Project description:Triple-negative breast cancer (TNBC) lacks therapeutic target and is difficult to treat. We report a cationic antimicrobial peptide (CAP), tilapia piscidin 4 (TP4), derived from Nile tilapia (Oreochromis niloticus), selectively toxic to TNBC. Here we aim to identify potential target in TNBC cell response to TP4 treatment by microarray study and to further address the role of TP4-resposive genes involved in TNBC cell death.
Project description:Evolutionary alterations to cis-regulatory sequences are likely to cause adaptive phenotypic complexity, through orchestrating changes in cellular proliferation, identity and communication. For non-model organisms with adaptive key-innovations, patterns of regulatory evolution have been predominantly limited to targeted sequence-based analyses. Chromatin-immunoprecipitation with high-throughput sequencing (ChIP-seq) is a technology that has only been used in genetic model systems and is a powerful experimental tool to screen for active cis-regulatory elements. Here, we show that it can also be used in ecological model systems and permits genome-wide functional exploration of cis-regulatory elements. As a proof of concept, we use ChIP-seq technology in adult fin tissue of the cichlid fish Oreochromis niloticus to map active promoter elements, as indicated by occupancy of trimethylated Histone H3 Lysine 4 (H3K4me3). The fact that cichlids are one of the most phenotypically diverse and species-rich families of vertebrates could make them a perfect model system for the further in-depth analysis of the evolution of transcriptional regulation. examination of H3K4me3 in adult fin tissue of the Nile tilapia (Oreochromis niloticus)
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: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:Transcriptional plasticity is a major driver of phenotypic differences between species. The lower temperature limit (LTL), namely the lower end of survival temperature, is an important trait delimiting the geographical distribution of a species, however, the genetic mechanisms are poorly understood. We investigated the inter-species transcriptional diversification in cold responses between zebrafish Danio rerio and tilapia Oreochromis niloticus, which were reared at a common temperature (28°C) but have distinct LTLs. We identified significant expressional divergence between the two species in the orthologous genes from gills when the temperature cooled to the LTL of tilapia (8°C). Five KEGG pathways were found sequentially over-represented in the zebrafish/tilapia divergently expressed genes in the duration (12 hour) of 8°C exposure, forming a signaling cascade from metabolic regulation to apoptosis via FoxO signaling. Consistently, we found differential progression of apoptosis in the gills of the two species in which zebrafish manifested a delayed and milder apoptotic phenotype than tilapia, corresponding with a lower LTL of zebrafish. We identified diverged expression in 25 apoptosis-related transcription factors between the two species which forms an interacting network with diverged factors involving the FoxO signaling and metabolic regulation. We propose a genetic network which regulates LTL in fishes. Examination of gene expressional divergence in gill between zebrafish and tilapia
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.
