Heterozygosity but not inbreeding coefficient predicts parasite burdens in the banded mongoose

Inbreeding is reduced and genetic diversity enhanced when a small isolated inbred population is crossed to another unrelated population. Crossing can have beneficial or harmful effects on fitness, but beneficial effects predominate, and the risks of harmful ones (outbreeding depression) can be predicted and avoided. For crosses with a low risk of outbreeding depression, there are large and consistent benefits on fitness that persist across generations in outbreeding species. Benefits are greater in species that naturally outbreed than those that inbreed, and increase with the difference in inbreeding coefficient between crossed and inbred populations in mothers and zygotes. However, benefits are similar across invertebrates, vertebrates and plants. There are also important benefits for evolutionary potential of crossing between populations.

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Allozyme variation and an estimate of the inbreeding coefficient in the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae)

Bulletin of Entomological Research ◽

10.1017/s000748530005197x ◽

1995 ◽

Vol 85 (1) ◽

pp. 21-28 ◽

Cited By ~ 9

Author(s):

Philippe Borsa ◽

D. Pierre Gingerich

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Population Genetic ◽

New Caledonia ◽

Allozyme Variation ◽

Inbreeding Coefficient ◽

Hypothenemus Hampei ◽

Coffee Berry ◽

Biological Features ◽

High Degree

AbstractSeven presumed Mendelian enzyme loci (Est-2, Est-3, Gpi, Idh-l, Idh-2, Mdh-2 and Mpi) were characterized and tested for polymorphism in coffee berry borers, Hypothenemus hampei (Ferrari), sampled in Côte d′Ivoire, Mexico and New Caledonia. The average genetic diversity was H = 0.080. Two loci, Mdh-2 and Mpi were polymorphic, and thus usable as genetic markers. The population structure of H. hampei was analysed using Weir & Cockerham's estimators of Wright's F-statistics. A high degree of inbreeding (f = 0.298) characterized the elementary geographic sampling unit, the coffee field. The estimate of gene flow between fields within a country was Nm = 10.6 and that between countries was Nm = 2. The population genetic structure in H. hampei could be related to its known population biological features and history.

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Evidence for a quantitative genetic influence on the formation of aortic valves with two leaflets in the Syrian hamster

Cardiology in the Young ◽

10.1017/s1047951100001396 ◽

1993 ◽

Vol 3 (2) ◽

pp. 132-140 ◽

Cited By ~ 18

Author(s):

Valentín Sans-Coma ◽

Manuel Cardo ◽

Ana C. Durán ◽

Diego Franco ◽

Borja Fernández ◽

...

Keyword(s):

Aortic Valve ◽

Inbreeding Coefficient ◽

Quantitative Inheritance ◽

Histologic Study ◽

Aortic Valves ◽

Aortic Sinus ◽

Quantitative Genetic ◽

Corrosion Cast ◽

The Right ◽

Cast Technique

SummaryWe studied the morphology of the aortic valves of 1,036 Syrian hamsters belonging to two families subjected to high endogamous pressure. Most (n=955) specimens were examined using a corrosion-cast technique. In the remaining 81 specimens, valvar morphology was assessed by means of a stereomicroscope, and in 18 of these cases a histologic study was also performed. In one of the families, a high proportion (30.5%) of hamsters had aortic valves with two leaflets, the aortic sinuses being oriented ventrodorsally. The percentage of such anomalous valves was found to be positively correlated with the inbreeding coefficient of specimens. In the other family, the occurrence of an aortic valve with two leaflets was a sporadic event. Stereoscopic and histologic observations demonstrated that, in 52 of 63 aortic valves with three leaflets, the ventral commissure between the right and left leaflets was partially fused, while in 10 other cases this commissure was completely fused. In addition, in nine of 18 aortic valves with two leaflets, there was a more or less well-developed raphe located in the ventral aortic sinus, approximately where the true ventral commissure would have been. Our observations suggest the existence of a continuous spectrum of aortic valvar morphology, ranging from a valve with three leaflets and no fusion of the ventral commissure to an aortic valve with two leaflets devoid of any raphe. This spectrum seems to be the result of the interaction of genetic and intrauterine environmental factors. Results of crosses between both related and unrelated hamsters suggest that the observed morphology in individuals is the result of quantitative inheritance.

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Effect of inbreeding and individual increase in inbreeding on growth in Nilagiri and Sandyno breeds of sheep

Animal Genetic Resources/Ressources génétiques animales/Recursos genéticos animales ◽

10.1017/s2078633615000338 ◽

2016 ◽

Vol 58 ◽

pp. 63-71 ◽

Cited By ~ 1

Author(s):

R. Venkataramanan ◽

A. Subramanian ◽

S.N. Sivaselvam ◽

T. Sivakumar ◽

C. Sreekumar ◽

...

Keyword(s):

Growth Traits ◽

Inbreeding Coefficient ◽

Pedigree Information ◽

Research Station ◽

Sheep Breeding ◽

Inbreeding Coefficients ◽

Equivalent Number ◽

Breeding Research ◽

Percent Increase ◽

Two Populations

SummaryIndividual increase in inbreeding coefficients (ΔFi) has been recommended as an alternate measure of inbreeding. It can account for the differences in pedigree knowledge of individual animals and avoids overestimation due to increased number of known generations. The effect of inbreeding (F) and equivalent inbreeding (EF) calculated fromΔFi, on growth traits were studied in Nilagiri and Sandyno flocks of sheep. The study was based on data maintained at the Sheep Breeding Research Station, Sandynallah. The pedigree information and equivalent number of generations were less in Sandyno compared with Nilagiri sheep. The average F and EF for the Nilagiri population were 2.17 and 2.44, respectively and the corresponding values for Sandyno sheep were 0.83 and 0.84, respectively. The trend of inbreeding over years in both the populations indicated that EF was higher during earlier generations when pedigree information was shallow. Among the significant effects of inbreeding, the depression in growth per 1 percent increase in inbreeding ranged from 0.04 kg in weaning weight to 0.10 kg in yearling weight. In general, more traits were affected by inbreeding in Nilagiri sheep, in which greater regression of growth traits was noticed with F compared with EF. Higher values of EF than F in earlier generations in both the populations indicate that EF avoided the potential overestimation of inbreeding coefficient during recent generations. In the Sandyno population, the magnitude of depression noticed among growth traits with significant effects of inbreeding was higher. The differences in response to F and EF noticed in the two populations and possible causes for the trait wise differences in response to F and EF are appropriately discussed.

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