Zoological Studies

Vol. 43 No. 3, 2004

Sex Ratio Distortion in Hybrids of Drosophila albomicans and D. nasuta

Yung-Yu Yang1, Fei-Jann Lin2 and Hwei-yu Chang1,2,*

1Department of Entomology, National Taiwan University, Taipei, Taiwan 106
2Institute of Zoology, Academia Sinica, Nankang, Taipei, Taiwan 115

Yung-Yu Yang, Fei-Jann Lin and Hwei-yu Chang (2004) A sex-ratio distorter in Drosophila albomicans was uncovered by the hybridization between Japanese Okinawa D. albomicans females and Indian D. nasuta males. The F1 male from this cross produces female-biased offspring. The genic nature demonstrated in the present study suggests that meiotic drive instead of non-disjunction of the sex chromosomes during meiosis is the major cause for this. The meiotic driver was found to be located on the neo-X chromosome of D. albomicans, whose genome also contains drive suppressors, while that of D. nasuta is suppressor-free. In addition, hybrid F1 and F2 males were found to be semisterile probably due to an interaction between the 3rd and Y chromosomes of D. nasuta and the autosomes of D. albomicans.

Key words: Drosophila albomicans, D. nasuta, Meiotic drive, Sex-ratio distortion.

*Correspondence: E-mail: hwei@gate.sinica.edu.tw