Spermatogenic cell specific gene expression in mammals : Enzymes of glycolysis

据报道，糖酵解途径中的几种酶具有致渗细胞特异性酶和基因。我们之前报道了从小鼠生精细胞文库中分离出生精细胞特异性甘油醛-3-磷酸脱氢酶（mGapd-s）和三种独特的生精细胞特异性己糖激酶I型cdna （mHk1-sa、mHk1-sb和mHk1-sc）及其在小鼠生精细胞中的表达模式[Mori等]。中国生物医学工程学报（英文版）；Mori等人。[j] .中国生物医学工程学报，2009,31(2):393 - 398。为了分析小鼠Gapd-s和小鼠Hk1-s的基因产物的功能，我们需要克隆人Gapd-s和人Hk1-s (t)，并比较小鼠和人的序列。我们在此报道了人类Gapd-s的克隆和三个独特的人类己糖激酶I型mrna （hHK1-ta， hHK1-tb和hHK1-tc）的鉴定，这些mrna在人类睾丸中表达。人GAPD- s氨基酸序列与小鼠GAPD- s序列的相似性为91%，但与人体细胞GAPD的相似性仅为71%。所有三种睾丸特异性人类己糖激酶I型mrna （hHK1-ta， hHK1-tb和hHK1-tc）都不含有孔蛋白结合蛋白（PBD），但它们含有一个共同的睾丸特异性序列和一个独特的cDNA序列。hHK1-ta、hHK1-tb和hHK1-tc mrna的睾丸特异性序列与mHk1-sa、mHk1-sb和mHk1-sc mrna的生精细胞特异性序列有一定的同源性，但与任何物种的基因库中报道的其他已知基因没有显著的同源性。我们的研究结果表明，缺乏PBD的己糖激酶I型mrna在其他哺乳动物的睾丸中也有表达，这似乎支持了其他人提出的哺乳动物己糖激酶基因进化模型。

Several enzymes in the glycolytic pathway are reported to have permatogenic cell-specific enzymes and genes. We previously reported isolation of spermatogenic cell specific glyceraldehyde-3-phosphate dehydrogenase (mGapd-s) and three unique spermatogenic cell specific hexokinase type I cDNAs (mHk1-sa, mHk1-sb and mHk1-sc) from mouse spermatogenic cell library and their expression patterns in mouse spermatogenic cells [Mori et al. Biol Reprod 46 : 859-868,1992 ; Mori et al. Biol Reprod 49 : 191-203,1993] . In order to analysis of function of gene products of mouse Gapd-s and mouse Hk1-s, we needed the cloning of human Gapd-s and human HK1-s (t) and the comparison of those sequences from mice and humans. We report here the cloning of human Gapd-s and the identification of three unique human hexokinase type I mRNAs (hHK1-ta, hHK1-tb and hHK1-tc) which are expressed in human testis. The amino acids of human GAPD-S have a 91% match with the mouse GAPD-S sequence, but only a 71% similarity to the human somatic GAPD.All three testis specific human hexokinase type I mRNAs (hHK1-ta, hHK1-tb and hHK1-tc) don't contain porin-binding protein (PBD) , but they contain a common testis-specific sequence and a sequence unique to each cDNA.This common testis-specific sequence in mRNAs of hHK1-ta, hHK1-tb, and hHK1-tc has some homology with a common spermatogenic cell-specific sequence in those of mHk1-sa, mHk1-sb and mHk1-sc, and but no significant homology with other known genes reported in GENE BANK in any species. Our findings show that hexokinase type I mRNAs lacking PBD are expressed in testes from other mammals, and appear to support a model proposed by others for hexokinase gene evolution in mammals.