel the growth of their offspring's large brains, rather than by the maintenance requirements of the adult brain.

  6. Status of dosage compensation of X chromosome in bovine genome.

    Science.gov (United States)

    Ka, Sojeong; Ahn, Hyeonju; Seo, Minseok; Kim, Heebal; Kim, Jin Nam; Lee, Hyun-Jeong

    2016-08-01

    Dosage compensation system with X chromosome upregulation and inactivation have evolved to overcome the genetic imbalance between sex chromosomes in both male and female of mammals. Although recent development of chromosome-wide technologies has allowed us to test X upregulation, discrete data processing and analysis methods draw disparate conclusions. A series of expression studies revealed status of dosage compensation in some species belonging to monotremes, marsupials, rodents and primates. However, X upregulation in the Artiodactyla order including cattle have not been studied yet. In this study, we surveyed the genome-wide transcriptional upregulation in X chromosome in cattle RNA-seq data using different gene filtration methods. Overall examination of RNA-seq data revealed that X chromosome in the pituitary gland expressed more genes than in other peripheral tissues, which was consistent with the previous results observed in human and mouse. When analyzed with globally expressed genes, a median X:A expression ratio was 0.94. The ratio of 1-to-1 ortholog genes between chicken and mammals, however, showed considerable reduction to 0.68. These results indicate that status of dosage compensation for cattle is not deviated from those found in rodents and primate, and this is consistent with the evolutionary history of cattle.

  7. Characterisation of the immune compounds in koala milk using a combined transcriptomic and proteomic approach

    Science.gov (United States)

    Morris, Katrina M.; O’Meally, Denis; Zaw, Thiri; Song, Xiaomin; Gillett, Amber; Molloy, Mark P.; Polkinghorne, Adam; Belov, Katherine

    2016-01-01

    Production of milk is a key characteristic of mammals, but the features of lactation vary greatly between monotreme, marsupial and eutherian mammals. Marsupials have a short gestation followed by a long lactation period, and milk constituents vary greatly across lactation. Marsupials are born immunologically naïve and rely on their mother’s milk for immunological protection. Koalas (Phascolarctos cinereus) are an iconic Australian species that are increasingly threatened by disease. Here we use a mammary transcriptome, two milk proteomes and the koala genome to comprehensively characterise the protein components of koala milk across lactation, with a focus on immune constituents. The most abundant proteins were well-characterised milk proteins, including β-lactoglobulin and lactotransferrin. In the mammary transcriptome, 851 immune transcripts were expressed, including immunoglobulins and complement components. We identified many abundant antimicrobial peptides, as well as novel proteins with potential antimicrobial roles. We discovered that marsupial VELP is an ortholog of eutherian Glycam1, and likely has an antimicrobial function in milk. We also identified highly-abundant koala endogenous-retrovirus sequences, identifying a potential transmission route from mother to young. Characterising the immune components of milk is key to understanding protection of marsupial young, and the novel immune compounds identified may have applications in clinical research. PMID:27713568

  8. Extreme telomere length dimorphism in the Tasmanian devil and related marsupials suggests parental control of telomere length.

    Directory of Open Access Journals (Sweden)

    Hannah S Bender

    Full Text Available Telomeres, specialised structures that protect chromosome ends, play a critical role in preserving chromosome integrity. Telomere dynamics in the Tasmanian devil (Sarcophilus harrisii are of particular interest in light of the emergence of devil facial tumour disease (DFTD, a transmissible malignancy that causes rapid mortality and threatens the species with extinction. We used fluorescent in situ hybridisation to investigate telomere length in DFTD cells, in healthy Tasmanian devils and in four closely related marsupial species. Here we report that animals in the Order Dasyuromorphia have chromosomes characterised by striking telomere length dimorphism between homologues. Findings in sex chromosomes suggest that telomere length dimorphism may be regulated by events in the parental germlines. Long telomeres on the Y chromosome imply that telomere lengthening occurs during spermatogenesis, whereas telomere diminution occurs during oogenesis. Although found in several somatic cell tissue types, telomere length dimorphism was not found in DFTD cancer cells, which are characterised by uniformly short telomeres. This is, to our knowledge, the first report of naturally occurring telomere length dimorphism in any species and suggests a novel strategy of telomere length control. Comparative studies in five distantly related marsupials and a monotreme indicate that telomere dimorphism evolved at least 50 million years ago.

  9. Fast running restricts evolutionary change of the vertebral column in mammals.

    Science.gov (United States)

    Galis, Frietson; Carrier, David R; van Alphen, Joris; van der Mije, Steven D; Van Dooren, Tom J M; Metz, Johan A J; ten Broek, Clara M A

    2014-08-05

    The mammalian vertebral column is highly variable, reflecting adaptations to a wide range of lifestyles, from burrowing in moles to flying in bats. However, in many taxa, the number of trunk vertebrae is surprisingly constant. We argue that this constancy results from strong selection against initial changes of these numbers in fast running and agile mammals, whereas such selection is weak in slower-running, sturdier mammals. The rationale is that changes of the number of trunk vertebrae require homeotic transformations from trunk into sacral vertebrae, or vice versa, and mutations toward such transformations generally produce transitional lumbosacral vertebrae that are incompletely fused to the sacrum. We hypothesize that such incomplete homeotic transformations impair flexibility of the lumbosacral joint and thereby threaten survival in species that depend on axial mobility for speed and agility. Such transformations will only marginally affect performance in slow, sturdy species, so that sufficient individuals with transitional vertebrae survive to allow eventual evolutionary changes of trunk vertebral numbers. We present data on fast and slow carnivores and artiodactyls and on slow afrotherians and monotremes that strongly support this hypothesis. The conclusion is that the selective constraints on the count of trunk vertebrae stem from a combination of developmental and biomechanical constraints.

  10. [Current views on vision of mammals].

    Science.gov (United States)

    Khokhlova, T V

    2012-01-01

    In the review, research data are presented on mammals' vision including visual pigments, color and contrast vision, and visual behaviour in different species. It is shown that in course of evolution mammals were gradually losing the elements of daylight cone vision system that are typical of other vertebrates. In monotremes, visual pigments SWS2 (cone blue-sensitive 2) and MWS/LWS (green/red-sensitive) are still present, as well as rod RH1. Theria, except some primates, also have two cone visual pigments: SWS1 (ultraviolet/violet or blue-sensitive 1) and MWS/LWS along with rod RH1. Humans and some other higher primates evolved the new visual pigment, MWS, and acquired trichromatic vision. Marine mammals (cetaceans and pinnipeds) and some species of other orders have lost also the visual pigment SWS1, probably due to specificity of processing the information received by these cones. Current view on mammals' vision with two cone pigments and rods is presented. Data on maximum spectral sensitivity of visual pigments in different species and orders are given along with data on spatial contrast sensation. High visual acuity has been acquired by ungulates, artiodactyls, and primates, while the highest one--by humans with their specialized fovea.

  11. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    ZHANG YiJun; QU LiangHu

    2009-01-01

    Genomic imprinting, representing parent-specific expression of alleles at a locus, Is mainly evident in flowering plants and placental mammals. Most imprinted genes, including numerous non-coding RNAs, are located in clusters regulated by imprinting control regions (ICRs). The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions. Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors, especially recent studies undertaken on the most ancient mammalian clades - the marsupials and monotremes from which model species genomes have recently been sequenced, are of high value. By reviewing and analyzing these studies, a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated. The evidence comes from two observations accompanied with the ac-quisition of the imprinting: (i) many novel non-coding RNA genes emerged in imprinted regions; (ii) the expressions of some conserved non-coding RNAs have changed dramatically. Furthermore, a system-atical analysis of imprinted snoRNA (small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials, followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals. Involved in the regulation of imprinted silencing and mediating the ohromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  12. Microsatellite landscape evolutionary dynamics across 450 million years of vertebrate genome evolution.

