Studies on isozyme variations in a few members ofDrosophila nasuta subgroup

Abstract

Abslract. Isozyme variation at six enzyme loci has been studied involving nine members of Drosophila nasuta subgroup, by employing polyacrylamide gel electrophoretic technique. Alleles at three loci namely Acph, Aph and tx-Est are found to be highly polymorphic; whereas at ~-Est locus the alleles are less variable while at a-Gpdh and To loci, the alleles are found to be least variable. Null alleles are encountered in low frequencies at rz-Est, ~-Est and c-Gpdh enzyme loci. The allelie frequencies obtained at the six enzyme loci have been utilised as a yardstick to measure the extent of genetic relationship between the species studied. The genetic identity and genetic distance between these closely-related species have been estimated by adopting the Nei's formula. These findings have been discussed with reference to earlier cytogenetic and hybridisation studies made on this subgroup.

Taxonomic identification of Drosophila nasuta subgroup strains by glue protein analysis

“…One knows that even the substitution of a single amino acid can already significantly change the mobility of a protein in a gel (Noel e t al., 1979). However, so far little is known about the phylogenetic relationships between different members of the n a s u t a subgroup on the basis of isoenzyme variations (Ramesh & Rajasekarasetty, 1980) and nothing is known about the gene structure of the n a s u t a subgroup on the DNA level. In another study (Ramesh & Kalisch, 1988) we were able to show that in D. n. n a s u t a the prominent glue proteins of domains I -III are PAS positive.…”

“…In several cases the dose relationship of the members allows for the obtainment of fertile hybrid progeny (cf: Ramesh & Rajasekarasetty, 1980;Ramachandra & Ranganath, 1986).…”

Molecular phylogeny of the <i>nasuta</i> subgroup of <i>Drosophila </i>based on 12S rRNA, 16S rRNA and CoI mitochondrial genes, RAPD and ISSR polymorphisms

“…From the beginning of the pioneering work of Wilson et al, (1969), phylogeny of the nasuta subgroup has been extensively studied at various levels of organiEdited by Masatoshi Yamamoto * Corresponding author. E-mail: drosrang@sancharnet.in zations namely, morphophenotypes (Nirmala and Krishnamurthy, 1972), hybridization and hybrid sterility (Ramachandra and Ranganath, 1988), karyotypes (Ranganath and Hägele, 1981;Wakahama et al, 1983;Ranganath and Ushakumari, 1987;Rao and Ranganath, 1991), hybrid salivary chromosomes (Lambert, 1978;Rajasekarasetty et al, 1980), heterochromatin and satellite DNA (Ranganath et al, 1982;Ranganath and Ushakumari, 1987), isozymes and allozymes (Kanapi and Wheeler, 1970;Ramesh and Rajasekarasetty, 1980), glue proteins (Ramesh and Kalisch, 1989), courtship patterns (Tanuja et al, 2001), courtship song (Shao et al, 1997), mitochondrial DNA (Chang et al, 1989;Yu et al, 1999), and male accessory gland proteins (Ram and Ramesh, 2001).…”