A comparative study of antioxidant enzyme activities in tissues of Helix aspersa (O.F.Mull.) and Pomacea bridgesi (Reeve)

Antioxidant enzymes: catalase (CAT) [EC 1.11.1.6], peroxidase [EC 1.11.1.7], glutathione reductase (GSSGR) [EC 1.6.4.2] and glucose-6-phosphate dehydrogenase (G6PDH) [EC 1.1.1.49] were investigated in terrestrial Helix aspersa (O.F. Müll.) and aquatic Pomacea bridgesi (Reeve). The activity was determined in the heamolymph and homogenates of hepatopancreas and foot muscle. No CAT and peroxidase activity was detected in the hepatopancreas and foot muscle of P. bridgesi, and its haemolymph displayed a very low CAT activity (0.005 U/mg of protein). In H. aspersa the highest activities (U/g) observed for CAT and GSSGR in the hepatopancreas were 0.40, and 1.05, respectively; for peroxidase and G6PDH in the foot muscle the respective values were 1.22 and 0.22. The activities of antioxidant enzymes determined in both snail species are much lower than the corresponding values for mammalian tissues

Identification of a fructose-1,6-bisphosphate aldolase gene and association of the single nucleotide polymorphisms with growth traits in the clam Meretrix meretrix

This study investigated whether there were single nucleotide polymorphisms (SNPs) in fructose-1,6-bisphosphate aldolase (FBA) gene associated with growth traits of the clam Meretrix meretrix. A FBA gene was identified in M. meretrix and its deduced amino acid residues shared high identity with type I aldolase. The FBA (MmeFBA) mRNA expression profile was examined by real-time PCR in different tissues and the significantly high expression level in foot and adduct muscle suggests that MmeFBA is a muscle type aldolase which functions in glycolytic pathway. In the MmeFBA gene, we identified four intron SNPs and three exon SNPs including a nonsynonymous SNP (mmfbae-2). These SNPs were genotyped in 205 clams from two clam populations with significantly different growth performance. Results showed that allele frequencies of three SNPs (mmfbai-1, mmfbai-3 and mmfbae-2) and the genotype frequency of mmfbai-1 were all significantly different between the two populations. The haplotype analysis further supported the three SNPs distributed differently between the two populations. This study successively characterized three growth-related SNPs in a gene involved in energy metabolism of M. meretrix. These findings could contribute the development of phenotype-selective breeding program in M. meretrix