Expression of a glyceraldehyde 3-phosphate dehydrogenase gene specific to mouse spermatogenic cells.
A cDNA clone encoding a putative glyceraldehyde 3-phosphate dehydrogenase (GAPD-S) protein specific to spermatogenic cells was isolated from a mouse spermatogenic cell expression library. The Gapd-s cDNA contained 1451 bp of transcribed sequence, including an ATG initiation codon and a poly(A) addition signal. The location of the Gapd-s initiation codon differed from that of other Gapd sequences, resulting in a germ cell GAPD-S protein predicted to contain 105 additional residues at the amino terminus. While GAPD is constitutively expressed in somatic tissues, Northern blot analysis demonstrated that a Gapd-s probe hybridized to a 1.5-kb transcript present only in the testis. The Gapd-s mRNA was first detected during postnatal development in the testes of 20-day-old mice, suggesting that gene expression begins shortly after the appearance of haploid round spermatids. Northern analysis of RNA from isolated mouse pachytene spermatocytes and spermatids confirmed that Gapd-s expression is confined to post-meiotic germ cells. GAPD has been previously proposed to be the key enzyme regulating glycolysis in isolated round spermatids. We hypothesize that the GAPD-S enzyme plays an important role in regulating the switch between different pathways for energy production during spermiogenesis and in the spermatozoon.
Welch
J E
JE
Gamete Biology Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709.
Schatte
E C
EC
O'Brien
D A
DA
Eddy
E M
EM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics*; D006238:Haploidy; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D012313:RNA / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013091:Spermatogenesis / Q000235:genetics; D013094:Spermatozoa / Q000201:enzymology*; D014158:Transcription, Genetic
D012313:RNA; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases