Inbreeding depression is the reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals. Population biological fitness refers to an organisms ability to survive and perpetuate its genetic material. Inbreeding depression is often the result of a population bottleneck. In general, the higher the genetic variation or gene pool within a breeding population, the less likely it is to suffer from inbreeding depression. Inbreeding depression seems to be present in most groups of organisms, but varies across mating systems. Hermaphroditic species often exhibit lower degrees of inbreeding depression than outcrossing species, as repeated generations of selfing is thought to purge deleterious alleles from populations. For example, the outcrossing nematode (roundworm) Caenorhabditis remanei has been demonstrated to suffer severely from inbreeding depression, unlike its hermaphroditic relative C. elegans, which experiences outbreeding depression. Inbreeding ...
Saha, N.,Hamad, R.E.,Mohammed, S. (1990). Inbreeding effects on reproductive outcome in a Sudanese population. Human Heredity 40 (4) : 208-212. [email protected] Repository ...
8. Inbreeding is expensive. For cows that survive to freshen the first time, each 1% increase in inbreeding reduces lifetime net income by $22 to $24.. 9. There is no magic level of inbreeding that is acceptable. Effects of inbreeding on performance of commercial dairy cattle are almost entirely negative.. 10. Inbreeding decreases performance. Inbreeding decreases cow survival, single lactation production and reproductive performance.. 11. Inbreeding increases negative factors. Inbreeding increases calf mortality, increases age at puberty through retarded growth, and increases rate of disposal or loss of replacement heifers prior to first calving.. 12. Inbreeding should be managed in herd breeding programs rather than avoided.. 13. Inbreeding in offspring differs for each sire-dam combination, making mate assignments important if inbreeding is to be managed properly.. 14. Blanket recommendations of a bull as an outcross to groups of cows may not be effective in reducing the impact of ...
MAIWASHE, A.; NEPHAWE, K.A. and THERON, H.E.. Estimates of genetic parameters and effect of inbreeding on milk yield and composition in South African Jersey cows. S. Afr. j. anim. sci. [online]. 2008, vol.38, n.2, pp.119-125. ISSN 2221-4062.. The effect of inbreeding on the 305-d yields of milk, fat and protein, and the percentages of fat and protein in the first three lactations was estimated using records on the South African Jersey cows that participated in the National Dairy Animal Improvement Scheme. Inbreeding coefficients were estimated using the entire pedigree records of the Jersey breed and ranged from 0 to 42%. Data were analyzed using a repeatability animal model. The statistical model included the fixed effects of herd-year-season, age of the cow at calving, calving interval, inbreeding as a discrete or continuous variable and random effects of direct additive genetic, permanent environment of the cow and the residual effects. The multitrait derivative-free REML algorithm was used ...
Inbreeding depression is assumed to be a central factor contributing to the stability of plant mating systems. Predicting the fitness consequence of inbreeding in natural populations is complicated, however, because it may be affected by the mating histories of populations generating variation in the amount of purging of deleterious alleles. Furthermore, the level of inbreeding depression may depend on environmental conditions and the intensity of pollen competition. In a greenhouse experiment comparing four populations of the neotropical vine Dalechampia scandens (Euphorbiaceae), we tested whether inbreeding depression for early-life fitness depended on the inferred mating history of each population, as indicated by genetically determined differences in herkogamy and autofertility rates. We also tested whether the intensity of pollen competition and the level of stress encountered by the seeds and seedlings affected the amount of inbreeding depression observed. Herkogamy was a good predictor of ...
Inbreeding is caused by mating between related individuals and its most common consequence is inbreeding depression. Several studies have detected heterogeneity in inbreeding depression among founder individuals, and recently a procedure for predicting hidden inbreeding depression loads associated with founders and the Mendelian sampling of non-founders has been developed. The objectives of our study were to expand this model to predict the inbreeding loads for all individuals in the pedigree and to estimate the covariance between the inbreeding loads and the additive genetic effects for the trait of interest. We tested the proposed approach with simulated data and with two datasets of records on weaning weight from the Spanish Pirenaica and Rubia Gallega beef cattle breeds. The posterior estimates of the variance components with the simulated datasets did not differ significantly from the simulation parameters. In addition, the correlation between the predicted and simulated inbreeding loads were
Inbreeding: refers to (preferential) mating between biological relatives. As relatives (i.e., ancestors of the first individuals are shared with those of the second individual), they carry genes which are identical by descent; extreme inbreeding: mating between sibs, half-sibs, parent-offspring Outbreeding: (preferential) mating between non-relatives Positive assortative mating: mating among individuals who share particular genes or phenotypes Negative assortative mating: mating among individuals who do not share particular genes or phenotypes Inbreeding Coefficients: Individual inbreeding coefficient (i.e., Pedigree inbreeding): F represents the probability that the offspring is homozygous due to identity by descent (ibd) at a randomly chosen autosomal locus, ranges in value from 0 (no locus ibd) to 1 (all loci ibd). Significant factors for pedigfree inbreeding are Factors which determine the probability that various kinds of individuals will come into contact, e.g., population demography ...
Inbreeding: refers to (preferential) mating between biological relatives. As relatives (i.e., ancestors of the first individuals are shared with those of the second individual), they carry genes which are identical by descent; extreme inbreeding: mating between sibs, half-sibs, parent-offspring Outbreeding: (preferential) mating between non-relatives Positive assortative mating: mating among individuals who share particular genes or phenotypes Negative assortative mating: mating among individuals who do not share particular genes or phenotypes Inbreeding Coefficients: Individual inbreeding coefficient (i.e., Pedigree inbreeding): F represents the probability that the offspring is homozygous due to identity by descent (ibd) at a randomly chosen autosomal locus, ranges in value from 0 (no locus ibd) to 1 (all loci ibd). Significant factors for pedigfree inbreeding are Factors which determine the probability that various kinds of individuals will come into contact, e.g., population demography ...