    Science.gov (United States)

    Adams, Richard H; Blackmon, Heath; Reyes-Velasco, Jacobo; Schield, Drew R; Card, Daren C; Andrew, Audra L; Waynewood, Nyimah; Castoe, Todd A

    2016-05-01

    The evolutionary dynamics of simple sequence repeats (SSRs or microsatellites) across the vertebrate tree of life remain largely undocumented and poorly understood. In this study, we analyzed patterns of genomic microsatellite abundance and evolution across 71 vertebrate genomes. The highest abundances of microsatellites exist in the genomes of ray-finned fishes, squamate reptiles, and mammals, while crocodilian, turtle, and avian genomes exhibit reduced microsatellite landscapes. We used comparative methods to infer evolutionary rates of change in microsatellite abundance across vertebrates and to highlight particular lineages that have experienced unusually high or low rates of change in genomic microsatellite abundance. Overall, most variation in microsatellite content, abundance, and evolutionary rate is observed among major lineages of reptiles, yet we found that several deeply divergent clades (i.e., squamate reptiles and mammals) contained relatively similar genomic microsatellite compositions. Archosauromorph reptiles (turtles, crocodilians, and birds) exhibit reduced genomic microsatellite content and the slowest rates of microsatellite evolution, in contrast to squamate reptile genomes that have among the highest rates of microsatellite evolution. Substantial branch-specific shifts in SSR content in primates, monotremes, rodents, snakes, and fish are also evident. Collectively, our results support multiple major shifts in microsatellite genomic landscapes among vertebrates.

  13. Mast cells are present in the choroid of the normal eye in most vertebrate classes.

    Science.gov (United States)

    McMenamin, Paul Gerard; Polla, Emily

    2013-07-01

    Mast cells are bone marrow-derived tissue-homing leukocytes, which have traditionally been regarded as effector cells in allergic disorders, responses against parasites, and regulation of blood flow, but a broader perspective of their functional heterogeneity, such as immunomodulation, angiogenesis, tissue repair, and remodeling after injury, is now emerging. The persistence of mast cells in connective tissues throughout the evolution of vertebrates is evidence of strong selective pressure suggesting that these cells must have multiple beneficial and important roles in normal homeostasis. While mast cells are present within the uveal tract of eutherian mammals, there is little known about their presence in the choroid of other vertebrate classes. Eye tissues from a range of vertebrate species (fish, amphibian, reptiles, birds, marsupials, monotreme, and eutherian mammals) were investigated. Tissues were fixed in either 2% glutaraldehyde, 2% paraformaldehyde or a mixture of both and processed for resin embedding. Semi-thin sections of the retina and choroid were cut and stained with toluidine blue. Mast cells were identified in the choroid of all classes of vertebrates investigated except sharks. Their morphology, location, and staining characteristics were remarkably similar from teleost fish through to eutherian mammals and bore close morphological resemblance to mammalian connective tissue mast cells. The similar morphology and distribution of mast cells in the choroid of all vertebrate classes studied suggest a basic physiological function that has been retained since the evolution of the vertebrate eye. © 2013 American College of Veterinary Ophthalmologists.

  14. Recurrent gene loss correlates with the evolution of stomach phenotypes in gnathostome history.

    Science.gov (United States)

    Castro, L Filipe C; Gonçalves, Odete; Mazan, Sylvie; Tay, Boon-Hui; Venkatesh, Byrappa; Wilson, Jonathan M

    2014-01-22

    The stomach, a hallmark of gnathostome evolution, represents a unique anatomical innovation characterized by the presence of acid- and pepsin-secreting glands. However, the occurrence of these glands in gnathostome species is not universal; in the nineteenth century the French zoologist Cuvier first noted that some teleosts lacked a stomach. Strikingly, Holocephali (chimaeras), dipnoids (lungfish) and monotremes (egg-laying mammals) also lack acid secretion and a gastric cellular phenotype. Here, we test the hypothesis that loss of the gastric phenotype is correlated with the loss of key gastric genes. We investigated species from all the main gnathostome lineages and show the specific contribution of gene loss to the widespread distribution of the agastric condition. We establish that the stomach loss correlates with the persistent and complete absence of the gastric function gene kit--H(+)/K(+)-ATPase (Atp4A and Atp4B) and pepsinogens (Pga, Pgc, Cym)--in the analysed species. We also find that in gastric species the pepsinogen gene complement varies significantly (e.g. two to four in teleosts and tens in some mammals) with multiple events of pseudogenization identified in various lineages. We propose that relaxation of purifying selection in pepsinogen genes and possibly proton pump genes in response to dietary changes led to the numerous independent events of stomach loss in gnathostome history. Significantly, the absence of the gastric genes predicts that reinvention of the stomach in agastric lineages would be highly improbable, in line with Dollo's principle.

  15. Evolution and the neurosciences down-under.

    Science.gov (United States)

    Macmillan, Malcolm

    2009-01-01

    At the end of the nineteenth and the beginning of the twentieth century three Australians made notable contributions to founding the neurosciences: Alfred Walter Campbell (1868-1937) conducted the first extensive histological studies of the human brain; Grafton Elliot Smith (1871-1937) studied the monotreme brain and established the basis for understanding the mammalian brain; and Stanley David Porteus (1883-1972) extended his studies of intellectual disability to encompass the relation between brain size and intelligence. The work of each was decisively influenced by important members of the Edinburgh medical school or by Edinburgh medical graduates: William Turner (1832-1916) and William Rutherford (1839-1899) Professors of Anatomy and Physiology respectively at Edinburgh; James Thomas Wilson (1861-1945) Professor of Anatomy at the University of Sydney; and Richard James Arthur Berry (1867-1962) Professor of Anatomy at the University of Melbourne. An important aspect of the influence on the Australians was a materialist view of brain function but the work of all was most important for a theory even more central held by the Scots who had influenced them: Darwin's theory of evolution. The importance of the work of Campbell and especially that of Smith for Darwinism is contrasted with Darwin's own indifference to the peculiarities of the Australian fauna he observed when he visited Australia during HMS Beagle's voyage of discovery in 1836.

  16. Pattern of the divergence of olfactory receptor genes during tetrapod evolution.

    Directory of Open Access Journals (Sweden)

    Takushi Kishida

    Full Text Available The olfactory receptor (OR multigene family is responsible for the sense of smell in vertebrate species. OR genes are scattered widely in our chromosomes and constitute one of the largest gene families in eutherian genomes. Some previous studies revealed that eutherian OR genes diverged mainly during early mammalian evolution. However, the exact period when, and the ecological reason why eutherian ORs strongly diverged has remained unclear. In this study, I performed a strict data mining effort for marsupial opossum OR sequences and bootstrap analyses to estimate the periods of chromosomal migrations and gene duplications of OR genes during tetrapod evolution. The results indicate that chromosomal migrations occurred mainly during early vertebrate evolution before the monotreme-placental split, and that gene duplications occurred mainly during early mammalian evolution between the bird-mammal split and marsupial-placental split, coinciding with the reduction of opsin genes in primitive mammals. It could be thought that the previous chromosomal dispersal allowed the OR genes to subsequently expand easily, and the nocturnal adaptation of early mammals might have triggered the OR gene expansion.

  17. The nocturnal bottleneck and the evolution of activity patterns in mammals.

    Science.gov (United States)

    Gerkema, Menno P; Davies, Wayne I L; Foster, Russell G; Menaker, Michael; Hut, Roelof A

    2013-08-22

    In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail.

  18. Evolution of V genes from the TRV loci of mammals.

    Science.gov (United States)

    Olivieri, David N; Gambón-Cerdá, Santiago; Gambón-Deza, Francisco

    2015-07-01

    Information concerning the evolution of T lymphocyte receptors (TCR) can be deciphered from that part of the molecule that recognizes antigen presented by major histocompatibility complex (MHC), namely the variable (V) regions. The genes that code for these variable regions are found within the TCR loci. Here, we describe a study of the evolutionary origin of V genes that code for the α and β chains of the TCR loci of mammals. In particular, we demonstrate that most of the 35 TRAV and 25 TRBV conserved genes found in Primates are also found in other Eutheria, while in Marsupials, Monotremes, and Reptiles, these genes diversified in a different manner. We also show that in mammals, all TRAV genes are derived from five ancestral genes, while all TRBV genes originate from four such genes. In Reptiles, the five TRAV and three out of the four TRBV ancestral genes exist, as well as other V genes not found in mammals. We also studied the TRGV and TRDV loci from all mammals, and we show a relationship of the TRDV to the TRAV locus throughout evolutionary time.

