Chromosomal Polymorphism in Drosophila nasuta: III. Inverted gene arrangements in South Indian populations

Abstract

Inversion polymorphism, including a total of 33 inverted gene orders, was studied in South Indian populations of D. nasuta nasuta. Of these, the X chromosome has one, chromosome 2 has 10, and chromosome 3 has 22 inversions. D. nasuta nasuta has simple, tandem, included, overlapping, and complex types of paracentrics in its polymorphic system. The phylogenetic considerations of these gene orders are discussed.

Inversion polymorphism in species of the Drosophila nasuta subgroup from Thailand

“…As neither species displayed any inversions on chromosome IIR and D. s. albostrigata only one, Wasserman's theory (1963), proposing that particular chromosome loci have historically been more predisposed to inversions may be correct. Ranganath and Krishnamurthy (1975) found a similar result with only one inversion on chromosome II and twenty-two on chromosome III, in South Indian populations of D. nasuta nasuta (D. nasuta). In collections ofD.…”

“…Inversion IILA appears to correspond with IIL-1 described by Clyde (1982) from Cebu, Kuala Lumpur, Hidden Valley Springs and Chiang Mai. It also appears to correspond with 2LB in D. nasuta described by Ranganath and Krishnamurthy (1975) from South Indian populations, with 2LA in/9. s. neonasuta described by Nirmala Sajjan and Krishnamurthy (1972) and with B1D 5 reported in D. albomicans from Taiwan by Lin et al (1977).…”

Crossing experiments within and between species of the nasuta complex of Drosophila

“…Since each sample of 10 virgin females was confined with 10 males for 28 days, it is apparent that the possibility of an interspecific cross occurring between any of these species in the wild is negligible. It has recently been suggested (Sajjan & Krishnamurthy, 1972;Ranganath & Krishnamurthy, 1975;Ranganath et al, 1974) that the Indian species D. nasuta should be considered a subspecies of D. a/-bomicans and that D. kepulauana should be considered a semispecies of D. nasuta. Data presented here show that D. albomicans and D. kepulauana are good species and could not exchange genes in the wild.…”

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“…Various species of this subgroup have been studied to understand their interrelationships (Ranganath & Krishnamurthy, 1975;Ranganath & Hägele, 1981Rajasekarasetty et al, 1979Rajasekarasetty et al, , 1980. D. n. nasuta was first described by Lamb (1914) from Seychelles Islands, Africa; while D. n. albomicans by Duda (1923) from Paroe, Formosa.…”