Dr. Namita Tripathi

During my PhD I have worked on a project involving molecular investigation of the composition, organization and evolution of sex chromosomes and genetic analysis of the sex chromosome linked traits of guppy (Poecilia reticulata). I  used a set of approaches to generate several EST or BAC linked molecular SNP markers for the sex chromosome of guppy. These markers have subsequently been used to genotype the individuals of several F2-type mapping crosses between two distant guppy populations, with many additional whole genome spanning SNP markers, also generated in our lab. I have constructed an integrated genetic linkage map for the guppy genome from these crosses, which places more than 750 SNP markers on 23 linkage groups, which is the known haploid number of guppy chromosomes. In addition I have predicted the broad regions with QTL for several traits which contribute to male phenotypic variation in guppy. Adult guppy males show high polymorphism for the colour patterns, size and shape of the body and fins. Most of these traits are male specific having a sex linked expression, with a clear genetic basis. My results with QTL prediction for these variable traits confirm presence of the major influencing genes, on sex chromsomes and many additional modifying loci on the autosomes.

I find genetics quite fascinating and I am deeply interested in the field of molecular and genetic basis of evolution, specifically the evolution of the genes and their functions through structural or regulatory changes, broadly in the context of the divergence of genomes, species and populations. In my future research career, I would like to address the questions broadly dealing with the evolution of genes and their functional roles at molecular and population levels, using relavant genetic and genomic approaches.

For my postdoc , I am analyzing the functional evolution of exapted repeat elements in human and mouse genomes. I am currently investigating the role of ancient conserved mobile elements, derived from  repeat families,  pervading vertebrate genomes, performing functional analysis of specific non coding conserved elements, in transcriptional regulation, using reporter assays in human cell lines and Mouse transgenics.

PUBLICATIONS:

Genetic linkage map of the guppy, Poecilia reticulata, and quantitative trait loci analysis of male size and colour variation.

Tripathi N, Hoffmann M, Willing EM, Lanz C, Weigel D, Dreyer C.

Proc Biol Sci. 2009 Jun 22;276(1665):2195-208. Epub 2009 Mar 18.

PMID: 19324769