scholarly journals Genetic polymorphism of the Landrace pig based on microsatellite markers

2017 ◽  
Vol 19 (74) ◽  
pp. 63-66
Author(s):  
S. I. Lugovoy ◽  
S. S. Kramarenko ◽  
V. Ya. Lykhach
Keyword(s):  
Genetic Variability ◽  
Microsatellite Markers ◽  
Effective Number ◽  
Effective Population ◽  
Two Phase ◽  
Infinite Allele Model ◽  
Exact Test ◽  
Information Index ◽  
Mutation Drift Equilibrium ◽  
Landrace Pig

The aim of this study was to analyze the genetic variability and population structure of the Landrace population by using 12 microsatellite markers. A total of 90 pigs representing one commercial breed (Landrace) were sampled. Twelve microsatellite loci (SW24, S0155, SW72, SW951, S0386, S0355, SW240, SW857, S0101, SW936 SW911 and S0228) were selected and belong to the list of microsatellite markers recommended by FAO/ISAG. GenAIEx software was used to calculate the allele frequencies, effective number of alleles (Ae), observed (Ho) and expected (He) heterozygosity, within-population inbreeding estimate (Fis), Shannon’s information index (ISh). Overall allele frequency values ranged from 0.006 to 0.9333 (at allele SW951120). The number of observed alleles (Na) detected ranged from 5 (S0155 and SW911) to 13 (SW72), with an overall mean of 9.00 ± 0.80 and a total of 108 alleles were observed at these loci. However, the effective number of alleles (Ae) ranged from 1.57 (SW951) to 5.49 (SW240) with a mean of 3.29 ± 0.33. Shannon’s information index (ISh) which measures the level of diversity, was sufficiently high – from 0.79 (for SW951) to 2.01 (for SW240) – with a mean of 1.43 ± 0.09. The overall means for observed (Ho) and expected (He) heterozygosities were 0.578 ± 0.009 and 0.662 ± 0.004, respectively, which ranged from 0.307 (SW951) to 0.814 (SW857) and 0.361 (SW951) to 0.818 (SW240), respectively. Of the 12 microsatellites analyzed using Fisher’s exact test, 50% were in Hardy-Weinberg equilibrium, and 6 were out of equilibrium (P < 0.05). Three mutation models namely, infinite allele model (I.A.M.), two phase model (T.P.M.), stepwise mutation model (S.M.M.) were estimated using the BOTTLENECK software. The results are indicated that the Landrace pig population is non-bottlenecked and remained at mutation-drift equilibrium. The study stands first in genetic characterization of the Ukrainian Landrace pig population through microsatellite markers. The various parameters and values used to quantify genetic variability, such as the high mean (and effective) number of alleles and the expected and observed heterozygosities, indicated high genetic variability in the Ukrainian Landrace pigs. The population has not undergone any recent and/or sudden reduction in the effective population size and remained at mutation-drift equilibrium.

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 BOTTLENECK ANALYSIS OF ANATOLIAN BLACK CATTLE (BOS TAURUS) USING MICROSATELLITE MARKERS

AGROFOR ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Zeynep SEMEN ◽  
Vedat KARAKAŞ ◽  
Tuncay ÇÖKÜLGEN ◽  
İlker ÜNAL ◽  
Onur YILMAZ
Keyword(s):  
Microsatellite Markers ◽  
Bos Taurus ◽  
Polymorphic Information Content ◽  
Cattle Breed ◽  
Two Phase ◽  
Infinite Allele Model ◽  
Mutation Model ◽  
Bottleneck Analysis ◽  
Hardy Weinberg Equilibrium ◽  
Phase Mutation

