Effects of Lycium barbarum polysaccharides on immunological parameters, apoptosis, and growth performance of Nile tilapia (Oreochromis niloticus).

In this study, the effect of Lycium barbarum polysaccharides (LBP) on immunological parameters, apoptosis, and growth performance of Nile tilapia (Oreochromis niloticus) was investigated. Dietary supplementation with LBP significantly increased complement 3 (C3) activity and promoted interleukin IL-1ß gene expression in spleen tissue, significantly reduced apoptosis in spleen tissue, increased the specific growth rate (SGR), relative length gain (LG), and relative weight gain (WG) of Nile tilapia. However, dietary supplementation with LBP did not have a significant effect on serum alkaline phosphatase (AKP), malondialdehyde (MDA), and superoxide dismutase (SOD), blood constituents, apoptosis, or gene expression of IL-1ß in liver tissue. Overall, the results showed that dietary supplementation with LBP increased the nonspecific immunity of Nile tilapia and reduced the apoptosis rate to promote growth and development. Thus, LBP has potential for use as a new immunostimulant in aquaculture.

Comprehensive Characterization of Circular RNAs in Ovary and Testis From Nile Tilapia.

Circular RNA (circRNA) is an endogenous biomolecule in eukaryotes. It has tissue- and cell-specific expression patterns and can act as a microRNA sponge or competitive endogenous RNA. Although circRNA has been found in several species in recent years, the expression profiles in fish gonad are still not fully understood. We detected the expression of circRNA in the ovary, testis, and sex-changed gonad of tilapia by high-throughput deep sequencing, and circRNA-specific computing tools. A total of 20,607 circRNAs were obtained, of which 141 were differentially expressed in the testis and ovary. Among these circRNAs, 135 circRNAs were upregulated and 6 circRNAs were downregulated in female fish. In addition, GO annotation and KEGG pathway analysis of the host genes of circRNAs indicated that these host genes were mainly involved in adherens junction, androgen production, and reproductive development, such as ZP3, PLC, delta 4a, ARHGEF10, and HSD17b3. It is worth noting that we found that circRNAs in tilapia gonads have abundant miRNA-binding sites. Among them, 935 circRNAs have a regulatory effect on miR-212, 856 circRNAs have a regulatory effect on miR-200b-3p, and 529 circRNAs have a regulatory effect on miR-200b-5p. Thus, our findings provide a new evidence for circRNA-miRNA networks in the gonads in tilapia.