Isozyme variation in quaking aspen in Minnesota

1992 ◽  
Vol 22 (4) ◽  
pp. 521-524 ◽  
Author(s):  
Steven T. Lund ◽  
Glenn R. Furnier ◽  
Carl A. Mohn
Keyword(s):  
Gene Flow ◽  
Mating System ◽  
Allele Frequencies ◽  
Quaking Aspen ◽  
Isozyme Variation ◽  
Weinberg Equilibrium ◽  
Genotype Frequencies ◽  
Hardy Weinberg Equilibrium ◽  
Isozyme Loci

Variation at 10 polymorphic isozyme loci was examined for nine populations of quaking aspen (Populustremuloides Michx.) in Minnesota. Mean observed and expected estimates of isozyme heterozygosity were 0.217 and 0.220, respectively, with no significant differences in allele frequencies among populations and no significant deviations from genotype frequencies expected under Hardy–Weinberg equilibrium. These results suggest relatively high levels of gene flow among populations and a mating system involving little inbreeding.

Genetics of Cronartium ribicola. III. Mating System

1996 ◽  
Vol 74 (11) ◽  
pp. 1852-1859 ◽  
Author(s):  
Matthew A. Gitzendanner ◽  
Gayle E. Dupper ◽  
Eleanor E. White ◽  
Brett M. Foord ◽  
Paul D. Hodgskiss ◽  
...  
Keyword(s):  
Mating System ◽  
Genetic Recombination ◽  
Random Mating ◽  
Cronartium Ribicola ◽  
White Pine Blister Rust ◽  
Mendelian Segregation ◽  
Weinberg Equilibrium ◽  
Forest Pathogen ◽  
Genotype Frequencies ◽  
Hardy Weinberg Equilibrium

Lack of genetic markers has hindered the study of the mating system of Cronartium ribicola, an exotic forest pathogen Meeting natural and cultivated white pines throughout North America. Isozymes, randomly amplified polymorphic DNA (RAPDs), and restriction length polymorphisms (RFLPs) were used to study the mating system of this rust. Heterozygosity (outcrossing) in diploid telia was demonstrated by analysis of cultures derived from the meiotic products (basidiospores) of individual telia. Families of basidiospores cultured from single telia were used to test for Mendelian segregation and for conformance of loci to Hardy–Weinberg equilibrium. A total of 18 polymorphic loci were identified with the three marker systems. All except for three RAPD loci showed Mendelian segregation in the single-telium families. To quantify the level of outcrossing, gene and genotype frequencies were calculated for families from a single population. Up to 24 families were surveyed with isozymes, 14 with RAPDs, and 18 with RFLPs. Except for one isozyme locus (MPI) in one sample, all 14 loci tested with these families were in Hardy–Weinberg equilibrium, indicating random mating. Further studies, with a different sample from the same population, showed all three isozyme loci to be in Hardy–Weinberg equilibrium. The three marker systems were consistent as to the amount of variation detected. Resistance selection and breeding programs must consider the implications of genetic recombination that outcrossing affords the rust. Keywords: isozymes, RAPDs, RFLPs, Hardy–Weinberg equilibrium, white pine blister rust.

scholarly journals A test for Hardy-Weinberg equilibrium on the X chromosome for sex-biased admixed populations

2019 ◽  
Author(s):  
Daniel Backenroth ◽  
Shai Carmi
Keyword(s):  
X Chromosome ◽  
Random Mating ◽  
Allele Frequencies ◽  
Ratio Test ◽  
Weinberg Equilibrium ◽  
Genotype Frequencies ◽  
Genome Wide ◽  
Control Step ◽  
Hardy Weinberg Equilibrium ◽  
Males And Females

AbstractGenome-wide scans for deviations from Hardy-Weinberg equilibrium (HWE) are commonly applied to detect genotyping errors. In contrast to the autosomes, genotype frequencies on the X chromosome do not reach HWE within a single generation. Instead, if allele frequencies in males and females initially differ, they oscillate for a few generations towards equilibrium. Several populations world-wide have experienced recent sex-biased admixture, namely, their male and female founders differed in ancestry and thus in allele frequencies. Sex-biased admixture makes testing for HWE difficult on X, because deviations are naturally expected, even under random mating post-admixture and error-free genotyping. In this paper, we develop a likelihood ratio test and a χ2 test that detect deviations from HWE on X while allowing for natural deviations due to sex-biased admixture. We demonstrate by simulations that our tests are powerful for detecting deviations due to non-random mating, while at the same time they do not reject the null under historical sex-biased admixture and random mating thereafter. We also demonstrate that when applied to 1000 Genomes project populations (e.g., as a quality control step), our tests reject fewer SNPs (among those showing frequency differences between the sexes) than other tests.

