Temperature sensitive periods ofcubitus interruptus mutants inDrosophila melanogaster

Abstract

The temperature sensitive period for mutant expression was determined incubitus interruptus ofDrosophila melanogaster. Two stocks carrying the dominant alleleci ^D were compared, in which under the influence of temperature, mutant expression of the most conspicuous character (gap in fourth vein) changes in opposite directions.

The effective period (T.E.P.) ofci ^D was found to be very similar in both stocks. It is relatively short and begins after puparium formation. The T.E.P. is also the same for mutant expression on the fourth and the fifth vein. But in contrast to the 4^th vein character, the 5^th vein reacted in the same direction in both stocks.

The T.E.P. was again determined in the same two stocks after the recessive alleleci had been introduced instead ofci ^D. The T.E.P. ofci in both stocks occupies a large part of the larval period including the first instar. The genetic background difference that causes opposite temperature reactions ofci ^D, does not show up in the temperature reactions ofci.

The significance of these facts and of T.E.P.'s in general are discussed.