| evolution of reptilian placentation: development of extraembryonic membranes of the australian scincid lizards, bassiana duperreyi (oviparous) and pseudemoia entrecasteauxii (viviparous). | a prominent model for the evolution of placentation among reptilia is based on placental structure among species in the eugongylus group of australian lygosomatine skinks. we studied the development of the extraembryonic membranes of an oviparous species, bassiana duperreyi, and a viviparous species, pseudemoia entrecasteauxii, within this taxonomic group. we observed differences in the timing of development of shared features and in the structure of extraembryonic membrane epithelia in the two ... | 1996 | 29852569 |
| comparative genomics of hormonal signaling in the chorioallantoic membrane of oviparous and viviparous amniotes. | in oviparous amniotes (reptiles, birds, and mammals) the chorioallantoic membrane (cam) lines the inside of the egg and acts as the living point of contact between the embryo and the outside world. in livebearing (viviparous) amniotes, communication during embryonic development occurs across placental tissues, which form between the uterine tissue of the mother and the cam of the embryo. in both oviparous and viviparous taxa, the cam is at the interface of the embryo and the external environment ... | 2017 | 27102939 |
| the regulation of uterine proinflammatory gene expression during pregnancy in the live-bearing lizard, pseudemoia entrecasteauxii. | the evolutionary transition from egg-laying to live-bearing in amniote vertebrates (reptiles and mammals) requires the development of a closer association between the maternal and embryonic tissue to facilitate gas and nutrient exchange with the embryo. because the embryo is an allograft to the father and mother, it could be considered foreign by the maternal immune system and thus be immunologically rejected during pregnancy. in eutherian ("placental") mammals, the proinflammatory genes interle ... | 2017 | 28296138 |
| transient receptor potential ion channels control thermoregulatory behaviour in reptiles. | biological functions are governed by thermodynamics, and animals regulate their body temperature to optimise cellular performance and to avoid harmful extremes. the capacity to sense environmental and internal temperatures is a prerequisite for the evolution of thermoregulation. however, the mechanisms that enable ectothermic vertebrates to sense heat remain unknown. the recently discovered thermal characteristics of transient receptor potential ion channels (trp) render these proteins suitable ... | 2007 | 17356692 |
| evidence for placental transfer of lipids during gestation in the viviparous lizard, pseudemoia entrecasteauxii. | during gestation in the viviparous lizard pseudemoia entrecasteauxii, the fetus obtains nutrients from two sources: uptake of yolk components from the retained egg (lecithotrophy) and transfer of nutrients from the maternal circulation via the placenta (placentotrophy). although net placentotrophy in this species is indicated by the observation that the neonate contains 1.7 times more dry matter than the egg, the placental transfer of lipid has not been previously demonstrated. lipid analysis wa ... | 2004 | 15528170 |
| uptake of dextran-fitc by epithelial cells of the chorioallantoic placentome and the omphalopleure of the placentotrophic lizard, pseudemoia entrecasteauxii. | placental nutrient provision has evolved in multiple lineages of squamate reptiles and although possible structural specializations for placentotrophy have been described in a variety of species, neither the pathways nor the mechanisms of placental transfer are known. lizards of the australian genus pseudemoia are placentotrophic and have elaborate placental structures that are thought to enhance nutrient transfer. the chorioallantoic placenta, which occupies the embryonic hemisphere of the egg, ... | 2006 | 16941652 |
| evidence for placental transfer of maternal corticosterone in a viviparous lizard. | in mammals, there is experimental evidence that circulating maternal cortisol is transferred to the embryos across the placenta during gestation. direct effects of this maternal cortisol may allow embryos to display phenotypic plasticity to cope with postnatal environments (i.e., pre-programming). the potential for maternal hormone induced-adaptation may be of considerable evolutionary significance in viviparous animals. however, to date, there is no such direct evidence that circulating materna ... | 2011 | 21664288 |
| do gravid females become selfish? female allocation of energy during gestation. | net energy availability depends on plasma corticosterone concentrations, food availability, and their interaction. limited net energy availability requires energy trade-offs between self-maintenance and reproduction. this is important in matrotrophic viviparous animals because they provide large amounts of energy for embryos, as well as self-maintenance, for the extended period of time during gestation. in addition, gravid females may transmit environmental information to the embryos in order to ... | 2013 | 22494979 |
| uterine epithelial morphology and progesterone receptors in a mifepristone-treated viviparous lizard pseudemoia entrecasteauxii (squamata: scincidae) during gestation. | structural and functional changes to the uterus associated with maintenance of pregnancy are controlled primarily by steroid hormones such as progesterone. we tested the hypothesis that progesterone regulates uterine structural changes during pregnancy in the viviparous skink, pseudemoia entrecasteauxii, by treating pregnant females with the progesterone receptor antagonist mifepristone at different stages of pregnancy. expression and distribution of progesterone receptor was determined using we ... | 2012 | 22532476 |
| a novel pattern of placental leucine transfer during mid to late gestation in a highly placentotrophic viviparous lizard. | placentotrophy is the nourishment of embryos by resources provided via the placenta during gestation. the magnitude and timing of placental nutrient support during pregnancy are important for embryonic growth, especially in highly placentotrophic animals such as mammals. however, no study has yet investigated how placental organic nutrient support may change during pregnancy in highly placentotrophic viviparous reptiles. amino acids are essential nutrients for embryonic growth and leucine is a c ... | 2012 | 22821866 |