The present study was conducted in order to reveal the genetic diversity andbottleneck in Anatolian Black Cattle (Bos Taurus). Animal material of the studyconsisted of 75 cattle raised in International Center for Livestock Research andTraining. The bottleneck in the cattle breed studied was checked with 10microsatellites markers, amplified in a multiplex polymerase chain reaction (PCR)were used according to recommendation of FAO (2011). A total of 116 alleles wasobserved from microsatellites studied. Overall value belongs to average number ofalleles (Na), effective number of alleles (Ne), observed heterozygosity (Ho),expected heterozygosity (He), the polymorphic information content (PIC), averageheterozygosity (Ĥ), and FIS, known as the inbreeding coefficient, were 11.60, 5.35,0.80, 0.78, 0.80 and 0.012, respectively. All microsatellite markers except INRA23and ETH3 deviated from Hardy Weinberg equilibrium (HWE). Bottleneck wasanalyzed with Bottleneck software according to three different mutation modelsincluding the infinite allele model (IAM), two-phase mutation model (TPM) andstepwise mutation model (SMM). It can be said that there is not any ultimate risk interms of bottleneck considering L–shaped curve showing normal distributionobtained from the analysis.

scholarly journals Genetic Variability and Population Structure of Polish Konik Horse Maternal Lines Based on Microsatellite Markers

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 546
Author(s):  
Agnieszka Fornal ◽  
Katarzyna Kowalska ◽  
Tomasz Zabek ◽  
Agata Piestrzynska-Kajtoch ◽  
Adrianna D. Musiał ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Microsatellite Markers ◽  
Pedigree Data ◽  
Horse Breed ◽  
K Value ◽  
Information Index ◽  
Genetic Clusters ◽  
The Mean ◽  
Index Value ◽  
F Statistics

The aim of the conservation programme is to maintain the population size of endangered livestock breeds of less economic importance at a level that ensures the survival of the breed, the preservation of genetic diversity, and the preservation of as many pedigree lines as possible. The Polish Konik, a native Polish primitive-type horse breed and is one of the breeds included in such a programme in Poland. Presently, there are only 16 (of the 35 maternal lines known in 1962), some of which are endangered. We examined the genetic variability and structure of the Polish Konik maternal lines (176 individuals) on the basis of the pedigree data and 17 microsatellite markers (STRs) from parentage testing. The overall mean number of alleles was 7.647 (±0.411), the effective number of alleles was 3.935 (±0.271), the mean number of alleles for which the frequency was equal to or lower than 5% was 4.471 (±0.286), and the mean information index was 1.506 (±0.087). The structure of the population and admixture patterns were calculated with the Structure and Structure Harvester software. The structural analysis indicated three likely genetic clusters; as the most optimal K value was estimated as 3, with ∆K of 15.4188. The F-statistics results indicated a low level of inbreeding (average inbreeding coefficient FIT was 0.0188, coefficient of differentiation FST was 0.0304, and mean inbreeding index value FIS was −0.0119). Variability monitoring should be carried out in order to avoid inbreeding depression, while breeding strategies should be designed to prevent the decrease of genetic variability in the Polish horse breed and to sustain the active female lines.

scholarly journals Genetic structure of a small closed population of the New Zealand white rabbit through pedigree analyses

2018 ◽  
Vol 26 (2) ◽  
pp. 101
Author(s):  
M. Sakthivel ◽  
D. Balasubramanyam ◽  
P. Kumarasamy ◽  
A. Raja ◽  
R. Anilkumar ◽  
...  
Keyword(s):  
New Zealand ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Population Size ◽  
Effective Population Size ◽  
Research Station ◽  
Percentage Increase ◽  
Effective Number ◽  
Effective Population ◽  
Mean Values