Temporal and spatial patterns of allele and genotype frequencies at the Ng locus in blue grouse (Dendragapus obscurus)

1972 ◽  
Vol 50 (12) ◽  
pp. 1657-1662 ◽  
Author(s):  
J. A. Redfield ◽  
F. C. Zwickel ◽  
J. F. Bendell ◽  
A. T. Bergerud
Keyword(s):  
Spatial Patterns ◽  
Population Studies ◽  
Allele Frequencies ◽  
Equilibrium Conditions ◽  
Weinberg Equilibrium ◽  
Temporal And Spatial Patterns ◽  
Genotype Frequencies ◽  
Dendragapus Obscurus ◽  
Hardy Weinberg Equilibrium ◽  
Temporal And Spatial

The frequency of alleles and genotypes at the Ng locus in blue grouse from nine populations on Vancouver Island and the adjacent mainland was examined in an effort to detect systematic variations. There were no significant variations in allele frequencies between populations. Three of the nine populations sampled had significant departures from Hardy-Weinberg equilibrium conditions. Samples of four different cohorts indicated no significant shifts in allele or genotype frequencies between cohorts. These data, combined with other observations, suggest that the alleles at this locus are being maintained by selection. Thus, the utility of this locus as a marker in population studies is strengthened.

scholarly journals Allele Frequencies of 15 AmpFISTR Identifiler loci in the Nepalese population

2012 ◽  
Vol 10 (10) ◽  
pp. 20-23 ◽  
Author(s):  
Dinesh Kumar Jha ◽  
Luis Javier Martinez Gonzalez ◽  
Jiwan Prasad Rijal ◽  
Bhinu Shova Tuladhar ◽  
Nirajan Thapa Chhetri
Keyword(s):  
Allele Frequencies ◽  
Statistical Parameters ◽  
Weinberg Equilibrium ◽  
Allelic Frequencies ◽  
Str Loci ◽  
Scientific World ◽  
Hardy Weinberg Equilibrium

Allele frequencies for the 15 STR loci in the AmpFlSTR® Identifiler® and statistical parameters were estimated from a sample of 233 unrelated individuals from different area of Nepal. A total of 161 alleles were found, with corresponding allelic frequencies ranging from 0.0021 to 0.4077. The MP, PD, PIC, PE, TPI, Ho and He ranged from 0.0282 to 0.1511, 0.8489 to 0.9717, 0.6478 to 0.8700, 0.4546 to 0.7631, 1.7651 to 4.3148, 0.7167 to 0.8841 and 0.7009 to 0.8833 respectively. Deviations from the Hardy–Weinberg Equilibrium were observed for D16S539, D18S51, D21S11 and TPOX Markers. One new allele has been detected in the process. Scientific World, Vol. 10, No. 10, July 2012 p20-23 DOI: http://dx.doi.org/10.3126/sw.v10i10.6856

Solving Hardy-Weinberg with Geometry: An Integration of Biology and Math

2017 ◽  
Vol 79 (4) ◽  
pp. 309-312
Author(s):  
Laura A. Schoenle ◽  
Matthew Thomas
Keyword(s):  
Scientific Theory ◽  
Geometric Interpretation ◽  
Student Understanding ◽  
Weinberg Equilibrium ◽  
The Core ◽  
Distributive Property ◽  
Genotype Frequencies ◽  
Hardy Weinberg Equilibrium ◽  
Using Data ◽  
And Mathematics

Introducing Hardy-Weinberg equilibrium into the high school or college classroom can be difficult because many students struggle with the mathematical formalism of the Hardy-Weinberg equations. Despite the potential difficulties, incorporating Hardy-Weinberg into the curriculum can provide students with the opportunity to investigate a scientific theory using data and integrate across the disciplines of biology and mathematics. We present a geometric way to interpret and visualize Hardy-Weinberg equilibrium, allowing students to focus on the core ideas without algebraic baggage. We also introduce interactive applets that draw on the distributive property of mathematics to allow students to experiment in real time. With the applets, students can observe the effects of changing allele frequencies on genotype frequencies in a population at Hardy-Weinberg equilibrium. Anecdotally, we found use of the geometric interpretation led to deeper student understanding of the concepts and improved the students' ability to solve Hardy-Weinberg-related problems. Students can use the ideas and tools provided here to draw connections between the biology and mathematics, as well as between algebra and geometry.

