Temperature and the progeny sex-ratio in Sciara ocellaris (Diptera, Sciaridae)

Genetics and Molecular Biology

Rogério G. Nigro¹  Maria Cristina C. Campos¹  André Luiz P. Perondini¹ 

[1] ,Universidade de São Paulo Instituto de Biociências Departamento de Genética e Biologia EvolutivaSão Paulo SP ,Brazil

关键词: sex determination;    chromosome elimination;    embryo;    insect;   

DOI  :  10.1590/S1415-47572007000100026

来源: SciELO

【 摘 要 】

We found that the sex-ratio of an amphigenic strain of Sciara ocellaris varied widely from progenies with few males to progenies containing a larger proportion of males, with single-sex progenies being rare. The sex-ratio distributions were dependent on the temperature at which the stocks of flies were raised, with the sex-ratio distributions being symmetrical (i.e. about 50% males) at 18 °C and 20 °C while at the higher temperatures of 24 °C and 28 °C the distributions were skewed toward a high proportion of females with the mean proportion of males decreasing to about 30-37% per progeny. Temperature-shift experiments showed that high temperatures were effective only during the last stages of female pupal development plus a period after adult emergence, stages corresponding to oocyte maturation. When imagine females were exposed to temperatures as low as 12 °C the sex-ratio distributions of their progeny were skewed toward a high proportion of males per progeny. No differential fecundity was involved in these progeny sex-ratio modifications. Egg-to-adult survival was lower at 18 °C and 28 °C but no correlations with skewing in the sex ratio distributions were observed, indicating that modifications in progeny sex-ratio did not involve the differential survival of a particular sex.

【 授权许可】

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