Nothobranchius annual killifishes
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ABSTRACT:
SUBMITTER: Terzibasi Tozzini E
PROVIDER: S-EPMC7739477 | biostudies-literature | 2020 Jan
REPOSITORIES: biostudies-literature
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Project description:BackgroundThe annual fish Nothobranchius furzeri is characterized by a natural dichromatism with yellow-tailed and red-tailed male individuals. These differences are due to different distributions of xanthophores and erythrophores in the two morphs. Previous crossing studies have showed that dichromatism in N. furzeri is inherited as a simple Mendelian trait with the yellow morph dominant over the red morph. The causative genetic variation was mapped by linkage analysis in a chromosome region containing the Mc1r locus. However, subsequent mapping showed that Mc1r is most likely not responsible for the color difference in N. furzeri. To gain further insight into the molecular basis of this phenotype, we performed RNA-seq on F2 progeny of a cross between N. furzeri male and N. kadleci female.ResultsWe identified 210 differentially-expressed genes between yellow and red fin samples. Functional annotation analysis revealed that genes with higher transcript levels in the yellow morph are enriched for the melanin synthesis pathway indicating that xanthophores are more similar to melanophores than are the erythrophores. Genes with higher expression levels in red-tails included xanthine dehydrogenase (Xdh), coding for a biosynthetic enzyme in the pteridine synthesis pathway, and genes related to muscle contraction. Comparison of DEGs obtained in this study with genes associated with pigmentation in the Midas cichlid (A. citrinellus) reveal similarities like involvement of the melanin biosynthesis pathway, the genes Ptgir, Rasef (RAS and EF-hand domain containing), as well as genes primarily expressed in muscle such as Ttn and Ttnb (titin, titin b).ConclusionsRegulation of genes in the melanin synthetic pathway is an expected finding and shows that N. furzeri is a genetically-tractable species for studying the genetic basis of natural phenotypic variations. The current list of differentially-expressed genes can be compared with the results of fine-mapping, to reveal the genetic architecture of this natural phenotype. However, an evolutionarily-conserved role of muscle-related genes in tail fin pigmentation is novel finding and interesting perspective for the future.
| S-EPMC4168119 | biostudies-literature
Project description:BackgroundAdaptive radiations are triggered by ecological opportunity - the access to novel niche domains with abundant available resources that facilitate the formation of new ecologically divergent species. Therefore, as new species saturate niche space, clades experience a diversity-dependent slowdown of diversification over time. At the other extreme of the radiation continuum, non-adaptively radiating lineages undergo diversification with minimal niche differentiation when 'spatial opportunity' (i.e. areas with suitable 'ancestral' ecological conditions) is available. Traditionally, most research has focused on adaptive radiations, while empirical studies on non-adaptive radiations remain lagging behind. A prolific clade of African fish with extremely short lifespan (Nothobranchius killifish), show the key evolutionary features of a candidate non-adaptive radiation - primarily allopatric species with minimal niche and phenotypic divergence. Here, we test the hypothesis that Nothobranchius killifish have non-adaptively diversified. We employ phylogenetic modelling to investigate the tempo and mode of macroevolutionary diversification of these organisms.ResultsNothobranchius diversification has proceeded with minor niche differentiation and minimal morphological disparity among allopatric species. Additionally, we failed to identify evidence for a role of body size or biogeography in influencing diversification rates. Diversification has been homogeneous within this genus, with the only hotspot of species-richness not resulting from rapid diversification. However, species in sympatry show higher disparity, which may have been caused by character displacement among coexisting species.ConclusionsNothobranchius killifish have proliferated following the tempo and mode of a non-adaptive radiation. Our study confirms that this exceptionally short-lived group have diversified with minimal divergent niche adaptation, while one group of coexisting species seems to have facilitated spatial overlap among these taxa via the evolution of ecological character displacement.
| S-EPMC6327596 | biostudies-literature
Project description:Nothobranchius is a genus of small annual killifish found in Africa. Due to the relatively short lifespan, as well as easy breeding and care, Nothobranchius fish are becoming widely used as a vertebrate model system. Studying the genome and transcriptome of these fish is essential for advancing the field. In this study, we performed de novo transcriptome assembly of brain tissues from Nothobranchius guentheri using Trinity. Annotation of 104,271 potential genes (with transcripts longer than 500 bp) was carried out; for 24,967 genes (53,654 transcripts), in which at least one GO annotation was derived. We also analyzed the effect of a long-term food supplement with Torin 2, second-generation ATP-competitive inhibitor of mTOR, on the gene expression changes in brain tissue of adult N. guentheri. Overall, 1491 genes in females and 249 genes in males were differently expressed under Torin 2-supplemented diet. According to the Gene Set Enrichment Analysis (GSEA), the majority of identified genes were predominantly involved in the regulation of metabolic process, dendritic spine maintenance, circadian rhythms, retrotransposition, and immune response. Thus, we have provided the first transcriptome assembly and assessed the differential gene expression in response to exposure to Torin 2, which allow a better understanding of molecular changes in the brain tissues of adult fish in the mTOR pathway inhibition.
