Project description:Cichlids fishes exhibit extensive phenotypic diversification and speciation. In this study we integrate transcriptomic and proteomic signatures from two cichlids species, identify novel open reading frames (nORFs) and perform evolutionary analysis on these nORF regions. We embark comparative transrcriptomics and proteogenomic analysis of two metabolically active tissues, the testes and liver, of two cichlid species Oreochromis niloticus (Nile tilapia, ON) and Pundamilia nyererei (Makobe Island, PN). Our results suggest that the time scale of speciation of the two species can be better explained by the evolutionary divergence of these nORF genomic regions.
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:The imbalance of intestinal flora can affect the immune function and structural integrity of the intestinal barrier, leading to the colonization and reproduction of opportunistic pathogenic bacteria in the intestine to become the dominant flora, eventually inducing enteritis. This study aimed to investigate whether fecal microbiota transplantation (FMT) could improve the gut barrier in Nile tilapia (Oreochromis niloticus). The experiment involved administering normal saline (NS group) and fecal microbiota (FMT group) (from the negative control group (C group)) to tilapia that had been treated with oxytetracycline hydrochloride (OTC) (M group) by gavage. A total of 300 male tilapia (mean body weight 596.65 ± 47.18 g) were used, with 180 of them being fed OTC (120 mg/kg body weight/day) for 7 days to induce intestinal oxidative stress, while the rest served as the control group. After confirmation of mild chronic enteritis, the tilapia were treated in different ways.
Project description:The elucidation of microRNA function and evolution depends on the identification and characterization of miRNA repertoire of strategic organisms, as the fast evolving cichlid fishes. Using RNA-seq and comparative genomics we carried out an in-depth report of miRNAs in Nile tilapia (Oreochromis niloticus). Our results enlarge vertebrate miRNAs collection and reveal a notable differential expression of miRNAs arms and isoforms influenced by sex and developmental life stage, providing a better picture of the evolutionary and spatiotemporal dynamics of miRNAs.
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.
Project description:Seawater (SW)-acclimated Nile tilapia, Oreochromis niloticus, can tolerate up to 30-ppt SW but rarely produce offspring. The embryos of SW-acclimated O. niloticus survived equally well from 0- to 10-ppt environment but not under 20 ppt. However, when the embryos were incubated under 10 ppt during days 0-3 and then the salinity was suddenly shifted to and maintained at 20 ppt during days 4-6, their survival rate was comparable to those incubated under 0 and 10 ppt. To elucidate a molecular adaptation of the embryos that survived different salinity environment, the proteomic profiles of the newly hatched embryos, or early larvae, hatched under 0 ppt, 10 ppt, and those being incubated at 10 ppt during days 0-3 followed by at 20 ppt during days 4-6 were compared.