Project description:Investigation of the genetic diversity of Emiliania huxleyi, genomic DNA from 15 different strains were compared with the genomic DNA of the sequenced E. huxleyi strain CCMP1516. Gephyrocapsa oceanica and Isochrysis galbana as phylogenetic closely related taxa were used as out-groups.
Project description:With the advent of advanced sequencing technology, studies of RNA viruses have shown that genetic diversity contribute to both attenuation and virulence. The differences in genetic diversity of wild-type Asibi virus and 17D-204 vaccine provides an unique opportunity to investigate RNA population theory in the context of a well described live attenuated vaccine. Utilizing infectious clone-derived viruses containing some of the amino acid substitutions that differentiate yellow fever wild-type Asibi strain from 17D vaccine and recovered in a controlled experiment, establishes that the genetic diversity differences that exist between wild-type Asibi and 17D-204 vaccine viruses are not influenced by either different passage history or source of samples, but rather resulted from the attenuation of wild-type Asibi virus to yield the 17D vaccine sub-strains.
Project description:Natural epigenetic variation provides a source for the generation of phenotypic diversity, but to understand its contribution to phenotypic diversity, its interaction with genetic variation requires further investigation. MethylC-seq from naturally-occurring Arabidopsis accessions
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:There are very few studies exploring the genetic diversity of tick-borne encephalitis complex viruses. Most of the viruses have been sequenced using capillary electrophoresis, however, very few viruses have been analyzed using deep sequencing to look at the genotypes in each virus population. In this study, different viruses and strains belonging to the tick-borne encephalitis complex were sequenced and genetic diversity was analyzed. Shannon entropy and single nucleotide variants were used to compare the viruses. Then genetic diversity was compared to the phylogenetic relationship of the viruses.
Project description:Natural epigenetic variation provides a source for the generation of phenotypic diversity, but to understand its contribution to phenotypic diversity, its interaction with genetic variation requires further investigation.
Project description:Glioblastoma multiforme (GBM) is a lethal malignancy whose clinical intransigence has been linked to extensive intra-clonal genetic and phenotypic diversity and therapeutic resistance of cancer stem cells (CSCs). This interpretation embodies an implicit assumption that CSCs are themselves genetically diverse. To test this, we screened neurosphere cultures by SNP arrays to identify copy number alterations (CNA) (minimum of three) that could be visualised in single cells by multi-colour FISH. Interrogation of neurosphere-derived cells (from four patients) and cells derived from secondary transplants of these same cells in Nod/Scid mice allowed us to infer clonal phylogenic architecture and the likely derivation of functional CSCs. This proof-of-principle experiment revealed that more than one sub-clone (but not all) in each GBM had functionally defined, genetically distinct stem cells.