Expression of mannose 6-phosphate receptor messenger ribonucleic acids in mouse spermatogenic and Sertoli cells.
Spermatogenic and Sertoli cells isolated from the mouse synthesize different proportions of the two mannose 6-phosphate receptors (MPR) during overnight culture periods (O'Brien et al., Endocrinology 1989; 125:2973). To determine the relative expression of MPR mRNAs in these cells, poly(A)+ RNAs were examined by Northern blot analysis using cDNA probes specific for the cation-independent (CI) and cation-dependent (CD) MPRs. A single CI-MPR transcript, approximately 10 kb in size, was present in all tissues and cell types examined. Like the CI-MPR protein, this transcript was more abundant in Sertoli cells than in spermatogenic cells isolated from adult testes. The CD-MPR is the predominant MPR synthesized by pachytene spermatocytes or round spermatids. Multiple CD-MPR transcripts were detected in these cells, including a 2.4-kb CD-MPR mRNA that was indistinguishable from CD-MPR transcripts in somatic tissues and Sertoli cells. Smaller CD-MPR mRNAs of approximately 1.4 and 1.6 kb were prominent in pachytene spermatocytes and round spermatids, respectively, but were faint or undetectable in somatic tissues. These smaller CD-MPR mRNAs did not hybridize with an 0.9-kb restriction fragment derived from the CD-MPR 3' untranslated region (UTR), suggesting that alternate polyadenylation signals are used to produce multiple CD-MPR transcripts in spermatogenic cells. When poly(A) tracts were selectively removed from germ cell RNAs by ribonuclease H treatment, identical 1.3-kb CD-MPR mRNAs were detected in pachytene spermatocytes and round spermatids, indicating that the size difference between the 1.4- and 1.6-kb transcripts is due to variations in poly(A) tail length.(ABSTRACT TRUNCATED AT 250 WORDS)
O'Brien
D A
DA
Department of Pediatrics, University of North Carolina at Chapel Hill 27599-7500.
Welch
J E
JE
Fulcher
K D
KD
Eddy
E M
EM
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D015342:DNA Probes; D015870:Gene Expression; D008297:Male; D051379:Mice; D009693:Nucleic Acid Hybridization; D011061:Poly A / Q000737:chemistry; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D017527:Receptor, IGF Type 2 / Q000096:biosynthesis / Q000235:genetics*; D012708:Sertoli Cells / Q000378:metabolism*; D013087:Spermatids / Q000378:metabolism; D013090:Spermatocytes / Q000378:metabolism; D013091:Spermatogenesis
D015342:DNA Probes; D012333:RNA, Messenger; D017527:Receptor, IGF Type 2; D011061:Poly A