Inbreeding depression, the reduced fitness of offspring of closely related parents, is commonplace in both captive and wild populations and has important consequences for conservation and mating system evolution. However, because of the difficulty of collecting pedigree and life-history data from wild populations, relatively few studies have been able to compare inbreeding depression for traits at different points in the life cycle. Moreover, pedigrees give the expected proportion of the genome that is identical by descent (IBDg) whereas in theory with enough molecular markers realized IBDg can be quantified directly. We therefore investigated inbreeding depression for multiple life-history traits in a wild population of banded mongooses using pedigree-based inbreeding coefficients (f(ped)) and standardized multilocus heterozygosity (sMLH) measured at 35-43 microsatellites. Within an information theoretic framework, we evaluated support for either f(ped) or sMLH as inbreeding terms and used ...
Our 3-year field study (2006-2009) using captive populations of D. melanogaster is the first field study to investigate the relationship between inbreeding depression and seasonal fluctuations in stress level. We found that stress levels were on average fourfold higher in the winter compared with the summer, and that this higher stress level increased the inbreeding depression affecting population productivity from 32 per cent in the summer to 65 per cent in the winter. Moreover, this covariation of stress level and inbreeding depression conformed to the same linear relationship seen in experimental Drosophila laboratory studies of stress and inbreeding (figure 2). The observation that inbreeding depression based on population productivity in the field follows the same relationship as inbreeding depression based on larval survival in the laboratory suggests that even in complex environments stress and inbreeding interact in the same predictable manner. This same general relationship has been ...
Estimating inbreeding coefficients from NGS data: impact on genotype calling and allele frequency estimation [METHOD]: . Most methods for Next-Generation Sequencing (NGS) data analyses incorporate information regarding allele frequencies using the assumption of Hardy-Weinberg Equilibrium (HWE) as a prior. However, many organisms including domesticated, partially selfing or with asexual life cycles show strong deviations from HWE. For such species, and specially for low coverage data, it is necessary to obtain estimates of inbreeding coefficients (F) for each individual beforecalling genotypes. Here, we present two methods for estimating inbreeding coefficients from NGS data based on an Expectation-Maximization (EM) algorithm. We assess the impact of taking inbreeding into account when calling genotypes or estimating the Site Frequency Spectrum (SFS), and demonstrate a marked increase in accuracy on low coverage highly inbred samples. We demonstrate the applicability and efficacy of these ...
The effect of inbreeding on egg to adult viability was determined for Drosophila virilis over a wide range of inbreeding levels (0 , F ,.734). The quantity -loge (Viability) was found to be a curvilinear function of F, indicating synergistic interaction among loci. The curvature was not evident, however, below F =.500. The values of A and B (Morton et al. 1956) were calculated to be.06 and.77-.86, respectively. This extremely small value of A yielded a very large value for the B/A ratio i.e., 12.51-14.99.. ...
In terms of sexual intercourse, the very last people we think about are our kin. Imagining inbreeding intercourse, whether it involves our closest kin or not, induces aversion in most people who invoke inbreeding depression problems or cultural considerations. Research has focused on the disgust felt when facing inbreeding intercourse between close kin but little is known about other responses. In this study, we considered the influence of fitness costs on aversive reactions by including disgust and emotional reaction as well as moral judgment and attitudes towards inbreeding: higher costs should induce a stronger aversive reaction. The fitness costs were manipulated by two factors: (i) the degree of the participants involvement in the story (themselves, a sib or an unknown individual), and (ii) the degree of relatedness between the two inbreeding people (brother/sister, uncle-aunt/niece-nephew, cousin). To test this hypothesis, 140 women read and assessed different inbreeding stories varying in the
A mating system to reduce the inbreeding of commercial females in the lower level was examined theoretically, assuming a hierarchical breed structure, in which favorable genes are accumulated in the upper level by artificial selection and the achieved genetic progress is transferred to the lower level through migration of males. The mating system examined was rotational mating with several closed sire lines in the upper level. Using the group coancestry theory, we derived recurrence equations for the inbreeding coefficient of the commercial females. The asymptotic inbreeding coefficient was also derived. Numerical computations showed that the critical factor for determining the inbreeding is the number of sire lines, and that the size of each sire line has a marginal effect. If four or five sire lines were available, rotational mating was found to be quite an effective system to reduce the short- and long-term inbreeding of the commercial females, irrespective of the effective size of each sire ...
Supplement Inbreeding is a mode of breeding involving two individuals or organisms that are closely or genetically related. The mating of genetically-related parents would produce progenies with traits of higher predictability. In humans, while inbreeding is acceptable in few certain cultures it is frowned upon largely by others and regarded as taboo. Medically, inbreeding in a consanguineous relationship is discouraged. It is because it increases the tendency of producing offspring with genetic anomalies and congenital birth defects. Inbreeding increases the chances of acquiring deleterious traits. And over time, there would be more individuals with recessive alleles or alleles in homozygous condition. An individual that acquires deleterious traits from inbreeding is referred to as an inbred. In other animals, inbreeding is a common mode of breeding. For instance, the common fruit fly females prefer to mate with their brothers than those who are not their brothers.1 A large gene pool is ...
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The kings of the Spanish Habsburg dynasty (1516-1700) frequently married close relatives in such a way that uncle-niece, first cousins and other consanguineous unions were prevalent in that dynasty. In the historical literature, it has been suggested that inbreeding was a major cause responsible for the extinction of the dynasty when the king Charles II, physically and mentally disabled, died in 1700 and no children were born from his two marriages, but this hypothesis has not been examined from a genetic perspective. In this article, this hypothesis is checked by computing the inbreeding coefficient (F) of the Spanish Habsburg kings from an extended pedigree up to 16 generations in depth and involving more than 3,000 individuals. The inbreeding coefficient of the Spanish Habsburg kings increased strongly along generations from 0.025 for king Philip I, the founder of the dynasty, to 0.254 for Charles II and several members of the dynasty had inbreeding coefficients higher than 0.20. In addition to
no common ancestral pathway to the individual, A (i.e., all parents are different). However, in Figure (b) inbreeding exists because B and C have common parents (D and E), that is, they are full sibs. To calculate the amount of inbreeding, the standard pedigree is converted to an arrow diagram, as shown in (c). Each individual contributes 1/2 of its genotype to its offspring. The coefficient of inbreeding (F) is calculated by summing up all the pathways between two individuals through a common ancestor as: , where s is the number of steps (arrows) from B to the common ancestor and back to C. For example, B and C probably inherited of their genes in common through ancestor D. Similarly, B and C probably inherited 1/4 of their genes in common through ancestor E. (Notice that individual whose inbreeding coefficient is being calculated does not constitute the loop and is hence ignored.) Given the proportion of common genes, F can be calculated by squaring the proportion -- i.e. . Here we sum twice ...
