Spermatid-specific expression of the novel X-linked gene product SPAN-X localized to the nucleus of human spermatozoa
Spermatid-specific expression of the novel X-linked gene product SPAN-X localized to the nucleus of human spermatozoa
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DOI：
10.1093/biolreprod/63.2.469
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发表时间：
2000-08-01
影响因子：
3.6
通讯作者：
Herr, JC
中科院分区：
文献类型：
--
作者：
Westbrook, VA;Diekman, AB;Herr, JC
成熟精子的形成涉及雄性生殖细胞谱系中一系列戏剧性的分子和形态学变化。这些变化的结果从时间调节转录和翻译的几个睾丸特异性基因产物。在这里，我们描述了一种新型的睾丸特异性蛋白质，命名为SPAN-X，用于与X染色体上的细胞核相关的精子蛋白。Span-X序列与已知的cDNA或肽序列没有显着的相似性。Span-X肽序列含有三个重叠的共有核定位信号，高百分比（33%-37%）的带电氨基酸残基，和相对酸性的等电点（pI; 4.88-6.05）。对多种人体组织mRNA的北方分析鉴定了仅在睾丸中的SPAN-X转录物。人睾丸切片的原位杂交显示，在单倍体，圆形和伸长的精子细胞中有SPAN-X mRNA表达。通过荧光原位杂交和人/小鼠体细胞杂交的Southern印迹分析，将SPAN基因定位于染色体Xq27.1。在人精子蛋白的Western印迹上，抗重组SPAN-X抗体与迁移在15-20 kDa之间的宽条带反应。人精子的免疫荧光标记证实了SPAN-X定位于核火山口和细胞质液滴。SPAN-X是一种X连锁基因产物，仅在单倍体精子细胞中表达，这引发了关于精子发生过程中性连锁基因转录的有趣问题。
Formation of mature spermatozoa involves a series of dramatic molecular and morphological changes in the male germ cell lineage. These changes result from the temporally regulated transcription and translation of several testis-specific gene products. Here, we describe a novel, testis-specific protein designated SPAN-X for sperm protein associated with the nucleus on the X chromosome. SPAN-X sequences showed no significant similarity with known cDNA or peptide sequences. The SPAN-X peptide sequences contained three overlapping consensus nuclear localization signals, a high percentage (33%-37%) of charged amino acid residues, and a relatively acidic isoelectric point (pI; 4.88-6.05). Northern analysis of mRNA from multiple human tissues identified a SPAN-X transcript exclusively in the testis. In situ hybridization of human testes sections showed SPAN-X mRNA expression in haploid, round, and elongating spermatids. The SPANX gene was mapped to chromosome Xq27.1 by fluorescence in situ hybridization and by Southern blot analysis of human/mouse somatic cell hybrids. On Western blots of human sperm proteins, antirecombinant SPAN-X antibodies reacted with broad bands migrating between 15-20 kDa, Immunofluorescent labeling of human spermatozoa demonstrated SPAN-X localization to nuclear craters and cytoplasmic droplets. Expression of SPAN-X, an X-linked gene product, exclusively in haploid spermatids reads to interesting questions regarding the transcription of sex-linked genes during spermiogenesis.