how do viviparity and the placenta affect mammalian reproduction?

Longmans, London, pp 127311, Bell AW, Ehrhardt RA (2002) Regulation of placental nutrient transport and implications for fetal growth. As the demands of the fetus increase, they will likely conflict with the ability of the mother to provide such resources. Kwan L, Fris M, Rodd FH, Rowe L, Tuhela L, Panhuis TM. 2005), possibly allowing both mutations to become fixed and the placenta to adapt to the constraints of a changing environment. Malassine A, Blaise S, Handschuh K, Lalucque H, Dupressoir A, Evain-Brion D, Heidmann T. Expression of the fusogenic HERV-FRD Env glycoprotein (syncytin 2) in human placenta is restricted to villous cytotrophoblastic cells. Your health care provider will examine the placenta to make sure it's intact. Facts You Should Know: The Human Body Quiz, https://www.britannica.com/science/viviparity, National Center for Biotechnology Information - PubMed Central - The Evolution of Viviparity. It is a specialized organ whose purpose is to provide continuing support to the developing young, through the provision of water, nutrients, and gasses, and to regulate maternal-fetal interactions often through hormone production. 2014). More than an insulator: multiple roles of CTCF at the H19-Igf2 imprinted domain. information is beneficial, we may combine your email and website usage information with Global assessment of imprinted gene expression in the bovine conceptus by next generation sequencing. Thomas JW. The co-existence of three matrilineal generations as one (mother . Viviparity is believed to be a mode of reproduction that evolved from the ancestral condition of oviparity or egg laying, where most of the fetal development occurs outside the body. The monotremes branched early from other mammals and do not have the teats seen in most mammals, but they do have mammary glands. The presence of a micro-RNA (Mir675) embedded in the first exon of paternal H19, and expressed exclusively in the placenta, has recently been identified (Keniry et al., 2012). Widespread monoallelic expression on human autosomes. Freyer C, Zeller U, Renfree MB. Placental mammals produce small numbers of large offspring. Food deprivation also produces a significant decrease of Peg3 expression in the placenta with consequences similar to many of the placental gene changes induced by the Peg3 mutation. Nutr Res Rev 15(2):211230 Cross JC, Baczyk D, Dobric N, Hemberger M, Hughes M, Simmons DG, Yamamoto H, Kingdom JC. To obtain Science 309: 22022204. Immunology of placentation in eutherian mammals. Author E B Keverne 1 Affiliation 1 Sub-Department of Animal Behaviour, University of Cambridge, Cambridge, UK. 2013) are expressed in the placenta, but roles for most are even more obscure than that of ERVFRD-1. It is a phenomenon whereby developing embryos are retained within the reproductive tract, leading to release of live offspring as an alternative to the more fecund egg laying or spawning. include protected health information. Morrison JT, Bantilan NS, Wang VN, Nellett KM, Cruz YP. 2014). Internal fertilization has the advantage of protecting the fertilized egg from dehydration on land. There are also indications that early lineage specification may be controlled by a similar set of transcription factors as in eutherians (Familari, et al. A second force driving placental evolution is undoubtedly avoidance of immune rejection (Hemberger 2013), a process still little understood, although speculation abounds. Inactivation of the imprinted Peg3 genes both suppresses many downstream co-expressed genes, desynchronises placental and hypothalamic expression of others, and disrupts co-ordinated function of mother and foetus. Two syncytin genes (Syna & Synb), products of separate integration events, are expressed in this tissue. Wallace RM, Pohler KG, Smith MF, Green JA. Placental abruption occurs when the placenta separates from the inner wall of the uterus before birth. H19 may have tumour-suppressor activity when combined with Igf2, whereas Peg10 encodes a protein with homologies to retrotransposons. The Evolution, Regulation, and Function of Placenta-Specific Genes. Unauthorized use of these marks is strictly prohibited. (2005). A placenta, as defined originally by Mossman, is the apposition or fusion of the fetal membranes to the uterine mucosa for physiological exchange (Burton and Jauniaux 2015). 