TY - JOUR. T1 - EFFECTS OF RAPID INBREEDING AND OF CROSSING OF INBRED LINES ON CONCEPTION RATE, PROLIFICACY AND EWE SURVIVAL IN SHEEP. AU - Wiener, G.. AU - Lee, G.J.. AU - Woolliams, John. N1 - WOS:A1992JH85100014 Times Cited: 19 Wiener, g lee, gj woolliams, ja Part 1. PY - 1992. Y1 - 1992. N2 - The effects of four generations of inbreeding, to achieve inbreeding coefficients (F) of 0.25, 0.375, 0.50 and 0.59, on conception rate, prolificacy, litter weight at birth and survival of breeding females, have been studied in sheep. Crosses of inbred lines were also examined. Three breeds, Scottish Black-face, Cheviot and Welsh Mountain, and the crosses among these breeds, were involved. Analyses were carried out both for the data overall and within inbred lines. Conception rate at the first oestrus at which the ewe was mated (in each year) declined almost linearly from 0.71 (F2 generation - inbreeding F = 0.0) to 0.44 (F = 0.59) with line crosses showing 0.78 conception rate. The corresponding ...
We describe a multilocus, marker-based regression method for inferring interactions between genes controlling inbreeding depression in self-fertile organisms. It is based upon selfing a parent heterozygous for several unlinked codominant markers, then analyzing the fitness of progeny marker genotypes. If loci causing inbreeding depression are linked to marker loci, then viability selection is manifested by distorted segregation of markers, and fecundity selection by dependence of the fecundity character upon the marker genotype. To characterize this selection, fitness is regressed on the proportion of loci homozygous for markers linked to deleterious alleles, and epistasis is detected by nonlinearity of the regression. Alternatively, fitness can be regressed on the proportion of heterozygous loci. Other modes of selection can be incorporated with a bivariate regression involving both homozygote and heterozygote marker genotypes. The advantage of this marker-based approach is that purging is ...
Why is self-fertilization in hermaphrodites relatively rare? One hypothesis is that inbreeding load must be low to enable the evolution of selfing (Maynard Smith 1978; Lande and Schemske 1985). Once selfing has evolved, inbreeding load is exposed to purging and should further decline. This is especially true for load caused by recessive mutations with large deleterious effects because of an increase in overall homozygosity levels (Lande and Schemske 1985). These two ideas together predict that selfing populations should have reduced inbreeding load, well below 0.5 (Lande and Schemske 1985). My results for A. lyrata do not support this prediction. Although the inbreeding load was indeed below 0.5 in selfing populations, it was equally low in outcrossing populations.. This finding of low inbreeding load in both selfing and outcrossing populations leads to three important conclusions. First, purging must have been an important force in this system in the past, leading to generally low inbreeding ...
This study of the relative effects of inbreeding and outbreeding on reproduction in the domestic fowl is based on two years observations of triallel matings of hens having an inbred, outbred, and crossbred origin. (P. 529.) Among the many relations established by these observations and reported in the following pages, the data with respect to inbreeding and outbreeding show that: Fertility was influenced indirectly but not directly by the breeding system. Hens of an inbred origin were definitely less fertile than those of an outbred origin, irrespective of the kind of male to which they were mated. (P. 535.) Hatchability decreased with inbreeding of outbred females (F = 0 to F = .25) but did not decrease with further inbreeding of inbred females. Inbred females showed lower hatchability than outbred females whatever the system of mating, but the difference was not statistically significant. (P.
Archiv Tierzucht 54 (2011) 4, 327-337, ISSN 0003-9438 © Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany Genetic variability of traits recorded during 100-day stationary performance test and inbreeding level in Polish warmblood stallions Alicja Borowska1, Anna Wolc1,2 and Tomasz Szwaczkowski1 Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Poznań, Poland, 2Department of Animal Science, Iowa State University, Ames, USA Abstract The objectives of
for the period the animal survives] for PVAs are typically 20, 50, 100, 200, or sometimes 1000 years.. MVP estimates may also be derived from population censuses or genetic analyses. Genetic analyses typically involve the estimation of loss of genetic diversity and fitness and projection to extinction. Some studies indicate that inbreeding depression alone can lead to extinction, even among wild populations. Thus, when considering the viability of a given population, one should consider whether the population is large enough to avoid inbreeding depression, if there is sufficient genetic diversity for adaptive change to occur, and if the population is large enough to avoid accumulating new deleterious mutations.. ….Estimates of the population numbers required to overcome these effects (effective population or Ne) are 50 to avoid inbreeding depression, 500-5000 to retain evolutionary potential, and 12 to 1000 to avoid the accumulation of deleterious mutations…. An Ne of 50 is required to ...
... Bizarre insect inbreeding signals an end to males ...A bizarre form of inbreeding could spell the end of males in one insec...Andy Gardner and Laura Ross The Evolution of Hermaphroditism by an I... ...,Bizarre,insect,inbreeding,signals,an,end,to,males:,News,tips,from,the,American,Naturalist,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters
The answer is indeed different for different animals so hard to answer this in any quantitative way. However, in basic terms inbreeding (mating among relatives) is more likely to occur as populations become smaller and more fragmented (with reduced dispersal among sub-populations). Often, but not always, inbreeding results in inbreeding depression which is a loss of evolutionary fitness (i.e. higher mortality risk and/or lower reproductive output). This happens because recessive deleterious alleles are more likely to come together in the homozygous state (so that the deleterious effecs are felt) in the offspring of related parents. The amount of inbreedfing depression in a population is therefore dependent on 1) the amount of inbreeding and 2) the load of deleterious mutations in the population. Both of these factors vary a lot among different animal populations.. ...
The answer is indeed different for different animals so hard to answer this in any quantitative way. However, in basic terms inbreeding (mating among relatives) is more likely to occur as populations become smaller and more fragmented (with reduced dispersal among sub-populations). Often, but not always, inbreeding results in inbreeding depression which is a loss of evolutionary fitness (i.e. higher mortality risk and/or lower reproductive output). This happens because recessive deleterious alleles are more likely to come together in the homozygous state (so that the deleterious effecs are felt) in the offspring of related parents. The amount of inbreedfing depression in a population is therefore dependent on 1) the amount of inbreeding and 2) the load of deleterious mutations in the population. Both of these factors vary a lot among different animal populations.. ...
