Differential expression and subcellular localization for subunits of cAMP-dependent protein kinase during ram spermatogenesis.
The expression of mRNAs for the RI alpha, RII alpha, and C alpha subunits of cAMP-dependent protein kinase has been studied in different ram germ cells. The sizes of the specific RI alpha, RII alpha, and C alpha mRNAs, observed in germ cells were 1.6, 2.0, and 2.6 kb, respectively. RI alpha and C alpha mRNAs were mainly expressed in primary spermatocytes. A postmeiotic expression predominating in early spermatids was unique to RII alpha mRNA. The location of RI, RII alpha, and C subunits in well-defined organelles of ram spermatids and epididymal sperm was assessed by immunogold electron microscopy. In spermatids, RI, RII alpha, and C were essentially present in the forming acrosome and, to a lesser extent, in the nucleus. During sperm epididymal maturation, the protein kinases disappeared from the acrosome and were detected in a variety of sperm functional areas, such as the tip of the acrosome, the motility apparatus, and the membrane network. The present study on subunits of cAMP-dependent protein kinase supports the concept that specific functions are attached to the different subunits in that it shows differential expression and differential subcellular localization in germ cells.
Pariset
C
C
Faculté de Médecine Saint-Antonie, Université Pierre et Marie Curie, Paris.
Feinberg
J
J
Dacheux
J L
JL
Oyen
O
O
Jahnsen
T
T
Weinman
S
S
D000818:Animals; D015342:DNA Probes; D006651:Histocytochemistry; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D008854:Microscopy, Electron; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012756:Sheep; D013087:Spermatids / Q000201:enzymology* / Q000648:ultrastructure; D013091:Spermatogenesis; D013094:Spermatozoa / Q000201:enzymology* / Q000648:ultrastructure; D013347:Subcellular Fractions / Q000201:enzymology; D013737:Testis / Q000201:enzymology / Q000648:ultrastructure
D015342:DNA Probes; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011494:Protein Kinases