Genetic analysis of a population of tribolium III. Fatty acid composition of unsaturated fatty acid sensitive mutant

The unsaturated fatty acid sensitive genotype (cos/cos) of Tribolium castaneum was compared with the normal (+/+) on diets with 0 and 4 per cent, corn oil. The relative percentages of fatty acids, wet weight, dry weight, per cent, lipids and per cent. water were monitored from 10 days to 28 days of age. The cos homozygote and +/+ genotypes on diet 0 show the same composition in all criteria examined. On diet 4 the cos/cos genotype has the same general pattern as the normal for wet weight, dry weight and percentage lipids except that the mutant is approximately 2 days out of phase. Critical to the hypothesis of a genetic block the distribution of fatty acids of both genotypes are quite similar, especially after 14 days of age, and does not reflect the altered growth pattern of the mutant. The apparent initial delay in response to the unsaturated fatty acid linoleate together with a subsequent normal pattern of development suggest that the genetic mutation may be associated with an inducible enzyme system.