POPULATION GENETICS OF DROSOPHILA NASUTA NASUTA, DROSOPHILA NASUTA ALBOMICANA AND THEIR HYBRIDS. I. KARYOTYPIC MOSAICISM IN THE HYBRID POPULATIONS

Abstract

ABSTRACT D. n. nasuta and D. n. albomicana constitute a pair of chromosomal races with 2n=8 and 2n=6, respectively. The F1 of these has 2n=7 and it is fertile. There exists a state of karyotypic mosaicism as evidenced by the presence of 26 types of chromosome combinations in F2, F3, and F10 populations. In the midst of this karyotypic noise, the karyotype similar to that of F1 reached 51% of the population. Implications of these findings are discussed.