Hundred years of Research on Drosophila ananassae has Revealed a Number of Unusual Features of this Species

Drosophila ananassae was originally described by Doleschall in 1858 from Ambon Island in Indonesia. This species came into notice when Morgan, Bridges and Sturtevant compiled data in a volume entitled ‘The Genetics of Drosophila’ in 1925 as D. caribbea Sturtevant in the chapter ‘other species of Drosophila’. Kikkawa in 1935 verified D. caribbea as D. ananassae. The first mutation in this species was curved wing, an autosomal recessive gene on II chromosome reported by Sturtevant in 1921. Since then D. ananassae has been utilized extensively for different kinds of studies and results of these studies conducted during the last hundred years have clearly revealed that D. ananassae is genetically unique species and stands distinct from other species of the genus Drosophila. The important unusual features of this species are: spontaneous meiotic male recombination, presence of chiasmata in males, high mutability, optic morphology hyper mutability system, absence of genetic coadaptation, Y-4 linkage of nucleolus organizer, high frequency of pericentric inversions and translocations, population substructing, parthenogenesis, extra chromosomal inheritance, incipient sexual isolation, inversion karyotypes and mate recognition system, spontaneous genetic mosaic, segregation distortion, lack of correlation between crossing-over and chromosome distance between inversions, rare male mating advantage, trait and sex specific fluctuating asymmetry, female and male remating and sperm displacement, speciation in south Pacific populations, association with a bacterium Wolbachia, variation in resistance to environmental stress, nutrition regulated stress resistance, correlation between inversion karyotypes and mating propensity and phylogenetic relationship with its sibling D. pallidosa which is in status nascendi.