Macdonald Lab

Luk, S.K-S., Kilpatrick, M., Kerr, K. and Macdonald, P.M. (1994).

Components acting in localization of bicoid mRNA are conserved among Drosophila species.

Genetics 137, 521-530.

Abstract

The Drosophila exuperantia (exu) gene, required for an early step in the localization of bicoid mRNA to the anterior pole of the oocyte and for an as yet undefined step in spermatogenesis, encodes a protein whose molecular function is unknown. To learn more about the exu protein we have isolated and characterized the exu genes from D. virilis and D. pseudoobscura. Surprisingly, D. pseudoobscura has two closely-related exu genes, while D. melanogaster and D. virilis have only one each. When expressed in D. melanogaster ovaries, the D. virilis exu gene and one of the D. pseudoobscura exu genes can substitute for the endogenous exu gene. Furthermore, the same D. pseudoobscura exu gene can provide partial male function. The second D. pseudoobscura exu gene provides neither exu function in D. melanogaster; patterns of sequence evolution suggest that this exu gene may be specialized for an as yet unrecognized function of exu. In an unsuccessful effort to ask if exu protein specifically recognizes bicoid mRNA, we demonstrate that information within the 3’ untranslated region of the D. pseudoobscura bicoid mRNA contains information sufficient to direct anterior localization in D. melanogaster embryos.