Molecular and Phenotypic Variation of the White Locus Region in Drosophila Melanogaster
AUTOR(ES)
Miyashita, N.
RESUMO
Restriction site and insertion/deletion polymorphism in a 45-kb region of the white locus on the X chromosome in Drosophila melanogaster was investigated for 64 X chromosome lines with six 6-cutter and ten 4-cutter restriction enzymes. A total of 109 polymorphisms were detected (54 restriction sites and 55 insertions/deletions). Estimated heterozygosity per nucleotide for this region (0.004-0.008) was similar to those of the Adh and 87A heat-shock locus regions located on the autosomes in D. melanogaster. This is contrary to a simple prediction based on the theory of mutation selection-balance of partially recessive deleterious mutants which predicts less variation on X chromosomes. Large linkage disequilibria between pairs of polymorphisms (including insertions and deletions) within the transcriptional unit (especially the 3' end of the 1st intron) were observed. As expected from population genetics theory, linkage disequilibria between these polymorphisms were greater for those pairs that are physically closer on the restriction map. Linkage equilibrium was typically observed when the pairs of sites were separated by 2 kb or more. Although significant between-line variation in eye pigment was observed (P < 0.05), there is little evidence for strong associations between this phenotype and the polymorphisms at the DNA level.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1203490Documentos Relacionados
- Molecular and Phenotypic Variation of the Zw Locus Region in Drosophila Melanogaster
- PHENOTYPIC VARIATION AND PSEUDO-ALLELISM AT THE FORKED LOCUS IN Drosophila Melanogaster
- Molecular cloning of the white locus region of Drosophila melanogaster using a large transposable element
- Multi-Locus Selection and the Structure of Variation at the White Gene of Drosophila Melanogaster
- A New Locus in the White-Notch Region of the DROSOPHILA MELANOGASTER X Chromosome