Sonal Joshi wins top prize at the Graduate Student Research Day

Sonal Joshi, a Ph.D. student in the Meller lab, won a top prize for her oral presentation at the Graduate Student Research Day, held at WSU School of Medicine on September 17.

Sonal studies how male fruit flies increase expression of their single X chromosome to achieve the same level as that from two female X chromosomes. She hypothesized that a family of repetitive DNA sequences found only on the X chromosome might guide this process, and devised a functional test of her idea.

Sonal discovered that when these repeats were inserted on an autosome they actually increased the expression of nearby autosomal genes! This study solves the mystery of how the X chromosome is distinguished from the autosomes. Sonal's discovery also has broader implications because repetitive DNA makes up half of the human and fly genomes, yet very little is known about the function of these sequences in any organism.