Utp14b:: A unique retrogene within a gene that has acquired multiple promoters and a specific function in spermatogenesis
Utp14b:: A unique retrogene within a gene that has acquired multiple promoters and a specific function in spermatogenesis
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DOI：
10.1016/j.ydbio.2007.01.005
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发表时间：
2007-04-15
影响因子：
2.7
通讯作者：
Meistrich, Marvin L.
中科院分区：
文献类型：
--
作者：
Zhao, Ming;Rohozinski, Jan;Meistrich, Marvin L.
小鼠逆转录酶基因Utp14b对男性生育能力是必需的，其序列突变导致不育幼年精原细胞枯竭(JSD)表型。它是Utp14a基因的逆转座拷贝，位于X染色体上，插入常染色体酰基辅酶A合成酶长链家族成员3(ACSL3)基因的内含子中。为了阐明Utp14基因在正常生精细胞发育中的作用，为理解导致JSD表型的缺陷奠定基础，我们分析了Utp.14b逆转录基因产生的各种mRNAs及其在不同细胞类型中的表达。确定了两类转录本：变体1，由宿主基因启动子驱动的转录本，主要在生殖细胞中发现，但在低水平普遍表达；变体2-5，一组选择性剪接的转录本，包含一些独特的未翻译外显子，从一种新的生殖细胞特异性启动子转录而来。Utp14b(主要是变异体1)在粗线期精母细胞中高水平表达，在这个发育阶段，X连锁的Utp14a的表达受到抑制。尽管Utp14a在圆形精子细胞中有转录，但这两类Utp14b转录本在这些细胞中的表达水平最高。VIE认为，当Utp14b最初插入ACSL3时，它利用ACSL3启动子驱动粗线期精母细胞中的表达，以补偿Utp14a表达的失活。Utp14b的新的细胞类型特异性启动子可能进化得更晚，因为该蛋白可能在精子细胞发育中获得了生殖细胞特异性功能。(C)2007 Elsevier Inc.保留所有权利。
The mouse retrogene Utp14b is essential for male fertility, and a mutation in its sequence results in the sterile juvenile spermatogonial depletion (jsd) phenotype. It is a retrotransposed copy of the Utp14a gene, which is located on the X chromosome, and is inserted within an intron of the autosomal acyl-CoA synthetase long-chain family member 3 (Acsl3) gene. To elucidate the roles of the Utp14 genes in normal spermatogenic cell development as a basis for understanding the defects that result in the jsd phenotype, we analyzed the various mRNAs produced from the Utp.14b retrogene and their expression in different cell types. Two classes of transcripts were identified: variant 1, a transcript driven by the host gene promoter, that is predominantly found in germ cells but is ubiquitously expressed at low levels; and variants 2-5, a group of alternatively spliced transcripts containing some unique untranslated exons that are transcribed from a novel promoter that is germ-cell-specific. Utp14b (predominantly variant 1) is expressed at moderately high levels in pachytene spermatocytes, the developmental stage at which the expression of the X-linked Utp14a is suppressed. The levels of both classes of Utp14b transcripts were highest in round spermatids despite the transcription of Utp14a in these cells. Vie propose that when Utp14b initially inserted into Acsl3, it utilized the Acsl3 promoter to drive expression in pachytene spermatocytes to compensate for inactivation of Utp14a expression. The novel cell-type-specific promoter for Utp14b likely evolved later, as the protein may have acquired a germ cell-specific function in spermatid development. (c) 2007 Elsevier Inc. All rights reserved.