title: The Drosophila melanogaster sir2+ gene is nonessential and has only minor effects on position-effect variegation.
abstract: Five Drosophila melanogaster genes belong to the highly conserved sir2 family, which encodes NAD(+)-dependent protein deacetylases. Of these five, dsir2(+) (CG5216) is most similar to the Saccharomyces cerevisiae SIR2 gene, which has profound effects on chromatin structure and life span. Four independent Drosophila strains were found with P-element insertions near the dsir2 transcriptional start site as well as extraneous linked recessive lethal mutations. Imprecise excision of one of these P elements (PlacW07223) from a chromosome freed of extraneous lethal mutations produced dsir2(17), a null intragenic deletion allele that generates no DSIR2 protein. Contrary to expectations from the report by Rosenberg and Parkhurst on their P-mobilization allele dSir2(ex10), homozygosity for dsir2(17) had no apparent deleterious effects on viability, developmental rate, or sex ratio, and it fully complemented sir2(ex10). Moreover, through a genetic test, we ruled out the reported effect of dSir2(ex10) on Sex-lethal expression. We did observe a modest, strictly recessive suppression of white(m4) position-effect variegation and a shortening of life span in dsir2 homozygous mutants, suggesting that dsir2 has some functions in common with yeast SIR2.
authors.affiliation: Department of Developmental Biology, Wennergren Institute, Stockholm University, SE-106 91 Stockholm, Sweden. stefan.astrom@devbio.su.se
authors.forename: Stefan U
authors.initials: SU
authors.lastname: Aström
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Cline
authors.forename: Jasper
authors.initials: J
authors.lastname: Rine
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D005804:Genes, Lethal; D005816:Genetic Complementation Test; D005838:Genotype; D006655:Histone Deacetylases / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D037761:Sirtuins / Q000737:chemistry / Q000235:genetics*; D015053:Zygote
chemical_list: D029721:Drosophila Proteins; C447899:Sirt2 protein, Drosophila; D037761:Sirtuins; D006655:Histone Deacetylases