Project description:The evolutionary origin of complex organs challenges empirical study because most organs evolved hundreds of millions of years ago. The placenta of live-bearing fish in the family Poeciliidae represents a unique opportunity to study the evolutionary origin of complex organs, because in this family a placenta evolved at least nine times independently. It is currently unknown whether this repeated evolution is accompanied by similar, repeated, genomic changes in placental species. Here, we compare whole genomes of 26 poeciliid species representing six out of nine independent origins of placentation. Evolutionary rate analysis revealed that the evolution of the placenta coincides with convergent shifts in the evolutionary rate of 78 protein-coding genes, mainly observed in transporter- and vesicle-located genes. Furthermore, differences in sequence conservation showed that placental evolution coincided with similar changes in 76 noncoding regulatory elements, occurring primarily around genes that regulate development. The unexpected high occurrence of GATA simple repeats in the regulatory elements suggests an important function for GATA repeats in developmental gene regulation. The distinction in molecular evolution observed, with protein-coding parallel changes more often found in metabolic and structural pathways, compared with regulatory change more frequently found in developmental pathways, offers a compelling model for complex trait evolution in general: changing the regulation of otherwise highly conserved developmental genes may allow for the evolution of complex traits.
Project description:Heterozygous OgtY851A/WT females were bred with hemizygous OgtY851A/Y males, placentas were dissected at E12.5 and single placenta's halves were processed for mRNA-Seq. Sex and genotypes of the embryos were determined by PCR genotyping of the DNA extracted from the embryonic heads.
Project description:A live-bearing reproductive strategy can induce large morphological changes in the mother during pregnancy. The evolution of the placenta in swimming animals involves a shift in the timing of maternal provisioning from pre-fertilization (females supply their eggs with sufficient yolk reserves prior to fertilization) to post-fertilization (females provide all nutrients via a placenta during the pregnancy). It has been hypothesised that this shift, associated with the evolution of the placenta, should confer a morphological advantage to the females leading to a more slender body shape during the early stages of pregnancy. We tested this hypothesis by quantifying three-dimensional shape and volume changes during pregnancy and in full-grown virgin controls of two species within the live-bearing fish family Poeciliidae: Poeciliopsis gracilis (non-placental) and Poeciliopsis turneri (placental). We show that P. turneri is more slender than P. gracilis at the beginning of the interbrood interval and in virgins, and that these differences diminish towards the end of pregnancy. This study provides the first evidence for an adaptive morphological advantage of the placenta in live-bearing fish. A similar morphological benefit could drive the evolution of placentas in other live-bearing (swimming) animal lineages.
Project description:IUGR (Intra-Uterine Growth Restriction) refers to a condition where the foetus does not reach its growth potential in utero. It is supposed to be often linked with placental dysfunction, especially of vascular origin. In this study, 4 pools of three placentas from human normal pregnancies and 4 pools of three placentas from IUGR human pregnancies, obtained after caesarean section near normal term , were used to prepare RNA. The cDNAs prepared from these RNA were hybridized to a Nimblegen expression array in order to detect differences in gene expression between normal and pathological placentas.
Project description:Here we use a proteomic approach to study the role of the placenta in ZIKV-induced microcephaly and the mechanisms of ZIKV to cross the placental barrier. Samples were separated into three groups: an uninfected control group (ZIKV-CZS-), a group of placentas infected by ZIKV with normal neonates (ZIKV+CZS-), and a group of placentas infected by ZIKV that developed microcephaly in newborns (ZIKV+CZS+). Zika virus causes DNA damage and impairs gene expression and mRNA translation during infection of the placenta. Processes related to viral transcytosis, like endocytosis, autophagy and disruption of actin filament were also observed in CZS-infected placentas, which could lead to a higher virus infiltration. Unncontrolled maternal immune response as well as greater expression of cellular adhesion proteins in the decidua could lead to a disruption of tolerance during pregnancy and induction of neurological malformation of the neonates
Project description:The goal of the study was to identify regions of differential methylation between e18.5 mouse placentas exposed to cadmium and control placentas.