On the genomic location of the exuperantia1 gene in Drosophila miranda: the limits of in situ hybridization experiments.
In situ hybridization to Drosophila polytene chromosomes is a powerful tool for determining the chromosomal location of genes. Using in situ hybridization experiments, Yi and Charlesworth recently reported the transposition of the exuperantia1 gene (exu1) from a neo-sex chromosome to the ancestral X chromosome of Drosophila miranda, close to exuperantia2 (exu2). By characterizing sequences flanking exu1, however, we found the position of exu1 to be conserved on the neo-sex chromosome. Further, the exu2 gene was found to be tandemly duplicated on the X chromosome of D. miranda. The misleading hybridization signal of exu1 may be caused by multiple copies of exu2, which interfere with the hybridization of the exu1 probe to its genomic position on the neo-X chromosome. This suggests that flanking DNA should be used to confirm the positions of members of gene families.
Bachtrog
Doris
D
Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom. doris.bachtrog@ed.ac.uk
Charlesworth
Brian
B
D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D004527:Egg Proteins / Q000235:genetics*; D017403:In Situ Hybridization / Q000379:methods*; D016601:RNA-Binding Proteins / Q000235:genetics*; D012107:Research Design; D020079:Terminal Repeat Sequences / Q000235:genetics
D029721:Drosophila Proteins; D004527:Egg Proteins; D016601:RNA-Binding Proteins; C072067:exu protein, Drosophila