scholarly journals Pedigree data indicate rapid inbreeding and loss of genetic diversity within populations of native, traditional dog breeds of conservation concern

PLoS ONE ◽  
2018 ◽  
Vol 13 (9) ◽  
pp. e0202849 ◽  
Author(s):  
Mija Jansson ◽  
Linda Laikre
Keyword(s):  
Genetic Diversity ◽  
Pedigree Data ◽  
Loss Of Genetic Diversity ◽  
Conservation Concern

Analysis of genetic diversity in four Canadian swine breeds using pedigree data

2010 ◽  
Vol 90 (3) ◽  
pp. 331-340 ◽  
Author(s):  
M G Melka ◽  
F. Schenkel
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Effective Population Size ◽  
Genetic Drift ◽  
Relative Proportion ◽  
Random Genetic Drift ◽  
Pedigree Data ◽  
Effective Population ◽  
Animal Genetic Resources ◽  
Loss Of Genetic Diversity

Conservation of animal genetic resources entails judicious assessment of genetic diversity as a first step. The objective of this study was to analyze the trend of within-breed genetic diversity and identify major causes of loss of genetic diversity in four swine breeds based on pedigree data. Pedigree files from Duroc (DC), Hampshire (HP), Lacombe (LC) and Landrace (LR) containing 480 191, 114 871, 51 397 and 1 080 144 records, respectively, were analyzed. Pedigree completeness, quality and depth were determined. Several parameters derived from the in-depth pedigree analyses were used to measure trends and current levels of genetic diversity. Pedigree completeness indexes of the four breeds were 90.4, 52.7, 89.6 and 96.1%, respectively. The estimated percentage of genetic diversity lost within each breed over the last three decades was approximately 3, 22, 12 and 2%, respectively. The relative proportion of genetic diversity lost due to random genetic drift in DC, HP, LC and LR was 74.5, 63.6, 72.9 and 60.0%, respectively. The estimated current effective population size for DC, HP, LC and LR was 72, 14, 36 and 125, respectively. Therefore, HP and LC have been found to have lost considerable genetic diversity, demanding priority for conservation. Key words: Genetic drift, effective population size

scholarly journals Monitoring of genetic diversity in autochthonous Czech poultry breeds assessed by genealogical data

2020 ◽  
Vol 65 (No. 6) ◽  
pp. 224-231
Author(s):  
Luboš Vostrý ◽  
Hana Vostrá-Vydrová ◽  
Nina Moravčíková ◽  
Barbora Hofmanová ◽  
Jana Rychtářová ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Inbreeding Coefficient ◽  
Pedigree Data ◽  
Allele Loss ◽  
Loss Of Genetic Diversity

Czech local poultry breeds face high risks of extinction. Because these populations are closed, they are more likely to lose genetic diversity. The aim of this analysis was to determine the loss of genetic diversity in three Czech autochthonous poultry breeds. Pedigree data from a total of 1 932 Czech Gold Speckled Hens, 325 Czech White Geese and 111 Czech Crested Geese registered in studbooks between 2000 and 2018 were evaluated. Data were analysed to determine the major factors that affect the genetic variability of these breeds. The average numbers of equivalent complete generations ranged from 2.53 to 4.82. The effective numbers of founders were from 29 to 59, representing from 43% to 62% of the total number of founders. The effective number of ancestors was estimated in the range of 21 to 41. The average inbreeding coefficient and relatedness coefficient (in parentheses) for the reference populations were 2.0% (6.5%), 1.9% (4.9%) and 2.1% (9.3%), respectively. The results showed that the effective population size derived from the rate of inbreeding ranged from 46 to 108 and if derived from the rate of coancestry it ranged from 35 to 74. With regard to these results, the analysed breeds showed a high probability of allele loss and consequent loss of genetic diversity.

scholarly journals Genetic Diversity and the Impact of the Breed Proportions of US Brown Swiss in German Brown Cattle

