Glorund interactions in the regulation of gurken and oskar mRNAs

AbstractPrecise temporal and spatial regulation of gene expression during Drosophila oogenesis is essential for patterning the anterior–posterior and dorsal–ventral body axes. Establishment of the anterior–posterior axis requires posterior localization and translational control of both oskar and nanos mRNAs. Establishment of the dorsal–ventral axis depends on the precise restriction of gurken mRNA and protein to the dorsal–anterior corner of the oocyte. We have previously shown that Glorund, the Drosophila hnRNP F/H homolog, contributes to anterior–posterior axis patterning by regulating translation of nanos mRNA, through a direct interaction with its 3′ untranslated region. To investigate the pleiotropy of the glorund mutant phenotype, which includes dorsal–ventral and nuclear morphology defects, we searched for proteins that interact with Glorund. Here we show that Glorund is part of a complex containing the hnRNP protein Hrp48 and the splicing factor Half-pint and plays a role both in mRNA localization and nurse cell chromosome organization, probably by regulating alternative splicing of ovarian tumor. We propose that Glorund is a component of multiple protein complexes and functions both as a translational repressor and splicing regulator for anterior–posterior and dorsal–ventral patterning