|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online March 1, 2004
doi: 10.1242/10.1242/dev.01012

1 Department of Genetics, Cell Biology and Development, University of Minnesota,
321 Church Street SE, Minneapolis, MN 55455, USA
2 Developmental Biology Center, University of Minnesota, 321 Church Street SE,
Minneapolis, MN 55455, USA
3 Department of Biochemistry, University of Wisconsin, 433 Babcock Drive,
Madison, WI 53706-1544, USA
4 Howard Hughes Medical Institute, University of Wisconsin, 433 Babcock Drive,
Madison, WI 53706-1544, USA
Author for correspondence (e-mail:
zarkower{at}gene.med.umn.edu)
Accepted 25 November 2003
In sex determination, globally acting genes control a spectrum of tissue-specific regulators to coordinate the overall development of an animal into one sex or the other. In mammals, primary sex determination initially occurs in the gonad, with the sex of other tissues specified as a secondary event. In insects and nematodes, globally acting regulatory pathways have been elucidated, but the more tissue- and organ-specific downstream effectors of these pathways remain largely unknown. We focus on the control of sexual dimorphism in the C. elegans gonad. We find that the forkhead transcription factor FKH-6 promotes male gonadal cell fates in XO animals. Loss-of-function fkh-6 mutant males have feminized gonads and often develop a vulva. In these mutant males, sex-specific cell divisions and migrations in the early gonad occur in the hermaphrodite mode, and hermaphrodite-specific gonadal markers are expressed. However, sexual transformation is not complete and the male gonad is malformed. By contrast, fkh-6 mutant hermaphrodites exhibit no sign of sex reversal. Most fkh-6 hermaphrodites form a two-armed symmetrical gonad resembling that of the wild type, but differentiation of the spermatheca and uterus is variably abnormal. The function of fkh-6 appears to be restricted to the gonad: fkh-6 mutants have no detectable defects in extra-gonadal tissues, and expression of a rescuing fkh-6 reporter is gonad-specific. Genetic and molecular analyses place fkh-6 downstream of tra-1, the terminal regulator of the global sex determination pathway, with respect to the first gonadal cell division. We conclude that fkh-6 regulates gonadogenesis in both sexes, but is male specific in establishing sexual dimorphism in the early gonad.
Key words: Sex determination, Gonad, Gonadogenesis, C. elegans, Forkhead
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
Related articles in Development:
This article has been cited by other articles:
![]() |
W. Chi and V. Reinke Promotion of oogenesis and embryogenesis in the C. elegans gonad by EFL-1/DPL-1 (E2F) does not require LIN-35 (pRB) Development, August 15, 2006; 133(16): 3147 - 3157. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. D. Mathies, M. Schvarzstein, K. M. Morphy, R. Blelloch, A. M. Spence, and J. Kimble TRA-1/GLI controls development of somatic gonadal precursors in C. elegans Development, September 1, 2004; 131(17): 4333 - 4343. [Abstract] [Full Text] [PDF] |
||||