Significant increase in the dominant lethal mutations: benzo(a)pyrene

The frequency of X ray-induced dominant and recessive lethal mutations in the rat.

P A R T of the genetic damage induced by X rays may be due to mutations which have harmful effects on viability. Such mutations may vary in the seventy of their effects from lethal to mildly detrimental, and in degree of dominance from completely dominant or overdominant to completely recessive. The difficulties of obtaining precise mutation rate estimates for viability mutations in mammals are...

Dominant lethal mutations in the honeybee: a perspective 50 years later.

IN the 1950s no one thought of the honeybee as particularly adapted to answering genetic questions that were difficult in other organisms. But it has some distinct advantages. For one thing, unfertilized eggs develop into haploid males, whereas fertilized eggs become females, aproperty it shareswithotherhymenoptera.But in addition, a queen bee lays some 1000 eggs per day and the drone cells in ...

Significant Increase in the Prevalence of Multiple Sclerosis in Iran in 2011

An Influence of Ploidy on the Time of Expression of Dominant Lethal Mutations in Habrobracon.

HEN Habrobracon eggs are X-rayed at metaphase I and subsequently fertiw l i z e d , the decreased hatchability is attributed to dominant lethal mutation, in the same sense in which the term is used when sperm are irradiated. This is justified by WHITING'S demonstration (1946, 1948, 1949, 1950, 1955) that cytoplasmic injury is not lethal a t the doses employed. In unfertilized eggs, which develo...

Effects of dose on the induction of dominant-lethal mutations with triethylenemelamine in male mice.

Dose effects of triethylenemelamine (TEM) in the induction of dominant-lethal mutations were studied at the early spermatozoon, midspermatid and spermatocyte stages. The pattern of effects on spermatocytes, unlike midspermatids and early spermatozoa, indicated possible cytotoxic damage, so for the determination of TEM dose-response curves in the induction of genetic damage only the data for mid...