RNA interference reveals chloride channel 7 gene helps short-term hypersalinity stress resistance in Hong Kong oyster Crassostrea hongkongensis

The chloride channel 7 gene(CLC 7)of the Hong Kong oyster Crassostrea hongkongensis was cloned and named ChCLC 7.The cDNA was 2572 bp in length,with a 5′non-coding region containing 25 bp,a 3′non-coding region containing 327 bp,and an open reading frame of 2298 bp.ChCLC 7 has 96.8%and 92.1%homology with CLC 7 of Crassostrea gigas and Crassostrea virginica,respectively,and it was clustered with CLC 7 of C.gigas and C.virginica.QRT-PCR showed that ChCLC 7 was expressed in all eight tissues,with the highest in adductor muscle and second in gill.The ChCLC 7 expression pattern in gill was altered significantly under high salinity stress with an overall upward and then downward trend.After RNA interference,the expression of ChCLC 7 and survival rate of oyster under high salinity stress was reduced significantly,and so did the concentration of hemolymph chloride ion in 48-96 h after RNA interference.We believed that ChCLC 7 could play an important role in osmoregulation of C.hongkongensis by regulating Cl^(-)transport.This study provided data for the analysis of molecular mechanism against oyster salinity stress.

Autosomal dominant osteopetrosis typeⅡresulting from a de novo mutation in the CLCN7 gene:A case report

BACKGROUND Osteopetrosis is a family of extremely rare diseases caused by failure of osteoclasts and impaired bone resorption. Among them, autosomal dominant osteopetrosis type Ⅱ(ADO Ⅱ), related to the chloride channel 7(CLCN7) gene, is the most frequent form of osteopetrosis. In this study, we report a de novo mutation of CLCN7 in a patient without the family history of ADO Ⅱ.CASE SUMMARY A 5-year-old Chinese boy with ADO Ⅱ was found to have a de novo mutation in the CLCN7 gene [c.746 C>T(p.P249 L)]. Typical clinical manifestations, including thickening of the cortex of spinal bones and long bones, non-traumatic fracture of the femoral neck, and femoral head necrosis, were found in this patient. The patient is the first reported case of ADO Ⅱ with the missense mutation c.746 C>T(p.P249 L) of the CLCN7 gene reported in China. We also review the available literature on ADO Ⅱ-related CLCN7 mutations, including baseline patient clinical features, special clinical significance, and common mutations.CONCLUSION Our report will enrich the understanding of mutations in ADO Ⅱ patients. The possibility of a de novo mutation should be considered in individuals who have no family history of osteopetrosis.