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Yes. Scientists have observed inbreeding in animal species in the wild. This has been observed in mammal, insect and bird species. The effects of inbreeding are quite negative for the animals that engage in it (poor health of newborns, low survival rates) so it is not often observed (and thus it has been difficult to demonstrate the negative effects) in the wild, but it has been done. ...
Case study of Leavenworthia suggests that loss of complex traits may be reversed. Many flowering plants are able to recognize and reject their own pollen, thereby preventing inbreeding despite the plants hermaphroditic nature. This mechanism is a complex trait that involves the interaction of a gene that tags the pollen with an identifier molecule, and a gene that produces a molecule capable of detecting pollen produced by the same plant. Evolutionary biologists have often argued that once complex traits are lost, they are seldom regained. But a new study, led by biologists at McGill University and published in the journal PLOS Biology, suggests that this may not be the case for self-pollen recognition. In the evolutionary lineage leading to the genus Leavenworthia (a plant group related to canola and cole crops such as broccoli and cabbage), the ancestral genes that code for self-pollen recognition were lost. But the self-pollen recognition function in Leavenworthia appears to have been taken up by
Estimates of inbreeding and relatedness are commonly calculated using molecular markers, although the accuracy of such estimates has been questioned. As a further complication, in many situations, such estimates are required in populations with reduced genetic diversity, which is likely to affect their accuracy. We investigated the correlation between microsatellite- and pedigree-based coefficients of inbreeding and relatedness in laboratory populations of Drosophila melanogaster that had passed through bottlenecks to manipulate their genetic diversity. We also used simulations to predict expected correlations between marker- and pedigree-based estimates and to investigate the influence of linkage between loci and null alleles. Our empirical data showed lower correlations between marker- and pedigree-based estimates in our control (nonbottleneck) population than were predicted by our simulations or those found in similar studies. Correlations were weaker in bottleneck populations, confirming ...
When two individuals mate, genetic material from both parents is passed on to the progeny. So even if one parent carries a harmful recessive trait, the other parent is likely to have a healthier version, which will manifest itself in the offspring. If both parents, however, carry a recessive allele-which is more likely to happen if they share much of their genetic material, as close relatives do-then they raise the chances that their child will have only the bad genes ...
When a previously stable population undergoes inbreeding, if nothing else changes, natural selection should consist mainly of purging. The joint consequences of inbreeding and purging on fitness vary depending on many factors: the previous history of the population, the rate of increase of inbreeding, the harshness of the environment or of the competitive conditions, etc. The effects of purging were first noted by Darwin[10] in plants, and have been detected in laboratory experiments and in vertebrate populations undergoing inbreeding in zoos or in the wild, as well as in humans.[11] The detection of purging is often obscured by many factors, but there is consistent evidence that, in agreement with the predictions explained above, slow inbreeding results in more efficient purging, so that a given inbreeding F leads to less threat to population viability if it has been produced more slowly.[12] Nevertheless, in practical situations, the genetic change in fitness also depends on many other ...
In line-breeding the idea is to always keep the amount that any one animal contributes to the DNA of any descendent at or below 50%. With inbreeding you regularly will find a higher degree of influence. For instance, a sire/daughter mating will result in an offspring which carries 75% of its DNA from the sire and only 25% from the maternal dam. Interestingly, before the advent of genetic testing for recessive traits the only way to statistically ensure genetic purity of a bull/ram/buck etc. was to breed that bull to 35 of his own daughters concurrently. If no genetic defects show up in any of the offspring, the bull is 99.7% likely to be genetic defect free.. In any case, mating two full siblings together does not qualify as inbreeding because the level of influence any one of the grandparents exercises is still only 50% on the individual resultant calf from that full-sib mating.. In conversation with Dr. tatiana Stanton (yes, she spells her given name entirely in lower case) from Cornell ...
ANSWER: Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. Inbreeding results in homozygosity, which can increase the chances of offspring being affected by deleterious or recessive traits.
Single nucleotide polymorphism (SNP) genotyping tools, which can analyse thousands of SNPs covering the whole genome, have opened new opportunities to estimate the inbreeding level of animals directly using genome information. One of the most commonly used genomic inbreeding measures considers the proportion of the autosomal genome covered by runs of homozygosity (ROH), which are defined as continuous and uninterrupted chromosome portions showing homozygosity at all loci. In this study, we analysed the distribution of ROH in three commercial pig breeds (Italian Large White, n = 1968; Italian Duroc, n = 573; and Italian Landrace, n = 46) and four autochthonous breeds (Apulo-Calabrese, n = 90; Casertana, n = 90; Cinta Senese, n = 38; and Nero Siciliano, n = 48) raised in Italy, using SNP data generated from Illumina PorcineSNP60 BeadChip. We calculated ROH-based inbreeding coefficients (FROH) using ROH of different minimum length (1, 2, 4, 8, 16 Mbp) and compared them with several other genomic ...
In Focus: Trask, A.E., Bignal, E.M., McCracken, D.I., Monaghan, P., Piertney, S.B. & Reid, J.M. (2016) Evidence of the phenotypic expression of a lethal recessive allele under inbreeding in a wild population of conservation concern. Journal of Animal Ecology, 85, 879-891. In this issue of Journal of Animal Ecology, Trask etal. () report on a strange, lethal, blindness that regularly affects chicks of an endangered bird population. The authors show that the inheritance mode of this blindness disease precisely matches the expectations of a recessive deleterious mutation. Intriguingly, there is also an indication that the disease-causing variant might be maintained in the population by balancing selection, due to a selective advantage for heterozygotes. Could this finding have consequences for conservation actions implemented for the population?. ...
The Hucul horses, native breed of Carpathians, are valued for their strongly consolidated features, like high fertility, fecundity and foaling rate. The relation between the inbred and the reproduction results of Hucul mares was analyzed using two-way ANOVA and one-way ANOVA with regression. The inbreeding level is negatively correlated with fertility and fecundity. Increase of inbred level of 1% causes loss of 0.98% fertility and loss of 1.03% fecundity.