2006). Elsevier; 2020. https://www.clinicalkey.com. Accessibility Genes, development and evolution of the placenta. The diagrams are based on Fig. Instead, the majority has arisen as a result of independent integration events and coopted for similar functions by different species. Placenta previa. As trophoblast cells, which subsequently divide to form the placenta, take their origin from the zygote before activation of the paternal genome, it is possible that the early trophoblast cell line is closely related to the maternal haplotype at implantation. (2009). In: Parkes A, editor. pp 148163. Stewart JR. Placental specializations in lecithotrophic viviparous squamate reptiles. Lockwood CJ, et al. The evolution of functionally novel proteins after gene duplication. Multiple levels of control for expression of paternal Igf2 thus involve the maternal genome. Structure Placental mammals, including humans, have a chorioallantoic placenta that forms from the chorion and allantois. Instead we have attempted to direct the reader to scholarly articles that do list the primary source material. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). The Gene of Retroviral Origin Syncytin 1 is Specific to Hominoids and is Inactive in Old World Monkeys. Indeed, the male brain is capable of maternalism in monogamous mammals and castration at birth enables the paternal care for offspring in many mammalian species (Lonstein et al., 2002). The co-existence of three matrilineal generations as one (mother, foetus and post-meiotic oocytes) has provided a maternal niche for transgenerational co-adaptive selection pressures to operate. Such changes in gene expression brought about by food deprivation are consistent with the foetal genome maintaining hypothalamic development at a cost to its placenta. The resultant yolkless zygote survived because 1) the mutation also affected a network of homeiotic genes controlling the ontogeny of the entire reproductive system and 2) the system contained enough hidden properties for the mutation to change the character of the oocyte, its granulosa cells and corpus luteum, the zygote, and the uterus in a wa. (2004). Gerstein MB, Kundaje A, Hariharan M, Landt SG, Yan K-K, Cheng C et al. H19 ICR itself contains an evolutionary conserved silencer element that functions autonomously even when inserted into Drosophila (Lyko et al., 1997). Friess AE, Sinowatz F, Skolek-Winnisch R, Trautner W. The placenta of the pig. For example, placentas come in a range of shapes and sizes and have been placed into groups based on the general gross morphologies of the sites where the chorion attaches to the endometrium (Fig. Of conflict, co-option, and cryptic choice. You may opt-out of email communications at any time by clicking on Repair of double-strand breaks is executed by non-homologous end joining during homologous recombination. Pask AJ, Papenfuss AT, Ager EL, MColl KA, Speed TP, Renfree MB . An imprinted element from the mouse H19 locus functions as a silencer in Drosophila. Overall, where placentation occurs in squamates, it bears a superficial resemblance to the epitheliochorial placentation encountered in some eutherian mammals and carries out many of the same functions, but its formation does not involve the formation of a trophoblast lineage, a feature unique to placental mammals. Disruption of maternal DNA repair increases sperm-derived chromosomal aberrations. Syncytin is a captive retroviral envelope protein involved in human placental morphogenesis. Heredity (Edinb) 113: 96103. Bazer FW, Spencer TE, Ott TL. Managing mom's health concerns. Google Scholar. In squamates the placenta is chorioallantoic, but unlike in mammals, does not develop from an early arising, extraembryonic, trophoblast layer. Depletion of NK cells in the mouse decidua result in abnormal implantation and inadequate modelling of spiral arteries that are essential for the development of normal pregnancy. Headaches during pregnancy: What's the best treatment? With the wealth of knowledge now available for the molecular genetic control of genomic imprinting and the phenotypes this represents, I now feel these theories can be viewed with a more critical eye. Renfree MB, Hore TA, Shaw G, Marshall-Graves JA, Pask AJ . 2003) that appear to have an entirely placental function in the sense that they have not been implicated in developmental events outside the trophoblast lineage. Science 329: 682685. Sumida N, Ohlsson R . In the case of the African skink T. ivensi, there is even a degree of invasive implantation, with direct contact between chorionic projections and maternal capillary endothelium (Blackburn and Flemming 2012). Following ovulation, secretory cells of the vascularized pouch enlarge. Although builds of the bovine genome have suggested the IFNT to be a relatively small gene family (Walker and Roberts 2009), large numbers of gene variants have been described in each species and even within single conceptuses, suggesting that the families continue to diverge rapidly. Accessed Feb. 6, 2020. PubMed Review: toward an integrated evolutionary understanding of the mammalian placenta. Journal of Zoological Systematics and Evolutionary Research. Among the likely advantages of a non-invasive placenta over the more primitive hemochorial and endotheliochorial types include reduced exposure to the potential threats of the maternal immune system, less damage to the uterus associated with birth and elimination of the placenta, and minimizing the transmission of fetal cells into the maternal blood circulation and vice versa. (1992). Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. Finally, endogenous retroviruses, with no obvious homology to each other, have been described in the placentas of a number of other species, including marsupials, ruminants, carnivores, and lagomorphs (Denner 2016). BMC Genomics 6: 111. Accessed June 6, 2020. If you have a C-section, your health care provider will remove the placenta from your uterus during the procedure. The Journal of Perinatal and Neonatal Nursing. An extensive literature has developed around this topic, with particular emphasis on the role played by imprinted genes in controlling nutrient supply and growth of the fetus (Reik, et al. Molecular evolution of imprinted genes: no evidence for antagonistic coevolution. Evolution of Oviductal Gestation in Amphibians. These same placental hormones induce nest building in advance of birth and also prime the hypothalamus for post-partum maternal care and milk letdown (Figure 1). Reproduction 136: 523531. Although exposed to the maternal immune system, this foeto-placental interface does not express leucocyte T-cell antigens. In Poeciliopsis fish, eggs are retained within the follicle after fertilization and throughout embryonic development (Wourms and Lombardi 1992). In: Parkes AS (ed) Marshalls physiology of reproduction, vol 2, 3rd edn. In: Encyclopedia of reproduction. The story of vertebrate placentation, therefore, is one of convergent evolution at both the macro- and molecular levels. Capillaries on the maternal and fetal sides come within a few microns of each other (Fig. In the elasmobranchs, two placental types are observed. Evolution of genomic imprinting as a coordinator of coadapted gene expression. Landon MB, et al., eds. CTCF-binding sites within the H19 ICR differentially regulate local chromatin structures and cis-acting functions. In eutherian mammals, H19 also undergoes DNA methylation on the paternal allele. 2004). Nor is the more superficial form of placenta evolutionarily more ancient than the kinds that are invasive and make direct contact with maternal blood. This content does not have an English version. Pink CJ, Hurst LD . H19 is a non-coding construct from the Igf2 genetic locus, which gave rise to the conflict theory (Haig, 1992). - Brainly.com 04/06/2023 Biology High School answered expert verified How do viviparity and the placenta affect mammalian reproduction? Mechanisms of activation of the paternally expressed genes by the Prader-Willi imprinting center in the Prader-Will/Angelman syndrome domains. Weiss RA. The convergent actions of Peg3 in mother and foetus illustrate its functional co-adaption for the hypothalamus and placenta. In addition to functional co-adaptation between the foetal placenta and maternal immune system, there is also functional co-adaptation across the placenta and developing brain, most notably the developing hypothalamus. (2007). In reproductively mature female mammals, an interaction of hormones from the pituitary gland and the ovaries produces a phenomenon known as the estrous cycle. During pregnancy, possible placental problems include placental abruption, placenta previa and placenta accreta. (2013). All rights reserved. Rabinovitz S, Kaufman Y, Ludwig G, Razin A, Shemer R . Hypoxia-activated genes from early placenta are elevated in preeclampsia, but not in intra-uterine growth retardation. BMC Genomics 11: 649. It is also possible that the hypomethylated state of the placental genome (Chuong 2013) has permitted relaxed silencing of gene control elements, including those of ERVs. Keverne EB . Epigenetics 7: 361369. In addition to the networks across and between imprinted genes, each imprinted gene may itself regulate a network of downstream genes engaged in specific functions. In general, assigning function of individual members within a family will be difficult. 2011) and for placental production of steroid hormones (Painter and Moore 2005). Fowden AL, Constancia M. Maternal-fetal resource allocation. 