نتایج جستجو برای: random mating
تعداد نتایج: 306452 فیلتر نتایج به سال:
Yeast cells mate by an inducible pathway that involves agglutination, mating projection formation, cell fusion, and nuclear fusion. To obtain insight into the mating differentiation of Saccharomyces cerevisiae, we carried out a large-scale transposon tagging screen to identify genes whose expression is regulated by mating pheromone. 91,200 transformants containing random lacZ insertions were sc...
The objective of this research was to simulate the genetic gains expected comparing random mating strategies and mate selection by optimum contribution with different penalty levels in inbreeding rate Santa Inês sheep. theory thus applied optimize gain long term twelve groups selectively 500 females respective males, increasingly penalizing increase function. Genetic algorithms were used find [...
Multiple mating was investigated in two tephritid species when females were under minimal male pressure because they were each confined with a single male in cages 20 x 20 x 20 cm and observed daily until they died. Laboratory-reared females of Bactrocera cucumis (French) lived up to 274 days and refractory periods averaged 59-63 days. However, the distribution of matings among B. cucumis femal...
EEVE (1953, 1955,1961) has suggested that assortative mating of parents be used to obtain data for estimation of heritability by parent-offspring regression. The advantage of this technique over the standard random mating procedure is that the variance of midparent values is increased, thereby providing greater accuracy in the estimation of the regression coefficient. Possible bias introduced a...
An experiment was made to test the fertility of ram semen showing morphological abnormality due to exposure of the rams to high ambient temperature. Pyriform cells distinguishable by posterior constriction of the head, tailless sperm and an acrosomal cap abnormality were identified. Three groups of 20 Merino ewes were each mated to two rams which had been heated for four days, or for two days, ...
Computation of inbreeding rate (DeltaF) must consider that inbreeding is delayed with one generation with respect to the idealized population when addressed using individual inbreeding coefficients. The expression relating inbreeding in generation t with inbreeding rate F(t) = 1 - (1-DeltaF)(t) should be more correctly written in real animal populations as F(t) = 1 - (1-DeltaF)(t-1), as changes...
Mating systems are an important factor influencing the variance in reproductive success among individuals within natural populations and thus have important ecological and evolutionary implications. We used molecular pedigree reconstruction techniques with microsatellite DNA data to characterize the genetic mating system and mate selection in adult smallmouth bass spawning in Lake Opeongo. The ...
Nonrandom mating can structure populations and has important implications for population-level processes. Investigating how and why mating deviates from random is important for understanding evolutionary processes as well as informing conservation and management. Prior to the implementation of parentage analyses, understanding mating patterns in solitary, elusive species like bears was virtuall...
BACKGROUND Non-random mating affects population variation for substance use and dependence. Developmentally, mate selection leading to positive spousal correlations for genetic similarity may result in increased risk for substance use and misuse in offspring. Mate selection varies by cohort and thus, assortative mating in one generation may produce marked changes in rates of substance use in th...
The adaptive significance of sequential polyandry is a challenging question in evolutionary and behavioral biology. Costs and benefits of different mating patterns are shaped by the spatial distribution of individuals and by genetic parameters such as the pairwise relatedness between potential mating partners. Thus, females should become less choosy as costs of mating and searching for mates in...
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