Role of LARP7 in meiotic sex chromosome silencing

Meiotic sex chromosome inactivation (MSCI) is an essential event in meiotic progression in mammalian spermatogenesis. We found that La Ribonucleoprotein 7 (LARP7) is involved in MSCI. LARP7 plays a role in fetal germ cells to promote their proliferation, but is once abolished in postnatal gonocytes and re-expresses in spermatocytes at the onset of meiosis. In spermatocytes, LARP7 localizes to the XY body, a compartmentalized chromatin domain on sex chromosomes. This study aimed to elucidate a possible function of LARP7 in the XY body by using germline-specific Larp7-deficient mice. To investigate the function of LRP7 in the spermatogenesis, we generated germline-specific Larp7 knockout mice and evaluated gene expression in the spermatocyte.减数分裂性染色体失活（Meiotic sex chromosome inactivation, MSCI）是哺乳动物精子发生过程中减数分裂进程的关键事件。本研究发现，La核糖核蛋白7（La Ribonucleoprotein 7, LARP7）参与了该生物学过程。LARP7可在胎儿生殖细胞中发挥促增殖作用，但在出生后的性原细胞中其表达被沉默，并在减数分裂起始阶段的精母细胞中重新表达。在精母细胞中，LARP7定位于性染色体上的区域化染色质结构XY小体（XY body）。本研究旨在通过构建生殖细胞特异性Larp7基因敲除小鼠，阐明LARP7在XY小体中可能具备的功能。为探究LARP7在精子发生中的功能，本研究生成了生殖细胞特异性Larp7基因敲除小鼠，并对精母细胞的基因表达情况进行了评估。