Project description:ZIKV strains belong to three phylogenetic lineages: East African, West African, and Asian/American. RNA virus genomes exist as populations of genetically-related sequences whose heterogeneity may impact viral fitness, evolution, and virulence. The genetic diversity of representative ZIKVs (N=7) from each lineage was examined using next generation sequencing (NGS) paired with downstream Shannon entropy calculation and single nucleotide variant (SNV) analysis. This comprehensive analysis of ZIKV genetic diversity provides insight into the genetic diversity of ZKIV and repository of SNV positions across lineages.
Project description:Zika virus (ZIKV) is a mosquito-transmitted positive-sense RNA virus in the family Flaviviridae. ZIKV infections are associated with neurodevelopmental deficiencies termed Congenital Zika Syndrome. ZIKV strains are grouped into three phylogenetic lineages: East African, West African, and Asian, which contains the American lineage. RNA virus genomes exist as genetically-related sequences. The heterogeneity of these viral populations is implicated in viral fitness, and genome diversity is correlated to virulence. This study examines genetic diversity of representative ZIKV strains from all lineages utilizing next generation sequencing (NGS). Inter-lineage diversity results indicate that ZIKV lineages differ broadly from each other; however, intra-lineage comparisons of American ZIKV strains isolated from human serum or placenta show differences in diversity when compared to ZIKVs from Asia and West Africa. This study describes the first comprehensive NGS analysis of all ZIKV lineages and posits that sub-consensus-level diversity may provide a framework for understanding ZIKV fitness during infection.
Project description:Naïve T cells respond to antigen stimulation by exiting from quiescence into clonal expansion and functional differentiation, but the control mechanism is elusive. Here we describe that Raptor/mTORC1-dependent metabolic reprogramming is a central determinant of this transitional process. Loss of Raptor abrogates T cell priming and Th2 cell differentiation, although Raptor function is less important for continuous proliferation of actively cycling cells. mTORC1 coordinates multiple metabolic programs in T cells including glycolysis, lipid synthesis and oxidative phosphorylation to mediate antigen-triggered exit from quiescence. mTORC1 further links glucose metabolism to the initiation of Th2 differentiation by orchestrating cytokine receptor expression and cytokine responsiveness. Activation of Raptor/mTORC1 integrates T cell receptor (TCR) and CD28 co-stimulatory signals in antigen-stimulated T cells. Our studies identify a Raptor/mTORC1-dependent pathway linking signal-dependent metabolic reprogramming to quiescence exit, and this in turn coordinates lymphocyte activation and fate decisions in adaptive immunity. We used microarrays to explore the gene expression profiles differentially expressed in CD4+ T-cells from wild-type (WT) and CD4(cre) x Raptor(fl/fl) mice before and after stimulation with anti CD3/CD28 antibodies.
Project description:Purpose: To investigate the involvement of mTORC1 as a mediator of the actions of the PPARγ ligand rosiglitazone in subcutaneous inguinal white adipose tissue transcriptome; Methods: Mice bearing regulatory associated protein of mTOR (Raptor) deletion and therefore mTORC1 deficiency exclusively in adipocytes (adiponectin Cre recombinase) and littermate controls were fed a high-fat diet supplemented or not with the PPARγ agonist rosiglitazone (30 mg/kg/day) for 8 weeks and evaluated for inguinal white adipose tissue transcriptome (Rnaseq); Results: 3,2425 genes had their correspondent mRNA levels altered by either adipocyte Raptor deficiency or rosiglitazone administration or their combination. Among those, 408 genes modulated by rosiglitazone required mTORC1. Conclusion: PPARγ and mTORC1 are essential partners in the regulation of a cluster of genes in inguinal white adipose tissue.
Project description:East African cichlid fishes have diversified in an explosive fashion, but the (epi)genetic basis of the phenotypic diversity of these fishes remains largely unknown. Although transposable elements (TEs) have been associated with phenotypic variation in cichlids, little is known about their transcriptional activity and epigenetic silencing. Here, we describe dynamic patterns of TE expression in African cichlid gonads and during early development. Orthology inference revealed an expansion of piwil1 genes in Lake Malawi cichlids, likely driven by PiggyBac TEs. The expanded piwil1 copies have signatures of positive selection and retain amino acid residues essential for catalytic activity. Furthermore, the gonads of African cichlids express a Piwi-interacting RNA (piRNA) pathway that target TEs. We define the genomic sites of piRNA production in African cichlids and find divergence in closely related species, in line with fast evolution of piRNA-producing loci. Our findings suggest dynamic co-evolution of TEs and host silencing pathways in the African cichlid radiations. We propose that this co-evolution has contributed to cichlid genomic diversity.