Reconstitution of the oocyte transcriptional network with transcription factors.

During female germline development, oocytes become a highly specialized cell type and form a maternal cytoplasmic store of crucial factors. Oocyte growth is triggered at the transition from primordial to primary follicle and is accompanied by dynamic changes in gene expression, but the gene regulatory network that controls oocyte growth remains unknown. Here we identify a set of transcription factors that are sufficient to trigger oocyte growth.

Germ cell-intrinsic effects of sex chromosomes on early oocyte differentiation in mice.

A set of sex chromosomes is required for gametogenesis in both males and females, as represented by sex chromosome disorders causing agametic phenotypes. Although studies using model animals have investigated the functional requirement of sex chromosomes, involvement of these chromosomes in gametogenesis remains elusive. Here, we elicit a germ cell-intrinsic effect of sex chromosomes on oogenesis, using a novel culture system in which oocytes were induced from embryonic stem cells (ESCs) harboring XX, XO or XY.

Hypoxia induces the dormant state in oocytes through expression of .

In mammals, most immature oocytes remain dormant in the primordial follicles to ensure the longevity of female reproductive life. A precise understanding of mechanisms underlying the dormancy is important for reproductive biology and medicine. In this study, by comparing mouse oogenesis in vivo and in vitro, the latter of which bypasses the primordial follicle stage, we defined the gene-expression profile representing the dormant state of oocytes.

Reconstitution of mouse oogenesis in a dish from pluripotent stem cells.

This protocol is an extension to: Nat. Protoc. 8, 1513-1524 (2013); doi: 10.

Reconstitution in vitro of the entire cycle of the mouse female germ line.

The female germ line undergoes a unique sequence of differentiation processes that confers totipotency to the egg. The reconstitution of these events in vitro using pluripotent stem cells is a key achievement in reproductive biology and regenerative medicine. Here we report successful reconstitution in vitro of the entire process of oogenesis from mouse pluripotent stem cells.

Sphere-formation culture of testicular germ cells in the common marmoset, a small New World monkey.

Spermatogonia are specialized cells responsible for continuous spermatogenesis and the production of offspring. Because of this biological property, in vitro culture of spermatogonia provides a powerful methodology to advance reproductive biology and engineering. However, methods for culturing primate spermatogonia are poorly established.

Generation of germ cells in vitro in the era of induced pluripotent stem cells.

Induced pluripotent stem cells (iPSCs) are stem cells that can be artificially generated via "cellular reprogramming" using gene transduction in somatic cells. iPSCs have enormous potential in stem-cell biology as they can give rise to numerous cell lineages, including the three germ layers. An evaluation of germ-line competency by blastocyst injection or tetraploid complementation, however, is critical for determining the developmental potential of mouse iPSCs towards germ cells.