Co-modulation of Liver Genes and Intestinal Microbiome of Largemouth Bass Larvae (Micropterus salmoides) During Weaning

Abstract

In recent years, largemouth bass have become one of the most commonly aquacultured species in China, however, its low survival rate during larval weaning has always been a bottleneck that has restricted industrial development. Understanding the changes in liver metabolism and intestinal microflora during the weaning of largemouth bass larvae can help to design better weaning strategies and improve survival. In this study, liver mRNA and intestinal microflora 16S rRNA genes were analyzed using high-throughput sequencing at the pre, mid, and post weaning stages [15, 30, 45 days post hatching; total length (cm) were 2.21 ± 0.12, 3.45 ± 0.21, 5.29 ± 0.33, respectively]. The transcriptome results revealed that the genes with increased expression were related to amino acid metabolism in the pre-weaning stage, but they were related to fatty acid metabolism in the post-weaning stage. A similar phenomenon was observed in the intestinal microflora where the dominant microbe Proteobacteria (relative abundance 56.32%) in the pre-weaning stage was gradually replaced by Firmicutes (relative abundance 62.81%) by the post-weaning stage. In addition, the three most important digestive enzymes (trypsin, lipase, and amylase) in the intestine were significantly decreased during the mid-weaning stage (P < 0.05), which was also true for some genes crucial to immune pathways in the liver. Overall, these findings showed that weaning in largemouth bass can cause changes in liver metabolism and intestinal microbial communities, which has improved our understanding of fish adaptation to changes in food sources during weaning.

Exploration of appetite regulation in Yangtze sturgeon (Acipenser dabryanus) during dietary transition

“…Peng et al [18] found that 24,819 genes were differentially expressed between mandarin sh fed live prey sh and dead prey sh. Kobayashi et al [29] found that the expression of C3, C4 and IGA in piglets was upregulated after dietary transition [30], and Ma et al found that the lack of magnesium or supplementation of zinc after dietary transition led to increased C3 levels in the plasma of mice and piglets [31,32], which was consistent with our results. In the failed Yangtze sturgeon, the expression levels of factors related to the complement and coagulation cascade pathway were up-regulated.…”

Effects of feed transition on digestive tract digestive enzyme, morphology and intestinal community in cuttlefish (Sepia pharaonis)

“…We observed significant decreases in chymotrypsin and lipase enzymes at 40 DPH. Similar to largemouth bass, the digestive enzymes and digestibility of commercial feeds decreased during feed transition (Zhao et al, 2020). Conversely, pike perch showed no difference in the digestibility of live prey with compound feed (Hamza et al, 2007), which may correlate with the digestive capacity of different species.…”

“…The animal intestine plays a crucial role in nutrient absorption and metabolism, and represents the first line of defense against pathogens and environmental stresses (Sonnenburg and Bäckhed, 2016). Several studies have shown that changes in the feed may significantly affect the composition of the intestine microbiota and digestive enzyme capabilities (Zhao et al, 2012;Iehata et al, 2015;Zhao et al, 2020). Animals possess indigenous intestinal microbiota and stable digestive enzymes play an important role in food digestion, nutrient absorption, and the health of the host (Nayak, 2010;Ray et al, 2012).…”

“…To further understand the connection between changes in the intestinal microbes and host metabolism, the amino acid and lipid metabolic pathways in the metabolome were further analyzed. A correlation analysis involving the top five microbial families, revealed the changes of several major microbes are strongly correlated with the host amino acid and lipid metabolic pathways (Zhao et al, 2020). Thus, the feed transition effects on cuttlefish should be further investigated at the transcriptomic and metabolomic levels.…”

Anisakis Allergy: Is Aquacultured Fish a Safe and Alternative Food to Wild-Capture Fisheries for Anisakis simplex-Sensitized Patients?

“…As previously reported, the aquaculture industry has outpaced wild-capture fisheries for over two decades and currently produce nearly 50% of all seafood consumed globally. As wild-capture fisheries continue to decline, aquaculture’s role in food production will continuously grow [ 47 , 48 , 49 ].…”