title: A genome-wide screen identifies genes that affect somatic homolog pairing in Drosophila.
abstract: In Drosophila and other Dipterans, homologous chromosomes are in close contact in virtually all nuclei, a phenomenon known as somatic homolog pairing. Although homolog pairing has been recognized for over a century, relatively little is known about its regulation. We performed a genome-wide RNAi-based screen that monitored the X-specific localization of the male-specific lethal (MSL) complex, and we identified 59 candidate genes whose knockdown via RNAi causes a change in the pattern of MSL staining that is consistent with a disruption of X-chromosomal homolog pairing. Using DNA fluorescent in situ hybridization (FISH), we confirmed that knockdown of 17 of these genes has a dramatic effect on pairing of the 359 bp repeat at the base of the X. Furthermore, dsRNAs targeting Pr-set7, which encodes an H4K20 methyltransferase, cause a modest disruption in somatic homolog pairing. Consistent with our results in cultured cells, a classical mutation in one of the strongest candidate genes, pebble (pbl), causes a decrease in somatic homolog pairing in developing embryos. Interestingly, many of the genes identified by our screen have known roles in diverse cell-cycle events, suggesting an important link between somatic homolog pairing and the choreography of chromosomes during the cell cycle.
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011, USA.
authors.forename: Jack R
authors.initials: JR
authors.lastname: Bateman
authors.forename: Erica
authors.initials: E
authors.lastname: Larschan
authors.forename: Ryan
authors.initials: R
authors.lastname: D'Souza
authors.forename: Lauren S
authors.initials: LS
authors.lastname: Marshall
authors.forename: Kyle E
authors.initials: KE
authors.lastname: Dempsey
authors.forename: Justine E
authors.initials: JE
authors.lastname: Johnson
authors.forename: Barbara G
authors.initials: BG
authors.lastname: Mellone
authors.forename: Mitzi I
authors.initials: MI
authors.lastname: Kuroda
mesh_terms: D000483:Alleles; D000818:Animals; D023902:Chromosome Pairing; D003434:Crossing Over, Genetic; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016678:Genome; D055106:Genome-Wide Association Study; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009154:Mutation; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000378:metabolism; D014960:X Chromosome
chemical_list: D029721:Drosophila Proteins; D020662:Guanine Nucleotide Exchange Factors; C121865:Pbl protein, Drosophila; D012330:RNA, Double-Stranded; D011495:Histone-Lysine N-Methyltransferase; C498199:PR-Set7 protein, Drosophila