title: First evidence of methylation in the genome of Drosophila willistoni.
abstract: DNA methylation has been studied abundantly in vertebrates and recent evidence confirms that this phenomenon could be disseminated among some invertebrates groups, including Drosophila species. In this paper, we used the Methylation-Sensitive Restriction Endonuclease (MSRE) technique and Southern blot with specific probes, to detect methylation in the Drosophila willistoni species. We found differential cleavage patterns between males and females that cannot be explained by Mendelian inheritance, pointing to a DNA methylation phenomenon different from the Drosophila melanogaster one. The sequencing of some of these bands showed that these fragments were formed by different DNA elements, among which rDNA. We also characterized the D. willitoni dDnmt2 sequence, through a Mega Blast search against the D. willistoni Trace Archive Database using the D. melanogaster dDnmt2 nucleotide sequence as query. The complete analysis of D. willistoni dDnmt2 sequence showed that its promoter region is larger, its dDnmt2 nucleotide sequence is 33% divergent from the D. melanogaster one, Inverted Terminal Repeats (ITRs) are absent and only the B isoform of the enzyme is produced. In contrast, ORF2 is more conserved. Comparing the D. willistoni and D. melanogaster dDnmt2 protein sequences, we found higher conservation in motifs from the large domain, responsible for the catalysis of methyl transfer, and great variability in the region that carries out the recognition of specific DNA sequences (TRD). Globally, our results reveal that methylation of the D. willistoni genome could be involved in a singular process of species-specific dosage compensation and that the DNA methylation in the Drosophila genus can have diverse functions. This could be related to the evolutionary history of each species and also to the acquisition time of the dDnmt2 gene.
authors.affiliation: Programa de Pós Graduação em Biologia Animal, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, CEP 91501-970 Porto Alegre, RS, Brazil. mshenz@terra.com.br
authors.forename: Rosane Nunes
authors.initials: RN
authors.lastname: Garcia
authors.forename: Marícia Fantinel
authors.initials: MF
authors.lastname: D'Avila
authors.forename: Lizandra Jaqueline
authors.initials: LJ
authors.lastname: Robe
authors.forename: Elgion Lúcio da Silva
authors.initials: EL
authors.lastname: Loreto
authors.forename: Yanina
authors.initials: Y
authors.lastname: Panzera
authors.forename: Fabiana Oliveira
authors.initials: FO
authors.lastname: de Heredia
authors.forename: Vera Lúcia da Silva
authors.initials: VL
authors.lastname: Valente
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics; D019175:DNA Methylation; D015257:DNA-Cytosine Methylases / Q000235:genetics; D004330:Drosophila / Q000166:cytology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D005260:Female; D016678:Genome; D008297:Male; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D029721:Drosophila Proteins; D004247:DNA; D015257:DNA-Cytosine Methylases