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Closing the (Ran)GAP on segregation distortion in Drosophila
Author(s) -
Kusano Ayumi,
Staber Cynthia,
Chan Ho Yin Edwin,
Ganetzky Barry
Publication year - 2003
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.10222
Subject(s) - ran , meiotic drive , biology , nuclear transport , microbiology and biotechnology , genetics , small gtpase , mutant , chromatid , gene , signal transduction , meiosis , cell nucleus , chromosome
Segregation Distorter ( SD ) is a meiotic drive system in Drosophila that causes preferential transmission of the SD chromosome from SD/SD + males owing to induced dysfunction of SD + spermatids. Since its discovery in 1956, SD and its mode of action have baffled biologists. Recently, substantial progress has been made in elucidating this puzzle. Sd , the primary gene responsible for distortion encodes a mutant RanGAP, a key protein in the Ran signaling pathway required for nuclear transport and other nuclear functions. The mutant protein is enzymatically active but mislocalized to nuclei, which apparently disrupts Ran signaling by reducing intranuclear Ran‐GTP levels. Some evidence suggests that a defect in nuclear transport may be the main cause of sperm dysfunction. Although important questions remain, the basic mechanism of distortion is now understood sufficiently well that specific hypotheses can be formulated and tested. This previously mysterious genetic system may now offer unique insights into novel aspects of regulation by Ran. BioEssays 25:108–115, 2003. © 2003 Wiley Periodicals, Inc.