Rare inherited genetic disorders worsened by repeated inbreeding may have brought down the powerful Spanish Habsburg dynasty, Spanish researchers said.
The body weight (BW) and shank length (SL) varied significantly (p≤0.01) among the generations, hatches and sexes. The least squares mean of SL at six weeks, the primary trait was 77.44±0.05 mm. All the production traits, viz., BWs, age at sexual maturity, egg production (EP) and egg weight were significantly influenced by generation. Model four with additive, maternal permanent environmental and residual effects was the best model for juvenile growth traits, except for zero-day BW. The heritability estimates for BW and SL at six weeks (SL6) were 0.20±0.03 and 0.17±0.03, respectively. The BV of SL6 in the population increased linearly from 0.03 to 3.62 mm due to selection. Genetic trend was significant (p≤0.05) for SL6, BW6, and production traits. The average genetic gain of EP40 for each generation was significant (p≤0.05) with an average increase of 0.38 eggs per generation. The average inbreeding coefficient was 0.02 in PD-1 line ...
Breeding systems have a dramatic impact on the effectiveness of recombination within plant and animal populations. Parametric estimates of recombination rate in the self-fertilizing species Hordeum vulgare (barley) suggest that a history of inbreeding in the species has not dramatically reduced the amount of recombination or extent of linkage disequilibrium in the species relative to that observed in many outcrossing plant species. The limited impact of inbreeding may result from a relatively recent transition to self-fertilization in barley. By comparing resequencing data in Hordeum bulbosum, a self-incompatible species that is the closest living relative of barley, these researchers hope to determine the likely ancestral levels of recombinational diversity within the lineage. Using resequencing data to estimate both a potential ancestral recombination rate and the divergence time between H. bulbosum and H. vulgare, it will be possible to estimate the transition time of transition to ...
The purebred Shorthorn beef cattle breeding project was continued during 1963 without modification. Inbreeding was continued in the two separate lines, which have remained closed to outside breeding since the study was ...
De Braekeleer, M. (1995). Inbreeding, kinship and surnames in hereditary disorders The experience in Sague-nay-Lac-Saint-Jean (Quebec). Collegium Antropologicum, 19, 289-304.
A genetic change that affects the coded protein (most changes are pretty neutral) is more likely to harm its effectiveness than enhance it. Such changed alleles are recessive, covered up when paired with codes that still produce good working proteins, and random, but passing down a family line. Inbreeding can put together 2 bad recessives - thats why its bad ...
It has long been known that inbreeding is bad for you. A new paper in Nature (Directional dominance on stature and cognition in diverse human populations) finally gives us a good quantitative estimate of just how bad it is. They find that the offspring of first cousins suffer an average reduction of 1.2 cm in…
Wow Michael, what a question! In order to answer this, we will have to first look at your underlying assuption that inbreeding causes deformation. What you are talking about when you say deformation is really a physical defect that results from a genetic defect. This occurs when a person has inherited two defective copies of a particular gene, one from each of the parents, and as a result that gene does not do what it is supposed to do. In extreme cases, babies can be born with obvious physical deformities, but in many cases, the resulting defects are subtle. Remember, in most cases, genetic defects only result in physical defects when a person has inherited two copies of the defective gene. Because the effect of a single defective copy can remain hidden, these are called recessive genes, and people who have a single defective copy are often called carriers of the disease. So, if the actual cause of a physical defect is often the inheritance of two defective copies of a gene, what does ...
Talk about blue in the face... Extraordinary story of Appalachias Blue Family whose bodies were discoloured after generations of inbreeding (Daily Mail) And just when was this phenomenon first noticed by the world beyond the familys isolated area? medical explanations, with pictures, at link above
Some animals (such as wolves, lions & elephants) prevent the chance of inbreeding by chasing off the young males as they near maturity, though this may not p...
The negative fitness consequences of close inbreeding are widely recognized, but predicting the long-term effects of inbreeding and genetic drift due to limited population size is not straightforward. As the frequency and homozygosity of recessive deleterious alleles increase, selection can remove (purge) them from a population, reducing the genetic load. At the same time, small population size relaxes selection against mildly harmful mutations, which may lead to accumulation of genetic load. The efficiency of purging and the accumulation of mutations both depend on the rate of inbreeding (i.e., population size) and on the nature of mutations. We studied how increasing levels of inbreeding affect offspring production and extinction in experimental Drosophila littoralis populations replicated in two sizes, N = 10 and N = 40. Offspring production and extinction were measured over 25 generations concurrently with a large control population. In the N = 10 populations, offspring production decreased ...
Looking for online definition of coefficient of inbreeding in the Medical Dictionary? coefficient of inbreeding explanation free. What is coefficient of inbreeding? Meaning of coefficient of inbreeding medical term. What does coefficient of inbreeding mean?
Y-STR profiling is gaining interest in forensic investigations. However, differentiation resulting from genetic stratification by genetic relatedness could be very pronou..
This study investigates the effects of seed dispersal through the European nutcracker (Nucifraga caryocatactes) on the genetic structure of Swiss stone pine (Pinus cembra). The corvid bird deposits several thousands of stone pine seeds annually in the soil as a future food resource. Since not all caches are recovered, this bird behaviour often leads to the establishment of Swiss stone pine seedlings. The combination of wind pollination with this bird-mediated seed dispersal can be expected to greatly shape the spatial distribution of genotypes and the genetic diversity within and among Swiss stone pine populations. Hence, the aim of this study was to investigate gene flow patterns, together with their effects on spatial genetic structure (SGS) and, thus, inbreeding probabilities in an exemplary P. cembra population. Furthermore, potential effects of inbreeding on offspring fitness were analysed, hypothesizing that rates of inbreeding and subsequent cumulative inbreeding depression are higher in ...
1. Introduction. A high degree of inbreeding increases the probability of homozygosity of recessive genes, and enhances the risk of hereditary diseases coming to expression. Inbreeding decreases the genetic diversity, and the degree of inbreeding will increase from one generation to the next if genetic diversity is low. However, information is lacking as to the degree of inbreeding that is still safe for healthy breeding.. Canine hip dysplasia (CHD) is related to single nucleotide polymorphisms in a relatively large number of quantitative trait loci [1] . This genetic trait may cause degenerative join disease through multifactorial mechanisms, including inflammation, oxidative overload and, probably, epigenetic changes [2] . It would be expected that the prevalence of CHD by breed should increase if genetic diversity is low, and the degree of inbreeding is high. However, this assumption was challenged by generation studies in Golden retrievers [3] [4] and by [5] reporting the prevalence of CHD ...
