S-EPMC9326183 - Chromosome-level genome of Tibetan naked carp (Gymnocypris przewalskii) provides insights into Tibetan highland adaptation. - OmicsDI

Unknown

Dataset Information

Chromosome-level genome of Tibetan naked carp (Gymnocypris przewalskii) provides insights into Tibetan highland adaptation.

ABSTRACT: Gymnocypris przewalskii, a cyprinid fish endemic to the Qinghai-Tibetan Plateau, has evolved unique morphological, physiological and genetic characteristics to adapt to the highland environment. Herein, we assembled a high-quality G. przewalskii tetraploid genome with a size of 2.03 Gb and scaffold N50 of 44.93 Mb, which was anchored onto 46 chromosomes. The comparative analysis suggested that gene families related to highland adaptation were significantly expanded in G. przewalskii. According to the G. przewalskii genome, we evaluated the phylogenetic relationship of 13 schizothoracine fishes, and inferred that the demographic history of G. przewalskii was strongly associated with geographic and eco-environmental alterations. We noticed that G. przewalskii experienced whole-genome duplication, and genes preserved post duplication were functionally associated with adaptation to high salinity and alkalinity. In conclusion, a chromosome-scale G. przewalskii genome provides an important genomic resource for teleost fish, and will particularly promote our understanding of the molecular evolution and speciation of fish in the highland environment.

SUBMITTER: Tian F

PROVIDER: S-EPMC9326183 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature

altmetric image

Publications

Chromosome-level genome of Tibetan naked carp (Gymnocypris przewalskii) provides insights into Tibetan highland adaptation.

Tian Fei F Liu Sijia S Zhou Bingzheng B Tang Yongtao Y Zhang Yu Y Zhang Cunfang C Zhao Kai K

DNA research : an international journal for rapid publication of reports on genes and genomes 20220601 4

Gymnocypris przewalskii, a cyprinid fish endemic to the Qinghai-Tibetan Plateau, has evolved unique morphological, physiological and genetic characteristics to adapt to the highland environment. Herein, we assembled a high-quality G. przewalskii tetraploid genome with a size of 2.03 Gb and scaffold N50 of 44.93 Mb, which was anchored onto 46 chromosomes. The comparative analysis suggested that gene families related to highland adaptation were significantly expanded in G. przewalskii. According t ...[more]

Similar Datasets

Project description:BackgroundThe Tibetan highland fish, Gymnocypris przewalskii, migrates from Lake Qinghai to its spawning grounds every summer. This seasonal reproduction is critically regulated by intrinsic and extrinsic signals. However, the molecular mechanisms that process environmental oscillations to initiate the seasonal mating are largely unknown.ResultsA transcriptomic analysis was conducted on the brain and gonad of male and female G. przewalskii in reproductive and nonreproductive seasons. We obtained 2034, 760, 1158 and 17,856 differentially expressed genes between the reproductively active and dormant female brain, male brain, ovary and testis. Among these genes, DIO2 was upregulated in the reproductively active brain and gonad of both males and females. Neuroactive ligand-receptor genes were activated in male and female brain. Functional enrichment analysis suggested that retinol metabolism was uniquely stimulated in reproductively active males. Genes involved in GnRH signaling and sex hormone synthesis exhibited higher expression levels in brain and gonad during the reproductive season. A co-expression network classified all the genes into 9 modules. The network pinpointed CDC42 as the hub gene that connected the pathways in responsible for modulating reproduction in G. przewalskii. Meanwhile, the sex pheromone receptor gene prostaglandin receptor was identified to link to multiple endocrine receptors, such as GnRHR2 in the network.ConclusionsThe current study profiled transcriptomic variations between reproductively active and dormant fish, highlighting the potential regulatory mechanisms of seasonal reproduction in G. przewalskii. Our data suggested that the seasonal regulation of reproduction in G. przewalskii was controlled by the external stimulation of photoperiodic variations. The activated transcription of neuroendocrine and sex hormone synthesis genes contributed to seasonal reproduction regulation in G. przewalskii, which was presumably influenced by the increased day-length during the breeding season.