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 152
Author(s):  
Anna Wirth ◽  
Jürgen Duda ◽  
Ottmar Distl
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Effective Population Size ◽  
Reference Population ◽  
Pedigree Data ◽  
Effective Population ◽  
Brown Swiss ◽  
Inbreeding Coefficients ◽  
Loss Of Genetic Diversity ◽  
The Impact

Increase of inbreeding and loss of genetic diversity have large impact on farm animal genetic resources. Therefore, the aims of the present study were to analyse measures of genetic diversity as well as recent and ancestral inbreeding using pedigree data of the German Brown population, and to identify causes for loss of genetic diversity. The reference population included 922,333 German Brown animals born from 1990 to 2014. Pedigree depth and completeness reached an average number of complete equivalent generations of 6.24. Estimated effective population size for the German Brown reference population was about 112 with a declining trend from 141 to 95 for the birth years. Individual inbreeding coefficients increased from 0.013 to 0.036. Effective number of founders, ancestors and founder genomes of 63.6, 36.23 and 20.34 indicated unequal contributions to the reference population. Thirteen ancestors explained 50% of the genetic diversity. Higher breed proportions of US Brown Swiss were associated with higher levels of individual inbreeding. Ancestral inbreeding coefficients, which are indicative for exposure of ancestors to identical-by-descent alleles, increased with birth years but recent individual inbreeding was higher than ancestral inbreeding. Given the increase of inbreeding and decline of effective population size, measures to decrease rate of inbreeding and increase effective population size through employment of a larger number of sires are advisable.

Evolutionary genetics of small populations

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Evolutionary Genetics ◽  
Small Population ◽  
Small Populations ◽  
Effective Population ◽  
Genetic Management ◽  
Evolutionary Genetic ◽  
Loss Of Genetic Diversity ◽  
Number Of Individuals

Genetic management of fragmented populations involves the application of evolutionary genetic theory and knowledge to alleviate problems due to inbreeding and loss of genetic diversity in small population fragments. Populations evolve through the effects of mutation, natural selection, chance (genetic drift) and gene flow (migration). Large outbreeding, sexually reproducing populations typically contain substantial genetic diversity, while small populations typically contain reduced levels. Genetic impacts of small population size on inbreeding, loss of genetic diversity and population differentiation are determined by the genetically effective population size, which is usually much smaller than the number of individuals.

scholarly journals GENOMIC DETERMINATION OF THE MOST IMPORTANT FATHER LINES OF SLOVAK PINZGAU COWS

AGROFOR ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Veronika KUKUČKOVÁ ◽  
Nina MORAVČÍKOVÁ ◽  
Radovan KASARDA
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
The State ◽  
Most Probable Number ◽  
Pedigree Data ◽  
Probable Number ◽  
Expected Heterozygosity ◽  
High Level ◽  
The Bayesian Approach

The aim of this study was to assess genetic structure of Slovak Pinzgau populationbased on polymorphism at molecular markers using statistical methods. Femaleoffspring of 12 most frequently used bulls in Slovak Pinzgau breeding programmewere investigated. Pinzgau cattle were found to have a high level of diversity,supported by the number of alleles observed across loci (average 5.31, range 2-11)and by the high within-breed expected heterozygosity (average 0.66, range 0.64-0.73). The state of genetic diversity is satisfying and standard for local populations.Detection of 12 possible subpopulation structures provided us with detailedinformation of the genetic structure. The Bayesian approach was applied, detectingthree, as the most probable number of clusters. The similarity of eachsubpopulation using microsatellites was confirmed also by high-throughputmolecular data. The observed inbreeding (FROH=2.3%) was higher than thatexpected based on pedigree data (FPED=0.4%) due to the limited number ofavailable generations in pedigree data. One of the most important steps indevelopment of efficient autochthonous breed protection programs ischaracterization of genetic variability and assessment of the population structure.The chosen set of microsatellites confirmed the suitability in determination of thesubpopulations of Pinzgau cattle in Slovakia. The state of genetic diversity at moredetailed level was successfully performed using bovineSNP50 BeadChip.

