Rat transition nuclear protein 2 regulatory region directs haploid expression of reporter gene in male germ cells of transgenic mice.
During spermiogenesis, the successive replacement of somatic histones by basic proteins, the transition nuclear proteins and protamines, allows normal sperm condensation. Transition nuclear protein 2 (TNP2) is transcribed postmeiotically in round spermatids. In order to determine regulatory flanking sequences responsible for stage specific expression of TNP2 gene, different transgenic mice were generated by microinjection of fertilized eggs. We demonstrate here that 525 bp of 5'- and 920 bp of 3'-flanking sequences of rat TNP2 gene could properly and efficiently direct chloramphenicol acetyltransferase gene expression to the postmeiotic male germ cells of transgenic mice. During male germ cell differentiation the first transgene transcripts were observed in round spermatids and translation started 6 days later in elongating spermatids, which is an evidence for posttranscriptional regulation of transgene expression. In contrast, transgenic mice bearing only the 525 bp 5'-flanking sequences of rat transition protein 2 gene and 3'-flanking sequences of the simian virus 40 large T antigen showed low levels of transgene expression in testis. From these results, it can be concluded that the 525 bp 5'-flanking sequences regulate the cell specific expression and the sequences located in 920 bp 3'-flanking region either enhance the transgene expression in the male germ cells or may have a posttranscriptional role in stabilizing the mRNA in addition to its function in delaying the mRNA translation. Using comparative alignment of 5'-flanking of TNP2 genes from different species, the putative regulatory sequences are identified.
Institute of Human Genetics, University of Göttingen, Heinrich Düker Weg 12, D-37073 Göttingen, Germany.
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Nayernia
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Böhm
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Topaloglu
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Schlüter
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Engel
D020413:3' Untranslated Regions; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000096:biosynthesis / Q000235:genetics; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005796:Genes; D017930:Genes, Reporter; D006238:Haploidy; D006801:Humans; D008297:Male; D008322:Mammals / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000502:physiology*; D009928:Organ Specificity; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics; D013087:Spermatids / Q000378:metabolism*; D013091:Spermatogenesis / Q000502:physiology*; D019076:Transgenes
D020413:3' Untranslated Regions; D000952:Antigens, Polyomavirus Transforming; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C489505:Tnp2 protein, mouse; C489504:Tnp2 protein, rat; C053886:spermatid transition proteins; D015500:Chloramphenicol O-Acetyltransferase