Disequilibrium of Human Platelet Antigen 1 (HPA-1) in U.S. Population

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5466-5466
Author(s):  
Tyler Davi d Hutchinson ◽  
Yuhua Song ◽  
Kevin Trainor ◽  
Ghazala Hashmi
Keyword(s):  
Human Platelet ◽  
Embryo Implantation ◽  
The United States ◽  
Implantation Failure ◽  
Random Group ◽  
Weinberg Equilibrium ◽  
Genotype Frequencies ◽  
Chi Squared ◽  
Human Platelet Antigen ◽  
Hardy Weinberg Equilibrium

Abstract Background: Alloimmunization against Human Platelet Antigens (HPA) is associated with Neonatal Alloimmune Thrombocytopenia (NAIT), post-transfusion purpura and refractoriness for platelet transfusion. A flexible BeadChip™ design was developed to simultaneously detect 22 platelet antigens, including HPA-1, and used to assay over 1,000 random blood donors from across the United States. Methods: Samples from 19 labs/centers from across the country were assayed for 11 HPA loci (HPA-1 through 9, 11 and 15) using the BioArray Solutions HPA Assay. Each locus was independently assessed for Hardy-Weinberg Equilibrium. Results: Allele and genotype frequencies for each locus were reported. Platelet antigens HPA-2 through HPA-9, HPA-11 and HPA-15 were all found to be in Hardy-Weinberg Equilibrium with a Chi-Squared value of <3.84 (1 degree of freedom, 5% confidence interval). HPA-1, however, did not exhibit Hardy-Weinberg Equilibrium yielding a Chi-Squared value of 43.4. Conclusions: After reaffirming there was no sampling preference by inclusion of a second blinded random group, it was acknowledged that HPA-1 did not conform to a Mendelian distribution of alleles. The lower incidence of heterozygote HPA-1 individuals may lend credence to the recent finding by Ivanov et al (Akush Ginekol, 2007) linking the polymorphism in GPIIIa that is responsible for the HPA-1 antigen with embryo implantation failure. Further research may help elucidate the causes behind the HPA-1 disequilibrium and how much implantation failure impacts HPA-1 frequencies.

scholarly journals ABCB1 variants C3435T and T129C are not associated with colorectal cancer risk

2019 ◽  
Vol 19 (3) ◽  
pp. 2476-2483 ◽  
Author(s):  
Areej M Al Qahtani ◽  
Ayat B Al-Ghafari ◽  
Huda A Al Doghaither ◽  
Anas H Alzahrani ◽  
Ulfat M Omar ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Saudi Arabia ◽  
Goodness Of Fit ◽  
Allele Frequencies ◽  
Genotype Distribution ◽  
Exact Test ◽  
Weinberg Equilibrium ◽  
Pcr Rflp ◽  
Hardy Weinberg Equilibrium ◽  
And Control

Background: Colorectal cancer (CRC) is one of the most prevalent cancers in Saudi Arabia that is highly characterized with poor survival rate and advanced metastasis. Many studies contribute this poor outcome to the expression of ABC transporters on the surface of cancer cells.Objectives: In this study, two ABCB1 variants, C3435T and T129C, were examined to evaluate their contribution to CRC risk.Methods: 125 subjects (62 CRC patients and 63 healthy controls) were involved. The DNA was isolated and analyzed with PCR-RFLP to determine the different genotypes. The hardy-Weinberg equilibrium was performed to determine genotype distribution and allele frequencies. Fisher’s exact test (two-tailed) was used to compare allele frequencies between patients and control subjects. Results: The study showed that for SNP C3435T, the population of both CRC patients and controls were out of Hardy-Weinberg equilibrium. Genotype distribution for CRC patients was (Goodness of fit χ2 = 20, df= 1, P≤0.05), whereas, for the controls the genotype distribution was (Goodness of fit χ2 = 21, df =1, P ≤0.05). For SNP T129C, all subjects showed normal (TT) genotype.Conclusion: There was no significant association between ABCB1 3435C>T and 129T>C polymorphisms with CRC risk.Keywords: Colorectal cancer, ABCB1 gene, SNP C3435T, SNP T129C, PCR-RFLP, Saudi Arabia.

