Null mutations in the lin-31 gene indicate two functions during Caenorhabditis elegans vulval development.
The lin-31 gene is required for the proper specification of vulval cell fates in the nematode Caenorhabditis elegans and encodes a member of the winged-helix family of transcription factors. Members of this important family have been identified in many organisms and are known to bind specific DNA targets involved in a variety of developmental processes. DNA sequencing of 13 lin-31 alleles revealed six nonsense mutations and two missense mutations within the DNA-binding domain, plus three deletions, one transposon insertion, and one frameshift mutation that all cause large-scale disruptions in the gene. The missense mutations are amino acid substitutions in the DNA-binding domain and probably disrupt interactions of the LIN-31 transcription factor with its DNA target. In addition, detailed phenotypic analysis of all 19 alleles showed similar penetrance for several characteristics examined. From our analysis we conclude: (1) the null phenotype of lin-31 is the phenotype displayed by almost all of the existing alleles, (2) the DNA-binding domain plays a critical role in LIN-31 function, and (3) direct screens for multivulva and vulvaless mutants will probably yield only null (or strong) alleles of lin-31.
Miller
L M
LM
Department of Biology, Santa Clara University, Santa Clara, California 95053, USA. lmiller@scu.edu
Hess
H A
HA
Doroquez
D B
DB
Andrews
N M
NM
D000483:Alleles; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D018509:DNA, Helminth / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D012734:Disorders of Sex Development; D005260:Female; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D009024:Morphogenesis; D005810:Multigene Family; D020125:Mutation, Missense; D010641:Phenotype; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology; D014844:Vulva / Q000002:abnormalities / Q000166:cytology / Q000196:embryology*
D029742:Caenorhabditis elegans Proteins; D018389:Codon, Nonsense; D018509:DNA, Helminth; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D014157:Transcription Factors; C081464:lin-31 protein, C elegans