Influence of temperature on the inheritance of adult life span in Drosophila melanogaster

Purification and characterization of a protein associated with genetically-determined longevity difference in Drosophila melanogaster

Earlier studies have shown a correlation between the presence of a 77 kDa protein in the proteins extracted from young adult Drosophila melanogaster (D.m.) and the autosomal longevity allele. A2 at the JmA locus. In this study, a 77 kDa protein has been isolated from pupae of D.m. of a long-lived strain of genotype A2A2, and was purified by DEAE chromatography, ConA column chromatography, and two cycles of gel filtration. The purified protein has a molecular weight of 76,600 (by SDS-PAGE), an isoelectric point of pH 6.5, and molar extinction coefficient A(280(1%) = 18.3. It is a glycoprotein containing 3.3% hexose. Supplementing the food of D.m. with the purified protein at 5 x 10(-4) micrograms/ml, beginning at day 5 after emergence, resulted in an increase in the survival rate and maximal life span of both short-lived and long-lived strains of D.m.

Cytoplasmic influence on the expression of nuclear genes affecting life span in Drosophila melanogaster

In earlier studies we have found that the difference between short and long life spans of two inbred strains of Drosophila melanogaster is controlled by nuclear major genes. The present study has revealed a cytoplasmic factor that influences the expression of the nuclear longevity genes. The factor shows a typical maternal inheritance and is considered to be an extranuclear gene, such as mitochondrial DNA (chondriome). This paper marks the discovery of two basic forms of inheritance, nuclear and extra-nuclear, in the genetics of life span of D. melanogaster. These findings suggest that further studies, including genetic engineering, on longevity and aging might enable direct manipulation of these characters.

Relationship between genotypes of longevity genes and developmental speed in Drosophila melanogaster

Hatching time (the period between egg-laying and hatching) and emerging time were surveyed and their relationship with the adult life span was investigated. A relationship between emerging time and adult life span was clearly evident: early emergers were often long-lived. This relation is considered to have a genetic basis because all the larvae in a group were bred in the same culture bottle. Thus, the longevity genes involved also appear to have control over the rate of development. No significant relation was observed between hatching time and adult life span or between hatching time and emerging time. These results suggest that the function of the longevity genes begins at the larval or pupal stage before emergence, and that adult life spans differentiate at this time.