2014). In the ruminants they are mainly associated with trophoblast binucleate cells that fuse with uterine epithelial cells, but are assumed in all these species to play somewhat similar roles to syncytins in the human placenta. This process involves the interaction of ERVW-1 with a receptor, most probably the neutral amino acid transporter, SLC5A1, on a neighboring cell. Placentas deal with nutrient and oxygen import, dispose of fetal waste products and gases, help physically retain the conceptus in the reproductive tract, commandeer the local maternal blood supply in some manner, release factors, including metabolic hormones to adjust the needs of the fetus to the resources provided by the mother, and provide immune protection. Correspondence to 1997, Roberts, et al. The IFNT proteins are secreted from mononucleated trophoblasts and act on the uterus by binding to type I interferon receptors, with the period of release occurring before the trophoblast has formed definite attachment to the uterine epithelium (Bazer, et al. We close the review by discussing mechanisms that might have favored diversity and hence evolution of the morphology and physiology of the placentas of eutherian mammals. Some 13 genes have been reported as specifically expressed in the mouse placenta all of which are maternally expressed (Hudson et al., 2010). However, viviparity and placental growth call for higher energy and resources from the mother, which can pose a possible trade-off in terms of her own survival and breeding success. However, the evolutionary significance of its imprinting is underpinned by its ability to regulate those large gene families (Prls, Psgs and ceacams), which have themselves undergone multiple duplications that are differentially represented across different mammalian species (Wildman, 2011). Genomic imprinting has not been found in the non-placental monotremes, although genes expressed in monotremes became imprinted in marsupials. Many of the genes that regulate placental development also regulate the developing hypothalamus under the coordinated expression of genes that are imprinted (E12-15, mouse). In addition to providing resources from mother over lengthy pregnancies, the placenta has to hormonally prime the mothers hypothalamus to ensure maternal care and provision of milk. (2014). Characterization of the bovine type I IFN locus: rearrangements, expansions, and novel subfamilies. In an era where the genomes of many vertebrate species are becoming available, studies are now exploring the molecular basis of this transition from oviparity to viviparity, and in some rare instances its possible reversibility, such as the Australian three-toed skink (Saiphos equalis). Mammals are different from other vertebrates in that their fertilized eggs are able to create a placenta during embryogenesis [Citation 18-20]. Mammalian viviparity emerged in the period when the atmospheric oxygen concentration was the lowest (~12%) during the last 550 million years (the Phanerozoic eon), implying this low oxygen concentration was a key factor in promoting mammalian viviparity as a response to a major evolutionary pressure. Genomic imprinting made its earliest appearance in the marsupials with only two DMRs, H19 and Peg10. Mess A, Carter AM. Typically, the placenta detaches from the uterine wall after childbirth. 2014). CTCF: master weaver of the genome. The Evolution of Viviparity in Vertebrates - PubMed Google Scholar. In: Mayo Clinic Guide to a Healthy Pregnancy. These ICRs, or differentially methylated regions (DMRs), are all reprogrammed and methylated in the female germline with the exception of H19, Rtl1 and Dlk1. Whether embryo-derived placental cells of other animals, which, unlike mammals, do not form an initiating trophectoderm, should be termed trophoblast is therefore questionable, despite many shared functions. In rare cases, the placenta might attach in the lower area of the uterus. 2016, Frankenberg, et al. 2002), thereby allowing exchange of nutrients. A female may spend a long time laying her eggs, ensuring they're securely fixed in a safe place. 