Jana Koubova

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In mammals, meiosis is initiated at different time points in males and females, but the mechanism underlying this difference is unknown. Female germ cells begin meiosis during embryogenesis. In males, embryonic germ cells undergo G0/G1 mitotic cell cycle arrest, and meiosis begins after birth. In mice, the Stimulated by Retinoic Acid Gene 8 (Stra8) has been(More)
Differentiation of mouse embryonic germ cells as male or female is dependent on the somatic environment of the gonad rather than the sex chromosome constitution of the germ cell. However, little is known about the initiation of germ cell sexual differentiation. Here, we traced the initiation of germ cell sexual differentiation in XX gonads using the Stra8(More)
Retinoic acid (RA) is an essential extrinsic inducer of meiotic initiation in mammalian germ cells. However, RA acts too widely in mammalian development to account, by itself, for the cell-type and temporal specificity of meiotic initiation. We considered parallels to yeast, in which extrinsic and intrinsic factors combine to restrict meiotic initiation. We(More)
For almost 70 years, calorie restriction has been known to extend life span. Despite the extensive physiological characterization of this dietary regimen, the molecular basis for the slowing in aging remains unsolved. Recent findings have pinpointed a few molecular pathways that appear to regulate the aging process. In this review, we propose a molecular(More)
In all sexually reproducing organisms, cells of the germ line must transition from mitosis to meiosis. In mice, retinoic acid (RA), the extrinsic signal for meiotic initiation, activates transcription of Stra8, which is required for meiotic DNA replication and the subsequent processes of meiotic prophase. Here we report that RA also activates transcription(More)
We screened high-density filters from the RPCI-43 male chimpanzee BAC library (BACPAC resources) using hybridization probes designed to detect sequences (1) near the inner boundaries of palindromes P1–P6 and P8; (2) near P7; and (3) from a nonampliconic region of the human MSY. STS content and BAC-end sequences confirmed that, among the candidate BACs(More)
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