  19. Evolution of the mammalian dentate gyrus.

    Science.gov (United States)

    Hevner, Robert F

    2016-02-15

    The dentate gyrus (DG), a part of the hippocampal formation, has important functions in learning, memory, and adult neurogenesis. Compared with homologous areas in sauropsids (birds and reptiles), the mammalian DG is larger and exhibits qualitatively different phenotypes: 1) folded (C- or V-shaped) granule neuron layer, concave toward the hilus and delimited by a hippocampal fissure; 2) nonperiventricular adult neurogenesis; and 3) prolonged ontogeny, involving extensive abventricular (basal) migration and proliferation of neural stem and progenitor cells (NSPCs). Although gaps remain, available data indicate that these DG traits are present in all orders of mammals, including monotremes and marsupials. The exception is Cetacea (whales, dolphins, and porpoises), in which DG size, convolution, and adult neurogenesis have undergone evolutionary regression. Parsimony suggests that increased growth and convolution of the DG arose in stem mammals concurrently with nonperiventricular adult hippocampal neurogenesis and basal migration of NSPCs during development. These traits could all result from an evolutionary change that enhanced radial migration of NSPCs out of the periventricular zones, possibly by epithelial-mesenchymal transition, to colonize and maintain nonperiventricular proliferative niches. In turn, increased NSPC migration and clonal expansion might be a consequence of growth in the cortical hem (medial patterning center), which produces morphogens such as Wnt3a, generates Cajal-Retzius neurons, and is regulated by Lhx2. Finally, correlations between DG convolution and neocortical gyrification (or capacity for gyrification) suggest that enhanced abventricular migration and proliferation of NSPCs played a transformative role in growth and folding of neocortex as well as archicortex.

  20. Insights into the evolution of mammalian telomerase: Platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes

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    Hrdličková Radmila

    2012-06-01

    Full Text Available Abstract Background The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT ortholog, and provide a comparison with genes of other vertebrates. Results The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. Conclusions OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes.

  1. Mechanisms and evolutionary patterns of mammalian and avian dosage compensation.

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    Philippe Julien

    Full Text Available As a result of sex chromosome differentiation from ancestral autosomes, male mammalian cells only contain one X chromosome. It has long been hypothesized that X-linked gene expression levels have become doubled in males to restore the original transcriptional output, and that the resulting X overexpression in females then drove the evolution of X inactivation (XCI. However, this model has never been directly tested and patterns and mechanisms of dosage compensation across different mammals and birds generally remain little understood. Here we trace the evolution of dosage compensation using extensive transcriptome data from males and females representing all major mammalian lineages and birds. Our analyses suggest that the X has become globally upregulated in marsupials, whereas we do not detect a global upregulation of this chromosome in placental mammals. However, we find that a subset of autosomal genes interacting with X-linked genes have become downregulated in placentals upon the emergence of sex chromosomes. Thus, different driving forces may underlie the evolution of XCI and the highly efficient equilibration of X expression levels between the sexes observed for both of these lineages. In the egg-laying monotremes and birds, which have partially homologous sex chromosome systems, partial upregulation of the X (Z in birds evolved but is largely restricted to the heterogametic sex, which provides an explanation for the partially sex-biased X (Z expression and lack of global inactivation mechanisms in these lineages. Our findings suggest that dosage reductions imposed by sex chromosome differentiation events in amniotes were resolved in strikingly different ways.

  2. Anterior commissure versus corpus callosum: A quantitative comparison across mammals.

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    Ashwell, Ken W S

    2016-04-01

    Mammals rely on two major pathways to transfer information between the two hemispheres of the brain: the anterior commissure and the corpus callosum. Metatheria and monotremes rely exclusively on the anterior commissure for interhemispheric transfer between the isocortices and olfactory allocortices of each side, whereas Eutheria use a combination of the anterior commissure and an additional pathway exclusive to Eutheria, the corpus callosum. Midline cross-sectional area of the anterior commissure and corpus callosum were measured in a range of mammals from all three infraclasses and plotted against brain volume to determine how midline anterior commissure area and its size relative to the corpus callosum vary with brain size and taxon. In Metatheria, the square root of anterior commissure area rises in almost direct proportion with the cube root of brain volume (i.e. the ratio of the two is relatively constant), whereas among Eutheria the ratio of the square root of anterior commissure area to the cube root of brain volume declines slightly with increasing brain size. The total of isocortical and olfactory allocortical commissure area rises more rapidly with increasing brain volume among Eutheria than among Metatheria. This means that the midline isocortical and olfactory allocortical commissural area of metatherians with large brains (about 70 ml) is only about 50% of that among eutherians with similarly sized brains. On the other hand, isocortical and olfactory allocortical commissural area is similar in Metatheria and Eutheria at brain volumes around 1 ml. Among the Eutheria, some groups make less use of the anterior commissure pathway than do others: soricomorphs, rodents and cetaceans have smaller anterior commissures for their brain size than do afrosoricids, erinaceomorphs and proboscideans. The findings suggest that use of the anterior commissural route for isocortical commissural connections may have placed limitations on interhemispheric transfer of

  3. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney.

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    Troy Camarata

    Full Text Available New nephron formation (nephrogenesis ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population.

  4. Independent evolution of transcriptional inactivation on sex chromosomes in birds and mammals.

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    Livernois, Alexandra M; Waters, Shafagh A; Deakin, Janine E; Marshall Graves, Jennifer A; Waters, Paul D

    2013-01-01

    X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination). We used RNA-fluorescent in situ hybridization (RNA-FISH) to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains) on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial) silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes.

  5. [Presence in a rodent of Chili of the nematode Inglamidinae (sub. fam. nov.) belonging to Amidostomatidae, a family known to be found in mammals of Australia].

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    Durette-Desset, M C; Denke, M A; Murua, R

    1976-01-01

    The Inglamidinae n. sub-fam., a new sub-family of Amidostomatidae from chilean Cricetidae is described with Inglamidum akodon gen. et sp. n. as the type genus and species. Out of the 23 Akodon captured in the same area, three samples of this nematode have been collected from two different species. These findings confirm that we are dealing with a well-adapted parasite and exclude the possibility of a fortuitous catch or an accidental transfer. This family displays two significant groups of taxonomic characters, including archaic characters such as cephalic structures which unite them to the Amidostomatidae, and on the other hand some more recently elaborated characters such as monodelphism and shape of synlophe and spicules which relate them to the Heligmosoms and more significantly to the line Viannaia-Viannella parasite of South-American Marsupials. We interpret this species as a "parasite of capture" and we assume that very similar species might occur in other endemic Mammals, mostly Marsupials. On a paleobiogeographical point of view this interpretation would make due allowance for postulating that the Amidostomatidae from Mammals have originated during the Secondary concurrently with the Marsupial expansion. These ancestral Nematodes would have given birth to the other Trichostrongyloidea through reduction of buccal cavity, and to the Ancylostomatoidea by further elaboration of buccal apparatus. Contrary to Inglis's hypothesis we are in favour of the genera Globocephaloides and Hypodontus to be assigned to the Globocephalinae and Uncinariinae (Ancylostomatidae) respectively, rather than to the Amidostomatidae. The occurrence of an Amidostomatidae in a South American Cricetidae is somewhat quite unexpected, mostly because this family is known to occur from australian Mammals only and also because the parasited Mammals are the most primitive of the group (Monotremes and Marsupials).

