Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

RELATIVE GENETIC LOADS DUE TO LETHAL AND DETRIMENTAL GENES IN IRRADIATED POPULATIONS OF DROSOPHILA MELANOGASTER

Journal Article · · Genetics (U.S.)
OSTI ID:4727403
The effect of irradiation on the reiative genetic loads due to detrimental and lethal genes expressed by inbreeding was studied by extracting 267 second chromosomes of Drosophila meianogaster and by examining their effects on viability in homozygous and heterozygous conditions for one nonirradiated and six irradiated populations. These irradiated groups had been maintained in the laboratory for several years after cessation of the irradiation. No consistent relation of these loads to the radiation history of the different population was found. The data indicated that the irradiated stocks are nearly at equilibrium for both detrimental (D) and lethal (L) loads. The overall mean ratio of D to L was estimated at.58. Slight increase of D but constant L with crowding condition of culture suggested that the D to L ratio may be underestimated under uncrowded laboratory conditions. The inbred genetic load effected through sterility was expressed in terms of sterile equivalent with two components of partial and complete sterility. Over both sexes the two components were found to be equally important in their harmful effects. Approximately one fourth of the total inbred load manifested through lowered viability and sterility is contributed by sterility factors. The second chromosomes of the irradiated populations in heterozygous arrangement with cn bw/sup D/ or Cy O marker chromosomes caused signlficantly reduced viability below the similar combinations of nonirradiated population. This increased heterozygous load due to irradiation was in the magnitude of.0225 plus or minus .0084. Implication of this finding relative to degree of dominance of detrimental genes is discus sed. (auth)
Research Organization:
Univ. of Wisconsin, Madison
NSA Number:
NSA-17-007839
OSTI ID:
4727403
Journal Information:
Genetics (U.S.), Journal Name: Genetics (U.S.) Vol. Vol: 47; ISSN GENTA
Country of Publication:
Country unknown/Code not available
Language:
English