Identification of ADAM10 and ADAM17 with potential roles in the spermatogenesis of the Chinese mitten crab, Eriocheir sinensis.

The ADAM (a disintegrin and metalloprotease) family plays an important role in sperm and egg fusion, development, inflammation, adhesion and migration. ADAM10 and ADAM17 are involved in the spermatogenesis. To better understand the role of ADAM10 and ADAM17 in the Chinese mitten crab, Eriocheir sinensis, the full-length cDNAs of ADAM10 and ADAM17 were cloned, and named Es-ADAM10 and Es-ADAM17, respectively. Sequence and structural analysis showed that Es-ADAM10 and Es-ADAM17 have the typical structure of the ADAM family. Quantitative real-time reverse transcription polymerase chain reaction analysis showed that Es-ADAM10 and Es-ADAM17 mRNAs were distributed in the heart, hepatopancreas, intestines, brain, muscle, thoracic ganglia, hemolymph, stomach, testis, ovary, gill and accessory gland. Both mRNAs were highly expressed in the muscles, and relatively high in the testis, ovary and accessory gland. In addition, the Es-ADAM17 mRNA level was detected in every stage of testis development, being relatively high from July to September, the lowest during October and November, increasing from December to January, and reached a peak in January. By contrast, the expression of Es-ADAM10 mRNA was constant during testis development. Immunofluorescence further showed that Es-ADAM10 and Es-ADAM17 proteins were present in the cytoplasm and cytomembrane of spermatocytes, and both detected in the sperm. Furthermore, etoposide induced upregulation of Es-ADAM17 and Es-ADAM10 at both the mRNA and protein levels. This study first showed that Es-ADAM10 and Es-ADAM17 were also involved in the spermatogenesis and mainly participated in the later germ cell apoptosis in E. sinensis.