scholarly journals Estructura Genética de la Población de Llamas (Lama glama del Banco de Germoplasma del Instituto Nacional de Innovación Agraria -Perú

2016 ◽  
Vol 18 (1) ◽  
pp. 55
Author(s):  
Rubén Mamani Catoa ◽  
Roberto Gallegos Acero ◽  
Teodosio Huanca Mamani ◽  
Juan P Ablo Gutiérrez
Keyword(s):  
Genetic Structure ◽  
Reference Population ◽  
Critical Value ◽  
Inbreeding Coefficient ◽  
Gene Bank ◽  
Effective Number ◽  
Effective Population ◽  
Generation Interval ◽  
Average Ratio ◽  
Lama Glama

<p><strong>RESUMEN</strong></p><p>El objetivo del  estudio fue evaluar la estructura genética de la población de llamas, del Banco de Germoplasma  de  Quimsachata Estación Experimental Illpa-Puno del Instituto Nacional de Innovación Agraria, durante el año 2015<a href="#_msocom_1">[h1]</a> <a href="#_msocom_2">[h2]</a> . Se analizó el archivo de pedigrí de 4698 animales nacidos en el periodo 1993 al 2014, de los cuales 2075 fueron machos y 2623 hembras<a href="#_msocom_3">[h3]</a> . Para el cálculo de los coeficientes individuales de consanguinidad (<em>F</em>), coeficiente de relación media (<em>AR</em>), tamaño efectivo de la población (<em>N<sub>e</sub></em>), de fundadores (<em>f<sub>e</sub></em>)  de ancestros (<em>f<sub>a</sub></em>), intervalo generacional (IG) y la profundidad de pedigrí se ha utilizado el programa ENDOG v.4.8. Los resultados para coeficiente de consanguinidad media y el promedio de relación media de la población de llamas fueron 0.11 y 0.25% respectivamente. Del total de 906 ancestros que dieron origen a la población de referencia, 102 explican el 50% de la variabilidad genética de la población. El número efectivo de fundadores fue 508 y de ancestros 284. El intervalo generacional medio fue  5.65 años, siendo mayor en las vías gaméticas padre-hijo y padre-hija. Para el grado de profundidad de pedigrí fueron identificados 65.88% de animales con información sobre los padres y 83.95% sobre las madres. El tamaño efectivo de la población  fue de 281.81, este valor está por encima del valor crítico. En conclusión la consanguinidad en la población de llamas del banco de germoplasma fue de pequeña magnitud y que las prácticas de apareamiento fueron adecuadas durante el periodo evaluado.</p><p> </p><p><strong>ABSTRACT</strong></p><p>The objective of the study was to describe the genetic structure of the population of llama’s gene bank National Institute of Innovation Agrarian INIA-Puno. The pedigree file of 4698 animals born in the period 1993 to 2014, of which 2075 were males and 2623 females were analyzed. For the calculation of individual coefficients of inbreeding (<em>F</em>), coefficient average ratio (<em>AR</em>), effective population size (<em>N<sub>e</sub></em>), of founders (<em>f<sub>e</sub></em>)  of ancestors (<em>f<sub>a</sub></em>), generation interval (IG) and depth of pedigree has been used ENDOG v.4.8 program. The results for inbreeding coefficient average and average mean ratio of the population were 0.11 and 0.25 flames% respectively. Of the total of 906 ancestors that gave rise to the reference population, 102 account for 50% of the genetic variability of the population. The effective number of founders and ancestors was 508 284. The average generation interval was 5.65 years, being higher in the gametic roads father-son and father-daughter. For the degree of depth of pedigree they were identified 65.88% of animals with information about parents and 83.95% on mothers. The effective size of the population was 281.81, this value is above the critical value. In conclusion inbreeding in the population of llamas gene bank was small in magnitude and mating practices were adequate during the period evaluated.</p><div><hr align="left" size="1" width="33%" /><div><div><p> </p></div></div></div>

scholarly journals Evaluation of selection program by assessing the genetic diversity and inbreeding effects on Nellore sheep growth through pedigree analysis

2020 ◽  
Vol 33 (9) ◽  
pp. 1369-1377
Author(s):  
Satish Kumar Illa ◽  
Gangaraju Gollamoori ◽  
Sapna Nath
Keyword(s):  
Genetic Diversity ◽  
Growth Traits ◽  
Selection Process ◽  
Reference Population ◽  
Inbreeding Coefficient ◽  
Research Station ◽  
Effective Population ◽  
Generation Interval ◽  
Nellore Sheep ◽  
Reference Cohort

