Expression of testicular messenger ribonucleic acid for luteinizing hormone receptor in the rat: developmental regulation of multiple transcripts during postnatal life.
On the basis of earlier observations of changing testicular LH receptor levels during postnatal development of the rat, we analyzed the levels of LH receptor mRNA transcripts in testes of rats at ages 5-70 days. Extracted testis RNA, prepared for Northern blotting, was hybridized with a specific LH receptor cRNA probe derived from subcloned cDNA corresponding to the extracellular domain of the receptor. Six LH receptor mRNA transcripts with molecular sizes of 7.8, 7.0, 4.2, 2.5, 1.8, and 1.2 kb were identified. Of these, the 1.2- and the 1.8-kb mRNA transcripts presumably code for truncated forms of LH receptor. At 5 days, only the 1.8- and the 4.2-kb mRNA transcripts were observed. Additional 7.0- and 1.2-kb transcripts appeared at 10 and 15 days, respectively. From the age of 25 days through adulthood, all six mRNA transcripts were observed. Densitometric analyses revealed that the amounts of the 7.0- and 1.8-kb mRNA transcripts correlated well with LH receptor levels, while the 4.2-kb transcript showed high levels earlier in life with poor correlation to LH receptor number. Because the 1.8 kb receptor transcript lacked transmembrane domains, the present results suggest the 7.0-kb LH receptor transcript as the likely candidate to encode the functional receptor. These data provide the basis for future analyses of the molecular regulation of LH receptor expression.
Vihko
K K
KK
Department of Gynecology and Obstetrics, Stanford University Medical Center, California 94305.
Nishimori
K
K
LaPolt
P S
PS
Hsueh
A J
AJ
D000818:Animals; D005786:Gene Expression Regulation; D008297:Male; D009929:Organ Size; D012333:RNA, Messenger / Q000032:analysis* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011974:Receptors, LH / Q000235:genetics* / Q000378:metabolism; D013737:Testis / Q000254:growth & development* / Q000378:metabolism; D014158:Transcription, Genetic
D012333:RNA, Messenger; D011974:Receptors, LH