Characterization of a Temperature-Sensitive Female Sterile Mutant (l(1)1074TS) in Drosophila Melanogaster

Abstract

A new X-linked temperature-sensitive female sterile mutant ((1)1074") is described. The nonpermissive temperature for this mutant is 29°C. There are two temperature-sensitive periods during development-one between the 6th and 12th hours of embryogenesis and a second commencing during the first larval instar and terminating at mid pupation. Embryological abnormalities first become apparent during gastrulation and eventually these result in the breakdown of organogenesis and the complete absence of normal muscular contractions. Preconditioning mutant females at the nonpermissive temperature for up to 48 h enhances the abnormal embryological effects produced by the mutant. When developing gastrulae of the mutant are fragmented and cultured in vitro at 29°C, many cell clumps fail to differentiate. This does not appear to be a consequence of cell death. Fragmented gastrulae of wild-type embryos always show cell differentiation following in vitro culture. On the basis of the studies reported in this paper, it is suggested that the (1)1074+ gene product is deposited within the ovum during oogenesis and is vital for a number of early embryonic developmental processes rather than being critical for any specific developmental event such as the differentiation of a particular cell type. © 1978 ASEG.