title: The Pristionchus HOX gene Ppa-lin-39 inhibits programmed cell death to specify the vulva equivalence group and is not required during vulval induction.
abstract: In the two nematode species Caenorhabditis elegans and Pristionchus pacificus the vulva equivalence group in the central body region is specified by the Hox gene lin-39. C. elegans lin-39 mutants are vulvaless and the vulval precursor cells fuse with the surrounding hypodermis, whereas in P. pacificus lin-39 mutants the vulval precursor cells die by apoptosis. Mechanistically, LIN-39 might inhibit non-vulval fate (cell fusion in C. elegans, apoptosis in P. pacificus), promote vulval fate or do both. To study the mechanism of lin-39 function, we isolated P. pacificus cell death mutants and identified mutations in ced-3. Surprisingly, P. pacificus ced-3; lin-39 double mutants form a functional vulva in the absence of LIN-39 activity. Thus, in P. pacificus lin-39 specifies the vulva equivalence group by inhibiting programmed cell death. Furthermore, these data reveal an important difference in a later function of lin-39 between the two species. In C. elegans, LIN-39 specifies vulval cell fates in response to inductive RAS signaling, and in P. pacificus LIN-39 is not required for vulval induction. Thus, the comparative analysis indicates that lin-39 has distinct functions in both species although the gene is acting in a homologous developmental system.
authors.affiliation: Max-Planck Institut für Entwicklungsbiologie, Abt. Zellbiologie, Spemannstrasse 35, Germany.
authors.forename: R J
authors.initials: RJ
authors.lastname: Sommer
authors.forename: A
authors.initials: A
authors.lastname: Eizinger
authors.forename: K Z
authors.initials: KZ
authors.lastname: Lee
authors.forename: B
authors.initials: B
authors.lastname: Jungblut
authors.forename: A
authors.initials: A
authors.lastname: Bubeck
authors.forename: I
authors.initials: I
authors.lastname: Schlak
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D005075:Biological Evolution; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins; D020169:Caspases; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D005260:Female; D017238:Genes, Helminth; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009348:Nematoda / Q000166:cytology / Q000235:genetics* / Q000254:growth & development*; D010641:Phenotype; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014844:Vulva / Q000254:growth & development*
chemical_list: D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D018509:DNA, Helminth; D018398:Homeodomain Proteins; C108673:lin-39 protein, C elegans; D020169:Caspases; D003546:Cysteine Endopeptidases; C089223:ced-3 protein, C elegans