Mukai Masanori, Hayashi Yoshiki, Kitadate Yu, Shigenobu Shuji, Arita Kayo, Kobayashi Satoru
Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan.
Mech Dev. 2007 Aug;124(7-8):570-83. doi: 10.1016/j.mod.2007.05.001. Epub 2007 May 21.
A hallmark of germline cells throughout the animal kingdom is their ability to execute meiosis. However, despite its prime importance, little is known about how germline progenitors acquire this ability. In Drosophila, the primordial germ cells (PGCs) are characterized by the inheritance of germ plasm, which contains maternal factors that have sufficient ability to direct germline development. Here, we show that a novel maternal factor, MAMO, is autonomously required in PGCs to produce functional gametes. MAMO protein which contains both a BTB/POZ (Broad Complex, Tramtrack, Bric-a-brac/Pox virus and Zinc finger) domain and C(2)H(2) zinc finger motifs is enriched in PGCs during embryogenesis. The PGCs with reduced maternal MAMO activity are able to undergo oogenesis, but fail to execute meiosis properly. In the resulting oocytes, meiosis-specific chromosomal configurations are impaired. We additionally show that the decondensation of fertilized sperm nuclei is also affected in the eggs. We propose that maternal MAMO activates downstream genes to promote specialized morphological changes of both female meiotic chromosomes and the sperm nucleus, which are critical in zygote formation.
在整个动物界，生殖细胞的一个标志是它们进行减数分裂的能力。然而，尽管其至关重要，但对于生殖祖细胞如何获得这种能力却知之甚少。在果蝇中，原始生殖细胞（PGCs）的特征是生殖质的遗传，生殖质包含具有足够能力指导生殖系发育的母体因子。在这里，我们表明一种新的母体因子MAMO在PGCs中是自主产生功能性配子所必需的。含有BTB/POZ（Broad Complex、Tramtrack、Bric-a-brac/痘病毒和锌指）结构域和C(2)H(2)锌指基序的MAMO蛋白在胚胎发育过程中在PGCs中富集。母体MAMO活性降低的PGCs能够进行卵子发生，但不能正常进行减数分裂。在产生的卵母细胞中，减数分裂特异性的染色体构型受损。我们还表明，受精卵细胞核的解聚在卵子中也受到影响。我们提出母体MAMO激活下游基因，以促进雌性减数分裂染色体和精细胞核的特殊形态变化，这对合子形成至关重要。
