Microsatellite markers reveal genetic divergence among wild and cultured populations of Chinese sucker Myxocyprinus asiaticus

Genetic Diversity Evaluation and Population Structure Analysis of Red Swamp Crayfish (Procambarus clarkii) from Lakes and Rice Fields by SSR Markers

The red swamp crayfish (Procambarus clarkii) is an important aquatic animal and has developed as a popular aquaculture species in China. In this study, a total of 72,839 SSR motifs were identified from transcriptional data, and 20 microsatellite markers of them were finally developed to assess the genetic diversities of seven wild populations from natural lakes and nine cultured populations from rice fields. Genetic diversity was slightly higher in the cultured populations than in the wild populations. The degree of genetic differentiation between cultured populations is slight, while a moderate to a large degree of genetic differentiation between wild populations and most of the variations occurred within individuals (79%). The analysis of cluster, principal coordinate analysis and STRUCTURE were similar, and they showed that isolation-by-distance pattern was not significant. The microsatellite markers developed in this study can not only be used for genetic monitoring of population but also provide important information for the management of breeding and cultured population in red swamp crayfish.

Molecular structure, expression, and function analysis of BAFF gene in Chinese sucker, Myxocyprinus asiaticus

B cell activating factor (BAFF), belonging to the tumor necrosis factor superfamily (TNFSF), is a critical cytokine for B cell survival and immunoglobulin secretion. Here, the BAFF gene of Chinese sucker (Myxocyprinus asiaticus) (MaBAFF) was cloned using RT-PCR and RACE (rapid amplification of cDNA end) techniques. The open reading frame (ORF) of MaBAFF encodes a 272-amino acid protein containing a transmembrane domain, a TNF family signature, and a putative furin protease cleavage site as seen in BAFFs from other species. Tissue expression profiles of MaBAFF determined by absolute and relative quantification of real-time quantitative PCR (qPCR) showed that MaBAFF is widely distributed in various tissues, with the highest expression in spleen. MaBAFF can be detected during fertilized egg period by RT-PCR. Upon induction by A. hydrophila, the expression of MaBAFF was up-regulated in spleen from 48 to 72 h, and the expression of BAFF and IgM all reached a peak at 48 h in head kidney. The soluble BAFF gene (MasBAFF) had been cloned into pET30a. SDS-PAGE and Western blotting analysis confirmed that the His-MasBAFF was efficiently expressed in Escherichia coli Rosset (DE3). CCK-8 assay indicated that the MasBAFF recombinant protein (200 ng/ml) could prolong the survival of peripheral blood leukocytes. Based on ELISA screening and Western blotting, monoclonal antibody 1-F2A3 against recombinant MasBAFF was selected and used for immunohistochemistry, which showed that BAFF-positive cells were detected in spleen and head kidney. Our results raise the possibility that MaBAFF may be useful to enhance immune efficacy in Chinese sucker disease defense.