Inbreeding butterflies - a problem for butterfly enthusiasts? It is totally safe to breed sibling butterflies together for a couple of generations. The genetic diversity is great. Although continuing to breed siblings for quite a few generations in a row could lead to serious problems, a couple of generations is fine. If you want to know more of the details of why it is fine, read on!. Quite often enthusiasts gather eggs that are laid by one female (or assumed to be laid by one female). The question is often asked whether breeding the offspring together (siblings) is dangerous for the offspring. Will there be inbreeding problems? Inbreeding often causes unusual traits to occur when both the male and female parent passes a recessive gene to their offspring. Some recessive genes are delightful and do not cause damage or weakness to the offspring. Other recessive genes are deadly, causing death. {Although this paragraph doesnt answer the question, we do want to point out that in the wild, eggs ...
Five randomly selected plants from each of 14 OP onion populations and two plants from A. vavilovii, and pooled DNA from seedlings of DH CU066619 were genotyped for 1692 SNPs. For the OP populations, a sample size of five plants should reveal alleles with frequencies greater than 0.25 at the 95% confidence level (Mansur et al., 1990). Two SNPs were heterozygous in DH CU066619 and were eliminated from analyses because they cannot be allelic. Of the remaining 1690 SNPs, 378 were discarded because of frequently missing genotypes and 86 discarded because they were monomorphic across all DNAs. The remaining 1226 SNPs provided genotypes across all populations (Supplemental Table 2). Overall heterozygosity averaged across the 14 OP populations was relatively low at 23.5% (Table 1). Onion shows significant inbreeding depression (Jones and Davis, 1944) and populations are generally considered to be highly heterozygous. McCallum et al. (2008) genotyped simple sequence repeats (SSRs) using bulked DNA from ...
Associations between heterozygosity and fitness traits have typically been investigated in populations characterized by low levels of inbreeding. We investigated the associations between standardized multilocus heterozygosity (stMLH) in mother trees (obtained from12 nuclear microsatellite markers) and five fitness traits measured in progenies from an inbred Scots pine population. The traits studied were proportion of sound seed, mean seed weight, germination rate, mean family height of one-year old seedlings under greenhouse conditions (GH) and mean family height of three-year old seedlings under field conditions (FH). The relatively high average inbreeding coefficient (F) in the population under study corresponds to a mixture of trees with different levels of co-ancestry, potentially resulting from a recent bottleneck. We used both frequentist and Bayesian methods of polynomial regression to investigate the presence of linear and non-linear relations between stMLH and each of the fitness ...
Effective mating between laboratory-reared males and wild females is paramount to the success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically modified male mosquitoes. However mosquito colonization and laboratory maintenance have the potential to negatively affect male genotypic and phenotypic quality through inbreeding and selection, which in turn can decrease male mating competitiveness in the field. To date, very little is known about the impact of those evolutionary forces on the reproductive biology of mosquito colonies and how they ultimately affect male reproductive fitness. Here several male reproductive physiological traits likely to be affected by inbreeding and selection following colonization and laboratory rearing were examined. Sperm length, and accessory gland and testes size were compared in male progeny from field-collected females and laboratory strains of Anopheles gambiae sensu stricto colonized from one to over 25 years
CULTURAL INBREEDING, the DEATH of SOCIETYS and NATIONS Incest/Inbreeding Taboos International Encyclopedia of Marriage and Family is quoted in this article The CULTural
Drosophila, melanogaster, commonly known as the fruit or vinegar fly, has been used in various biological experiments since 1905 when Carpenter studied its reactions to light, to gravity, and to agitation. In 1906 Castle, Carpenter, Clark, Mast and Burrows published the results of their investigations on the effect of inbreeding. Their work showed that there is no decrease in the fertility of an individual as a result of close inbreeding. In 1907 Lutz reported that the result of some observations on the inheritance of a wing-vein modification. In 1910-11 a paper by Delcourt and Guyenet appeared which dealt with the effect of food conditions on Drosophila. The question of the effect of inbreeding on fertility was also studied by Moenkhaus. He also made observations on the variations of the sex-ratio in relation to selection. This work was published in 1911. The work then, up to this time, had practically all been of a non-genetical nature for the value of D. melanogaster for genetic work had not ...
2016 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0 ...
The offspring resulting from inbreeding tend to have health problems and lower reproductive success. This is known as inbreeding depression. Inbreeding depression occurs because of a quirk of natural selection and genetics. As natural selection acts on a population, it weeds out genes that have disadvantageous effects, but it can only weed out these genes if they are actually expressed in an individual. For dominant gene versions, thats no problem. Individuals carrying dominant genes with a detrimental effect will be selected against, and eventually, these genes will be purged from the population. For recessive gene versions, however, the story is a bit different. Recessive genes are only expressed when an individual carries two copies of them. Once natural selection has removed most of the detrimental recessive genes from a population, these seldom wind up paired with an identical copy and are effectively hidden from the effects of natural selection. This means that most populations carry many ...
Our results show that within a representative UK population sample there was a weak nominally significant association between burden of autosomal runs of homozygosity and higher non-verbal cognitive ability. This nominal association with increased cognitive ability is counterintuitive when compared with the results from more extreme inbreeding based on pedigree information.1, 2, 3 A potential explanation for this direction of effect is that individuals with higher cognitive ability might show greater positive assortative mating, which would lead to increased homozygosity at loci for higher cognitive ability in their offspring. However, in a separate sample we showed that greater positive assortative mating was not associated with higher cognitive ability. While these findings seem to provide clear evidence against this hypothesis, it is possible that the genome-wide genetic findings reflect historical mating habits that no longer exist today. It should also be noted that there was a reduction in ...
