Hemocyanin is an important respiratory protein in many arthropod and mollusk species. Here, four cDNAs (SpHc1, SpHc2, SpHc3, and SpHc4), encoding distinct hemocyanin subunits from Scylla paramamosain were cloned using EST analyses and the rapid amplification of cDNA ends. The four full-length cDNA fragments (SpHc1-4) were 2281, 2002, 2184, and 2069 bp, respectively, and they encoded four putative proteins (570-676 amino acids) with a molecular mass of ~65.0-76.8 kDa.
Prophenoloxidase activating factors (PPAFs) are a group of clip domain serine proteinases that can convert prophenoloxidase (pro-PO) to the active form of phenoloxidase (PO), causing melanization of pathogens. Here, two full-length PPAF cDNAs from Scylla paramamosain (SpPPAF1 and SpPPAF2) were cloned and characterized. The full-length SpPPAF1 cDNA was 1677 bp in length, including a 5'-untranslated region (UTR) of 52 bp, an open reading frame (ORF) of 1131 bp coding for a polypeptide of 376 amino acids, and a 3'-UTR of 494 bp.
The mud crab (Scylla paramamosain) is considered a potentially important marine crab species for selective breeding. Here, we first examined sex ratio and differences in 16 growth traits between females and males in a G1 population of S. paramamosain, and we then analyzed the correlation between these growth traits and their effects on body weight (BW). Of these growth traits, nine were significantly different between sexes. In females, the correlation coefficients in all trait pairs ranged from 0.524 to 0.997.
The thioredoxin (Trx) system consists of thioredoxin reductase (TrxR), Trx, and nicotinamide adenine dinucleotide phosphate (NADPH). TrxR is an NADPH-dependent oxidoreductase. Trx is a ubiquitous small protein with a redox-active disulfide bridge that plays important regulatory roles in some vital metabolic reactions. In this study, a cDNA sequence (SpTrx1) showing high identity to the first Trx gene was isolated from a hepatopancreas cDNA library of the mud crab Scylla paramamosain.
Scylla paramamosain is a widespread and commercially important species of coastal marine crab. We identified 13 polymorphic microsatellite loci from a genome library constructed with 5ꞌ-anchored PCR method. Thirty-two S. paramamosain from the East China Sea were used to analyze the characteristics of these loci. The number of alleles per locus ranged from 3 to 8, with a mean of 5.923. Observed and expected heterozygosities ranged from 0.500 to 0.875 and from 0.500 to 0.859, respectively.
In this study, we analyzed the correlation of 20 growth-related traits and their effects on body weight of Scylla paramamosain. The correlation coefficients in all trait pairs were significantly high, ranging from 0.551 to 0.999. Among 19 X-Y pairs, the correlation coefficient between traits X1 and Y was the highest, whereas that between X13 and Y was the lowest.