Two novel genes expressed in Xenopus germ line: Characteristic features of putative protein structures, their gene expression profiles and their possible roles in gametogenesis and embryogenesis
Two novel genes expressed in Xenopus germ line: Characteristic features of putative protein structures, their gene expression profiles and their possible roles in gametogenesis and embryogenesis
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非洲爪蟾种系中表达的两个新基因：假定蛋白质结构的特征、它们的基因表达谱及其在配子发生和胚胎发生中的可能作用
DOI：
10.1002/mrd.90003
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发表时间：
2002
影响因子：
2.5
通讯作者：
K. Takamune
中科院分区：
文献类型：
--
作者：
Y. Ikema;M. Hiyoshi;H. Daiyasu;H. Toh;Mitsuaki Mori;K. Takamune
我们比较了非洲爪哇次级精原细胞和初级精母细胞微粒体部分中的蛋白质，发现了一个新合成的蛋白质(94 KDa)和另外三个蛋白质(99、85和72 kDa)，它们在进入减数分裂阶段后数量增加。以这四种蛋白为抗原制备多克隆抗体，并与这四种蛋白和另外两种蛋白(208 kDa和60 kDa)发生反应。用该多克隆抗体免疫筛选非洲爪哇睾丸cDNA文库，得到两个编码新蛋白的cDNA克隆(Xmegs和XtR)。Xmegs mRNA在粗线期中期至两次减数分裂完成的生精细胞中特异表达。推测的Xmegs蛋白包含19个串联重复序列，由26个富含脯氨酸的氨基酸残基和潜在的磷酸化位点(即丝氨酸和苏氨酸残基)组成。在这个重复区周围，我们发现了五个害虫序列，它们被称为蛋白质降解信号，目的是降解蛋白质。PEST序列的存在被认为使蛋白质水平与mRNA丰度密切相关。这些结果表明，这种新的蛋白质可能以一种依赖于磷酸化和/或去磷酸化的方式调节精子发生的两个减数分裂。Xtr基因在生精细胞和卵母细胞中均有表达，但在圆形精子细胞和后期细胞中均有表达。该基因在早期胚胎中也有表达，其含量从St.I卵母细胞到原肠胚期保持不变，之后逐渐减少。在果蝇Tudor蛋白中发现了4个完整的Tudor结构域和1个部分Tudor样结构域，在PGC分化和腹段分化中起重要作用。XtR的特征表达谱和与果蝇Tudor蛋白相似的蛋白质结构提示它可能在减数分裂和PGC分化过程中发挥作用。摩尔。是Reprod。戴夫。2002年，62：421-430。©2002 Wiley-Liss公司
We compared the secondary spermatogonia and the primary spermatocytes of Xenopus for the proteins in their microsomal fractions and identified a newly synthesized protein (94 kDa) and three other proteins (99, 85, and 72 kDa) which increased their amount after entering the meiotic phase. These four proteins were used as antigens to produce polyclonal antibody which was found to react with the four proteins as well as two other proteins (208 and 60 kDa). Immunoscreening of Xenopus testis cDNA library with this polyclonal antibody yielded two cDNA clones (Xmegs and Xtr) encoding novel proteins. Xmegs mRNA was specifically expressed in the spermatogenic cells from the mid‐pachytene stage to completion of two meiotic divisions. The putative Xmegs protein contained 19 tandem repeats of 26 amino acid residues rich in proline as well as potential phosphorylation sites (i.e., serine and threonine residues). Around this repetitive area, we found five PEST sequences known as a proteolytic signal to target protein for degradation. The presence of PEST sequences was believed to allow protein levels to closely parallel mRNA abundance. These results suggested the possible role of this novel protein in the regulation of two meiotic divisions specific to the spermatogenesis in a phosphorylation‐ and/or dephosphorylation‐dependent manner. On the other hand, Xtr mRNA was expressed in both spermatogenic and oogenic cells except for round spermatids and the later stage cells. This mRNA was also expressed in the early stage embryos and its amount was kept constant from the St. I oocyte to the gastrula stage and decreased thereafter. The putative Xtr protein contained four complete and one partial tudor‐like domains that were discovered in Drosophila tudor protein which plays an important role in PGC differentiation and abdominal segmentation. The characteristic expression profile of Xtr and the protein structure similar to the Drosophila tudor protein suggested its possible role in the progression of meiosis and PGC differentiation. Mol. Reprod. Dev. 62:421–430, 2002. © 2002 Wiley‐Liss, Inc.
DOI：
10.1073/pnas.82.23.7934
发表时间：
1985-01-01
影响因子：
11.1
作者：
CORDEN, JL;CADENA, DL;DAHMUS, ME
通讯作者：
DAHMUS, ME
DOI：
10.1073/pnas.93.16.8253
发表时间：
1996-08-06
影响因子：
11.1
作者：
Mortillaro, MJ;Blencowe, BJ;Berezney, R
通讯作者：
Berezney, R
在无血清培养基中培养的非洲爪蟾睾丸外植体中精子发生的体外维持。
影响因子：
3.6
作者：
Risley,MS;Miller,A;Bumcrot,DA
通讯作者：
Bumcrot,DA