Identification of multifunctionality of glutamate dehydrogenase gene (CsGDH) and development of SNPs associated with ammonia nitrogen tolerance in clam <em>Cyclina sinensis</em>

Abstract

The full length of the CsGDH gene was 1683 bp, with an open reading frame (ORF) of 1176 bp, encoding 391 amino acids. The predicted CsGDH protein contained the conserved ELFV_dehydrog (IPR006096) functional domain at 98 aa-387 aa. Exposed to ammonia nitrogen, the transcript level of CsGDH mRNA in the hepatopancreas showed a decreasing trend, then increasing and finally decreasing. Association analysis for ammonia nitrogen tolerance traits was performed, and seven SNPs (264bp A/G, 435bp A/G, 504bp A/T, 582bp C/T, 648bp C/T, 933bp C/T, and 969bp A/G) located in the region of ORF were screened for ammonia nitrogen tolerance in the CsGDH. The two SNPs mutations of 504bp A/T and 582bp C/T were significantly associated with ammonia nitrogen tolerance (P<0.05). The above findings suggest that the CsGDH gene can be used as one of the candidate marker genes to improve ammonia nitrogen tolerant of the clam Cyclina sinensis.