Objective: The main objectives of the present study were to assess the genetic diversity,population structure and to appraise the efficiency of ongoing selective breeding program in the closed nucleus herd of Nellore sheep through pedigree analysis.Methods: Information utilized in the study was collected from the pedigree records of Livestock Research Station, Palamaner during the period from 1989 to 2016. Genealogical parameters like generation interval, pedigree completeness, inbreeding level, average relatedness among the animals and genetic conservation index were estimated based on gene origin probabilities. Lambs born during 2012 and 2016 were considered as reference population. Two animal models either with the use of Fi or ∆Fi as linear co-variables were evaluated to know the effects of inbreeding on the growth traits of Nellore sheep.Results: Average generation interval and realized effective population size for the reference cohort were estimated as 3.38±0.10 and 91.56±1.58, respectively and the average inbreeding coefficient for reference population was 3.32%. Similarly, the effective number of founders, ancestors and founder genome equivalent of the reference population were observed as 47, 37, and 22.48, respectively. Fifty per cent of the genetic variability was explained by 14 influential ancestors in the reference cohort. The ratio fe/fa obtained in the study was 1.21, which is an indicator of bottlenecks in the population. The number of equivalent generations obtained in the study was 4.23 and this estimate suggested the fair depth of the pedigree.Conclusion: Study suggested that the population had decent levels of genetic diversity and a non-significant influence of inbreeding coefficient on growth traits of Nellore lambs. However, small portion of genetic diversity was lost due to a disproportionate contribution of founders and bottlenecks. Hence, breeding strategies which improve the genetic gain, widens the selection process and with optimum levels of inbreeding are recommended for the herd.

scholarly journals Population structure of Brazilian Gyr dairy cattle

2010 ◽  
Vol 39 (12) ◽  
pp. 2640-2645 ◽  
Author(s):  
João Cruz Reis Filho ◽  
Paulo Sávio Lopes ◽  
Rui da Silva Verneque ◽  
Robledo de Almeida Torres ◽  
Roberto Luiz Teodoro ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Inbreeding Coefficient ◽  
Mating Strategies ◽  
Future Generations ◽  
Breeding Value ◽  
Effective Number ◽  
Generation Interval ◽  
Inbreeding Coefficients

The objective of the present study was to evaluate the genetic structure of Gyr cattle selected for milk production. Files of pedigree and production were composed of 27,610 animals. The ENDOG program was used for the calculation of individual inbreeding coefficient (F) and coefficient of average relatedness (AR), effective number of animals(Ne), effective number of founders (f e) and ancestors (f a), and generation interval (GI). Individual inbreeding coefficients and average relatedness in the population were 2.82% and 2.10%, respectively. It was observed a reduction in the effective number of animals, especially after publication of the results of the first progeny test. The estimated effective number of founders was 146 and 75 for the ancestrals. Out of those, only 28 ancestors accounted for the origin of 50% of the population genes. The average generation interval was 8.41 years and it was longer for males than for females. For maintaining genetic variability in future generations, it should be invested mating strategies that reduce inbreeding and which do not use massively only some high breeding value sires.

scholarly journals Joint genealogical analysis as a tool for diversity evaluation in Pinzgau cattle populations

2014 ◽  
Vol 57 (1) ◽  
pp. 1-12
Author(s):  
Ivan Pavlík ◽  
Johann Sölkner ◽  
Ondrej Kadlečík ◽  
Radovan Kasarda ◽  
Gábor Mészáros ◽  
...  
Keyword(s):  
Reference Population ◽  
Pedigree Analysis ◽  
Inbreeding Coefficient ◽  
Foreign Gene ◽  
Effective Number ◽  
Effective Population ◽  
Identity By Descent ◽  
Dual Purpose ◽  
Gene Origin ◽  
Diversity Evaluation

Abstract. The presented paper gives an overview about genetic diversity in Pinzgau populations in Austria and Slovakia. In total, 12 442 animals were included in the study representing the reference population. All living herdbook cows, dual purpose and beef, from both countries with a maximum foreign gene proportion of 12.5 % were considered. Thus, four subpopulations were analysed. Parameters of diversity based on probability of identity-by-descent and probability of gene origin were computed by the methods of pedigree analysis. The average inbreeding coefficient (five generations taken into account) was 0.0186 (ΔF=0.0041), 0.0242 (ΔF=0.0047), 0.0151 (ΔF=0.0026), and 0.0126 (ΔF=0.0006) in the Austrian dairy (AD), the Austrian beef (AB), the Slovak dairy (SD) and the Slovak beef (SB) subpopulation, respectively. Effective population size ranged from 122.5 (AD) to 809.4 (SB). Effective number of founders was 67.3 and 106.6 in AD and SD and 73 and 212.3 in the AB and SB subpopulations. Effective number of ancestors was 29.59; 34.42; 42.36 and 73.81 in AD, AB, SD and SB, respectively. Effective number of founder genomes was 15.32; 18.15; 23.41 and 41 in AD, AB, SD and SB subpopulations, respectively. Similarities between subpopulations were calculated based on a cosine approach. The highest similarity was found between AD and AB (cosine value 0.9954). SD and AD subpopulations were very similar (cosine value 0.9181).

