Cytogenetic Effects of Chemosterilants in Mosquitoes

I. Apholate-induced aberrations in the somatic chromosomes of Aedes aegypti L

Abstract

Some cytological effects of an alkylating agent, apholate, a commonly used chemosterilant, on the Rock strain of Aedes aegypti were studied. Two to four days old larvae were reared until pupation in 10ppm apholate. Mitotic chromosomes were studied from squash preparations of larval brains stained with acetolactic orcein.
Apholate induced numerous chromosomal aberrations by virtue of its ability to break and physiologically modify chromosomes. Among the chromosomal aberrations observed were stickiness, deletions, ring chromosomes, dicentric chromosomes and anaphase bridges. Chromosome breakage appeared to be frequently induced in the region of the secondary constriction in one of the larger chromosomes. Also, treatment with apholate resulted in the induction of somatic tetraploidy in some brain cells. It may also interfere with normal replication of chromosomes.
Explanations for the induction of these aberrations have been discussed.