  6. Chromosomal gene movements reflect the recent origin and biology of therian sex chromosomes.

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    Lukasz Potrzebowski

    2008-04-01

    Full Text Available Mammalian sex chromosomes stem from ancestral autosomes and have substantially differentiated. It was shown that X-linked genes have generated duplicate intronless gene copies (retrogenes on autosomes due to this differentiation. However, the precise driving forces for this out-of-X gene "movement" and its evolutionary onset are not known. Based on expression analyses of male germ-cell populations, we here substantiate and extend the hypothesis that autosomal retrogenes functionally compensate for the silencing of their X-linked housekeeping parental genes during, but also after, male meiotic sex chromosome inactivation (MSCI. Thus, sexually antagonistic forces have not played a major role for the selective fixation of X-derived gene copies in mammals. Our dating analyses reveal that although retrogenes were produced ever since the common mammalian ancestor, selectively driven retrogene export from the X only started later, on the placental mammal (eutherian and marsupial (metatherian lineages, respectively. Together, these observations suggest that chromosome-wide MSCI emerged close to the eutherian-marsupial split approximately 180 million years ago. Given that MSCI probably reflects the spread of the recombination barrier between the X and Y, crucial for their differentiation, our data imply that these chromosomes became more widely differentiated only late in the therian ancestor, well after the divergence of the monotreme lineage. Thus, our study also provides strong independent support for the recent notion that our sex chromosomes emerged, not in the common ancestor of all mammals, but rather in the therian ancestor, and therefore are much younger than previously thought.

  7. Design and implementation of degenerate microsatellite primers for the mammalian clade.

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    Emmanuel Buschiazzo

    Full Text Available Microsatellites are popular genetic markers in molecular ecology, genetic mapping and forensics. Unfortunately, despite recent advances, the isolation of de novo polymorphic microsatellite loci often requires expensive and intensive groundwork. Primers developed for a focal species are commonly tested in a related, non-focal species of interest for the amplification of orthologous polymorphic loci; when successful, this approach significantly reduces cost and time of microsatellite development. However, transferability of polymorphic microsatellite loci decreases rapidly with increasing evolutionary distance, and this approach has shown its limits. Whole genome sequences represent an under-exploited resource to develop cross-species primers for microsatellites. Here we describe a three-step method that combines a novel in silico pipeline that we use to (1 identify conserved microsatellite loci from a multiple genome alignments, (2 design degenerate primer pairs, with (3 a simple PCR protocol used to implement these primers across species. Using this approach we developed a set of primers for the mammalian clade. We found 126,306 human microsatellites conserved in mammalian aligned sequences, and isolated 5,596 loci using criteria based on wide conservation. From a random subset of ~1000 dinucleotide repeats, we designed degenerate primer pairs for 19 loci, of which five produced polymorphic fragments in up to 18 mammalian species, including the distinctly related marsupials and monotremes, groups that diverged from other mammals 120-160 million years ago. Using our method, many more cross-clade microsatellite loci can be harvested from the currently available genomic data, and this ability is set to improve exponentially as further genomes are sequenced.

  8. On the haptic nature of the active electric sense of fish.

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    Caputi, Angel A; Aguilera, Pedro A; Carolina Pereira, Ana; Rodríguez-Cattáneo, Alejo

    2013-11-06

    Electroreception is a sensory modality present in chondrichthyes, actinopterygii, amphibians, and mammalian monotremes. The study of this non-intuitive sensory modality has provided insights for better understanding of sensory systems in general and inspired the development of innovative artificial devices. Here we review evidence obtained from the analysis of electrosensory images, neurophysiological data from the recording of unitary activity in the electrosensory lobe, and psychophysical data from analysis of novelty responses provoked in well-defined stimulus conditions, which all confirm that active electroreception has a short range, and that the influence of exploratory movements on object identification is strong. In active electric images two components can be identified: a "global" image profile depending on the volume, shape and global impedance of an object and a "texture" component depending on its surface attributes. There is a short range of the active electric sense and the progressive "blurring" of object image with distance. Consequently, the lack of precision regarding object location, considered together, challenge the current view of this sense as serving long range electrolocation and the commonly used metaphor of "electric vision". In fact, the active electric sense shares more commonalities with human active touch than with teleceptive senses as vision or audition. Taking into account that other skin exteroceptors and proprioception may be congruently stimulated during fish exploratory movements we propose that electric, mechanoceptive and proprioceptive sensory modalities found in electric fish could be considered together as a single haptic sensory system. This article is part of a Special Issue entitled Neural Coding 2012. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Independent evolution of transcriptional inactivation on sex chromosomes in birds and mammals.

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    Alexandra M Livernois

    Full Text Available X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination. We used RNA-fluorescent in situ hybridization (RNA-FISH to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes.

  10. A cross-species comparison of escape from X inactivation in Eutheria: implications for evolution of X chromosome inactivation.

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    Al Nadaf, Shafagh; Deakin, Janine E; Gilbert, Clément; Robinson, Terence J; Graves, Jennifer A M; Waters, Paul D

    2012-02-01

    Sex chromosome dosage compensation in both eutherian and marsupial mammals is achieved by X chromosome inactivation (XCI)--transcriptional repression that silences one of the two X chromosomes in the somatic cells of females. We recently used RNA fluorescent in situ hybridization (FISH) to show, in individual nuclei, that marsupial X inactivation (in the absence of XIST) occurs on a gene-by-gene basis, and that escape from inactivation is stochastic and independent of gene location. In the absence of similar data from fibroblast cell lines of eutherian representatives, a meaningful comparison is lacking. We therefore used RNA-FISH to examine XCI in fibroblast cell lines obtained from three distantly related eutherian model species: African savannah elephant (Loxodonta africana), mouse (Mus musculus) and human (Homo sapiens). We show that, unlike the orthologous marsupial X, inactivation of the X conserved region (XCR) in eutherians generally is complete. Two-colour RNA-FISH on female human, mouse and elephant interphase nuclei showed that XCR loci have monoallelic expression in almost all nuclei. However, we found that many loci located in the evolutionarily distinct recently added region (XAR) displayed reproducible locus-specific frequencies of nuclei with either one or two active X alleles. We propose that marsupial XCI retains features of an ancient incomplete silencing mechanism that was augmented by the evolution of the XIST gene that progressively stabilized the eutherian XCR. In contrast, the recently added region of the eutherian X displays an incomplete inactivation profile similar to that observed on the evolutionarily distinct marsupial X and the independently evolved monotreme X chromosomes.

  11. Ancient exaptation of a CORE-SINE retroposon into a highly conserved mammalian neuronal enhancer of the proopiomelanocortin gene.

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    Andrea M Santangelo

    2007-10-01

    Full Text Available The proopiomelanocortin gene (POMC is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5' distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution.

  12. A Polychaete's powerful punch: venom gland transcriptomics of Glycera reveals a complex cocktail of toxin homologs.

    Science.gov (United States)

    von Reumont, Björn M; Campbell, Lahcen I; Richter, Sandy; Hering, Lars; Sykes, Dan; Hetmank, Jörg; Jenner, Ronald A; Bleidorn, Christoph

    2014-09-05

    Glycerids are marine annelids commonly known as bloodworms. Bloodworms have an eversible proboscis adorned with jaws connected to venom glands. Bloodworms prey on invertebrates, and it is known that the venom glands produce compounds that can induce toxic effects in animals. Yet, none of these putative toxins has been characterized on a molecular basis. Here we present the transcriptomic profiles of the venom glands of three species of bloodworm, Glycera dibranchiata, Glycera fallax and Glycera tridactyla, as well as the body tissue of G. tridactyla. The venom glands express a complex mixture of transcripts coding for putative toxin precursors. These transcripts represent 20 known toxin classes that have been convergently recruited into animal venoms, as well as transcripts potentially coding for Glycera-specific toxins. The toxins represent five functional categories: Pore-forming and membrane-disrupting toxins, neurotoxins, protease inhibitors, other enzymes, and CAP domain toxins. Many of the transcripts coding for putative Glycera toxins belong to classes that have been widely recruited into venoms, but some are homologs of toxins previously only known from the venoms of scorpaeniform fish and monotremes (stonustoxin-like toxin), turrid gastropods (turripeptide-like peptides), and sea anemones (gigantoxin I-like neurotoxin). This complex mixture of toxin homologs suggests that bloodworms employ venom while predating on macroscopic prey, casting doubt on the previously widespread opinion that G. dibranchiata is a detritivore. Our results further show that researchers should be aware that different assembly methods, as well as different methods of homology prediction, can influence the transcriptomic profiling of venom glands. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  13. A Polychaete’s Powerful Punch: Venom Gland Transcriptomics of Glycera Reveals a Complex Cocktail of Toxin Homologs