scholarly journals Population structure of Czech cold-blooded breeds of horses

2011 ◽  
Vol 54 (1) ◽  
pp. 1-9
Author(s):  
L. Vostrý ◽  
Z. Čapková ◽  
J. Přibyl ◽  
B. Hofmanová ◽  
H. Vostrá Vydrová ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Population Size ◽  
Effective Population Size ◽  
Inbreeding Coefficient ◽  
Effective Population ◽  
The Czech Republic ◽  
Generation Interval ◽  
Average Value ◽  
Inbreeding Coefficients

Abstract. In order to estimate effective population size, generation interval and the development of inbreeding coefficients (Fx) in three original breeds of cold-blooded horses kept in the Czech Republic: Silesian Noriker (SN), Noriker (N) and Czech-Moravian Belgian horse (CMB) all animals of the particular breeds born from 1990 to 2007 were analysed. The average values of generation interval between parents and their offspring were: 8.53 in SN, 8.88 in N and 8.56 in CMB. Average values of effective population size were estimated to be: 86.3 in SN, 162.3 in N and 104.4 in CMB. The average values of inbreeding coefficient were 3.13 % in SN stallions and 3.39 % in SN mares, in the N breed 1.76 % and 1.26 % and in the CMB breed 3.84 % and 3.26 % respectively. Overall averages of Fx were: 3.23 %, 1.51 % and 3.55 % for the breeds SN, N and CMB. The average value of inbreeding coefficient Fx increased by 1.22 % in SN, by 0.35 % in N and by 1.01 % in CMB, respectively. This may lead to a reduction in genetic variability. Reduction in genetic variability could be either controlled in cooperation with corresponding populations of cold-blooded breeds in other European countries or controlled by number of sires used in population

scholarly journals Using pedigree information to study genetic diversity and re-evaluating a selection program in an experimental flock of Afshari sheep

2012 ◽  
Vol 55 (4) ◽  
pp. 375-384 ◽  
Author(s):  
F. Ghafouri-Kesbi
Keyword(s):  
Genetic Diversity ◽  
Phenotypic Selection ◽  
Reference Population ◽  
Pedigree Information ◽  
Selection Experiment ◽  
Founder Population ◽  
Effective Number ◽  
Effective Population ◽  
Breeding Values ◽  
Closed Population

Abstract. The purpose of this paper was to evaluate the inbreeding consequences of a short-term selection experiment which was initiated in 1998 in an Afshari sheep flock. Moreover, the conducted selection experiment was re-evaluated through assessing change in ranking of the first 10 influential ancestors when their genetic contributions were replaced with their breeding values. A total of 1714 animals were registered in the herdbook with a founder population comprised of 243 animals. The average coancestry (f) and inbreeding (F) in the reference population were 2.1% and 1.2%, respectively. Estimated value of the effective population size (Ne) was 50. The effective number of founders (fe) was estimated to be 40 and the effective number of ancestors (fa) was 34. Estimates of breeding values revealed that owing to phenotypic selection some ancestors with lower breeding values had greater contribution to the reference genome than those with greater breeding values and, for this reason, the population has been deprived from the maximum genetic improvement that could be achieved if selection was based on breeding values. The effective number of founder genomes (fg) was computed to be 23 and the effective number of non-founder genomes (fne) was 55. The index of genetic diversity decreased by almost 2.2% over the period studied. In general, decrease in genetic variability was low and Ne was not very low for a small-closed population under selection, indicating even in populations which undergo selection, besides achieving genetic gain, the rate of inbreeding is controllable if matings carefully planned.

scholarly journals Pedigree Analysis of Mangalica Pig Breeds

2016 ◽  
Vol 16 (3) ◽  
pp. 701-709 ◽  
Author(s):  
János Posta ◽  
Péter Szabó ◽  
István Komlósi
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Gene Pool ◽  
Reference Population ◽  
Pedigree Analysis ◽  
Small Populations ◽  
Gene Conservation ◽  
Generation Interval ◽  
Pig Breeds ◽  
Gene Origin

