VARIATION IN Y-CHROMOSOME MEIOTIC DRIVE IN AEDES-AEGYPTI (DIPTERA, CULICIDAE) - A POTENTIAL GENETIC APPROACH TO MOSQUITO-CONTROL

Reciprocal crosses between strains of Aedes aegypti (Linnaeus) from di fferent geographical areas have revealed an unexpectedly complex patte rn of holandrically inherited male biased sex ratios in F2. The variat ion has been interpreted in terms of a web of X-Y interactions in F1, in which the Y chromosome may or may not show meiotic drive against th e X chromosome with which it is paired. The pattern of inheritance is not in agreement with a single form of Y chromosome, driving with diff erent degrees of intensity against Xs of different sensitivity, but in dicates different forms of driving Y chromosome. A rule has emerged th at if F1 males from any cross give rise to a male distorted sex ratio in their progeny (F2), the males from the reciprocal cross give rise t o a normal sex ratio. All eleven newly colonized strains from Ghana sh owed Y meiotic drive against the Xs of five strains, one of American a nd four of Australian origin, although one of the eleven showed a grea ter degree of drive than the other ten against the same sensitive stra ins. The variation observed is discussed in relation to previous studi es on meiotic drive by the MD haplotype, and to the possible exploitat ion of sex ratio distortion in controlling this potentially dangerous insect.