Open Access Research article

The RGS gene loco is essential for male reproductive system differentiation in Drosophila melanogaster

Leeanne McGurk1, Stephen Pathirana2, Kathleen Rothwell3, Thorsten Trimbuch4, Paolo Colombini5, Fengwei Yu6, William Chia6 and Mary Bownes3*

Author Affiliations

1 Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, EH4 2XU, UK

2 European Commission Enterprise and Industry Director General, BREY 07/318 45, Brussels 1040, Belgium

3 University of Edinburgh, Institute of Cell Biology, Edinburgh EH9 3JR, UK

4 Charite – Universitaetsmedizin Berlin, Centrum fur Anatomie, Insitut fur Zell- und Neurobiologie, Charitéplatz 1, 10117 Berlin, Germany

5 Via Giovanni Guareschi, 16, 41010 Cognento, Modena, Italy

6 Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 117604, Singapore

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BMC Developmental Biology 2008, 8:37  doi:10.1186/1471-213X-8-37

Published: 3 April 2008



The loco gene encodes several different isoforms of a regulator of G-protein signalling. These different isoforms of LOCO are part of a pathway enabling cells to respond to external signals. LOCO is known to be required at various developmental stages including neuroblast division, glial cell formation and oogenesis. Less is known about LOCO and its involvement in male development therefore to gain further insight into the role of LOCO in development we carried out a genetic screen and analysed males with reduced fertility.


We identified a number of lethal loco mutants and four semi-lethal lines, which generate males with reduced fertility. We have identified a fifth loco transcript and show that it is differentially expressed in developing pupae. We have characterised the expression pattern of all loco transcripts during pupal development in the adult testes, both in wild type and loco mutant strains. In addition we also show that there are various G-protein α subunits expressed in the testis all of which may be potential binding partners of LOCO.


We propose that the male sterility in the new loco mutants result from a failure of accurate morphogenesis of the adult reproductive system during metamorphosis, we propose that this is due to a loss of expression of loco c3. Thus, we conclude that specific isoforms of loco are required for the differentiation of the male gonad and genital disc.