Project description:Primordial germ cells (PGCs), the embryonic precursors of eggs and sperm, are a unique model for identifying and studying regulatory mechanisms in singly migrating cells. From their time of specification to eventual colonization of the gonad, mouse PGCs traverse through and interact with many different cell types, including epithelial cells and mesenchymal tissues. Work in drosophila and zebrafish have identified many genes and signaling pathways involved in PGC migration, but little is known about this process in mammals. We have generated a point mutation in the Ror2 gene that we know disrupts primordial germ cell migration in the developing mouse embryo. We used microarray analysis to determine if this defect is mediated through genome-wide or pathway-specific transcriptional changes. We analyzed primordial germ cells (PGCs) from 4 wild-type (WT) and 4 Ror2Y324C/Y324C mutant embryos using Oct4-DPE-EGFP. PGCs were collected during their active migratory state at embryonic day 9.5 (somite range 20-25).
Project description:Maintenance and maturation of primordial germ cells is controlled by complex genetic and epigenetic cascades, and disturbances in this network lead to either infertility or malignant aberration. Transcription factor Tcfap2c / TFAP2C has been described to be essential for primordial germ cell maintenance and to be upregulated in several human germ cell cancers. Using global gene expression profiling, we identified genes deregulated upon loss of Tcfap2c in primordial germ cell-like cells. We show that loss of Tcfap2c affects many aspects of the genetic network regulating germ cell biology, such as downregulation maturation markers and induction of markers indicative of somatic differentiation, cell cycle, epigenetic remodeling, and pluripotency associated genes. Chromatin-immunoprecipitation analyses demonstrated binding of Tcfap2c to regulatory regions of deregulated genes (Sfrp1, Dmrt1, Nanos3, c-Kit, Cdk6, Cdkn1a, Fgf4, Klf4, Dnmt3b and Dnmt3l) suggesting that these genes are direct transcriptional targets of Tcfap2c in primordial germ cells. Since Tcfap2c deficient primordial germ cell like cells display cancer related deregulations in epigenetic remodeling, cell cycle and pluripotency control, the Tcfap2c-knockout allele was bred onto 129S2/Sv genetic background. There, mice heterozygous for Tcfap2c develop germ cell cancer with high incidence. Precursor lesions can be observed as early as E16.5 in developing testes displaying persisting expression of pluripotency markers. We further demonstrate, that mice with a heterozygous deletion of the Tcfap2c target gene Nanos3 are also prone to develop teratoma. These data highlight Tcfap2c as a critical and dose-sensitive regulator of germ cell fate. 8 samples were analyzed. Ctrl ESC: Control mouse embryonic stem cells (ESCs), 2 biological rep KO ESC: Tcfap2c knock-out mouse embryonic stem cells (ESCs), 2 biological rep Ctrl PGC: Control mouse primordial germ cells (PGCs), 2 biological rep KO PGC: Tcfap2c knock-out mouse primordial germ cells (PGCs), 2 biological rep
Project description:Primordial germ cells (PGCs), the embryonic precursors of eggs and sperm, are a unique model for identifying and studying regulatory mechanisms in singly migrating cells. From their time of specification to eventual colonization of the gonad, mouse PGCs traverse through and interact with many different cell types, including epithelial cells and mesenchymal tissues. Work in drosophila and zebrafish have identified many genes and signaling pathways involved in PGC migration, but little is known about this process in mammals. We have generated a point mutation in the Ror2 gene that we know disrupts primordial germ cell migration in the developing mouse embryo. We used microarray analysis to determine if this defect is mediated through genome-wide or pathway-specific transcriptional changes.
Project description:Female primordial germ cell differentiation undergoes sex determination and meiosis initiation asynchronously. Here we investigate the transcriptional profiles of 20519 single cells collected from E12.5, E14.5 and E16.5 mouse fetal ovaries. Clustering analysis identifies ten clusters and defines dozens of corresponding marker genes and provides a global view of cellular differentiation from undifferentiated primordial germ cells towards meiotic oocytes. We explore the dynamics of gene expression within the differentiation trajectory with special focus on the mechanisms for meiotic initiation.