scholarly journals Loss of Genetic Diversity with Captive Breeding and Re-Introduction: A Case Study on Pateke/Brown Teal (Anas chlorotis)

2021 ◽  
Author(s):  
◽  
Gemma Bowker-Wright
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Captive Breeding ◽  
Barrier Island ◽  
Breeding Population ◽  
Island Population ◽  
Wildlife Sanctuary ◽  
Management Options ◽  
Introduced Populations ◽  
Loss Of Genetic Diversity

<p>Pateke/brown teal (Anas chlorotis) have experienced a severe population crash leaving only two remnant wild populations (at Great Barrier Island and Mimiwhangata, Northland). Recovery attempts over the last 35 years have focused on an intensive captive breeding programme which breeds pateke, sourced almost exclusively from Great Barrier Island, for release to establish re-introduced populations in areas occupied in the past. While this important conservation measure may have increased pateke numbers, it was unclear how much of their genetic diversity was being retained. The goal of this study was to determine current levels of genetic variation in the remnant, captive and re-introduced pateke populations using two types of molecular marker, mitochondrial DNA (mtDNA) and microsatellite DNA. Feathers were collected from pateke at Great Barrier Island, Mimiwhangata, the captive breeding population and four re-introduced populations (at Moehau, Karori Wildlife Sanctuary, Tiritiri Matangi Island and Mana Island). DNA was extracted from the base of the feathers, the mitochondrial DNA control region was sequenced, and DNA microsatellite markers were used to genotype individuals. The Great Barrier Island population was found to have only two haplotypes, one in very high abundance which may indicate that historically this population was very small. The captive breeding population and all four re-introduced populations were found to contain only the abundant Great Barrier Island haplotype as the vast majority of captive founders were sourced from this location. In contrast, the Mimiwhangata population contained genetic diversity and 11 haplotypes were found, including the Great Barrier Island haplotype which may have been introduced by captive-bred releases which occurred until the early 1990s. From the microsatellite results, a loss of genetic diversity (measured as average alleles per locus, heterozygosity and allelic richness) was found from Great Barrier Island to captivity and from captivity to re-introduction. Overall genetic diversity within the re-introduced populations (particularly the smaller re-introduced populations at Karori Wildlife Sanctuary, Tiritiri Matangi Island and Mana Island) was much reduced compared with the remnant populations, most probably as a result of small release numbers and small population size. Such loss of genetic diversity could render the re-introduced populations more susceptible to inbreeding depression in the future. Suggested future genetic management options are included which aim for a broader representation of genetic diversity in the pateke captive breeding and release programme.</p>

scholarly journals Genetic diversity increases food-web persistence in the face of climate warming

2020 ◽  
Author(s):  
Matthew A. Barbour ◽  
Daniel J. Kliebenstein ◽  
Jordi Bascompte
Keyword(s):  
Genetic Diversity ◽  
Food Web ◽  
Allelic Variation ◽  
Chemical Defenses ◽  
Trophic Levels ◽  
Raw Material ◽  
Ecological Communities ◽  
Warming Scenario ◽  
The Face ◽  
Loss Of Genetic Diversity

Genetic diversity provides the raw material for species to adapt and persist in the face of climate change. Yet, the extent to which these genetic effects scale at the level of ecological communities remains unclear. Here we experimentally test the effect of plant genetic diversity on the persistence of an insect food web under a current and future warming scenario. We found that plant genetic diversity increased food-web persistence by increasing the intrinsic growth rates of species across multiple trophic levels. This positive effect was robust to a 3°C warming scenario and resulted from allelic variation at two genes that control the biosynthesis of chemical defenses. Our results suggest that the ongoing loss of genetic diversity may undermine the persistence and functioning of ecosystems in a changing world.One Sentence SummaryThe loss of genetic diversity accelerates the extinction of inter-connected species from an experimental food web.

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