ADAM7, a member of the ADAM (a disintegrin and metalloprotease) gene family is specifically expressed in the mouse anterior pituitary and epididymis.
The maturation of spermatozoa in the epididymis is a complex process that requires the active involvement of the epididymal epithelium. The primary focus toward elucidating the role of the epididymis in the maturation process has been the study of epididymal secretory proteins and their interaction with spermatozoa. To date there is a paucity of information regarding epididymal epithelial cell surface proteins, which may also play important roles in epididymal function. Through a subtractive hybridization approach to identify genes specifically expressed in the caput epididymidis, the mouse homologue of a member of the ADAM (a disintegrin and metalloprotease) family of proteins was identified. This rapidly growing gene family encodes cell surface proteins that possess putative adhesion and protease domains. Northern blot analyses demonstrated that the mouse ADAM gene, termed ADAM7, is expressed in the caput region of the epididymis and in the anterior pituitary gonadotropes with no detectable expression in the twenty-six other tissues examined. Furthermore, in situ hybridization experiments revealed that the ADAM7 messenger RNA (mRNA) exhibited an apical localization within the proximal caput epididymal epithelium that may correlate with an unusual sparsely granulated endoplasmic reticulum uniquely present in the proximal region of the epididymidis and to which no known function has been ascribed. Hormonal, surgical, and genetic strategies demonstrated that ADAM7 gene expression requires, in a region-dependent manner, androgens as well as testicular factors for expression. Interestingly, the apical localization of ADAM7 mRNA is dependent upon an intact testis, because in situ hybridization analyses of the proximal caput epididymidis from a testosterone maintained castrate mouse did not show the apical localization of ADAM7 mRNA. Finally, chromosomal mapping demonstrated that the ADAM7 gene maps to the central region of mouse Chromosome 14, approximately 4-5 cM distal from the fertilin beta locus, which encodes another reproductive-specific ADAM protein.
Cornwall
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Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
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D051722:ADAM Proteins; D000595:Amino Acid Sequence; D000728:Androgens / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002478:Cells, Cultured; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D004822:Epididymis / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D013739:Testosterone / Q000494:pharmacology
D000728:Androgens; D018076:DNA, Complementary; D008565:Membrane Proteins; D012333:RNA, Messenger; D013739:Testosterone; D051722:ADAM Proteins; C484106:Adam7 protein, mouse