    Science.gov (United States)

    von Reumont, Björn M.; Richter, Sandy; Hering, Lars; Sykes, Dan; Hetmank, Jörg; Jenner, Ronald A.; Bleidorn, Christoph

    2014-01-01

    Glycerids are marine annelids commonly known as bloodworms. Bloodworms have an eversible proboscis adorned with jaws connected to venom glands. Bloodworms prey on invertebrates, and it is known that the venom glands produce compounds that can induce toxic effects in animals. Yet, none of these putative toxins has been characterized on a molecular basis. Here we present the transcriptomic profiles of the venom glands of three species of bloodworm, Glycera dibranchiata, Glycera fallax and Glycera tridactyla, as well as the body tissue of G. tridactyla. The venom glands express a complex mixture of transcripts coding for putative toxin precursors. These transcripts represent 20 known toxin classes that have been convergently recruited into animal venoms, as well as transcripts potentially coding for Glycera-specific toxins. The toxins represent five functional categories: Pore-forming and membrane-disrupting toxins, neurotoxins, protease inhibitors, other enzymes, and CAP domain toxins. Many of the transcripts coding for putative Glycera toxins belong to classes that have been widely recruited into venoms, but some are homologs of toxins previously only known from the venoms of scorpaeniform fish and monotremes (stonustoxin-like toxin), turrid gastropods (turripeptide-like peptides), and sea anemones (gigantoxin I-like neurotoxin). This complex mixture of toxin homologs suggests that bloodworms employ venom while predating on macroscopic prey, casting doubt on the previously widespread opinion that G. dibranchiata is a detritivore. Our results further show that researchers should be aware that different assembly methods, as well as different methods of homology prediction, can influence the transcriptomic profiling of venom glands. PMID:25193302

  14. Losses of functional opsin genes, short-wavelength cone photopigments, and color vision--a significant trend in the evolution of mammalian vision.

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    Jacobs, Gerald H

    2013-03-01

    All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wavelengths. With the exception of a number of primate taxa, the modal pattern for mammals is to have two types of cone photopigment, one drawn from each of the gene families. In recent years, it has been discovered that the SWS1 opsin genes of a widely divergent collection of eutherian mammals have accumulated mutational changes that render them nonfunctional. This alteration reduces the retinal complements of these species to a single cone type, thus rendering ordinary color vision impossible. At present, several dozen species from five mammalian orders have been identified as falling into this category, but the total number of mammalian species that have lost short-wavelength cones in this way is certain to be much larger, perhaps reaching as high as 10% of all species. A number of circumstances that might be used to explain this widespread cone loss can be identified. Among these, the single consistent fact is that the species so affected are nocturnal or, if they are not technically nocturnal, they at least feature retinal organizations that are typically associated with that lifestyle. At the same time, however, there are many nocturnal mammals that retain functional short-wavelength cones. Nocturnality thus appears to set the stage for loss of functional SWS1 opsin genes in mammals, but it cannot be the sole circumstance.

  15. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Genomic imprinting,representing parent-specific expression of alleles at a locus,is mainly evident in flowering plants and placental mammals.Most imprinted genes,including numerous non-coding RNAs,are located in clusters regulated by imprinting control regions(ICRs).The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions.Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors,especially recent studies undertaken on the most ancient mammalian clades-the marsupials and monotremes from which model species genomes have recently been sequenced,are of high value.By reviewing and analyzing these studies,a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated.The evidence comes from two observations accompanied with the acquisition of the imprinting:(i) many novel non-coding RNA genes emerged in imprinted regions;(ii) the expressions of some conserved non-coding RNAs have changed dramatically.Furthermore,a systematical analysis of imprinted snoRNA(small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials,followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals.Involved in the regulation of imprinted silencing and mediating the chromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  16. Phylogeny of whey acidic protein (WAP) four-disulfide core proteins and their role in lower vertebrates and invertebrates.

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    Smith, Valerie J

    2011-10-01

    Proteins containing WAP (whey acidic protein) domains with a characteristic WFDC (WAP four-disulfide core) occur not only in mammals (including marsupials and monotremes) but also in birds, reptiles, amphibians and fish. In addition, they are present in numerous invertebrates, from cnidarians to urochordates. Many of those from non-mammalian groups are poorly understood with respect to function or phylogeny. Those well characterized so far are waprins from snakes, perlwapins from bivalves and crustins from decapod crustaceans. Waprins are venom proteins with a single WAP domain at the C-terminus. They display antimicrobial, rather than proteinase inhibitory, activities. Perlwapins, in contrast, possess three WAP domains at the C-terminus and are expressed in the shell nacre of abalones. They participate in shell formation by inhibiting the growth of calcium crystals in the shell. The crustin group is the largest of all WFDC-containing proteins in invertebrates with the vast majority being highly expressed in the haemocytes. Most have a single WAP domain at the C-terminus. The presence and type of the domains between the signal sequence and the C-terminus WAP domain separate the different crustin types. Most of the Type I and II crustins are antimicrobial towards Gram-positive bacteria, whereas the Type III crustins tend to display protease inhibition. Expression studies show that at least some crustins have other important biological effects, as levels change with physiological stress, wound repair, tissue regeneration or ecdysis. Thus WAP domains are widely distributed and highly conserved, serving in diverse physiological processes (proteinase inhibition, bacterial killing or inhibition of calcium transport).

  17. Epidermal sensory organs of moles, shrew moles, and desmans: a study of the family talpidae with comments on the function and evolution of Eimer's organ.

    Science.gov (United States)

    Catania, K C

    2000-09-01

    The epidermal sensory organs of members of the family Talpidae (moles, shrew-moles, and desmans) were investigated and compared to determine the range of sensory specializations and better understand how they evolved. Small domed mechanosensory organs called 'Eimer's organs' were present on the rhinarium of nearly all species of talpids, but not among the sister group of shrews (Soricidae) or other insectivore families. This suggests that the common ancestor to the talpids possessed Eimer's organs. Two species of moles from the driest habitats did not exhibit Eimer's organs - suggesting that their sensory organs degenerated in response to harsh, abrasive soil conditions. The semi-aquatic desmans uniquely possessed tiny sensory hairs interspersed with their Eimer's organs; these may act to sense water currents. Some species exhibited a subdivided, star-like, rhinarium - resembling an early embryonic stage of the star-nosed mole and providing clues to the evolution of the star. A single genera (Uropsilus) that branched off early in the evolution of the talpids had Eimer's organ-like structures but lacked some typical components. These findings fill a major gap in our knowledge of talpid sensory biology and suggest (1) how Eimer's organs evolved, (2) how the unusual appendages of the star-nosed mole evolved, (3) that the evolution of Eimer's organ is convergent with the mechanosensory push-rod of monotremes. The results also demonstrate the features that distinguish Eimer's organ from similar configurations of sensory receptors in other mammalian skin surfaces. Finally, a mechanism for Eimer's organ function in detecting object and prey specific surface features is proposed.

  18. A second corticotropin-releasing hormone gene (CRH2) is conserved across vertebrate classes and expressed in the hindbrain of a basal neopterygian fish, the spotted gar (Lepisosteus oculatus).

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    Grone, Brian P; Maruska, Karen P

    2015-05-01

    To investigate the origins of the vertebrate stress-response system, we searched sequenced vertebrate genomes for genes resembling corticotropin-releasing hormone (CRH). We found that vertebrate genomes possess, in addition to CRH, another gene that resembles CRH in sequence and syntenic environment. This paralogous gene was previously identified only in the elephant shark (a holocephalan), but we find it also in marsupials, monotremes, lizards, turtles, birds, and fishes. We examined the relationship of this second vertebrate CRH gene, which we name CRH2, to CRH1 (previously known as CRH) and urocortin1/urotensin1 (UCN1/UTS1) in primitive fishes, teleosts, and tetrapods. The paralogs CRH1 and CRH2 likely evolved via duplication of CRH during a whole-genome duplication early in the vertebrate lineage. CRH2 was subsequently lost in both teleost fishes and eutherian mammals but retained in other lineages. To determine where CRH2 is expressed relative to CRH1 and UTS1, we used in situ hybridization on brain tissue from spotted gar (Lepisosteus oculatus), a neopterygian fish closely related to teleosts. In situ hybridization revealed widespread distribution of both crh1 and uts1 in the brain. Expression of crh2 was restricted to the putative secondary gustatory/secondary visceral nucleus, which also expressed calcitonin-related polypeptide alpha (calca), a marker of parabrachial nucleus in mammals. Thus, the evolutionary history of CRH2 includes restricted expression in the brain, sequence changes, and gene loss, likely reflecting release of selective constraints following whole-genome duplication. The discovery of CRH2 opens many new possibilities for understanding the diverse functions of the CRH family of peptides across vertebrates. © 2015 Wiley Periodicals, Inc.

  19. What lies beneath: sub-articular long bone shape scaling in eutherian mammals and saurischian dinosaurs suggests different locomotor adaptations for gigantism.

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    Bonnan, Matthew F; Wilhite, D Ray; Masters, Simon L; Yates, Adam M; Gardner, Christine K; Aguiar, Adam

    2013-01-01

    Eutherian mammals and saurischian dinosaurs both evolved lineages of huge terrestrial herbivores. Although significantly more saurischian dinosaurs were giants than eutherians, the long bones of both taxa scale similarly and suggest that locomotion was dynamically similar. However, articular cartilage is thin in eutherian mammals but thick in saurischian dinosaurs, differences that could have contributed to, or limited, how frequently gigantism evolved. Therefore, we tested the hypothesis that sub-articular bone, which supports the articular cartilage, changes shape in different ways between terrestrial mammals and dinosaurs with increasing size. Our sample consisted of giant mammal and reptile taxa (i.e., elephants, rhinos, sauropods) plus erect and non-erect outgroups with thin and thick articular cartilage. Our results show that eutherian mammal sub-articular shape becomes narrow with well-defined surface features as size increases. In contrast, this region in saurischian dinosaurs expands and remains gently convex with increasing size. Similar trends were observed in non-erect outgroup taxa (monotremes, alligators), showing that the trends we report are posture-independent. These differences support our hypothesis that sub-articular shape scales differently between eutherian mammals and saurischian dinosaurs. Our results show that articular cartilage thickness and sub-articular shape are correlated. In mammals, joints become ever more congruent and thinner with increasing size, whereas archosaur joints remained both congruent and thick, especially in sauropods. We suggest that gigantism occurs less frequently in mammals, in part, because joints composed of thin articular cartilage can only become so congruent before stress cannot be effectively alleviated. In contrast, frequent gigantism in saurischian dinosaurs may be explained, in part, by joints with thick articular cartilage that can deform across large areas with increasing load.

  20. What lies beneath: sub-articular long bone shape scaling in eutherian mammals and saurischian dinosaurs suggests different locomotor adaptations for gigantism.

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    Matthew F Bonnan

    Full Text Available Eutherian mammals and saurischian dinosaurs both evolved lineages of huge terrestrial herbivores. Although significantly more saurischian dinosaurs were giants than eutherians, the long bones of both taxa scale similarly and suggest that locomotion was dynamically similar. However, articular cartilage is thin in eutherian mammals but thick in saurischian dinosaurs, differences that could have contributed to, or limited, how frequently gigantism evolved. Therefore, we tested the hypothesis that sub-articular bone, which supports the articular cartilage, changes shape in different ways between terrestrial mammals and dinosaurs with increasing size. Our sample consisted of giant mammal and reptile taxa (i.e., elephants, rhinos, sauropods plus erect and non-erect outgroups with thin and thick articular cartilage. Our results show that eutherian mammal sub-articular shape becomes narrow with well-defined surface features as size increases. In contrast, this region in saurischian dinosaurs expands and remains gently convex with increasing size. Similar trends were observed in non-erect outgroup taxa (monotremes, alligators, showing that the trends we report are posture-independent. These differences support our hypothesis that sub-articular shape scales differently between eutherian mammals and saurischian dinosaurs. Our results show that articular cartilage thickness and sub-articular shape are correlated. In mammals, joints become ever more congruent and thinner with increasing size, whereas archosaur joints remained both congruent and thick, especially in sauropods. We suggest that gigantism occurs less frequently in mammals, in part, because joints composed of thin articular cartilage can only become so congruent before stress cannot be effectively alleviated. In contrast, frequent gigantism in saurischian dinosaurs may be explained, in part, by joints with thick articular cartilage that can deform across large areas with increasing load.

  1. Comparative aspects of gait, scaling and mechanics in mammals.

    Science.gov (United States)

    Gasc, J P

    2001-12-01

    In phylogenetically based systematics, Mammalia is the nomenclatural term which designates the clade stemming from the most recent common ancestry of monotremes and theria [, Sys. Biol. 43 (1994) 497]. Considering that locomotor performance is a prevalent function to provide the necessary conditions to survive and transmit genes, it may be questioned if the diverse types of locomotion exhibited by extant mammals could have played a role in their evolution, or have only followed it. We may look after the structural and behavioural features which are involved in mammal locomotion compared to other tetrapods and test if they fit with the proposed phylogeny. Several factors may be checked: scaling effect in relation to gravitational constraints; geometrical distribution of masses in the body, and relative mechanical role of the limbs in the production of the external forces necessary to forward motion. Classically, it was thought that the fastest gaits used by terrestrial mammals were based upon a unique kind of limb motion co-ordination, called asymmetrical gaits, which in turn may be thought to be related to a peculiar neuronal wiring. Kinematic analysis brings an insight to this topic. Is the search for an ancestral mammalian locomotor pattern judicious? Notice the small size of many of the first mammals and their probable locomotor plasticity. (relation between grain size of the elements within the substrate and the organism scale). At a small size, the gravitational constraint is less important, and the distinction between terrestrial and arboreal has probably no sense when the limbs are the principal motor elements. There remains the importance of the geometrical distribution of body elements, the proportions of the limbs and of the head-neck complex, the tail merely as an appendix, a set of factors which may have generated the frame of constraints within which diverse locomotor modes have evolved.

  2. A manual collection of Syt, Esyt, Rph3a, Rph3al, Doc2, and Dblc2 genes from 46 metazoan genomes - an open access resource for neuroscience and evolutionary biology

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    Craxton Molly

    2010-01-01

    Full Text Available Abstract Background Synaptotagmin proteins were first identified in nervous tissue, residing in synaptic vesicles. Synaptotagmins were subsequently found to form a large family, some members of which play important roles in calcium triggered exocytic events. These members have been investigated intensively, but other family members are not well understood, making it difficult to grasp the meaning of family membership in functional terms. Further difficulty arises as families are defined quite legitimately in different ways: by common descent or by common possession of distinguishing features. One definition does not necessarily imply the other. The evolutionary range of genome sequences now available, can shed more light on synaptotagmin gene phylogeny and clarify family relationships. The aim of compiling this open access collection of synaptotagmin and synaptotagmin-like sequences, is that its use may lead to greater understanding of the biological function of these proteins in an evolutionary context. Results 46 metazoan genomes were examined and their complement of Syt, Esyt, Rph3a, Rph3al, Doc2 and Dblc2 genes identified. All of the sequences were compared, named, then examined in detail. Esyt genes were formerly named Fam62. The species in this collection are Trichoplax, Nematostella, Capitella, Helobdella, Lottia, Ciona, Strongylocentrotus, Branchiostoma, Ixodes, Daphnia, Acyrthosiphon, Tribolium, Nasonia, Apis, Anopheles, Drosophila, Caenorhabditis, Takifugu, Tetraodon, Gasterosteus, Oryzias, Danio, Xenopus, Anolis, Gallus, Taeniopygia,Ornithorhynchus, Monodelphis, Mus and Homo. All of the data described in this paper is available as additional files. Conclusions Only a subset of synaptotagmin proteins appear able to function as calcium triggers. Syt1, Syt7 and Syt9 are ancient conserved synaptotagmins of this type. Some animals carry extensive repertoires of synaptotagmin genes. Other animals of no less complexity, carry only a small