AbstractAn effective gene conservation programme requires the knowledge of genetic variability of the population. The genetic structure of Mangalica pig breeds (Blonde, Red and Swallow-bellied) was studied from pedigree records. Herdbook data available up to 2011 of registered Mangalica pig breeds (Blonde, Red and Swallow-bellied) were analysed. The number of complete generations was 6 for Blonde and 5 for Red and Swallow-bellied Mangalica whereas the average complete generation equivalent was between 3.51 and 6.01. The average level of inbreeding of the reference population was low (4.07–5.87%). The investigated breeds could be considered as small populations based on the probability of gene origin. The most important ancestor contributed between 9 and 16% of the gene pool of the reference populations. The longest generation interval was found for the sire-to-son pathways whereas the shortest for dam-to-daughter pathways for each breed.

scholarly journals Genetic diversity, viability and conservation value of the global captive population of the Moroccan Royal lions

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0258714
Author(s):  
Kristina Lehocká ◽  
Simon A. Black ◽  
Adrian Harland ◽  
Ondrej Kadlečík ◽  
Radovan Kasarda ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Effective Population Size ◽  
North Africa ◽  
Reference Population ◽  
Captive Population ◽  
Effective Number ◽  
Pedigree Data ◽  
Effective Population ◽  
Loss Of Diversity

This study evaluates the diversity of the so-called ‘Moroccan Royal lions’ using genealogical information. Lions are no longer extant in North Africa, but the previous wild population was an important element of the now-recognised northern subspecies (Panthera leo leo) that ranged across West Africa, North Africa and the Middle East into India. The remaining captive population of ‘Moroccan Royal lions’ seems to be significantly endangered by the loss of diversity due to the effective population size decrease. The pedigree file of this captive lion population consisted of 454 individuals, while the reference population included 98 animals (47 males and 51 females). The completeness of the pedigree data significantly decreased with an increasing number of generations. The highest percentage of pedigree completeness (over 70%) was achieved in the first generation of the reference population. Pedigree-based parameters derived from the common ancestor and gene origin were used to estimate the state of diversity. In the reference population, the average inbreeding coefficient was 2.14%, while the individual increase in inbreeding over generations was 2.31%. Overall, the reference population showed lower average inbreeding and average relatedness compared with the pedigree file. The number of founders (47), the effective number of founders (24) and the effective number of ancestors (22) were estimated in the reference population. The effective population size of 14.02 individuals confirms the critically endangered status of the population and rapid loss of diversity in the future. Thus, continuous monitoring of the genetic diversity of the ‘Moroccan Royal lion’ group is required, especially for long-term conservation management purposes, as it would be an important captive group should further DNA studies establish an affinity to P. leo leo.

scholarly journals Structure and genetic variability of the Mexican Sardo Negro breed

2022 ◽  
Vol 52 (5) ◽  
Author(s):  
Joel Domínguez-Viveros ◽  
Antonio Reyes-Cerón ◽  
Juan Fernando Saiz-Pineda ◽  
Cesar Villegas-Gutiérrez ◽  
Guadalupe Nelson Aguilar-Palma ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Population Genetic ◽  
Genetic Parameters ◽  
Inbreeding Coefficient ◽  
Structure Evolution ◽  
Effective Number ◽  
Effective Population ◽  
Population Genetic Parameters ◽  
Additive Genetic Relationship ◽  
Over Time

ABSTRACT: This study analyzed the Sardo Negro breed pedigree (41,521 animals registered from 1958 to 2019) to determine its structure, evolution, and genetic variability (GV). The population genetic parameters evaluated were effective number of founders (fe) and ancestors (fa), pedigree integrity, additive genetic relationship (AGR); number of complete generations (NCG), maximum generations traced (NMGT), and equivalent complete generations (NECG); effective population size (Ne), inbreeding coefficient (F), and generation interval (GI). The average GI was 7.45 years. A total of 7,804 founders and 4,856 ancestors were identified for a fe of 185 and a fa of 97. The average and maximum values of NCG, NECG, and NMGT were 1.6 and 5.0, 2.5 and 6.5, 4.3 and 12, with Ne estimates of 15.9, 25.9, and 69.0, respectively. The increase in F, linked to Ne, ranged from 0.72% to 3.1% per generation. The average values for F and AGR were 3.6% and 1.0%, respectively. The proportion of inbred individuals was 32.0%, with F values ranging from 0.01 to 62.2% and an average of 11.3%. The rate of inbred population was 1.3% per year. The annual rate of AGR was 0.04%. For the continuity and projection of the breed, the evolution of F as a function of Ne and the possible implications of the selection schemes must be considered. The genetic variability sustained over time results from the Ne.