The genetic structure of a small population of New Zealand White rabbits maintained at the Sheep Breeding and Research Station, Sandynallah, The Nilgiris, India, was evaluated through pedigree analyses. Data on pedigree information (n=2503) for 18 yr (1995-2012) were used for the study. Pedigree analysis and the estimates of population genetic parameters based on the gene origin probabilities were performed. The analysis revealed that the mean values of generation interval, coefficients of inbreeding and equivalent inbreeding were 1.49 yr, 13.23 and 17.59%, respectively. The proportion of population inbred was 100%. The estimated mean values of average relatedness and individual increase in inbreeding were 22.73 and 3.00%, respectively. The percentage increase in inbreeding over generations was 1.94, 3.06 and 3.98 estimated through maximum generations, equivalent generations and complete generations, respectively. The number of ancestors contributing the majority of 50% genes (f<sub>a50</sub>) to the gene pool of reference population was only 4, which might have led to reduction in genetic variability and increased the amount of inbreeding. The extent of genetic bottleneck assessed by calculating the effective number of founders (f<sub>e</sub>) and the effective number of ancestors (f<sub>a</sub>), as expressed by the f<sub>e</sub>/f<sub>a</sub> ratio was 1.1, which is indicative of the absence of stringent bottlenecks. Up to 5th generation, 71.29% pedigree was complete, reflecting the well maintained pedigree records. The maximum known generations were 15, with an average of 7.9, and the average equivalent generations traced were 5.6, indicating a fairly good depth in pedigree. The realized effective population size was 14.93, which is very critical, and with the increasing trend of inbreeding the situation has been assessed as likely to become worse in future. The proportion of animals with the genetic conservation index (GCI) greater than 9 was 39.10%, which can be used as a scale to use such animals with higher GCI to maintain balanced contribution from the founders. From the study, it was evident that the herd was completely inbred, with a very high inbreeding coefficient, and the effective population size was critical. Recommendations were made to reduce the probability of deleterious effects of inbreeding and to improve genetic variability in the herd. The present study can help in carrying out similar studies to meet the demand for animal protein in developing countries.

Evaluation of genetic variability and mutation drift equilibrium of Banni buffalo using multi locus microsatellite markers

2009 ◽  
Vol 41 (7) ◽  
pp. 1203-1211 ◽  
Author(s):  
B. P. Mishra ◽  
R. S. Kataria ◽  
P. Kathiravan ◽  
S. S. Bulandi ◽  
K. P. Singh ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Microsatellite Markers ◽  
Mutation Drift Equilibrium

scholarly journals Evaluation of genetic variability and genetic distances between eight chicken lines using microsatellite markers

1998 ◽  
Vol 77 (6) ◽  
pp. 783-790 ◽  
Author(s):  
T Vanhala ◽  
M Tuiskula-Haavisto ◽  
K Elo ◽  
J Vilkki ◽  
A Maki-Tanila
Keyword(s):  
Genetic Variability ◽  
Microsatellite Markers ◽  
Genetic Distances

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 IDENTITY COEFFICIENTS IN FINITE POPULATIONS. I. EVOLUTION OF IDENTITY COEFFICIENTS IN A RANDOM MATING DIPLOID DIOECIOUS POPULATION

Genetics ◽  
1977 ◽  
Vol 86 (3) ◽  
pp. 697-713
Author(s):  
C Chevalet ◽  
M Gillois ◽  
R F Nassar
Keyword(s):  
Genetic Variability ◽  
Population Size ◽  
Effective Population Size ◽  
Random Mating ◽  
Matrix Multiplication ◽  
Inbred Lines ◽  
Inbreeding Coefficient ◽  
Effective Population ◽  
The Mean ◽  
Over Time

ABSTRACT Properties of identity relation between genes are discussed, and a derivation of recurrent equations of identity coefficients in a random mating, diploid dioecious population is presented. Computations are run by repeated matrix multiplication. Results show that for effective population size (Ne) larger than 16 and no mutation, a given identity coefficient at any time t can be expressed approximately as a function of (1—f), (1—f)3 and (1—f)6, where f is the mean inbreeding coefficient at time t. Tables are presented, for small Ne values and extreme sex ratios, showing the pattern of change in the identity coefficients over time. The pattern of evolution of identity coefficients is also presented and discussed with respect to N eu, where u is the mutation rate. Applications of these results to the evolution of genetic variability within and between inbred lines are discussed.

Sign in / Sign up

Export Citation Format

Share Document