title: The prolactin gene, but not the growth hormone gene, is located on chromosome 9 in the rat.
abstract: Experiments from a number of laboratories, employing clonal lines of rat pituitary tumor cells (GH cells), have shown that the cellular levels of the mRNAs for prolactin and growth hormone are subject to regulation by a variety of hormones and other factors. To provide a framework for further studies of the regulation of the expression of these two genes, we have studied their chromosomal locations in the rat, employing our recently developed technique for identifying a unique gene by direct hybridization in situ with a 125I-labeled cDNA plasmid. A rat prolactin cDNA plasmid ( pPRL -1) yielded a signal significantly above that expected on a random basis over chromosomes 9 and 15 from rat FRE cells. Both chromosomes exhibited a subchromosomal clustering of silver grains near the telomere of chromosome 9 and on the short arm of chromosome 15. Control experiments with plasmid pBR322 also yielded a significant signal clustered over the short arm of chromosome 15. Hence, we conclude that chromosome 15 contains sequences homologous to pBR322 and that the prolactin gene is located near the telomere of chromosome 9 in the rat. A rat growth hormone cDNA plasmid (pBR322-GH1) yielded a signal above that expected on a random basis over FRE cell chromosomes 7, 13, and 15, although the labeling was poorer than with prolactin. The signal over chromosome 15 is probably due to sequences homologous to plasmid pBR322. The signals over chromosomes 7 and 13 showed a clear subchromosomal clustering near the centromere on chromosome 7 and near the telomere on the long arm of chromosome 13.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D005796:Genes; D008040:Genetic Linkage; D013006:Growth Hormone / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D011388:Prolactin / Q000235:genetics*; D051381:Rats
chemical_list: D011388:Prolactin; D013006:Growth Hormone