The fatty acid constitution and ordering state of membranes in dominant temperature-sensitive lethal mutation and wild-typeDrosophila melanogaster larvae

Abstract

The ordering state and changes in fatty acid composition of microsomal (MS) and mitochondrial (MC) membranes of two dominant temperature-sensitive (DTS) lethal mutations and the wild-type Oregon-R strain larvae of Drosophila melanogaster have been studied at 18 and 29 degrees C and after temperature-shift experiments. The membranes of wild-type larvae have a stable ordering state, with "S" values between 0.6 (18 degrees C) and 0.5 (29 degrees C) in both membranes which remained unchanged in shift experiments, although the ratios of saturated/unsaturated fatty acids were changed as expected. The strongly DTS mutation 1(2) 10DTS forms very rigid membranes at the restrictive temperature (29 degrees C) which cannot be normalized after shift down, while shift up or development at the permissive temperature results in normal ordering state. This mutant is less able to adjust MS and MC fatty acid composition in response to the growth temperature than the wild type. The less temperature-sensitive 1(2)2DTS allele occupies an intermediate state between Oregon-R and 1(2)10DTS in both respects. We assume and the genetical data suggest that the DTS mutant gene product is in competition with the wild-type product, resulting in a membrane structure which is not able to accommodate to the restrictive temperature.

Drosophila basement membrane collagen col4a1 mutations cause severe myopathy

“…Allele-specific survival was further supported by the ratio of DTS/+ pupae/adults that varied between 10 and 60% (Table 2). These results were consistent with the semi-lethality observed in previous temperature-shift experiments with increasingly reduced number of survivors during all developmental phases (Szidonya et al, 1990).…”

“…DTS/DTS homozygotes perish under permissive temperatures principally as late embryos, a minor amount of animals hatch and the emerging adults are extremely weak, and die prematurely (Suzuki and Procunier, 1969;Szidonya and Reuter, 1988;Szidonya et al, 1990). Adult DTS/+ heterozygotes are viable, but become gradually female-sterile under restrictive temperatures (Suzuki and Procunier, 1969).…”

Catalytic function of Drosophila melanogaster glutathione S‐transferase DmGSTS1‐1 (GST‐2) in conjugation of lipid peroxidation end products

“…Drosophila lacks arachidonic acid, at least in some tissues [51,52]. However, 4‐HNE can be formed from all ω‐6 polyunsaturated fatty acids [27,53] which, in addition to arachidonic acid, includes linoleic acid which is present in large amounts in larval and adult stages of Drosophila [54–56]. Moreover, 4‐hydroxyalkenals of chain lengths different from the nine carbon atoms of 4‐HNE may arise from peroxidation of other polyunsaturated fatty acids [27].…”

Genotype - phenotype relationship in Drosophila type IV collagen mutants

“…persists throughout development without a sharp lethal phase, resulting in gradually decreasing number of survivors. DTS/DTS homozygotes perish under permissive temperatures principally as late embryos, a minor amount of animals hatch and the emerging adults are extremely weak, and die prematurely Szidonya and Reuter, 1988;Szidonya et al, 1990). Adult DTS/+ heterozygotes are viable, but become gradually female-sterile under restrictive temperatures .…”