Project description:BackgroundCopper was used for many years in aquaculture operations as an effective algaecide or a parasite treatment of fish. It is an essential nutrient with numerous functions in organisms, but is toxic at high concentrations. However, the toxicity of copper to fish remains unclear. In this study, we used the piebald naked carp, Gymnocypris eckloni, as a model. RNA-seq data from different tissues, including gills, kidney, and liver, were used to investigate the underlying mechanism of copper toxicology in G. eckloni.ResultsWe compared the transcriptomes from different tissues with different time durations of copper ion treatment. After 72 h copper ion treatment, the number of genes with different expression in gills and liver changed dramatically, but not in kidneys. In KEGG functional enrichment, the pattern of differentially expressed genes (DEGs) was also similar in the gills and liver. The most enriched pathway of DEGs was "Ribosome" in both tissues. Furthermore, we analyzed the expression levels of genes involved in oxidative stress response and protein synthesis using qPCR and RNA-seq data. Our results showed that several genes involved in oxidative stress response were up-regulated both in gills and liver. Up-regulation of these genes indicated that copper treatment caused oxidative stress, which is likely to result in ribosome damage. In addition, our results showed that the expression of Eef1b2, a transcription elongation factor, was decreased in the liver under oxidative stress, and the expression of translation initiation factors Eif4ebp1 and eIF2α, and elongation factor eEF2 was up-regulated. These results supported the idea that oxidative stress inhibits protein synthesis in cells.ConclusionsOur results indicate that copper exposure caused different responses in different tissues, since the gene expression patterns changed substantially either in the gills or liver, while the effect on the kidney was relatively weak. Furthermore, our results indicated that the expression pattern of the genes involved in the ribosome, which is a complex molecular machine orchestrating protein synthesis in the cell, together with translation initiation factor and elongation factors, were affected by copper exposure both in the gills and liver of piebald naked carp. This result leads us to speculate that the downregulation of global protein synthesis is an acute response strategy of fish to metal-induced oxidative stress. Moreover, we speculate that this strategy not only exists in the selective translation of proteins but also exists in the specific translation of functional proteins in tissues and cells.

Project description:Gymnocypris przewalskii is an exclusively cyprinid fish that inhabits Lake Qinghai, which is characterized by high salinity and alkalinity. To elucidate the molecular basis of the adaptation of G. przewalskii to a wide range of salinity‒alkalinity conditions, we performed morphological, biochemical, transcriptomic and proteomic analyses of the major osmoregulatory organs of the gills and kidney. Morphological examination revealed that mitochondria-rich cells were replaced by mucus cells in the gills during the transition of G. przewalskii from freshwater to lake water. In the kidney, the tight junction formed dense structure in the renal tubules under lake water condition compared with the loose structure in freshwater. The results of the biochemical assays revealed an increased content of total amino acids, indicating their potential roles as osmolytes and energy supplies in freshwater. The decreased urea concentration suggested that urea synthesis might not be involved in the detoxicity of ammonia. The transcriptomic and proteomic data revealed that genes involved in ion absorption and ammonia excretion were activated in freshwater and that genes involved in cell junction and glutamine synthesis were induced in lake water, which was consistent with the morphological and biochemical observations. Together with the higher levels of glutamine and glutamate, we proposed that G. przewalskii alleviated the toxic effect of ammonia direct excretion through gills under freshwater and the activation of the conversion of glutamate to glutamine under high saline-alkaline condition. Our results revealed different expression profiles of genes involved in metabolic pathways, including the upregulation of genes involved in energy production in freshwater and the induction of genes involved in the synthesis of acetylneuramic acid and sphingolipid in soda lake water. In conclusion, the appearance of mitochondria-rich cells and increased energy production might contribute to ion absorption in G. przewalskii to maintain ion and solute homeostasis in freshwater. The existence of mucus cells and dense junctions, which are associated with increased gene expression, might be related to the adaptation of G. przewalskii to high salinity-alkalinity.