Project description:<p>Copy number variation (CNV) has been recognized as a major contributor to human genome diversity. It plays an important role in determining phenotypes and has been associated with a number of common and complex diseases. However the CNV data from diverse populations is rather limited. Here we report the first investigation of copy number variation (CNV) in the indigenous populations from Peninsular Malaysia. We genotyped 34 Negrito genomes from Peninsular Malaysia using the Affymetrix SNP 6.0 microarray and identified 62 putative novel CNVs, consisting of 25 gains and 37 losses. These CNVs appear unique to the Negrito population and were absent in the DGV, HapMap3 and Singapore Genome Variation Project (SGVP) datasets. Analysis of gene ontology revealed that genes within these CNVs were enriched in the immune system (GO:0002376), response to stimulus mechanisms (GO:0050896), as well as the metabolic pathways (GO:0001852). Copy number gains in CNVRs enriched with genes were significantly higher than the losses (P value <0.001). Therefore, in view of the small population size, relative isolation and semi-normadic lifestyles of this community, we speculate that these CNVs may be attributed to recent local adaptation of Negritos from Peninsular Malaysia.</p>
Project description:Genotyping of RpoD mutants via amplicon sequencing from the following manuscript: \\"Systematic dissection of σ70 sequence diversity and function in bacteria\\" by Park and Wang (2020). Includes raw sequencing reads from samples from MAGE-seq single codon saturation mutagenesis and high-throughput fitness competition experiment as well as the RpoD ortholog mutants generated through recombineering and CRISPR selection.
Project description:Bats are remarkably long-lived for their size with many species living more than 20-40 years, suggesting that they possess efficient anti-aging and anti-cancer defenses. Here we investigated requirements for malignant transformation in primary bat fibroblasts in four bat species - little brown bat (Myotis lucifugus), big brown bat (Eptesicus fuscus), cave nectar bat (Eonycteris spelaea) and Jamaican fruit bat (Artibeus jamaicensis) – spanning the bat evolutionary tree and including the longest-lived genera. We show that bat fibroblasts do not undergo replicative senescence and express active telomerase. Bat cells displayed attenuated stress induced premature senescence with a dampened secretory phenotype. Unexpectedly, we discovered that bat cells could be readily transformed by only two oncogenic perturbations or “hits”: inactivation of either p53 or pRb and activation of oncogenic RASV12. This was surprising because other long-lived mammalian species require up to five hits for malignant transformation. Additionally, bat fibroblasts exhibited increased p53 and MDM2 transcript levels, and elevated p53-dependent apoptosis. The little brown bat showed a genomic duplication of the p53 gene. We hypothesize that bats evolved enhanced p53 activity through gene duplications and transcriptional upregulation as an additional anti-cancer strategy, similar to elephants. In summary, active telomerase and the small number of oncogenic hits sufficient to malignantly transform bat cells suggest that in vivo bats rely heavily on non-cell autonomous mechanisms of tumor suppression.