scholarly journals Analysis of Prolactin and Kappa-Casein Genes Polymorphism in Four Cattle Breeds in Turkey

2014 ◽  
Vol 14 (4) ◽  
pp. 799-806
Author(s):  
Bilal Akyüz ◽  
Mehmet Ulaş Çınar
Keyword(s):  
Restriction Enzymes ◽  
Chi Square ◽  
Brown Swiss ◽  
Weinberg Equilibrium ◽  
Cattle Breeds ◽  
Genotype Frequencies ◽  
Pcr Rflp ◽  
Chi Square Test ◽  
Hardy Weinberg Equilibrium ◽  
Casein Genes

Abstract The objective of this study was to identify allele and genotype frequencies of CSN3 and PRL genes in four cattle breeds in Turkey. For this purpose, a total of 390 cattle of East Anatolian Red (EAR), Zavot, Brown Swiss (BS) and Simmental (SIM) breeds were genotyped by PCR-RFLP method. A 443 bp fragment of CSN3 and a 156 bp fragment of PRL were amplified and digested with HindIII and RsaI restriction enzymes, respectively. For CSN3 and PRL genes, two types of alleles (A and B) and three types of genotypes (AA, BB, and AB) were observed. The highest frequencies for CSN3-A and CSN3-B alleles were estimated for the EAR breed (0.743) and for the BS breed (0.556), respectively. The highest frequency for PRL-A and PRL-B alleles was estimated for the SIM breed (0.801) and for the BS breed (0.315), respectively. The Chi-square test among the investigated cattle breeds showed that only the Zavot breed was in Hardy-Weinberg equilibrium (HWE) for both loci.

Genetic variation within and relationships among five subpopulations of Slovak Thoroughbred

2004 ◽  
Vol 52 (3) ◽  
pp. 259-265
Author(s):  
Daniela Šátková-Jakabová ◽  
J. Trandžík ◽  
Ľudmila Hudecová-Kvasňáková ◽  
Erika Hegedüšová-Zetochová ◽  
A. Bugarský ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Differentiation ◽  
International Society ◽  
Microsatellite Loci ◽  
Genetic Relationships ◽  
Allele Frequencies ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium

Genetic variation at six microsatellite loci was analysed for five Thoroughbred subpopulations to determine the magnitude of genetic differentiation and the genetic relationships among the subpopulations. Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, with all subpopulations. The genetic diversities and relationships of five Thoroughbred subpopulations were evaluated using six microsatellites recommended by the International Society of Animal Genetics (ISAG). The allele frequencies, the effective numbers of alleles, and the observed and expected heterozygosities were calculated. POPGENE v. 1.31 (Yeh et al., 1997) was used to test for deviations from the Hardy-Weinberg (H-W) equilibrium and to assign FIS estimates (Weir, 1990). The utility of microsatellites for evaluating genetic diversity of horses is discussed.

A Misconception About the Hardy–Weinberg Law

2021 ◽  
pp. 1-3
Author(s):  
Alan E. Stark
Keyword(s):  
Population Genetics ◽  
Mating System ◽  
Random Mating ◽  
Autosomal Locus ◽  
Weinberg Equilibrium ◽  
Numerical Example ◽  
Genotypic Distribution ◽  
Hardy Weinberg Equilibrium

Abstract The Hardy–Weinberg law of population genetics is usually associated with the notion of random mating of parents. A numerical example for a triallelic autosomal locus shows that an uncountable set of mating combinations can maintain Hardy–Weinberg proportions. Therefore, one cannot infer random mating in a population from the observation of Hardy–Weinberg equilibrium. The mating system which ensures that the genotypic distribution of offspring is the same as that of the parents is specified.

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