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The Centropristis striata is an important economically marine fish and facing a serious threat from various pathogens. Edwardsiella piscicida is one of the fish pathogens that seriously infect cultured and wild fish species. To understand the molecular immune mechanisms underlying the response to E. piscicida, a comparative gene transcription analysis was performed through RNA‐Seq technology. The low‐quality sequences were excluded, and the high‐quality sequences were assembled into a total of 60,759 contigs with an average length of 988.95 bp. A gene ontology (GO) analysis was employed to classify 5744 genes according to three major functional categories: molecular function, cellular component and biological process. A total of 19,918 genes were successfully annotated into 26 functional categories according to the clusters of orthologous groups (COG) classification. Furthermore, 15,006 genes were classified into 332 KEGG pathways. The q‐value was introduced to estimate 5109 genes significantly differentially expressed which includes 1781 up‐regulated genes and 3328 down‐regulated genes. The differentially expressed genes were involved in the major immune‐related pathways which refer to the pathogen recognition, inflammation, Toll‐like receptor and chemokine signalling pathways. Moreover, 24,487 potential simple sequence repeats (SSRs) and 193,760 candidate single nucleotide polymorphisms (SNPs) were detected and identified in the C. striata liver transcriptome. This work not only provides a valuable resource for further understanding of the antibacterial molecular mechanism of C. striata but also contributes to facilitate future studies on gene expression and functional genomics. [ABSTRACT FROM AUTHOR]

Amphioxus occupies a transitional position between invertebrates and vertebrates and is therefore a promising laboratory model animal. As a powerful molecular marker in population genetics studies, microsatellite DNA is required for both the investigation of genetic diversity of a wild amphioxus population and strain breeding of laboratory cultured amphioxus. In the present study, we constructed a microsatellite-enriched DNA library of amphioxus Branchiostoma belcheri to develop this molecular marker. After screening the library and combining it with the data obtained from a public database, we successfully developed 21 pair of primers that could effectively amplify the microsatellite loci of amphioxus. Of those primer pairs, seven were in deviation of Hardy–Weinberg equilibrium, mostly caused by null alleles. The others had no linkage disequilibrium, indicating they are applicable for the genetic studies. Using those primer pairs, we further detected the genetic diversity of the wild amphioxus population in Xiamen waters. The results revealed that the number of alleles of each microsatellite locus was between three and 18 in the population, and observed and expected heterozygosities of the loci ranged from 0.415 to 0.947 and from 0.300 to 1.000, indicating very high genetic diversity of the population. [ABSTRACT FROM AUTHOR]

Objective: To analysis the effects of Talpha1 on the immune effector molecules in mouse immune system., Methods: Sixty five BABL/c mice were divided into four groups: CsA group (n=20), Talpha1 group (n= 20), CsA+Talpha1 group (n=20) and control group (n=5). In the 3 experimental groups, 10 mg/kg CsA, 400 microg/ kg Talpha1, 10 mg/kg CsA+400 microg/kg Talpha1 were respectively administrated by intraperitoneal injection daily. Luminex was performed for cytokine detection at 1 d, 7 d, 14 d, 21 d day after the above treatments. Lymphocyte culture was prepared with the mouse spleen suspension, and then treated with 0. 25 mg/mL CsA, 10 microg/mL Talpha1 or 0.25 mg/mL CsA+10 microg/mL Talpha1 in vitro, respectively. Three days later, OD values of each treated lymphocyte culture and several cytokines in the culture were measured., Results: Compared with other groups, CsA+Talpha1 group had significant lower IL-1alpha, IL-2, IL-6, IL-17, and significant higher IL-10 at 1 d, 7 d, 14 d, 21 d after the treatments (P < 0.05). Three days after the culture, OD value in the control group was significantly higher than that in Talppha1 group, CsA group, and CsA+ Talpha1 group (P < 0.05). IL-1alpa and IL-6 in the control group were significantly higher than those in the experiment groups (P < 0.05), while IL-10 in the control group was significantly lower than that in the experiment groups (P < 0.05). IL-2 and IL-17 were similar., Conclusion: Talpha1 show regulatory effect on the immune effector molecules which could promote Th1 cells transforming to Th2 cells.

One general requirement of individual laboratory animals is that they have known genetic backgrounds. However, ensuring such genetic similarity is difficult, and can be facilitated by breeding a full strain for experimentation. To this end, the authors bred 34 full-sib families of amphioxus larvae/embryos. Due to the high mortality of the embryos and larvae, only seven full-sib families of juvenile amphioxus Branchiostoma japonicum were obtained. Among them, the highest and lowest survival ratios were 32.4% and 1.67%, respectively, whereas the shortest metamorphosis and longest larva duration were 24 d and 42 d, respectively. These results demonstrate the feasibility of establishing full-sib families of amphioxus, and provide fundamental data needed for the future breeding of amphioxus strains.

Endogenous green fluorescent proteins (GFPs) have recently been found in amphioxus, where different characteristics of light production in different development stages and between different individuals have manifested. We identified the GFP genes in an amphioxus species Branchiostoma belcheri and monitored real time fluorescence signals of GFPs during different developmental stages to provide an insight on the GFP function in amphioxus. We found there are at least 12 endogenous GFP genes in amphioxus genome, and fluorescent expression changes in body position during different developmental stages. Additionally, GFP expression after metamorphosis development differed significantly among different amphioxus individuals, suggesting that there are multiple GFP homologous genes responsible for fluorescent expression. Expression levels of these genes varied significantly during different developmental stages, indicating that different GFP genes may have their unique functions in the development of amphioxus during specific phases of growth.

Amphioxus (lancelet) is an important model animal in the field of Evo-Devo study. However, the specimens for laboratorial experiments are usually sampled directly from the field. Thus, it is necessary to correctly identify species and evaluate the genetic diversity of geographic populations. In the present investigation, we amplified and sequenced COX I gene of amphioxus collected from various localities of the West Pacific Ocean and downloaded all available sequences of the gene from NCBI. Based on those sequences data, we constructed NJ tree to decide the taxonomic status of those amphioxus and performed AMOVA analysis to estimate genetic diversities among geographic populations and individuals. The current results supported the validity of the three amphioxus species, Branchiostoma malayanum, B. belcheri and B. japonicum. We also proposed that some amphioxus species names recorded in NCBI sequence database might be inaccurate. Genetic analysis on the geographic populations of amphioxus species suggested that each examined amphioxus species have a high level of genetic diversity. However, the genetic divergences among geographic populations of the same species are indetectable, indicating a frequent gene flow among them.