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Parasites and Conservation Biology
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
Some host populations by virtue of suffering losses in numbers consequently experience loss of genetic diversity. This diversity is needed to withstand both short-term environmental perturbations and, on longer time scales, to evolve in response to environmental changes (recall the example of the Hawaii ‘amakihi and ‘i’iwi mentioned earlier). Small host populations can lose genetic diversity as a result of random events (genetic drift; see Chapter 7) or as a consequence of inbreeding if the diversity of potential mates is limited. Inbreeding refers to reproduction by mates who are closely related, which leads to homozygosity, loss of genetic diversity and increased chances that offspring can be affected by deleterious traits. Inbreeding depression refers to the loss of fitness in a population from the breeding of related individuals.
Inbred Laboratory Mice as Animal Models and Biomedical Tools: General Concepts
Published in John P. Sundberg, Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
Laboratory mice have proven to be extraordinarily useful for biomedical research due to their small size, short breeding time, polytoceous nature, relatively low husbandry costs, and short life span. Inbreeding (20 generations of brother-sister matings) can essentially eliminate genetic variability between individuals of the same sex. Controlled environment and specific pathogen-free status of the animals further increases the repeatability of biological studies.
Assigning the LR
Published in Jo-Anne Bright, Michael D. Coble, Forensic DNA Profiling, 2019
Jo-Anne Bright, Michael D. Coble
Of interest in a forensic DNA context is inbreeding. Inbreeding is when individuals mate who are more closely related than if they had been chosen at random from a population. Related individuals have ancestors in common (coancestry), and their offspring are more likely to inherit the same copy of an ancestral allele from each parent (these alleles are described as being identical by descent [IBD]). Inbreeding may be due to religious or language reasons and rates increase in smaller populations. Inbreeding leads to an increased number of homozygotes within the population compared with expectation.
Induced mutation in Agaricus bisporus by gamma ray to improve genetic variability, degradation enzyme activity, and yield
Published in International Journal of Radiation Biology, 2021
Tayebeh Harfi, Motallebi-Azar Alireza, Rasouli Farzad, Zaare-Nahandi Fariborz
One of the main goals of inbreeding in any agricultural crop is the improvement of yield. Since the main goal of this study was to create diversity and then improve the traits, such as yield, high- and low-yield variants were obtained in the first experiment. The best variants were selected from the first culture medium. The results of the second experiment on two substrates of culture medium (100:0 and 75:25) showed that the yields of variants were consistent with those of the first experiment, which well demonstrated the superiority of GR9, GR3, GR61, GR4, GR74, and GR72 variants. Furthermore, the variants had a more fruiting body number with less fruiting body fresh weight. With three methods of mutagenesis (spore suspension, spore droplets spread on Potato Dextrose Agar, and mycelium fragments), Motallebi-Azar et al. (2017) obtained variants with higher yields and number of fruiting bodies and showed significant positive correlation between the yield and number of the fruit body. Liu et al. (2019) obtained high-yield, high-quality Agaricus brasiliensis using irradiating the mycelium by gamma-ray.
Unusual β-Globin Haplotype Distribution in Newborns from Bengo, Angola
Published in Hemoglobin, 2019
Eliana Borges, Chissengo Tchonhi, Cátia S.B. Couto, Verónica Gomes, António Amorim, Maria João Prata, Miguel Brito
According to the available data on human societies, the ratio of male to female variance in reproductive success differs significantly with mating system, with polygynous societies showing significantly higher ratios than monogamous societies, meaning that the male mating success varies considerably more than the female mating success in a polygynous system [17]. Population genetics theory predicts that large variance in the reproductive success contributes to decrease the effective population size, to increase the inbreeding effective size (used to describe the average accumulation of identity by descent in a population), and consequently to reduce the observed heterozygosity in a population (reviewed in [18] but see also [19]). Furthermore, it is widely acknowledged that inbreeding increases the prevalence of autosomal recessive disorders in a population.
Biomedical and genetic characteristics of the Ryukyuans: demographic history, diseases and physical and physiological traits
Published in Annals of Human Biology, 2019
Kae Koganebuchi, Ryosuke Kimura
The Ryukyu Islands are surrounded by the Pacific Ocean and the East China Sea, suggesting that the people in the islands, the Ryukyuans, were isolated not only from other populations, but also between island groups. To date, many morphological and genetic studies have discussed migration processes into and between the islands. Population isolation can result in genetic differentiation from other populations and inbreeding within the population. Medical studies have shown that some infectious and lifestyle-related diseases are more prevalent in the Ryukyu Islands than in the main islands of Japan. In this review, we describe the demographic history, diseases and physical and physiological traits of the Ryukyuans and discuss future directions of genetic research among the population.