It has been previously demonstrated (1) that the length of the period of DNA synthesis (S period) as measured by uptake of tritiated thymidine is approximately the same in several animal cells. Since the length of this period (with a range of 6/~ to 8 hours) appears to be independent of the species of the cell, the chromosome number, the cells of human diploid strains in long term cultivation.

An Evaluation of the Relative Performance of Diploid versus Triploid Brook Trout with Consideration of the Influence of Lake Characteristics

We study the Fisher model describing natural selection in a population with a diploid structure of a genome by differential- geometric methods. For the selection dynamics we introduce an affine connection which is shown to be the projectively Euclidean and the equiaffine one. The selection dynamics is reformulated similar to the motion of an effective particle moving along the geodesic lines in...

Despite a great deal of theoretical attention, we have limited empirical data about how ploidy influences the rate of adaptation. We evolved isogenic haploid and diploid populations of Saccharomyces cerevisiae for 200 generations in seven different environments. We measured the competitive fitness of all ancestral and evolved lines against a common competitor and find that in all seven environm...

Protein electrophoretic profiles cast doubt upon the prevalent theory that the B genome of the polyploid wheats was derived from a species of Aegilops. They suggest, instead, that the wild tetraploid wheats comprise a complex, whose components were derived from various combinations of diploid Triticum types, which evidently include the B-genome type.

In the present study 25 specimens of Rhamdia quelen from four different localities were analyzed cytogenetically. All showed a diploid number of 58 chromosomes, with a karyotypic formula of 36m + 16sm + 6st and FN = 116. Metacentric B chromosomes showing inter- and intraindividual variation were observed in all populations. C-banding revealed differences in the heterochromatin distribution patt...

A species of DNA that is apparently associated with the plasma membrane of diploid human lymphocytes that are continously growing is described. This DNA differes from nuclear or mitochondrial DNA by virtue of its location in the cell, time of synthesis in the cell cycle, and various physical properties. At present, the role of this DNA is unknown.

We have used viscoelastometry in an attempt to understand the physical organization of genetic material in Tetrahymena nuclei. The micronucleus or germ line nucleus is diploid. It divides mitotically during vegetative growth, and five pairs of chromosomes are seen in meiosis. The macronucleus, or somatic nucleus, is approximately 45-ploid, divides amitotically, and has no visible chromosomes at...

The distribution of gene frequency a t a single locus in a population of diploid individuals, w ith two sexes, subject to m utation , non-random m ating and phenotypic selection, is obtained in the case where the generations are overlapping so th a t individuals die one by one. This d istribution is of the same form as th a t obtained by heuristic m ethods by S. W right in a random ly m ating p...