DNA SEQUENCE COMPARISON AMONG CLOSELY RELATED DROSOPHILA SPECIES IN THE MULLERI COMPLEX

Dan H. Schulze ¹ and C. S. Lee ¹

¹ Department of Zoology, University of Texas, Austin, Texas 78712

DNA hybridization was used to establish DNA sequence relationships among seven Drosophila species. Single-copy DNA was isolated from four species within the Drosophila mulleri complex, D. mojavensis, D. arizonensis, D. ritae and D. starmeri. These single-copy DNAs were used as tracers to be hybridized with each other and one additional member of the mulleri complex, D. aldrichi, a member of a closely related complex, D. hydei, and a distantly related species, D. melanogaster . Two methods have been used to determine the relatedness between these species: (1) the extent of duplex formed as measured by binding to hydroxyapatite and (2) the thermal stability of the duplexed DNA. Moderately repetitive DNA was purified from these species and used similarly to determine the divergence of this family of sequences. The rate of nucleotide substitution was estimated to be 0.2 ± 0.1% base pair change per million years for both single-copy and middle-repetitive DNAs. The size of the D. arizonensis genome, a representative of the mulleri complex, was calculated to be 2.2 x 10⁸ base pairs from its kinetic complexity similar to that of D. hydei. The relative amounts (18%) and average reiteration frequency (100 copies) of the middle-repetitive DNA are similar for all Drosophila species studied. Finally, the data are presented in a phylogenetic tree.

This article has been cited by other articles:

				G. Bosco, P. Campbell, J. T. Leiva-Neto, and T. A. Markow Analysis of Drosophila Species Genome Size and Satellite DNA Content Reveals Significant Differences Among Strains as Well as Between Species Genetics, November 1, 2007; 177(3): 1277 - 1290. [Abstract] [Full Text] [PDF]

				J. Gonzalez, F. Casals, and A. Ruiz Testing Chromosomal Phylogenies and Inversion Breakpoint Reuse in Drosophila Genetics, January 1, 2007; 175(1): 167 - 177. [Abstract] [Full Text] [PDF]

				J. Gonzalez, J. M. Ranz, and A. Ruiz Chromosomal Elements Evolve at Different Rates in the Drosophila Genome Genetics, July 1, 2002; 161(3): 1137 - 1154. [Abstract] [Full Text] [PDF]

				J. M. Ranz, F. Casals, and A. Ruiz How Malleable is the Eukaryotic Genome? Extreme Rate of Chromosomal Rearrangement in the Genus Drosophila Genome Res., February 1, 2001; 11(2): 230 - 239. [Abstract] [Full Text]