Expression of a large number of novel testis-specific genes during spermatogenesis coincides with the functional reorganization of the male germ cell.
Structural and functional changes, essential for the formation of mature male germ cells, are known to take place at specific stages of the mammalian spermatogenic process. To identify novel genes that are involved in this developmental process, we have initiated a large-scale cDNA sequencing project (Hoog+, Nucleic Acids Res. 19: 93-98, 1991; Starborg et al., Mol. Reprod. Dev. 33: 243-251, 1992; Yuan et al., Biol. Reprod., 1995). Five-hundred and forty cDNAs have been isolated from testicular cDNA libraries and partially sequenced, 355 of which were found to represent genes previously not described in the literature. In addition, a number of cDNAs was found to be related to genes previously identified only in lower eukaryotes, suggesting that these murine genes encode functions that are evolutionary conserved. One of these murine cDNAs was related to the Aspergillus nidulans BimE gene, a putative cell cycle checkpoint regulator (Starborg et al., J. Biol. Chem., 1994). Southern blot analysis revealed that the murine BimE-related gene is strongly conserved in mammals. RNA blotting experiments of 361 novel murine cDNAs have identified 52 cDNAs that are expressed only during spermatogenesis, 36 of which are expressed only in spermatids, and 16 cDNAs that are expressed in both spermatocytes and spermatids. A survey of the literature revealed 40 mammalian genes that have previously been shown to be expressed mainly during spermatogenesis, and together with our results, they define three dominating temporal patterns of gene expression during spermatogenesis, each pattern coinciding with known functional or structural changes occurring during this differentiation process.
Höög
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Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, Stockholm, Sweden.
D000375:Aging / Q000502:physiology; D000818:Animals; D001230:Aspergillus / Q000235:genetics; D001483:Base Sequence; D002453:Cell Cycle; D017124:Conserved Sequence; D018507:Gene Expression Regulation, Developmental; D005796:Genes; D005800:Genes, Fungal; D005809:Genes, Regulator; D008297:Male; D008322:Mammals; D051379:Mice; D013087:Spermatids; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology / Q000502:physiology*