Effects of Different Farming Modes on Salmo trutta fario Growth and Intestinal Microbial Community.

The gut microbiota plays a pivotal role in upholding intestinal health, fostering intestinal development, fortifying organisms against pathogen intrusion, regulating nutrient absorption, and managing the body's lipid metabolism. However, the influence of different cultivation modes on the growth indices and intestinal microbes of Salmo trutta fario remains underexplored. In this study, we employed high-throughput sequencing and bioinformatics techniques to scrutinize the intestinal microbiota in three farming modes: traditional pond aquaculture (TPA), recirculating aquaculture (RA), and flow-through aquaculture (FTA). We aimed to assess the impact of different farming methods on the water environment and Salmo trutta fario's growth performance. Our findings revealed that the final weight and weight gain rate in the FTA model surpassed those in the other two. Substantial disparities were observed in the composition, relative abundance, and diversity of Salmo trutta fario gut microbiota under different aquaculture modes. Notably, the dominant genera of Salmo trutta fario gut microbiota varied across farming modes: for instance, in the FTA model, the most prevalent genera were SC-I-84 (7.34%), Subgroup_6 (9.93%), and UTCFX1 (6.71%), while, under RA farming, they were Bacteroidetes_vadinHA17 (10.61%), MBNT15 (7.09%), and Anaeromyxoactor (6.62%). In the TPA model, dominant genera in the gut microbiota included Anaeromyxobacter (8.72%), Bacteroidetes_vadinHA17 (8.30%), and Geobacter (12.54%). From a comparative standpoint, the genus-level composition of the gut microbiota in the RA and TPA models exhibited relative similarity. The gut microbiota in the FTA model showcased the most intricate functional diversity, while TPA farming displayed a more intricate interaction pattern with the gut microbiota. Transparency, pH, dissolved oxygen, conductivity, total dissolved solids, and temperature emerged as pivotal factors influencing Salmo trutta fario gut microbiota under diverse farming conditions. These research findings offer valuable scientific insights for fostering healthy aquaculture practices and disease prevention and control measures for Salmo trutta fario, holding substantial significance for the sustainable development of the cold-water fish industry in the Qinghai-Tibet Plateau.

Deefgea salmonis sp. nov., isolated from gills of rainbow trout (Oncorhynchus mykiss).

A Gram-stain-negative, milky white, aerobic, rod-shaped bacterium named strain H3-26T was isolated from gills of Oncorhynchus mykiss in Lhasa, Tibet Autonomous Region, PR China. Strain H3-26T grew at 4-30 °C and pH 5.0-11.0 (optimum, 25 °C and pH 7.0) with 0-1% (w/v) NaCl (optimum, 0%). The 16S rRNA gene sequence of strain H3-26T showed the highest similarity to Deefgea rivuli WB 3.4-79T (98.42%), followed by Deefgea chitinilytica Nsw-4T (96.91%). Phylogenetic analysis based on 16S rRNA genes indicated that strain H3-26T was a new member of the genus Deefgea. The digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain H3-26T and Deefgea spp. were 21.2-21.9% and 76.3-77.4%, respectively. The genomic DNA G+C content of strain H3-26T was 48.74%. The predominant fatty acids were C12:0, C14:0, C16:0 and C16:1 ω7c. Based on phenotypic, phylogenetic, and genotypic data, strain H3-26T is considered to represent a novel species of the genus Deefgea, for which the name Deefgea salmonis sp. nov. is proposed. The type strain is H3-26T (= JCM 35050T = CICC 25103T).

Polymorphisms of the bone morphogenetic protein 7 gene (BMP7) and association analysis with sow productive traits.

Bone morphological protein 7 (BMP7) has been proposed to be an osteoinductive protein. Recent data have shown that BMP7 also plays a crucial role in the growth and development, and physiological function of reproductive system. To date, studies have shown an association between the BMP gene family and reproduction in many populations, but few studies have completely described this association in sow. In the present study, three sow breeds were screened out to investigate the genetic effects of the BMP7 gene. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, three single nucleotide polymorphisms (SNPs) (g.35161T>C, g.35175T>C and g.35216C>T) were identified in intron 2 of the BMP7 gene. Associations between the three SNPs and the number of piglet born alive (NBA), litter weight at birth (LBW), total number of piglet born (TNB) and litter weight at 21 days were analyzed using association analysis. Among the three SNPs, g.35161T>C was significantly associated with NBA and LBW (p<0.05), and the litter weight at 21 days (p<0.01). These results suggest that g.35161T>C is a potential candidate gene locus for litter size traits and the BMP7 gene might be associated with the quantitative trait locus (QTL) controlling the litter size. These data will provide a background for more extensive characterization of the BMP7 gene.