Functional analysis of a conserved tudor domain protein, tejas, in the germline of drosophila melanogaster

• Main Author: Veena Shivagouda Patil
• Other Authors: School of Biological Sciences
• Format: Theses and Dissertations
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Biological sciences::Genetics
• Online Access: http://hdl.handle.net/10356/43882
• Institution: Nanyang Technological University

Maintaining genome integrity in germline cells is critical for faithful reproduction of genetic material in the next generation. Retroelements are known to populate germline cells in eukaryotes and cause the genomic instability when derepressed (reviewed in Malone and Hannon, 2009). Recently, the Piwi interacting RNAs (piRNA) have been shown to safeguard the germline genome against retroelements in many animals (Aravin et al., 2007; Brennecke et al., 2007; Gunawardane et al., 2007; Houwing et al., 2007; Lau et al., 2009; Saito et al., 2006; Vagin et al., 2006). Here, I report a conserved, yet uncharacterized component of the piRNA pathway, Tejas (Tej). Tej contains a predicted tudor domain at the C-terminus, and a previously uncharacterized conserved domain (tejas domain) at the N-terminus. Drosophila Tej localizes to nuage, a conserved perinuclear structure found in germline cells across the animal kingdom (Eddy, 1975). The loss-of-function allele of tej shares some of the defects in piRNA pathway mutants: female sterility, failure of oocyte nucleus compaction, persistence of DNA double stranded breaks (DSBs) caused independent of DNA damage signal transduction pathway genes, derepression of some retroelements and reduced piRNA levels. tej is required for repression of those retroelements that are specifically regulated by germline piRNAs generated in ping-pong cycle, one of the two known mechanisms for the piRNA production. tej shows genetic hierarchical relation with other piRNA components for nuage localization.