title: Cytogenetic mapping of the Muller F element genes in Drosophila willistoni group.
abstract: Comparative genomics in Drosophila began in 1940, when Muller stated that the ancestral haploid karyotype of this genus is constituted by five acrocentric chromosomes and one dot chromosome, named A to F elements. In some species of the willistoni group such as Drosophila willistoni and D. insularis, the F element, instead of a dot chromosome, has been incorporated into the E element, forming chromosome III (E + F fusion). The aim of this study was to investigate the scope of the E + F fusion in the willistoni group, evaluating six other species. Fluorescent in situ hybridization was used to locate two genes of the F element previously studied-cubitus interruptus (ci) and eyeless (ey)-in species of the willistoni and bocainensis subgroups. Moreover, polytene chromosome photomaps corresponding to the F element (basal portion of chromosome III) were constructed for each species studied. In D. willistoni, D. paulistorum and D. equinoxialis, the ci gene was located in subSectction 78B and the ey gene in 78C. In D. tropicalis, ci was located in subSection 76B and ey in 76C. In species of the bocainensis subgroup, ci and ey were localized, respectively, at subsections 76B and 76C in D. nebulosa and D. capricorni, and 76A and 76C in D. fumipennis. Despite the differences in the subsection numbers, all species showed the same position for ci and ey. The results confirm the synteny of E + F fusion in willistoni and bocainensis subgroups, and allow estimating the occurrence of this event at 15 Mya, at least.
authors.affiliation: Sección Genética Evolutiva, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Calle Iguá 4225, 11400, Montevideo, Uruguay.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Pita
authors.forename: Yanina
authors.initials: Y
authors.lastname: Panzera
authors.forename: Vera
authors.initials: V
authors.lastname: Lúcia da Silva Valente
authors.forename: Zilpa das Graças Silva
authors.initials: Zd
authors.lastname: de Melo
authors.forename: Carolina
authors.initials: C
authors.lastname: Garcia
authors.forename: Ana Cristina Lauer
authors.initials: AC
authors.lastname: Garcia
authors.forename: Martín Alejandro
authors.initials: MA
authors.lastname: Montes
authors.forename: Claudia
authors.initials: C
authors.lastname: Rohde
mesh_terms: D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D059006:Chromosomes, Insect / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000145:classification / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics; D019143:Evolution, Molecular; D017344:Genes, Insect / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D008856:Microscopy, Fluorescence; D059007:Polytene Chromosomes / Q000235:genetics; D013045:Species Specificity; D026801:Synteny; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors; C092937:ci protein, Drosophila; C113278:ey protein, Drosophila