  3. Origin, evolution, and biological role of miRNA cluster in DLK-DIO3 genomic region in placental mammals.

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    Glazov, Evgeny A; McWilliam, Sean; Barris, Wesley C; Dalrymple, Brian P

    2008-05-01

    MicroRNAs (miRNAs) are a rapidly growing family of small regulatory RNAs modulating gene expression in plants and animals. In animals, most of the miRNAs discovered in early studies were found to be evolutionarily conserved across the whole kingdom. More recent studies, however, have identified many miRNAs that are specific to a particular group of organisms or even a single species. These present a question about evolution of the individual miRNAs and their role in establishing and maintaining lineage-specific functions and characteristics. In this study, we describe a detailed analysis of the miRNA cluster (hereafter mir-379/mir-656 cluster) located within the imprinted DLK-DIO3 region on human chromosome 14. We show that orthologous miRNA clusters are present in all sequenced genomes of the placental (eutherian) mammals but not in the marsupial (metatherian), monotreme (prototherian), or any other vertebrate genomes. We provide evidence that the locus encompassing this cluster emerged in an early eutherian ancestor prior to the radiation of modern placental mammals by tandem duplication of the ancient precursor sequence. The original amplified cluster may have contained in excess of 250 miRNA precursor sequences, most of which now appear to be inactive. Examination of the eutherian genomes showed that the cluster has been maintained in evolution for approximately 100 Myr. Analysis of genes that contain predicted evolutionarily conserved targets for miRNAs from this cluster revealed significant overrepresentation of the Gene Ontology terms associated with biological processes such as neurogenesis, embryonic development, transcriptional regulation, and RNA metabolism. Consistent with these findings, a survey of the miRNA expression data within the cluster demonstrates a strong bias toward brain and placenta samples from adult organisms and some embryonic tissues. Our results suggest that emergence of the mir-379/mir-656 miRNA cluster was one of the factors that

  4. Responses of electroreceptors in the snout of the echidna.

    Science.gov (United States)

    Gregory, J E; Iggo, A; McIntyre, A K; Proske, U

    1989-01-01

    , one of which had a weak electric field across it. The animal learned to detect field strengths down to 1.8 mV cm-1 which corresponded to threshold for the most sensitive receptor measured in a subsequent electro-physiological experiment. It is concluded that the echidna, like the other Australian representative of the monotremes, the platypus, has an electric sense. It remains to be determined what kinds of sources of electric fields the animal encounters in its normal habitat. Images Fig. 7 PMID:2607440

  5. Structure and diversity in mammalian accessory olfactory bulb.

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    Meisami, E; Bhatnagar, K P

    1998-12-15

    The accessory olfactory bulb (AOB) is the first neural integrative center for the olfactory-like vomeronasal sensory system. In this article, we first briefly present an overview of vomeronasal system organization and review the history of the discovery of mammalian AOB. Next, we briefly review the evolution of the vomeronasal system in vertebrates, in particular the reptiles. Following these introductory aspects, the structure of the rodent AOB, as typical of the well-developed mammalian AOB, is presented, detailing laminar organization and cell types as well as aspects of the homology with the main olfactory bulb. Then, the evolutionary origin and diversity of the AOB in mammalian orders and species is discussed, describing structural, phylogenetic, and species-specific variation in the AOB location, shape, and size and morphologic differentiation and development. The AOB is believed to be absent in fishes but present in terrestrial tetrapods including amphibians; among the reptiles AOB is absent in crocodiles, present in turtles, snakes, and some lizards where it may be as large or larger than the main bulb. The AOB is absent in bird and in the aquatic mammals (whales, porpoises, manatees). Among other mammals, AOB is present in the monotremes and marsupials, edentates, and in the majority of the placental mammals like carnivores, herbivores, as well as rodents and lagomorphs. Most bat species do not have an AOB and among those where one is found, it shows marked variation in size and morphologic development. Among insectivores and primates, AOB shows marked variation in occurrence, size, and morphologic development. It is small in shrews and moles, large in hedgehogs and prosimians; AOB continues to persist in New World monkeys but is not found in the adults of the higher primates such as the Old World monkeys, apes, and humans. In many species where AOB is absent in the adult, it often develops in the embryo and fetus but regresses in later stages of

  6. The evolution of milk secretion and its ancient origins.

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    Oftedal, O T

    2012-03-01

    Lactation represents an important element of the life history strategies of all mammals, whether monotreme, marsupial, or eutherian. Milk originated as a glandular skin secretion in synapsids (the lineage ancestral to mammals), perhaps as early as the Pennsylvanian period, that is, approximately 310 million years ago (mya). Early synapsids laid eggs with parchment-like shells intolerant of desiccation and apparently dependent on glandular skin secretions for moisture. Mammary glands probably evolved from apocrine-like glands that combined multiple modes of secretion and developed in association with hair follicles. Comparative analyses of the evolutionary origin of milk constituents support a scenario in which these secretions evolved into a nutrient-rich milk long before mammals arose. A variety of antimicrobial and secretory constituents were co-opted into novel roles related to nutrition of the young. Secretory calcium-binding phosphoproteins may originally have had a role in calcium delivery to eggs; however, by evolving into large, complex casein micelles, they took on an important role in transport of amino acids, calcium and phosphorus. Several proteins involved in immunity, including an ancestral butyrophilin and xanthine oxidoreductase, were incorporated into a novel membrane-bound lipid droplet (the milk fat globule) that became a primary mode of energy transfer. An ancestral c-lysozyme lost its lytic functions in favor of a role as α-lactalbumin, which modifies a galactosyltransferase to recognize glucose as an acceptor, leading to the synthesis of novel milk sugars, of which free oligosaccharides may have predated free lactose. An ancestral lipocalin and an ancestral whey acidic protein four-disulphide core protein apparently lost their original transport and antimicrobial functions when they became the whey proteins β-lactoglobulin and whey acidic protein, which with α-lactalbumin provide limiting sulfur amino acids to the young. By the late

  7. The mammalian PYHIN gene family: Phylogeny, evolution and expression

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    Cridland Jasmyn A

    2012-08-01

    Full Text Available Abstract Background Proteins of the mammalian PYHIN (IFI200/HIN-200 family are involved in defence against infection through recognition of foreign DNA. The family member absent in melanoma 2 (AIM2 binds cytosolic DNA via its HIN domain and initiates inflammasome formation via its pyrin domain. AIM2 lies within a cluster of related genes, many of which are uncharacterised in mouse. To better understand the evolution, orthology and function of these genes, we have documented the range of PYHIN genes present in representative mammalian species, and undertaken phylogenetic and expression analyses. Results No PYHIN genes are evident in non-mammals or monotremes, with a single member found in each of three marsupial genomes. Placental mammals show variable family expansions, from one gene in cow to four in human and 14 in mouse. A single HIN domain appears to have evolved in the common ancestor of marsupials and placental mammals, and duplicated to give rise to three distinct forms (HIN-A, -B and -C in the placental mammal ancestor. Phylogenetic analyses showed that AIM2 HIN-C and pyrin domains clearly diverge from the rest of the family, and it is the only PYHIN protein with orthology across many species. Interestingly, although AIM2 is important in defence against some bacteria and viruses in mice, AIM2 is a pseudogene in cow, sheep, llama, dolphin, dog and elephant. The other 13 mouse genes have arisen by duplication and rearrangement within the lineage, which has allowed some diversification in expression patterns. Conclusions The role of AIM2 in forming the inflammasome is relatively well understood, but molecular interactions of other PYHIN proteins involved in defence against foreign DNA remain to be defined. The non-AIM2 PYHIN protein sequences are very distinct from AIM2, suggesting they vary in effector mechanism in response to foreign DNA, and may bind different DNA structures. The PYHIN family has highly varied gene composition between

  8. Ecotoxicology of Wild Mammals

    Science.gov (United States)

