Discovery of tMAC:: a Drosophila testis-specific meiotic arrest complex paralogous to Myb-Muv B
Discovery of tMAC:: a Drosophila testis-specific meiotic arrest complex paralogous to Myb-Muv B
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DOI：
10.1101/gad.1516607
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发表时间：
2007-04-15
影响因子：
10.5
通讯作者：
Botchan, Michael R.
中科院分区：
文献类型：
--
作者：
Beall, Eileen L.;Lewis, Peter W.;Botchan, Michael R.
果蝇Myb-Muv B(MMB)/DREAM复合体特异性地调控基因表达和DNA复制位点，但其在体内的活性尚未得到深入研究。在卵巢增殖期的卵泡细胞核中，最大的亚单位Mip130是复制的负调节因子，而另一个亚单位Myb是正调节因子。在这里，我们确定了mip40的突变，并在mip120产生了突变，mip120是另外两个MMB亚基。这两个突变体都是可行的，但mip120突变体具有许多复杂的表型，包括缩短寿命和严重的眼睛缺陷。Mip40突变雌鼠生育力严重下降，而mip120突变雌鼠则不育，证实了MMB的卵巢调节作用(S)。MYB的积累和与多线染色体的结合取决于MMB复合体的核心因素。与已记录的mip130突变表型相反，mip40和mip120突变雄性都是不育的。我们从睾丸核提取液中纯化了含有Mip40的复合体，并鉴定了一种新的睾丸特异的减数分裂抑制复合体TMAC，它包含Mip40、CAF1/P55、Mip130家族成员Always Easy(Aly)和Mip120家族成员Tombola(Tomb)。综上所述，这些数据表明，MMB在不同的发育途径中发挥着不同的作用，MMB的成员可以在不同细胞类型的替代的、非相互作用的复合体中找到。
The Drosophila Myb-Muv B (MMB)/dREAM complex regulates gene expression and DNA replication site-specifically, but its activities in vivo have not been thoroughly explored. In ovarian amplification-stage follicle cell nuclei, the largest subunit, Mip130, is a negative regulator of replication, whereas another subunit, Myb, is a positive regulator. Here, we identified a mutation in mip40 and generated a mutation in mip120, two additional MMB subunits. Both mutants were viable, but mip120 mutants had many complex phenotypes including shortened longevity and severe eye defects. mip40 mutant females had severely reduced fertility, whereas mip120 mutant females were sterile, substantiating ovarian regulatory role(s) for MMB. Myb accumulation and binding to polytene chromosomes was dependent on the core factors of the MMB complex. In contrast to the documented mip130 mutant phenotypes, both mip40 and mip120 mutant males were sterile. We purified Mip40-containing complexes from testis nuclear extracts and identified tMAC, a new testis-specific meiotic arrest complex that contained Mip40, Caf1/p55, the Mip130 family member, Always early (Aly), and a Mip120 family member, Tombola (Tomb). Together, these data demonstrate that MMB serves diverse roles in different developmental pathways, and members of MMB can be found in alternative, noninteracting complexes in different cell types.