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Animal Biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
Mice are the most commonly used animal models with hundreds of established inbred, outbred, and transgenic strains. Mice are common experimental animals in biology and psychology primarily because they are mammals and thus share a high degree of homology with humans. The mouse genome has been sequenced, and virtually all mouse genes have human homologs. They can also be manipulated in ways that would be considered unethical in humans. Mice are a primary mammalian model organism, as are rats. There are many additional benefits of mice in laboratory research. Mice are small, inexpensive, easily maintained, and can reproduce quickly. Several generations of mice can be observed in a relatively short period of time. Some mice can become docile if raised from birth and given sufficient human contact. However, certain strains have been known to be quite temperamental.
Animal biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2018
Mice are the most commonly used animal models with hundreds of established inbred, outbred, and transgenic strains. Mice are common experimental animals in biology and psychology primarily because they are mammals and thus share a high degree of homology with humans. The mouse genome has been sequenced, and virtually all mouse genes have human homologs. They can also be manipulated in ways that would be considered unethical to do with humans. Mice are a primary mammalian model organism, as are rats. There are many additional benefits of mice in laboratory research. Mice are small, inexpensive, and easily maintained and can reproduce quickly. Several generations of mice can be observed in a relatively short period of time. Some mice can become docile if raised from birth and given sufficient human contact. However, certain strains have been known to be quite temperamental.
Sustainable Agriculture and Industry
Published in Julie Kerr, Introduction to Energy and Climate, 2017
Because the goal of hybridization is to ultimately create a superior product, an important factor is the heterosis (the tendency of a cross-bred individual to show qualities superior to those of both parents) or combining ability of the parent plants. Crossing any particular pair of inbred strains may or may not result in better, stronger, or enhanced offspring. Because of this, the parent strains used are very carefully selected in order to achieve the uniformity that comes from the uniformity of the parents, and the superior performance that comes from heterosis.
Consequences of space radiation on the brain and cardiovascular system
Published in Journal of Environmental Science and Health, Part C, 2021
Catherine M. Davis, Antiño R. Allen, Dawn E. Bowles
Rodent models are important resources for identifying genetic factors influencing complex traits. Conventional crosses are widely used for behavioral testing after radiation exposure. However, the intense breeding selection is likely to have eliminated many behavioral genetic variants.143 In addition, genetic background influences the phenotype of the brain. The population of hippocampal neural stem cells differs among mouse strains, and genetic influence on hippocampal neurogenesis has been demonstrated in C57BL/6, BALB/c, ICR, and 129/SvJ.144 Recent efforts to expand the genetic resources available in the mouse have resulted in the development of the Diversity Outbred panel,143 Collaborative Cross and Collaborative Cross heterogenous stock.145 Conventional crosses, widely used for behavioral and cognitive testing after radiation exposure lack of genetic diversity. Genetically diverse mice better recapitulate the range of phenotypes seen in the human population compared to a single inbred strain.146 Future studies are warranted to understand how the genetic difference influence cognitive outcomes after space radiation exposure.
Methods for evaluating variability in human health dose–response characterization
Published in Human and Ecological Risk Assessment: An International Journal, 2020
Daniel A. Axelrad, R. Woodrow Setzer, Thomas F. Bateson, Michael DeVito, Rebecca C. Dzubow, Julie W. Fitzpatrick, Alicia M. Frame, Karen A. Hogan, Keith Houck, Michael Stewart
These new rodent models should provide improved approaches to understand and predict human population variability in response to chemical exposures as compared to use of inbred strains. The studies by French et al. (2015) and Church et al. (2015) demonstrate the models’ strength in identifying genetic polymorphisms that influence chemical toxicity. Directly translating identified polymorphisms from these rodent models to humans is challenging because not all mouse genes have human orthologues (French et al.2015). Experience using these models to evaluate variability in chemical sensitivity is limited, and these studies have focused on identifying genetic polymorphisms involved in altered susceptibility. Another challenge is the large number of animals necessary to identify genetic polymorphisms in these experiments. Churchill et al. (2012) estimated that, depending on the phenotype studied, between 200 and 800 mice per treatment group are required to identify any polymorphism related to the variance in response with sufficient confidence. As it stands, the use of mouse models to efficiently identify polymorphisms and quantify population variability in response to chemical exposure requires further optimization of study designs.
Thirty years of conservation genetics in New Zealand: what have we learnt?
Published in Journal of the Royal Society of New Zealand, 2019
It is not widely appreciated that differences in H among individuals as measured at a small portion of the genome will only reflect genomic diversity if there is a degree of inbreeding. H is otherwise independent among loci; an enormous number of loci would need to be genotyped to estimate differences in H among individuals in an outbred population. Even when a population is inbred, one needs a large enough variance in inbreeding coefficient for fitness effects to be measurable. Indeed, a survey of diversity across ten threatened bird species showed no relationship between individual H for microsatellites and multiple toll-like receptor loci coding for innate immunity genes (Grueber et al. 2015). In an important paper, Townsend and Jamieson (2013a) controlled for the effects of inbreeding on HFCs by examining sibs from the same nest. Remarkably, juvenile survival was 17.2% higher for robins one standard deviation above the family mean for H measured by 35 microsatellite loci. Presumably, H across these loci is a proxy for H at numerous linked functional loci (local effect), a conclusion supported by the fact that the effect is only found in families that are to some extent inbred. In outbred families, either linkage disequilibrium is not sufficient to detect an HFC, or there are simply more loci segregating alleles that contribute to fitness differences among sibs.