Autor(es): BERTRAM D S

Resumo: 1. 1) Anopheles gambiae var. melas in the Gambia and colony A. g. gambiae and Aedes aegypti in London were exposed to contact with an alkylating agent, thio-tepa, by resting on a treated surface at 18-20 mg. per sq. ft. for 1-3 hours. 2. 2) Chemosterilization was highly effective in treated females previously mated to normal males. With wild-caught female A. g. var. melas in Gambia, 68.7 per cent. of 6,369 control eggs hatched, but only 0.8 per cent. of 6,913 eggs from treated females, and these few fertile eggs were probably laid too soon after exposure of the females to be affected by the treatment. With female Ae. aegypti, 86.8 per cent. of 4,105 control eggs hatched, but only 2.3 per cent. of 2,270 eggs from treated females. The cause of hatches in these few eggs is uncertain. 3. 3) Sperms from normal males of Ae. aegypti remained numerous and active in the spermathecae of treated females for 6 weeks after their exposure to thio-tepa. 4. 4) Nevertheless, the females laid sterile eggs, some of abnormal shape and pigmentation, for four gonotrophic cycles over 6 weeks; and fecundity also appeared to be declining over this period. 5. 5) Active sperms were still present in treated male Ae. aegypti 32 days after treatment, and insemination of the female could still take place; reduction of testes appeared to be occurring with time. 6. 6) Normal female Ae. aegypti mated, over 15 days, to treated males laid, almost exclusively, infertile eggs. Females mated to these males later, 18-28 days after the male treatment, produced considerably more fertile eggs. 7. 7) This capacity of males to begin producing fertile sperm again in a relatively short time after treatment could prejudice the success of control operations based on male chemosterilization. 8. 8) The cytogenetic and cytostatic mechanisms of mutagenic chemicals, as observed in Drosophila in researches of others relating to cancer therapy, are briefly discussed and some interpretation offered on this basis for the chemosterilant effects of thio-tepa on mosquitoes.

Palavras-Chave: Alkylating agents; Africa; Western; Anopheles; Chemosterilants; Culicidae; Cytogenetics; Drosophila; Eggs; Fertility; Gambia; Infertility; Insemination; Melas; Syndrome; Pigmentation; Prejudice; Sperm cell; Thiotepa; Testis; Cancer therapy; Aedes aegypti

Imprenta: Transactions of the Royal Society of Tropical Medicine and Hygiene, v. 57, n. 322-335, 1963

Identificador do objeto digital: 10.1016/0035-9203(63)90095-6

Descritores: Aedes aegypti - Sexual ; Aedes aegypti - Public health

Data de publicação: 1963

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