Genetic variability of a Criollo cattle population under conservation

2005 ◽  
Vol 143 (2-3) ◽  
pp. 209-216 ◽  
Author(s):  
L. M. MELUCCI ◽  
C. DÍAZ ◽  
C. A. MEZZADRA
Keyword(s):  
Genetic Variability ◽  
Population Size ◽  
Genetic Drift ◽  
Germplasm Conservation ◽  
Reference Population ◽  
Effective Number ◽  
Effective Population ◽  
The Impact

The active germplasm Bank of the Integrated Unit (Facultad de Ciencias Agrarias, Unversidad Nacional de Mar del Plata and the Experimental Station of INTA) at Balcarce, keeps both in vivo (live herd) and in vitro Criollo Cattle (samples of semen and embryos cryogenically), with the aim of preserving genetic variability for potential future use. Parameters based on probable origin of genes, on population size and on the estimation of components of (co)variances for birth and weaning weights were estimated to evaluate the genetic variability of the material contained in the Bank. The information available came from 667 individuals, of which 84 had unknown parents, and 142 half-founders (only one parent known), having a mean number of births per year of 24 calves from four different sires. AI was performed during the mating season almost every year. The evolution of effective number of founders (fe), effective number of ancestors (fa), effective number of founder genomes (Ng) and the ratio fe/fa over different periods from the creation of the Bank, were analysed. Annual increase of inbreeding coefficient (F) was 0·2% and the effective population size (Ne) was estimated as 23, 14 and 25 individuals for the periods defined by years 1978–82, 1983–87 and 1993–97, respectively. The ratio fe/fa was higher in the years where the ratio number of sires/number of dams was lower, indicating that the impact of the effective number of sires is more important than the effective number of females in generating genetic bottlenecks. When the reference population was taken for the period 1989–97, 16·45 out of the 85·63 founders of the population made contributions not explained by other ancestors, but if possible losses of genomes due to genetic drift are considered, the number of genomes still present was reduced to 9·09 indicating a possible narrow genetic bottleneck in the last period. The Ng/fe ratio was 0·11, 0·10 and 0·11 for the reference populations defined by years 1989–92, 1993–97 and 1989–97, respectively. The main objective in germplasm conservation programmes should be the maintenance of genetic variability. Thus, matings in the population under conservation should be designed in order to mate those animals that maximize the effective number of genome founders (Ng) to avoid losses due to genetic drift.

scholarly journals Microsatellite DNA Analysis of Genetic Diversity and Parentage Testing in the Popular Dog Breeds in Poland

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 485
Author(s):  
Anna Radko ◽  
Angelika Podbielska
Keyword(s):  
Genetic Diversity ◽  
Dna Analysis ◽  
Inbreeding Coefficient ◽  
Effective Number ◽  
Effective Population ◽  
German Shepherd ◽  
Medium Level ◽  
The Mean ◽  
French Bulldog ◽  
Yorkshire Terrier

There is growing concern that extreme breed standardization contributes to a reduction of the effective population size and high levels of inbreeding, resulting in the loss of genetic diversity in many breeds. This study examined genetic diversity among eight popular dog breeds in Poland and evaluated the effectiveness of a 21-microsatellite (STR) panel recommended by the International Society for Animal Genetics (ISAG) for parent verification. The following breeds were characterized: German Shepherd, Maltese, Irish Wolfhound, Yorkshire Terrier, Biewer Yorkshire Terrier, Golden Retriever, Labrador Retriever, and French Bulldog. STRUCTURE analysis showed breed distinctiveness among all the dog breeds under study. Reynold’s distance ranged between θw = 0.634 and θw = 0.260. The studied breeds showed a medium level of genetic differentiation; the mean number of alleles per locus ranged from 3.4 to 6.6, and the effective number of alleles from 2.1 to 3.5. The mean degree of heterozygosity varied from 49% to 69% and from 47% to 68% for HO and HE, respectively. The population inbreeding coefficient (FIS) indicated an absence of inbreeding in the studied breeds. The average polymorphism information content (PIC) values for most of the breeds were higher than 0.5. The cumulative power of discrimination (PD) for all the markers in all breeds reached high values (close to 1.0), while the probability of identity (PID) was low, ranging between 10−11 and 10−19. The cumulative exclusion probability when the genotypes of one (PE1) and both parents (PE2) are known and showed that the parentage can be confirmed with a probability of 94.92% to 99.95% and 99.78% to 99.9999%, respectively.

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