| effects of maternal basking and food quantity during gestation provide evidence for the selective advantage of matrotrophy in a viviparous lizard. | the evolution of matrotrophy (i.e., direct supply of nutrients by the mother during gestation) may be associated with high maternal energy availability during gestation. however, we lack knowledge about the selective advantages of matrotrophic viviparity (live-bearing) in reptiles. in reptiles, the interaction between body temperature and food intake affect maternal net energy gain. in the present study, we examined the effects of basking and food availability (2 by 2 factorial design) during ge ... | 2012 | 22848629 |
| no implantation in an extra-uterine pregnancy of a placentotrophic reptile. | placentation is a common feature of live-bearing reptiles and mammals. placentae are variable between species and can be classified by the extent that embryonic tissue breaches (invades) the uterus. non-invasive placentation in eutherians is maternally imposed as extra-uterine embryos of species with epitheliochorial placentation will readily invade non-uterine tissues. this study documents the first observation of an extra-uterine pregnancy in a reptile; pseudemoia entrecasteauxii, which in-ute ... | 2013 | 23522396 |
| placental lipoprotein lipase (lpl) gene expression in a placentotrophic lizard, pseudemoia entrecasteauxii. | viviparity (live birth) relies on a functional placenta, which is formed by cooperating maternal and embryonic tissues. in some viviparous lineages, mothers use this placenta to transport nutrients to feed developing embryos through pregnancy (placentotrophy). the australian lizard, pseudemoia entrecasteauxii, provides approximately 60% of the lipid for embryonic growth and metabolism to embryos across the placenta. lipoprotein lipase (lpl) is an important enzyme in lipid transport in vertebrate ... | 2013 | 23939756 |
| high food abundance permits the evolution of placentotrophy: evidence from a placental lizard, pseudemoia entrecasteauxii. | mechanisms of reproductive allocation are major determinants of fitness because embryos cannot complete development without receiving sufficient nutrition from their parents. the nourishment of offspring via placentas (placentotrophy) has evolved repeatedly in vertebrates, including multiple times in squamate reptiles (lizards and snakes). placentotrophy has been suggested to evolve only if food is sufficiently abundant throughout gestation to allow successful embryogenesis. if scarcity of food ... | 2014 | 25058280 |
| phylogenetic evidence of historic mitochondrial introgression and cryptic diversity in the genus pseudemoia (squamata: scincidae). | the australian scincid genus pseudemoia comprises six morphologically similar species restricted to temperate south-eastern australia. due to the high degree of morphological conservatism, phylogenetic relationships and taxonomic status within the pseudemoia entrecasteauxii complex (comprising the nominal species p. entrecasteauxii, p. cryodroma, and p. pagenstecheri) remains unresolved. to further investigate the phylogenetic relationships and taxonomic status of pseudemoia spp., and to test th ... | 2014 | 25242002 |
| carbonic anhydrase ii is found in the placenta of a viviparous, matrotrophic lizard and likely facilitates embryo-maternal co2 transport. | the evolution of viviparity requires the development of mechanisms that facilitate transport of respiratory gases between mother and developing embryo. of particular importance is maternal excretion of embryonic carbon dioxide (co2 ), which increases as the embryo grows in size during development. the carbonic anhydrases are a family of enzymes that convert co2 to bicarbonate for transport throughout the cardiovascular system and which may also be important for co2 transport from embryo to mothe ... | 2015 | 26055428 |
| allelic expression of mammalian imprinted genes in a matrotrophic lizard, pseudemoia entrecasteauxii. | genomic imprinting is a process that results in the differential expression of genes depending on their parent of origin. it occurs in both plants and live-bearing mammals, with imprinted genes typically regulating the ability of an embryo to manipulate the maternal provision of nutrients. genomic imprinting increases the potential for selection to act separately on paternally and maternally expressed genes, which increases the number of opportunities that selection can facilitate embryonic cont ... | 2016 | 26943808 |
| reptile pregnancy is underpinned by complex changes in uterine gene expression: a comparative analysis of the uterine transcriptome in viviparous and oviparous lizards. | the evolution of new organs is difficult to study because most vertebrate organs evolved only once, more than 500 million years ago. an ideal model for understanding complex organ evolution is the placenta, a structure that is present in live bearing reptiles and mammals (amniotes), which has evolved independently more than 115 times. using transcriptomics, we characterized the uterine gene expression patterns through the reproductive cycle of a viviparous skink lizard, pseudemoia entrecasteauxi ... | 2016 | 27635053 |
| cyto-epitheliochorial placenta of the viviparous lizard pseudemoia entrecasteauxii: a new placental morphotype. | the structural features of the uterine epithelium of the chorioallantoic placenta and omphalloplacenta in the viviparous australian skink, pseudemoia entrecasteauxii, were investigated using sem and tem techniques. in particular, the structural characteristics that would allow interpretation of function were analyzed, particularly those of gas exchange in the chorioallantoic placenta and histotrophy in the omphaloplacenta. pseudemoia entrecasteauxii has a complex placenta consisting of a placent ... | 2005 | 15803489 |
| a comparison of uterine contractile responsiveness to arginine vasopressin in oviparous and viviparous lizards. | nonapeptides and their receptors regulate a diverse range of physiological processes. we assessed the contractile responsiveness of uteri from the squamate viviparous-oviparous species pair, pseudemoia entrecasteauxii and lampropholis guichenoti, as well as the bimodally reproductive species, saiphos equalis, to arginine vasopressin (avp). we assessed the resulting uterine contractility as a function of pregnancy status, species and parity mode. we also measured mrna abundance for the nonapeptid ... | 2020 | 31858229 |
| corrigenda: the regulation of uterine proinflammatory gene expression during pregnancy in the live-bearing lizard, pseudemoia entrecasteauxii. | | 2017 | 28815920 |