    2001-01-01

    An international group of 32 scientists has critically reviewed the scientific literature on exposure and effects of environmental contaminants in wild mammals. The underlying theme of this text is encompassed by the following four questions: What exactly do we know about environmental contaminants in mammals? What are the commonalities and differences between mammal orders/species in the effects that contaminants have? How and to what degree of accuracy can we predict the adverse effects of environmental contaminants on mammalian wildlife? How significant are contaminant insults compared with other density-independent and -dependent factors such as habitat loss, climatic factors and disease? The book is organized three topical sections including introductory chapters that provide a background on environmental contaminants and the mammalian orders, eight taxonomic chapters discussing all aspects of the exposure to and effects of contaminants in mammalian orders, and four thematic chapters that review and discuss generic issues including biomarkers, prediction and extrapolation of exposure and effects, hazard and risk assessment, and the relative significance of contaminants on mammals compared with other commonly encountered stressors. A final a summary chapter identifies phylogenetic trends, critical data gaps, and overarching research needs. Although the absolute number of toxicological studies in domesticated and wild mammals eclipses that wildlife species, a detailed examination of our knowledge base reveals that information for 'wild' birds is actually greater than that for 'wild' mammals. Of the various mammalian taxa, ecotoxicological data is most noticeably lacking for marsupials and monotremes. In contrast, rodents (comprising 43% of all mammal species) have been studied extensively, despite evidence of their tolerance to some organochlorine compounds, rodenticides, and even radionuclides. Mammalian species at greatest risk of exposure include those that

  9. Fabrication of anisotropic multifunctional colloidal carriers

    Science.gov (United States)

    Jerri, Huda A.

    The field of colloidal assembly has grown tremendously in recent years, although the direct or template-assisted methods used to fabricate complex colloidal constructions from monodisperse micro- and nanoparticles have been generally demonstrated on model materials. In this work, novel core particle syntheses, particle functionalizations and bottom-up assembly techniques are presented to create functional colloidal devices. Using particle lithography, high-information colloidal vectors have been developed and modified with imaging and targeting agents. Localized nanoscale patches have been reliably positioned on microparticles to serve as foundations for further chemical or physical modifications. Site-specific placement of RGD targeting ligands has been achieved in these lithographed patches. Preferential uptake of these targeted vectors by RGD-specific 3T3 fibroblasts was verified using confocal laser scanning microscopy. A transition was made from the functionalization of model imaging core particles to the lithography of colloidal cartridges, in an effort to construct colloidal syringes with specialized, programmable release profiles. A variety of functional, pH-sensitive fluorescent cores were engineered to respond to solution conditions. When triggered, the diverse composite core microparticles and reservoir microcapsules released embedded fluorescent moieties such as dye molecules, and fluorophore-conjugated nanoparticles. The microcapsules, created using layer-by-layer polyelectrolyte deposition on sacrificial templates, were selectively modified with a robust coating. The pH-responsive anisotropic reservoir microcapsules were extremely stable in solution, and exhibited a "Lazarus" functionality of rehydrating to their original state following desiccation. A snapshot of focused-release of core constituents through the lone opening in colloidal monotremes has been obtained by anisotropically-functionalizing degradable cores with barrier shells. Additionally

  10. Evolution of UCP1 Transcriptional Regulatory Elements Across the Mammalian Phylogeny

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    Michael J. Gaudry

    2017-09-01

    Full Text Available Uncoupling protein 1 (UCP1 permits non-shivering thermogenesis (NST when highly expressed in brown adipose tissue (BAT mitochondria. Exclusive to placental mammals, BAT has commonly been regarded to be advantageous for thermoregulation in hibernators, small-bodied species, and the neonates of larger species. While numerous regulatory control motifs associated with UCP1 transcription have been proposed for murid rodents, it remains unclear whether these are conserved across the eutherian mammal phylogeny and hence essential for UCP1 expression. To address this shortcoming, we conducted a broad comparative survey of putative UCP1 transcriptional regulatory elements in 139 mammals (135 eutherians. We find no evidence for presence of a UCP1 enhancer in monotremes and marsupials, supporting the hypothesis that this control region evolved in a stem eutherian ancestor. We additionally reveal that several putative promoter elements (e.g., CRE-4, CCAAT identified in murid rodents are not conserved among BAT-expressing eutherians, and together with the putative regulatory region (PRR and CpG island do not appear to be crucial for UCP1 expression. The specificity and importance of the upTRE, dnTRE, URE1, CRE-2, RARE-2, NBRE, BRE-1, and BRE-2 enhancer elements first described from rats and mice are moreover uncertain as these motifs differ substantially—but generally remain highly conserved—in other BAT-expressing eutherians. Other UCP1 enhancer motifs (CRE-3, PPRE, and RARE-3 as well as the TATA box are also highly conserved in nearly all eutherian lineages with an intact UCP1. While these transcriptional regulatory motifs are generally also maintained in species where this gene is pseudogenized, the loss or degeneration of key basal promoter (e.g., TATA box and enhancer elements in other UCP1-lacking lineages make it unlikely that the enhancer region is pleiotropic (i.e., co-regulates additional genes. Importantly, differential losses of (or mutations

  11. Molecular evolution of the polyamine oxidase gene family in Metazoa

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    Polticelli Fabio

    2012-06-01

    monophyletic clades including, respectively, all the SMOs and APAOs from vertebrates. The two vertebrate monophyletic clades clustered strictly mirroring the organismal phylogeny of fishes, amphibians, reptiles, birds, and mammals. Evidences from comparative genomic analysis, structural evolution and functional divergence in a phylogenetic framework across Metazoa suggested an evolutionary scenario where the ancestor PAO coding sequence, present in invertebrates as an orthologous gene, has been duplicated in the vertebrate branch to originate the paralogous SMO and APAO genes. A further genome evolution event concerns the SMO gene of placental, but not marsupial and monotremate, mammals which increased its functional variation following an alternative splicing (AS mechanism. Conclusions In this study the explicit integration in a phylogenomic framework of phylogenetic tree construction, structure prediction, and biochemical function data/prediction, allowed inferring the molecular evolutionary history of the PAO gene family and to disambiguate paralogous genes related by duplication event (SMO and APAO and orthologous genes related by speciation events (PAOs, SMOs/APAOs. Further, while in vertebrates experimental data corroborate SMO and APAO molecular function predictions, in invertebrates the finding of a supported phylogenetic clusters of insect PAOs and the co-occurrence of two PAO variants in the amphioxus urgently claim the need for future structure-function studies.

  12. Paleobiogeografía y paleoecología de los mamíferos continentales de América del Sur durante el Cretácico tardío-Paleoceno: una revisión

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    Ortiz Jaureguizar, E.

    1996-04-01

    Full Text Available The purpose of this paper is to outline the most recent advances in the knowledge of paleobiogeography and paleoecology of the South American continental mammals during the late Cretaceous-Paleocene span. Two basic parameters were considered: (1 taxonomic richness; and (2 trophic diversity. The genera recorded in the four «land-mammal Ages» (SALMAs that represent the late Cretaceous-Paleocene span, i.e., Alamitian (late Cretaceous, Tiupampian (early Paleocene, Itaboraian (middle Paleocene, and Riochican (late Paleocene, were used as analytical units. As conclusion, is possible to point out that: 1 During the Alamitian SALMA the faunistic composition of South America was markedly different of that of the holarctic continents, due to the exclusive presence of pre-tribosphenic taxa of pangeic jurassic ancestry, although mostly showing a marked degree of endemism. 2 The tiupampian fauna was basically characterized by the absence of most of the alamitian pre-tribosphenic groups (except the gondwanatherian «multituberculates» and by the presence of a «mix» of taxa with narrow relationships with North America (e.g., pantodonts in association with other proper of South America but with holarctic (e.g., marsupial s or eastern gondwanic ancestry (i.e., monotremes. 3 The most marked compositional change in the South American mammal fauna was recorded between the Alamitian and Tiupampian SALMAs. 4 Beginning to the Itaboraian SALMA, the South American mammal fauna newly shows a marked endemic character that will distinguish all the continental mammal faunas throughout the rest of the Cenozoico 5 The absence of xenarthrans in the pre-itaboraian mammal- bearing sediments is particularly surprising. 6 The diversity of trophic types increases from Alamitian to Riochican SALMAs, because of the progressive occupation of the empty adaptive zones after the dinosaurs extinction, and the opening of new ones. 7 The «cast- of the trophic types