Project description:Commercial production of tilapia relies on monosex cultures of males, which so far proved difficult to maintain in large scale production facilities. Thus, a better understanding of the genetic architecture of the complex trait of sex determination in tilapia is needed.We aimed to detect genes that were differentially expressed by gender at early embryonic development. Artificial fertilization of O. niloticus females with either sex-reversed males (ΔXX) or genetically-modified YY 'supermales' resulted in all-female and all-male embryos, respectively. Pools of all-female and all-male embryos at 2, 5 and 9 days post fertilization were used for custom Agilent eArray. 56 pool samples of Nile tilapia full siblings groups (female or male) at day 2, 5 or 9 post fertilization were subjected to total RNA extraction from whole embryo tissues and hybridized to the custom Agilent array. Each sample was yielded from different cross of artificial fertilization: six dams X five sires. The resulting gender were known based on the sire, sex-reversed males (ΔXX) or genetically-modified YY 'supermales' resulted in all-female and all-male embryos, respectively.
Project description:Oreochromis niloticus represents a critically important species in the aquaculture industry due to its economic significance. Probiotics used as feed additives are known to enhance the growth performance and health of tilapia. However, the underlying mechanisms by which these benefits are conferred remain poorly understood. Here, we demonstrate that Lactobacillus salivarius exhibits significant growth performance-enhancing effects when used as a feed additive. Utilizing multi-omics approaches, our results revealed that L. salivarius significantly modulates the composition and abundance of the intestinal microbiota. Bile acids, choline, and tryptophan were identified as pivotal factors in the microbial-mediated modulation of systemic metabolism. Additionally, we have delineated a single-cell atlas of the tilapia intestine for the first time, discovering that L. salivarius_01 increases the populations of intestinal epithelial cells, immune cells, and epithelial stem cells. A broad spectrum of developmentally relevant genes and pathways were found to be activated. This study significantly advances the application of probiotics in promoting sustainable aquaculture practices.