2). Arguably, however, a structure found outside the reproductive tract, especially following external fertilization as occurs in these frogs and the sea horses described earlier, does not fit the typical definition of a placenta. Point mutations, expanded tandem repeats and structural chromosome mutations predominate through partilineal transmission (Marchetti et al., 2007). National Library of Medicine Reik W, Constancia M, Fowden A, Anderson N, Dean W, Ferguson-Smith A, Tycko B, Sibley C. Regulation of supply and demand for maternal nutrients in mammals by imprinted genes. All except prolactin itself are expressed in the placenta. CAS An official website of the United States government. PLoS Biol 4: e380. Oviparity; Parity evolution; Viviparity. Neither of these gene products, however, is related to human syncytins, except for the fact they are derived from ERV genes and placentally expressed. The placental hormones terminate fertility and suppress sexual behaviour in most female species, ensuring that maternal feeding time and energy expenditure are directed towards a successful pregnancy. Placenta accreta. Stem Cells 28: 443449. Martin RJ, et al., eds. Walker AM, Roberts RM. The authors concluded that these results do not provide genetic support for imprinted genes being involved in antagonistic co-evolution via a parental conflict. Among Syngnathid fish (pipefish and seahorses) the males and not the females become pregnant, after the females transfer the fertilized eggs to a brood pouch on the ventral side of either the trunk (Gastrophori) or the tail (Urophori) of the males body. Expression and function of endogenous retroviruses in the placenta. In the pig, where maternal recognition of pregnancy is also achieved during the period when the conceptuses are elongating within the uterine lumen, the antiluteolytic factor appears not to be a protein, but is instead the steroid hormone estrogen (Spencer, et al. (2012). With placenta accreta, part or all of the placenta remains firmly attached to the uterus. The strength of correlation between female recombination rate and local GC content is more than doubled by controlling for replication timing (Pink and Hurst, 2011). The uterine glands of the pig, for example, release uteroferrin, a bi-iron containing acid phosphatase to supply iron. Evolution of mammalian reproductive success has witnessed a strong dependence on maternal resources through placental in utero development. 3). These create a pregnancy favourable environment by inducing angiogenesis, trophoblast invasion of the uterus and vascular remodelling (Moffett and Loke, 2006). Co-adapted functions revealed by the mutation of Peg3 in the placenta (but not maternal hypothalamus) and the future maternal consequences of this same gene inactivated in the foetal hypothalamus, (but not in the placenta) of this next generation. -. The placenta is a structure that develops in the uterus during pregnancy. To know more about placenta, visit, Mayo Clinic; 2018. In viviparity the young develop within the female, receiving nourishment from the mother's blood through a placenta. 2007). 1C.S. A phylogenetic approach to test for evidence of parental conflict or gene duplications associated with protein-encoding imprinted orthologous genes in placental mammals. Careers. Any remaining fragments must be removed from the uterus to prevent bleeding and infection. Cell Mo Immunol 8: 111. 2020 Apr;29(7):1315-1327. doi: 10.1111/mec.15409. In this case the embryo derives food from the yolk present in the egg and is not dependent on the mother except for physical protection. Elsevier; 2019. https://www.clinicalkey.com. Renegar RH, Bazer FW, Roberts RM. The management of this condition depends on the amount of bleeding, whether the bleeding stops, how far along your pregnancy is, the position of the placenta, and your and your baby's health. Viviparous animals give birth to living young that have been nourished in close contact with their mothers' bodies. 2013 Nov 20;147(1):R15-26. Federal government websites often end in .gov or .mil. Proc Biol Sci 264: 739746. Moreover, the molecular mechanisms governing replication timing are not only stable but also meet requirements to be readily reprogrammed in the next generation (Shufaro et al., 2010). Males do not, of course, undergo pregnancy and parturition but they nevertheless benefit from viviparity and have been subject to the same placental hormones and selection pressures from viviparous in utero development. Placental development: lessons from mouse mutants. What is clear is that the mechanisms are highly variable, evolving rapidly, and no one approach is used widely across taxa. Phillips JE, Corces VG . 15.5 and 15.7 from E.C. The prolactin family: effectors of pregnancy-dependent adaptations. Iron deficiency anemia during pregnancy: Prevention tips. (2010). Viviparity in reptiles: A, Drawing from a section of the mature chorio-allantoic placenta of the Australian skink Egernia cunninghami carrying developing young, showing the maternal capillaries closely adjoining the allantoic capillaries on the fetal side. Viviparity has had a major role in shaping mammalian evolution as characterised by invasive placentation, maintenance of body temperature (homeothermy), milk production and enlargement of the . (2010). Proc Natl Acad Sci USA 109: 74037408. Placental protection of the fetal brain during short-term food deprivation. 