| S-EPMC7916979 | biostudies-literature
Project description:BACKGROUND: A laboratory inbred strain of the annual fish Nothobranchius furzeri shows exceptionally short life expectancy and accelerated expression of age markers. In this study, we analyze new wild-derived lines of this short-lived species. METHODOLOGY/PRINCIPAL FINDINGS: We characterized captive survival and age-related traits in F1 and F2 offspring of wild-caught N. furzeri. Wild-derived N. furzeri lines showed expression of lipofuscin and neurodegeneration at age 21 weeks. Median lifespan in the laboratory varied from to 20 to 23 weeks and maximum lifespan from 25 to 32 weeks. These data demonstrate that rapid age-dependent decline and short lifespan are natural characteristics of this species. The N. furzeri distribution range overlaps with gradients in altitude and aridity. Fish from more arid habitats are expected to experience a shorter survival window in the wild. We tested whether captive lines stemming from semi-arid and sub-humid habitats differ in longevity and expression of age-related traits. We detected a clear difference in age-dependent cognitive decline and a slight difference in lifespan (16% for median, 15% for maximum lifespan) between these lines. Finally, we observed shorter lifespan and accelerated expression of age-related markers in the inbred laboratory strain compared to these wild-derived lines. CONCLUSIONS/SIGNIFICANCE: Owing to large differences in aging phenotypes in different lines, N. furzeri could represent a model system for studying the genetic control of life-history traits in natural populations.
| S-EPMC2585814 | biostudies-literature
Project description:BACKGROUND:Intraspecific genetic variation of African fauna has been significantly affected by pronounced climatic fluctuations in Plio-Pleistocene, but, with the exception of large mammals, very limited empirical data on diversity of natural populations are available for savanna-dwelling animals. Nothobranchius furzeri is an annual fish from south-eastern Africa, inhabiting discrete temporary savannah pools outside main river alluvia. Their dispersal is limited and population processes affecting its genetic structure are likely a combination of those affecting terrestrial and aquatic taxa. N. furzeri is a model taxon in ageing research and several populations of known geographical origin are used in laboratory studies. Here, we analysed the genetic structure, diversity, historical demography and temporal patterns of divergence in natural populations of N. furzeri across its entire distribution range. RESULTS:Genetic structure and historical demography of N. furzeri were analysed using a combination of mitochondrial (partial cytochrome b sequences, 687 bp) and nuclear (13 microsatellites) markers in 693 fish from 36 populations. Genetic markers consistently demonstrated strong population structuring and suggested two main genetic groups associated with river basins. The split was dated to the Pliocene (>2 Mya). The northern group inhabits savannah pools across the basin of the intermittent river Chefu in south-western Mozambique and eastern Zimbabwe. The southern group (from southernmost Mozambique) is subdivided, with the River Limpopo forming a barrier (maximum divergence time 1 Mya). A strong habitat fragmentation (isolated temporary pools) is reflected in significant genetic structuring even between adjacent pools, with a major influence of genetic drift and significant isolation-by-distance. Analysis of historical demography revealed that the expansion of both groups is ongoing, supported by frequent founder effects in marginal parts of the range and evidence of secondary contact between Chefu and Limpopo populations. CONCLUSIONS:We demonstrated: (1) ancient (pre-Pleistocene) divergence between the two main N. furzeri lineages, their recent secondary contact and lack of reproductive isolation; (2) important genetic structuring attributed to the fragmented nature of their environment and isolation-by-distance, suggesting that dispersal is limited, occurs over short distances and is not directly associated with river routes; (3) an apparent role of the River Limpopo as a barrier to dispersal and gene flow.
| S-EPMC4231482 | biostudies-literature
Project description:Resveratrol, SIRT1 activator, inhibits carcinogenesis predominantly performed in transgenic animal models, orthotopic cancers of nude mice or different cancer cell lines, but its effects during process of spontaneous tumors using vertebrate models remain untested. Spontaneous liver neoplasm is an age-related disease and is inhibited by resveratrol in the annual fish Nothobranchius guentheri, which indicates that the fish can act as an excellent model to study spontaneous tumorigenesis. Totally, 175 fish were fed with resveratrol and another 175 fish for controls. Treated fish were fed with resveratrol (25 ?g/fish/day) from sexual maturity (4-month-old) until they were sacrificed at 6-, 9- and 12-month-old. Immunoblot, immunohistochemistry and co-immunoprecipitation were employed to investigate the underlying mechanisms that resveratrol inhibited age-dependent spontaneous tumorigenesis in the fish. Results showed that resveratrol increased protein level of SIRT1 and alleviated age-associated tumorigenesis in liver. With SIRT1 up-regulation, resveratrol reduced proliferation by deacetylating K-Ras and inactivating K-Ras/PI3K/AKT pathway; and promoted apoptosis through deacetylation and dephosphorylation of FoxOs, up-regulation of DLC1 and interaction between SIRT1 and DLC1, and dephosphorylation of DLC1 in spontaneous neoplasms. We established a novel short-lived fish model for understanding the molecular mechanisms of drugs on age-dependent spontaneous tumorigenesis.