The powerful Habsburg dynasty ruled Spain and its empire from 1516 to 1700 but when King Charles II died in 1700 without any children from his two marriages, the male line died out and the French Bourbon dynasty came to power in Spain. Reporting in the open-access, peer-reviewed journal PLoS ONE, April 15, Gonzalo Alvarez and colleagues at the University of Santiago de Compostela, Spain, provide genetic evidence to support the historical evidence that the high frequency of inbreeding (mating between closely related individuals) within the dynasty was a major cause for the extinction of its male line.
I have found out I am actually from West Virginia. Ok, I am just joking.. I knew that my family had a history of marriages among relatives. After all I have only 10 great-great-grandparents instead of the usual 16. With my genome in hand, I set about to quantify the inbreeding.. First, I used David Pikes Homozygosity tool. It analyzes your genome to find significant runs where the same haplotype is inherited from both parents. Large portions of the human genome are like that. The length of these homozygous regions, however, varies depending on the relation of your parents. If your parents are closely related (first cousins in my case), then you will have longer runs. If your parents are distantly related, then over the generations those genes have had a chance to recombine and so you will have shorter runs that are homozygous.. Overall, the percentage of my autosomal (i.e. on chromosomes 1-22) SNPs that are homozygous is 71.767 and I have 41 runs of homozygosity (ROH) of length at least 200. ...
Mountain gorillas are currently suffering from a serious inbreeding problem, and while scientists everywhere worry that this will lead them down the path to extinction, one new genetic study says that it might in fact be their salvation.
Neanderthal genome shows high levels of inbreeding | I ****ing Love Science ...Grandparent and grandchild? Do I even want to know?! Ewwwwwwww...
Researchers studying banded mongooses in Uganda have discovered that these small mammals are able to discriminate between relatives and non-relatives to avoid inbreeding even when mating within their own closely related social group.
Unintentionally hijacked another thread when I mentioned inbreeding so thought I had better start my own. Had two opposite opinions on whether or not...
(CNN) -- An online petition to save a healthy young giraffe from death has failed, despite thousands of signatures.Copenhagen Zoo said it was putting down the male, named Marius, on Sunday because of a duty to avoid inbreeding.
Inbreeding Rabbits Its Just Darn Bad Luck... My bun of love, Slurpee passed away from sudden bloat. It was a horrible 20 hours in the animal hospital.
Quality Traditional and Parti Yorkshire Terriers - Dark Side of Inbreeding - Parti Yorkies and Traditional Color Champion bred yorkies For Sale
On the other hand single alleles would have spread randomly beyond the region of inbreeding. And the mutation may not even have originated in that region to start with. So, if the inbred population with the advantageous double allele were able to form hybrids with another population containing members with the single allele then the alleles expansion could become rapid. Especially considering that those with the double recessive allele would now have restored hybrid vigour. The population with restored hybrid vigour that carried the advantageous allele would be the one that expanded. Not the original inbred population. Presumably this method of allele expansion is a reasonably common pheneomenon. It certainly seems to explain our evolution right back to, and even beyond, Australopithecus. So hybrid vigour is just as important as inbreeding. ...
Inbreeding, and more importantly its consequences, has long been a concern of breeders as it reduces production, lowers fertility, results in more stillbirths and leads to fewer days in the herd. When genomics was first introduced, the theory was that it could help limit the amount of inbreeding in Holsteins. In reality it has done the exact opposite. Research indicates that relationships within respective breeds could be accelerating even faster since genomics introduction five years ago and there is also evidence that genetic diversity, another factor of inbreeding, is shrinking.. When you look at the sires of the top 100 genomic young sires lists, you notice a decent variety of sires with 30 bulls siring the top 100 sires. However, a pedigree analysis on only the paternal side reveals that 90 percent of the bulls either have Oman, Planet or Shottle represented as the sire or grandsire. The remaining 10 bulls represent genetic diversity. However, the list needs further refining because 3 of ...
One advantage, I will say, that goes along with breeding for a dominant phenotype is there is little to no inbreeding required to get the gene to be fairly consistent. In contrast, the easiest way to get a recessive gene to be consistently produced is very heavy inbreeding. For example, if there is a single dog that appears with a recessively inherited color that a breeder is interested in, and they are the only one of their kind, inbreeding is the only way to guarantee the reappearance of the gene. Lets say a female puppy is born who is an unusual color. As an experiment, shes bred to a male and all of the puppies dont look like her. This means the trait is recessive, and all of the puppies are guaranteed to be carriers. Breeding two of them together would lead to a litter that would likely contain 25% homozygous recessive puppies. If two of those recessive phenotype puppies happen to be opposite genders, then breeding them together would produce an entire litter of recessives! Or, if only a ...
Interpretive Summary: Technical Abstract: The goat is adapted to most of the environmental conditions found around the world. The species has evolved to be tolerant to diseases, productive in tropical or arid regions, and culturally and economically important in developing countries. Characterization of these genetic adaptations and development of SNP-based tools for genetic improvement in indigenous goats requires a high quality reference genome sequence. Male goats from breeds or populations expected to have a high level of inbreeding were screened with the Illumina GoatSNP50. Fifteen male goats from four breeds (San Clemente, Boer, Myotonic, Kiko) were evaluated for genomic coefficients of inbreeding (FROH) using runs of homozygosity. This analysis identified Papadom, a San Clemente buck, as the most inbred male goat for deep sequencing (FROH=0.46). Paired end reads from long (5 and 20 kb) and short (300 and 500 bp) insert libraries and single end shotgun reads are being sequenced using ...
The Habsburgs learned about inbreeding the hard way. Centuries of marriages between close relatives in this Austrian-Spanish royal family led to mental illness, infertility, and the eventual extinction of the entire bloodline. For more than a hundred years, scientists have chalked up such problems to rare genetic mutations, which come to the fore only when related individuals breed. But a new study in plants indicates that its not just genes that lead to this so-called inbreeding depression; its also how these genes are switched on and off ...
Cost of selfing; Genetic drift; Heterosis; Inbreeding load; Plant mating; System evolution; Sexual reproduction; Sporophytic self-incompatibility ...
For those not in the know, conservation biologists use something called the 50/500 Rule when assessing endangered species for extinction risk. At an effective population size of 500, there is concern that the species will not be able to maintain genetic diversity over a long period of time. At an effective population size of 50, the species is at immediate risk for extinction. Theyre circling the drain. Domestic animals have the advantage of veterinary care, but no owner in their right mind would prefer to have a sick pet. While the 50/500 Rule definitely doesnt bode well for the health of the aforementioned collie, the Labrador isnt in much better shape. When nearly one hundred thousand dogs have genetic variation equal to little more than one hundred individuals, there is a serious problem. For one thing, it makes it that much harder to avoid mating a certain dog to another that doesnt share a significant percentage of its genotype ...
