Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1263912 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Two thirds of Earth’s species have undergone population declines, leaving many vulnerable to genomic erosion and inbreeding depression. Genetic rescue can boost fitness of small populations, but perceived risks of outbreeding depression can limit its use. We quantified these trade-offs in hundreds of endangered Pacific pocket mice (Perognathus longimembris pacificus), combining whole genome sequences with fitness data. The impacts of genomic erosion in remnant populations were reversed in an admixed breeding program, suggesting potential benefits of genetic rescue. However, differences in chromosome numbers increase the risk of genetic incompatibilities. Fitness analyses suggested that although admixed karyotypes may have reduced fertility, non-admixed mice with low heterozygosity and high genetic load had even lower fitness, pointing to a greater risk of extinction if populations remain isolated.
2025-07-12 | GSE302104 | GEO
Project description:Genomic and fitness consequences of inbreeding in an endangered carnivore
| PRJEB43377 | ENA
Project description:Metabarcoding sequencing of fecal samples to determine herbivore diets: a case study of the endangered Pacific pocket mouse
| PRJNA339295 | ENA
Project description:Background: The rapid evolution and dissemination of mobilized colistin resistance gene (mcr) family has revealed as a severe threat to the global public health. Nevertheless, dramatic reduction in the prevalence of mcr-1, the major member of mcr family, was observed after the withdrawal of colistin in animal fodder in China since 2017, demonstrating that colistin acts as a selective stress to promote the dissemination of mcr-1. As the second largest lineage, mcr-3 was firstly discovered in 2017 and has been identified from numerous sources. However, whether the spreading of mcr-3 is driven by colistin remains unknown. Methods: To this end, we investigated the global prevalence of mcr-3 from 2005 to 2022 by an up-to-date systematic review, along with a nation-wide epidemiological study to establish the change of mcr-3 prevalence in China before and after 2017. To investigate the fitness cost imposed by MCR-3 upon bacterial host, in vitro and in vivo competitive assays were employed, along with morphological study and fluorescent observation. Moreover, by replacing non-optimal codons with optimal codons, synonymous mutations were introduced into the 5’-coding region of mcr-3 to study mechanisms accounting for the distinct fitness cost conferred by MCR-1 and MCR-3. Furthermore, by combining AlphaFold and molecular dynamics (MD) simulation, we provided a complete characterization on the putative lipid A binding pocket localized at the linker domain of MCR-3. Crucially, inhibitors targeting at the putative binding pocket of MCR-1 or MCR-3 were identified from small molecules library using the pipeline of virtual screening. Findings: The global prevalence of mcr-3 increased continuously from 2005 to 2022. The average prevalence was 0.18% during 2005-2014 and rapidly increased to 3.41% during 2020-2022. The prevalence of mcr-3 in China increased from 0.79% in 2016 to 5.87% in 2019. We found that the fitness of mcr-3-bearing E. coli and empty plasmid control was comparable but higher than that of mcr-1-positive strain. Although the putative lipid A binding pocket of MCR-3 was similar to that of in MCR-1, mcr-3 occupies remarkable codon bias at the 5’-end of coding region that disrupted the stability of mRNA, further reduced its protein expression in E. coli, resulting in the low fitness burden of bacterial host. Moreover, the 5’-end codon usage frequency appeared as a critical factor related with the evolution of mcr family. Furthermore, based on the similar lipid A binding pocket among MCR family protein, we identified three novel MCR inhibitors targeting at such pocket by screening from small-molecule library, which effectively restored the colistin susceptibility of mcr-bearing E. coli. Interpretation: For the first time, we found that the prevalence of mcr-3 increased continuously during 2016-2019 in China, demonstrating that the withdrawal of colistin in husbandry failed to prevent the dissemination of mcr-3. Our study evidenced that the 5’-end codon bias appeared as a crucial regulator upon the fitness cost conferred by horizontally transferred genes. Most importantly, the putative lipid A binding pocket verified from current study was a promising target site for designing inhibitors against mcr-positive strains.
2025-06-29 | GSE300593 | GEO
Project description:A hallmark of RNA silencing is a class of ~22 nt RNAs which are processed from dsRNA precursor by Dicer. Accurate processing by Dicer is critical for the functionality of microRNAs (miRNAs). According to the current model, Dicer measures the length by anchoring the 3' overhang of the dsRNA terminus. Here we find that human Dicer binds to the 5' end of RNA and utilizes the 5' end as an additional reference point for cleavage site selection (5' counting rule). We further identify a novel motif (5'-pocket) in Dicer, which recognizes the 5' end of RNA. By analyzing miRNA population from 5'-pocket mutant Dicer expressing Dicer-null mES, we provide that the 5' pocket is significant for Dicer processing in vivo. Examination of small RNA profiles from Dicer-null mouse embryonic stem cells transfected with either wild-type or 5' pocket mutant Dice expression plasmids.
2011-07-12 | E-GEOD-27903 | biostudies-arrayexpress
Project description:Aneuploidy results in decreased cellular fitness in many different species and model systems. However, aneuploidy is commonly found in cancer cells and often correlates with aggressive growth and poor prognosis, suggesting that the impact of aneuploidy on cellular fitness is context dependent. The BRG1 (SMARCA4) subunit of the SWI/SNF chromatin remodelling complex is a tumour suppressor that is frequently lost in cancer cells. Here, we used a chromosomally stable cell line to test the effect of BRG1 loss on the evolution of aneuploidy. We find that BRG1 deletion leads to an initial loss of fitness in this cell line that improves over time. The improved fitness correlates with a gain of extra copies of chromosome 18. Notably, changes in pathways that are known to promote tolerance to aneuploidy are evident immediately upon loss of BRG1, providing an environment where karyotype changes associated with a fitness advantage can be explored. At least in some genetic backgrounds, therefore, loss of the SWI/SNF complex can contribute to tumourigenesis through tolerance of aneuploidy.
2022-03-23 | PXD014954 | Pride
Project description:Migration speed of captured breast cancer subpopulations correlates with metastatic fitness
| PRJNA777947 | ENA
Project description:This study was aimed to do genome-wide identification of fitness factors of ExPEC using an mouse infection model. A transposon (Tn) mutagenesis library (input) containing insertions of 72% of the total chromomose encoded genes was used to infect mouse. Bacteria were then recovered from the brain, lung, and spleen (output libraries) at 12 hours post infection. The genomic DNA was extracted from the input and the output libraries. The genomic fragment flanking the transposon was enriched by PCR which was then sequenced by Illumina sequencing. The insertion sites were then mapped to the genome of ExPEC PCN033 strain to identify differentially depleted genes which are genes potentially involved in fitness during infection.
2022-04-30 | GSE197084 | GEO
Project description:The delta smelt (Hypomesus transpacificus) is a pelagic fish species endemic to the Sacramento-San Joaquin Estuary in Northern California, listed as endangered under both the USA Federal and Californian State Endangered Species Acts and acts as an indicator of ecosystem health in its habitat range. Interrogative tools are required to successfully monitor effects of contaminants upon the delta smelt, and to research potential causes of population decline in this species. We used microarray technology to investigate genome-wide effects in 57-day old larvae after a 4-day exposure to ammonia; one of multiple contaminants arising from wastewater treatment plants and agricultural runoff. Genomic assessments were carried out between larvae exposed to 10 mg/L total ammonium; the lowest observed effect concentration (LOEC), and controls.
2011-05-05 | GSE29089 | GEO