Evidence of a responsible gene for the thermosensibility during laying-season with Drosophila melanogaster

Summary A recessive gene that makes oogenesis and development heat sensitive has been found in a laboratory strain of Drosophila melanogaster homozygous for sepia. The new mutation called pts (ponte thermosensible) is located on chromosome III, near the locus of sepia. When eggs are collected from females kept at 30°C, two observations can be made:The rate of egg laying is reduced, oogenesis being stopped reversibly at stage 7 of ovarian cystes.Eggs which have gone through this stage before the temperature was raised are deposited, but fail to hatch, even when their own genotype is heterozygous pts/pts⁺.Heat shocks applied at later periods to pts/pts homozygous show the existence of two others periods of temperature sensitivity located respectively at the beginning of embryogenesis and of larval stage.

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Directeur: Ph. L'Héritier

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Mémoire présenté par E. Hadorn