Essential genes in proximal 3L heterochromatin of Drosophila melanogaster.
We have further characterized essential loci within the centric heterochromatin of the left arm of chromosome 3 (3L) of Drosophila melanogaster, using EMS, radiation and P element mutagenesis. We failed to find any new essential genes, a result that suggests a lower-than-average gene density in this region. Mutations affecting expression of the most proximal gene [lethal 1, l1 or l(3)80Fj] act as dominant suppressors of Polycomb (Pc), behavior which is consistent with a putative trithorax group (trx-G) gene. The third gene to the left of the centromere [lethal 3, l3 or l(3)80Fh] is likely to correspond to verthandi (vtd), a known trx-G gene that plays a role in the regulation of hedgehog (hh) expression and signalling. The intervening gene [lethal 2, l2 or l(3)80Fi] is required throughout development, and mutant alleles have interesting phenotypes; in various allelic combinations that survive, we observe fertility, bristle, wing, eye and cuticle defects.
Schulze
S
S
Department of Molecular Biology and Biochemistry, Simon Fraser University Burnaby, BC, Canada.
Sinclair
D A
DA
Silva
E
E
Fitzpatrick
K A
KA
Singh
M
M
Lloyd
V K
VK
Morin
K A
KA
Kim
J
J
Holm
D G
DG
Kennison
J A
JA
Honda
B M
BM
D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D005260:Female; D020043:Genes, Essential; D005819:Genetic Markers; D006570:Heterochromatin / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*; D008297:Male; D016254:Mutagenesis, Insertional; D010641:Phenotype; D063150:Polycomb Repressive Complex 1; D012097:Repressor Proteins / Q000235:genetics; D013489:Suppression, Genetic; D014921:Wings, Animal / Q000033:anatomy & histology
D029721:Drosophila Proteins; D005819:Genetic Markers; D006570:Heterochromatin; D019476:Insect Proteins; C066770:Pc protein, Drosophila; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1