Systems and methods are used to analyze a sample using variable mass selection window widths. A tandem mass spectrometer is instructed to perform at least two fragmentation scans of a sample with diff
The breed structure and genetic history of the New Zealand pedigree Angus breed were analysed by Robertson and Askers (1951) modification of the Wright-McPhee (1925) pedigree sampling method. The pattern of the breed structure obtained is generally similar to that found in other studies, but it is both diffuse and dynamic owing to the present rapid expansion of the breed. There are changes taking place in the herd composition of the major breeders herds and many new herds have yet to find their level in the structure. Considerable emphasis has been placed on the use of imported animals in the development of the breed. Of all herds registering in Volume 61 of the herd book, 20.5% used imported sires, and the percentage of genes in the breed in 1966/67 derived from animals imported since 1863 was 85.4. The most important herd in 1969 has a genetic contribution to the breed of 21.9 per cent:, while the contributions of the four next most important herds were 8.72, 8.7, 4.7 and 3.7 per cent. In ...
Background Domestication, breed formation and intensive selection have resulted in divergent cattle breeds that likely exhibit their own genomic signatures. In this study, we used genotypes from...
BREEDING: IN AND OUT IT GOES by Robert Frenz 25 November 2000 The process of reproduction requires hardly a shred of talent or intelligence. First there is the brainless erection followed by the search for an available orifice - usually by trial and error. This is why so many end up engaging sheep, llama, heifers, and even orifices not equipped for reproduction. If finding an orifice was an intellectual feat, then there wouldnt be so many perversions of such a simple act. Once the orifice is stuffed, a transient burst of whoopee follows and it isnt long before Mr. Sperm finds someplace to bury his head. Junior is on his way. Inbreeding is the breeding of that which is biologically similar. The paramount example of inbreeding would be between a lifeform and itself. As far as mammals are concerned, the closet biological combinations are brothers and sisters. I shall refrain from any discussion of incest, or forbidden marriages, as they are rooted in tradition and religious taboos. Also, I have ...
Group Serama Negeri @ GSN breed high quality Serama birds in Malaysia. GSN is a club promoting the breeding and characteristics of Malaysian Serama. We can be reached at mobile +60129020416 (Ram) +60123600881 (Zan) (Dinend) + ...
China will tag all of its 163 captive pandas in an effort to better monitor the population and prevent inbreeding, Xinhua news agency has announced. According to an unnamed state forestry administration official, information about pedigree, age and other basic data will be permanently incorporated into the giant pandas by ways of molecular labeling or hypodermic implantation of sensing chips.. No further details are forthcoming, but we think that the RFID panda is a sound plan. Pandas are legendarily energetic and difficult to monitor - capable of bursts of speed of 0.001mph for up to three seconds. They will also, as we all know, take any opportunity to indulge in a quick bit of inbreeding.. The programme offers the additional benefit that should Wal-Mart decide to add pandas to its product roster, they are already tagged for stock control purposes. ®. ...
self-sterility genes). Genes that prevent self-fertilization by controlling the growth of the pollen tube, thus causing male sterility and preventing inbreeding depression in monoecious plants. Gametophytic tissue containing the same sterility allele as the sporophyte is discriminated against. ...
http://www.iflscience.com/sites/www.iflscience.com/files/styles/ifls_large/public/blog/%5Bnid%5D/mc76zgg5-1458217423.jpg?itok=7gbjkYYz http://www.scienceofwonder.org/how-serious-is-inbreeding-in-show-dogs/ A German shepherd with a sloping back that was awarded best of breed brought the dog show Crufts in for this years annual bout of criticism. Viewers took to social media to accuse the owner of animal cruelty by suggesting that its unusual shape meant the dog must suffer health problems brought on…
The authority on an authoritative amalgamation of sundry items (ie: contests, sweepstakes, instant win sites, email forwards, funny videos, winning money the easy way, becoming a better version of yourself, etc...) from my life to yours ...
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Principal Investigator:AKIMOTO Shin-ichi, Project Period (FY):1998 - 1999, Research Category:Grant-in-Aid for Scientific Research (C), Section:一般, Research Field:生態
(2002) Manning et al. Mammalian Genome. We measured telomere lengths of blood leukocytes in several inbred and outbred mammalian species, using a telomere-specific fluorescent probe and flow cytometry. Humans, non-human primates, and thr...
Alexander III of Macedon (20/21 July 356 - 10/11 June 323 BC), commonly known as Alexander the Great , was a Greek king of Macedon ...
The concept of identity by descent (IBD), which is used to indicate when alleles at a given locus in two individuals are inherited from a common ancestor, has played a fundamental role in many genetic studies. Analyses of IBD are commonly used in pedigree data for linkage mapping [1]. IBD also has many uses in population-based studies, including mapping disease genes [2, 3], estimating haplotypic phase [4] and inferring evolutionary history (e.g., natural selection and inbreeding depression) [5, 6]. More recently, IBD has been applied to analyzing gene expression in related or unrelated individuals [7]. Incorporating such information about shared genetic material between individuals in linkage/association analyses has been shown to improve statistical power for mapping disease genes in some studies [8-10].. The length of an IBD segment will depend on the number of generations between the individuals under study and their common ancestor, as IBD tracts are broken down by recombination events over ...
Bulk breeding the growing of genetically diverse populations of self-pollinated crops in a bulk plot with or without mass selection, generally followed by a single-plant selection it is a procedure for inbreeding a segregating population until the desired level of homozygosity is achieved the seeds to grow each generation is a sample of that harvested from plants of the previous generation it is usually used for the development of self-pollinated crops it is an easy way to maintain populations.... ...
There are close to 28 million nurses around the world who comprise a global workforce that delivers about 90 percent of primary healthcare, including frontline response to the COVID-19 pandemic. Ensuring their optimal contribution and continued well-being amid the myriad consequences of COVID-19 will increase the potential for measurable and improved health outcomes.. ...