Expression of a rat vasopressin transgene in rat testes.
The rat vasopressin gene contains two transcriptional promoters; the activity of one is confined to the hypothalamus, while the other is testis specific. To define the sequences mediating the cell-specific expression of the vasopressin gene, we introduced rat vasopressin transgenes into the rat germ line. Neither transgene 1.5-V beta gal-0.2, which consists of the entire vasopressin structural gene containing a 3 kbp beta-galactosidase reporter element in exon III, flanked by 1.5 kbp upstream of the start of hypothalamic transcription and 0.2 kbp downstream of the polyadenylation site, nor transgene 3-V beta gal-0.2, which consists of the entire VP structural gene containing a 3 kbp beta-galactosidase reporter element in exon III, flanked by 3 kbp upstream of the start of hypothalamic transcription and 0.2kbp downstream of the polyadenylation site, were expressed in the hypothalamus. This contrasts with a previously described transgene consisting of the rat vasopressin structural gene containing a reporter in exon III, flanked by 5 kbp of upstream and 3 kbp of downstream sequences, which is expressed in vasopressinergic hypothalamic neurons. Both the 3-V beta gal-0.2 and 1.5-V beta gal-0.2 transgenes were expressed in testicular germ cells using a promoter located within the beta-galactosidase reporter element. Transgene RNA was most abundant during the late stages of meiosis. Rats bearing vasopressin-beta-galactosidase transgenes provide new models for the study of the mechanisms whereby an epigenetic choice is made between the use of a germ cell or a somatic promoter, and the stage-specific transcriptional regulation of a germ cell promoter during spermatogenesis.
Zeng
Q
Q
Neuropeptide Laboratory, Institute of Molecular and Cell Biology, Republic of Singapore.
Foo
N C
NC
Funkhouser
J M
JM
Carter
D A
DA
Murphy
D
D
D000818:Animals; D030801:Animals, Genetically Modified; D002874:Chromosome Mapping; D005091:Exons; D015870:Gene Expression; D005796:Genes; D016678:Genome; D007031:Hypothalamus / Q000502:physiology; D017403:In Situ Hybridization; D008297:Male; D011401:Promoter Regions, Genetic; D012313:RNA / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000502:physiology*; D014667:Vasopressins / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics
D014667:Vasopressins; D012313:RNA; D001616:beta-Galactosidase