C. elegans HIM-8 functions outside of meiosis to antagonize EGL-13 Sox protein function.
egl-13 encodes a Sox domain protein that is required for proper uterine seam cell development in Caenorhabditis elegans. We demonstrate that mutations of the C2H2 zinc fingers encoded by the him-8 (high incidence of males) gene partially suppress the egg-laying and connection-of-gonad morphology defects caused by incompletely penetrant alleles of egl-13. him-8 alleles have previously characterized recessive effects on recombination and segregation of the X chromosome during meiosis due to failure of X chromosome homolog pairing and subsequent synapsis. However, we show that him-8 alleles are semi-dominant suppressors of egl-13, and the semi-dominant effect is due to haplo-insufficiency of the him-8 locus. Thus, we conclude that the wild-type him-8 gene product acts antagonistically to EGL-13. Null alleles of egl-13 cannot be suppressed, suggesting that this antagonistic interaction most likely occurs either upstream of or in parallel with EGL-13. Moreover, we conclude that suppression of egl-13 is due to a meiosis-independent function of him-8 because suppression is observed in mutants that have severely reduced meiotic germ cell populations and suppression does not depend on the function of him-8 in the maternal germ line. We also show that the chromosomal context of egl-13 seems important in the him-8 suppression mechanism. Interactions between these genes can give insight into function of Sox family members, which are important in many aspects of metazoan development, and into functions of him-8 outside of meiosis.
Department of Biochemistry and Molecular Biology, The Pennsylvania State University, 201 Life Science Building, Room 104D, University Park, PA 16802, USA.
Brian L
BL
Nelms
Wendy
W
Hanna-Rose
D000483:Alleles; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D018509:DNA, Helminth / Q000235:genetics; D005260:Female; D017238:Genes, Helminth; D008297:Male; D008540:Meiosis; D009154:Mutation; D034622:RNA Interference; D013489:Suppression, Genetic; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D014599:Uterus / Q000254:growth & development; D014844:Vulva / Q000254:growth & development
D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D018509:DNA, Helminth; C491546:EGL-13 protein, C elegans; C507738:HIM-8 protein, C elegans; D014157:Transcription Factors