2003). In this short review, we first describe the emergence of placental-like structures in non-mammalian vertebrates and then transition to mammals themselves. Thus, some genes may evolve imprinting status because selection favours parent-of-origin dependent status, other genes may evolve imprinting as a co-evolutionary response to match the expression pattern of their interacting neighbours (Wolf, 2013). Trophoblast and hypoblast in the monotreme, marsupial and eutherian mammal: evolution and origins. 24.2. Fertilization - Concepts of Biology - 1st Canadian Edition One is undoubtedly the struggle for control of maternal physiology in terms of nutrient allocation (Fowden and Constancia 2012). The evolution of viviparity: molecular and genomic data from squamate reptiles advance understanding of live birth in amniotes. (2009). Moreover, the organization of the domains in human and mouse PSG proteins are quite different (McLellan, et al. Which of the following deuterostomes is most likely to be found in nature? Interestingly Sry is a hybrid gene of Dgcr8 and Sox3 (Sato et al., 2010), and serves as the master switch for testes development (Kashimada and Koopman, 2010). In marsupials, the yolk sac forms the definitive placenta being responsible for physiological exchange whereas eutherian mammalian placentae can be deeply invasive into the maternal endometrium (haemochorial), requiring increased maternalfoetal co-adaptation. J Biol Chem 277: 623629. Wolf JB . Compare, for example, the relative maturity and independence of a newborn horse, pig or whale, supported during their gestations by diffuse epitheliochorial placentas, to a hapless pup born to a mouse or a baby born to a human, species where the placenta is hemochorial and discoid. Annu Rev Genomics Hum Genet 10: 11.1111.22. We close the review by discussing mechanisms that might have favored diversity and hence evolution of the morphology and physiology of the placentas of eutherian mammals. and transmitted securely. In some cases, early delivery is needed. Roberts RM, Ealy AD, Alexenko AP, Han CS, Ezashi T. Trophoblast interferons. It is assumed that to minimize attention from various arms of the maternal immune system, the trophoblast must continue to evolve counter-measures for its own protection and even advantage. Genomic imprinting in marsupial placentation. Mammalian viviparity has to contend with a semi-allogenic foetus, especially during invasive haemochorial placentation, which characterises rodents and primates where foetal trophoblast cells intermingle with maternal tissue (Rossant and Cross, 2001). 8600 Rockville Pike This concurrent co-activation provides a transgenerational template on which selection pressures have operated to ensure optimal maternalisation of the next generation. The placenta as a model for understanding the origin and - Nature This lineage, usually called trophoblast (or, because it forms the exterior of the conceptus, trophectoderm) diverges early from the pluripotent lineage that advances to form the inner cell mass, the cells that give rise to the hypoblast and epiblast, is unique to mammals. 8th ed. Amey KL, Bae E, Olsen C, Drewell RA . Late in pregnancy, this balanced regulation of growth is a function of the paternal H19 locus itself. The evolution of the placenta drives a shift in sexual selection in livebearing fish. Early cell lineage specification in a marsupial: a case for diverse mechanisms among mammals. All mammals except the egg-laying platypus and the five species of echidnas, the only surviving monotremes, rely on a placenta for their reproduction. The placentas of ruminants, with the exception of the phylogenetically more primitive tragulids, are also characterized as cotyledonary (Fig. Hutter B, Bieg M, Helms V, Paulsen M . Placenta abruption could result in an emergency situation requiring early delivery. (2008). Low birth weight also impairs postnatal growth and delays puberty onset. Work with your health care provider to manage any health conditions, such as high blood pressure. Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. There are a few coding genes, e.g. Genomic imprinting and the theory of parent-offspring conflict. Journal of Experimental Zoology Part B-Molecular and Developmental Evolution. Enders AC, Carter AM. It is generally recognized that there are additional driving forces promoting adaptive changes in the placenta and hence contributing to its rapid evolution.

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