| S-EPMC5589669 | biostudies-literature
Project description:In the last decade, our group has intensively studied the annual fish Nothobranchius furzeri as a new experimental model in Biology specifically applied to aging research. We previously studied adult neuronal stem cells of N. furzeri in vivo and we demonstrated an age-dependent decay in adult neurogenesis. More recently we identified and quantified the expression of miRNAs in the brain of N. furzeri and we detected 165 conserved miRNAs and found that brain aging in this fish is associated with coherent up-regulation of well-known tumor suppressor miRNAs, as well as down-regulation of well-known onco miRNAs~- In the present work we characterized the expression of miR-15a, miR-20a, and microRNA cluster 17-92 in the principal neurogenic niches of the brain of young and old subjects of N. furzeri, by using in situ hybridization techniques, together with proliferating-cell nuclear antigen immuno-staining for a simultaneous visualization of the neuronal progenitors. We found that: (1) the expression of miR-15a is higher in the brain of old subjects and concentrates mainly in the principal neurogenic niches of telencephalon and optic tectum, (2) the expression of miR-20a is higher in the brain of young subjects, but more widespread to the areas surrounding the neurogenic niches, (3) finally, the expression of the microRNA cluster 17-92 is higher in the brain of young subjects, concentrated mainly in the principal neurogenic niches of telencephalon and cerebellum, and with reduced intensity in the optic tectum. Taken together, our data show that these microRNAs, originally identified in whole-brain analysis, are specifically regulated in the stem cell niche during aging.
| S-EPMC3930850 | biostudies-literature
Project description:Summer holidays as break-point in shaping a tannery sludge microbial community around a stable core microbiota.
| PRJEB12249 | ENA
Project description:BACKGROUND: The annual fish Nothobranchius furzeri is the vertebrate with the shortest known life span in captivity. Fish of the GRZ strain live only three to four months under optimal laboratory conditions, show explosive growth, early sexual maturation and age-dependent physiological and behavioral decline, and express aging related biomarkers. Treatment with resveratrol and low temperature significantly extends the maximum life span. These features make N. furzeri a promising new vertebrate model for age research. RESULTS: To contribute to establishing N. furzeri as a new model organism, we provide a first insight into its genome and a comparison to medaka, stickleback, tetraodon and zebrafish. The N. furzeri genome contains 19 chromosomes (2n = 38). Its genome of between 1.6 and 1.9 Gb is the largest among the analyzed fish species and has, at 45%, the highest repeat content. Remarkably, tandem repeats comprise 21%, which is 4-12 times more than in the other four fish species. In addition, G+C-rich tandem repeats preferentially localize to centromeric regions. Phylogenetic analysis based on coding sequences identifies medaka as the closest relative. Genotyping of an initial set of 27 markers and multi-locus fingerprinting of one microsatellite provides the first molecular evidence that the GRZ strain is highly inbred. CONCLUSIONS: Our work presents a first basis for systematic genomic and genetic analyses aimed at understanding the mechanisms of life span determination in N. furzeri.
| S-EPMC2688266 | biostudies-literature
Project description:One of the most studied and widely accepted conjectures of aging process is the oxidative stress theory. Previous studies have shown that salidroside can protect D-galactose-induced mouse model against aging and a formulation of Rhodiola rosea extracts (SHR-5) containing salidroside increases lifespan of fruit fly. However, direct evidence linking salidroside itself with the observed anti-aging effect in vivo and relevant molecular mechanisms are poorly defined. In this study, we first demonstrated that salidroside exhibited a time-dependent effect, and late-onset long-term salidroside dietary intake extended the lifespan in the annual fish Nothobranchius guentheri. We then showed that salidroside reduced the accumulation of lipofuscin in the gills as well as the levels of protein oxidation, lipid peroxidation and reactive oxygen species in the muscles; enhanced the activities of catalase, glutathione peroxidase, and superoxide dismutase in the fish; and decelerated the increase of P66shc, a critical factor for regulation of intracellular reactive oxygen species contents. Collectively, these data indicate that salidroside can prolong the lifespan and retard the onset of age-related biomarkers via the antioxidant system in aging fish. It also suggests that salidroside may have a potential usefulness in prolonging the lifespan of the elderly.
| S-EPMC5871084 | biostudies-literature