Project description:Transposable elements are increasingly appreciated as regulatory elements in early mammalian development, especially in cells which exhibit pluripotency. Mammalian primordial germ cells (PGCs) must exit latent pluripotency in a process termed determination before they are competent to differentiate and enter sex-specific developmental programs. Here, we find that determination is marked by large changes to the transposable element (TE) repertoire, a phenomenon driven by TRIM28, after which testicular and ovarian PGCs exhibit district transposable element repertoires. We find that loss of TRIM28 perturbs entry into determination as marked by expression of DAZL in a sex-specific manner, but does not result in a failure to downregulate markers of latent pluripotency, including SOX2 and NANOG in either sex. Despite downregulation of some early PGC markers, both ovarian and testicular PGCs fail to properly enter into their meiotic germ cell or prospermatogonial programs, respectively. Thus, we show that TRIM28-mediated reorganization of the TE repertoire is necessary to establish a PGC epigenome competent for proper germline commitment and gametogenesis.
Project description:Transposable elements are increasingly appreciated as regulatory elements in early mammalian development, especially in cells which exhibit pluripotency. Mammalian primordial germ cells (PGCs) must exit latent pluripotency in a process termed determination before they are competent to differentiate and enter sex-specific developmental programs. Here, we find that determination is marked by large changes to the transposable element (TE) repertoire, a phenomenon driven by TRIM28, after which testicular and ovarian PGCs exhibit district transposable element repertoires. We find that loss of TRIM28 perturbs entry into determination as marked by expression of DAZL in a sex-specific manner, but does not result in a failure to downregulate markers of latent pluripotency, including SOX2 and NANOG in either sex. Despite downregulation of some early PGC markers, both ovarian and testicular PGCs fail to properly enter into their meiotic germ cell or prospermatogonial programs, respectively. Thus, we show that TRIM28-mediated reorganization of the TE repertoire is necessary to establish a PGC epigenome competent for proper germline commitment and gametogenesis.
Project description:Plasmodium falciparum gametocyte stages represent a small fraction of the entire parasite biomass that is present during human malaria infection, yet they alone lead to the transmission of this devastating disease. One of the critical gaps in malaria transmission biology and surveillance is our lack of knowledge about gametocyte biology, especially sexual dimorphic development that may influence transmission from the human to the mosquito. Ratios of male and female gametocytes in the peripheral blood can vary significantly; influenced in part by asexual blood stage and gametocyte density as well as vertebrate and invertebrate host factors. Moreover, the role of sex ratios on gametocyte transmission potential to mosquitoes is unknown and dissecting this process has been hampered by the lack of sex-specific protein markers for the circulating, mature stage V gametocytes. The current evidence suggests a high degree of conservation in gametocyte gene complement across Plasmodium, and therefore presumably for sex-specific genes as well. Therefore, to better our understanding of gametocyte development and subsequent infectiousness to mosquitoes, we undertook a two pronged approach. First, we acquired the mixed, male and female stage V gametocyte proteomes of the NF54 isolate and mature stage V female proteome from Dd2, a strain that is defective in producing mature males. Second, we then undertook a Systematic Subtractive Bioinformatic analysis (filtering) approach to identify sex-specific P. falciparum NF54 protein markers based on a comparison with the Dd2 strain and syntenic male and female proteins from the reanalyzed and updated P. berghei (related rodent malaria parasite) gametocyte proteomes. This has produced a short list of putative 174 male- and 258 female-specific P. falciparum stage V proteins. Furthermore, we generated antibodies against three putative female-specific gametocyte stage V proteins in P. falciparum and confirmed sex-specificity for two proteins and also the loss sex-partitioning for a putative female-specific protein in rodent malaria parasites.
2014-07-25 | PXD000813 | Pride
Project description:Albacore Genome Assembly and identification fo Sex Markers