Significance of allelic diversity and 2n gametes for approaching maximum heterozygosity in 4 x ppotatoes

Euphytica ◽  
1991 ◽  
Vol 58 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Joanna E. Werner ◽  
Stanley J. Peloquin
Keyword(s):  
Allelic Diversity ◽  
2N Gametes ◽  
Maximum Heterozygosity

Genetic significance of mode of polyploidization: somatic doubling or 2n gametes?

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Kazuo Watanabe ◽  
Stanley J. Peloquin ◽  
Masatoshi Endo
Keyword(s):  
Combining Ability ◽  
Allelic Diversity ◽  
2N Gametes ◽  
Genotypic Diversity ◽  
P Value ◽  
Sexual Polyploidization ◽  
Gamete Formation ◽  
Single Exchange ◽  
Genetic Significance ◽  
2N Gamete

Computer simulation was undertaken to compare the genetic consequences of asexual (somatic doubling) and sexual (2n gametes) polyploidization. The coefficient of inbreeding at a locus, the number and frequency of genotypes at a locus, and the proportion of tri- and tetra-allelic genotypes were considered. The factors considered to estimate the genetic consequences were (i) mechanisms of sexual polyploidization, by first division restitution (FDR) × second division restitution (SDR), FDR × FDR, or SDR × SDR; (ii) position of the locus in relation to the centromere, which affects the gametic output in 2n gamete formation and thus the probability of single-exchange tetrads in meiosis during 2n gamete formation (p value); and (iii) allelic diversity at a locus. In comparing asexual and sexual polyploidization, regardless of the position of a locus in relation to the centromere, sexual polyploidization generally indicated less inbreeding, more genotypic diversity, and a higher proportion of tri- and tetra-allelic genotypes. When allelic diversity at a locus was increased, these characteristics were even more prominent. When only two alleles are possible at a locus, somatic doubling would not be inferior to sexual polyploidization. Overall results favored SDR × FDR and FDR × FDR as a mode and mechanisms of polyploidization. The genetic variations produced by 2n gametes could be attributed to "combining ability of 2n gametes."Key words: asexual polyploidization, sexual polyploidization, inbreeding, heterozygosity, combining ability of 2n gametes.

Potato breeding with haploids and 2n gametes

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 1000-1004 ◽  
Author(s):  
S. J. Peloquin ◽  
Georgia L. Yerk ◽  
Joanna E. Werner ◽  
Elizabeth Darmo
Keyword(s):  
Genetic Diversity ◽  
Specific Gravity ◽  
Potato Breeding ◽  
Germ Plasm ◽  
Allelic Diversity ◽  
2N Gametes ◽  
Potato Seed ◽  
True Potato Seed ◽  
Breeding Method ◽  
Essential Components

Potato breeding methods that utilize haploids of Solanum tuberosum group Tuberosum or group Andigena and 2n gametes exploit the genetic diversity, including both valuable traits and allelic diversity, available in exotic germ plasm. Three essential components are involved: (i) the wild and cultivated 2x relatives of the cultivated 4x potato are a valuable source of genetic diversity; (ii) haploids (2n = 2x = 24) of cultivars (2n = 4x = 48) are effective in capturing diversity (germ plasm enhancement); (iii) 2n gametes, resulting from first division restitution, are an efficient method of transmitting this genetic diversity to cultivated 4x potatoes. Heterosis for total and marketable tuber yield and specific gravity occurs in 4x families from crosses between 4x cultivars and 2x haploid Tuberosum × 'Phureja' hybrids. Selected 4x clones from relatively small 4x × 2x families have been released as cultivars based on their earliness and heat tolerance in the tropics. Other 4x clones from 4x × 2x crosses, where the 2x parents were haploid – wild species hybrids, have good yield, excellent tuber type, high specific gravity, low reducing sugars, storage quality, and stress tolerance. The seedling vigor, uniformity, and large tuber yields of progeny from 4x × 2x crosses also makes this an effective breeding method for producing potatoes from true potato seed. This breeding method is also being successfully exploited in alfalfa, red clover, sweet potatoes, yams and several species of grasses, fruits, and ornamentals.Key words: potato, haploids, 2n gametes, germ plasm, allelic diversity.

scholarly journals Unexpectedly High Allelic Diversity at the KIT Locus Causing Dominant White Color in the Domestic Pig

Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 305-311
Author(s):  
G Pielberg ◽  
C Olsson ◽  
A-C Syvänen ◽  
L Andersson
Keyword(s):  
Coat Color ◽  
Allelic Diversity ◽  
Growth Factor Receptor ◽  
Small Sample ◽  
Color Variation ◽  
Large White ◽  
High Genetic Diversity ◽  
High Allelic Diversity ◽  
Stem Cell Growth Factor ◽  
New Alleles

Abstract Mutations in KIT encoding the mast/stem cell growth factor receptor (MGF) are responsible for coat color variation in domestic pigs. The dominant white phenotype is caused by two mutations, a gene duplication and a splice mutation in one of the copies leading to skipping of exon 17. Here we applied minisequencing and pyrosequencing for quantitative analysis of the number of copies with the splice form. An unexpectedly high genetic diversity was revealed in white pigs. We found four different KIT alleles in a small sample of eight Large White females used as founder animals in a wild boar intercross. A similar number of KIT alleles was found in commercial populations of white Landrace and Large White pigs. We provide evidence for at least two new KIT alleles in pigs, both with a triplication of the gene. The results imply that KIT alleles with the duplication are genetically unstable and new alleles are most likely generated by unequal crossing over. This study provides an improved method for genotyping the complicated Dominant white/KIT locus in pigs. The results also suggest that some alleles may be associated with negative pleiotropic effects on other traits.

scholarly journals A Microsatellite Genotyping-Based Genetic Study of Interspecific Hybridization between the Red and Sika Deer in the Western Czech Republic

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1701
Author(s):  
Lenka Štohlová Putnová ◽  
Radek Štohl ◽  
Martin Ernst ◽  
Kateřina Svobodová
Keyword(s):  
Red Deer ◽  
Sika Deer ◽  
Molecular Genetic ◽  
Allelic Diversity ◽  
Molecular Genetic Analysis ◽  
Genetic Introgression ◽  
Statistical Framework ◽  
Western Bohemia ◽  
The Mean ◽  
Species Hybrids

Although inter-species hybrids between the red and sika deer can be phenotypically determined only exceptionally, there is the eventuality of identification via molecular genetic analysis. We used bi-parentally inherited microsatellite markers and a Bayesian statistical framework to re-examine the proportion of hybrids in the Czech red and sika deer populations. In total, 123 samples were collected, and the nuclear dataset consisted of 2668 allelic values. The number of alleles per locus ranged from 10 (BM1818) to 22 (BM888 and T193), yielding the mean of 16 alleles per locus across the deer. The mean allelic diversity of the red deer markedly exceeded that of the Japanese sika deer. Interspecific hybrids were detected, enabling us to confirm the genetic introgression of the sika deer into the red deer populations and vice versa in western Bohemia. The mean hybrid score equaled 10.6%, with 14.3% of the hybrids being among red deer–like individuals and 6.7% among sika-like ones. At two western Bohemian locations, namely, Doupovské hory and Slavkovský les, the total percentages of hybrid animals equaled 18.8 and 8.9, respectively. No red deer alleles were detected in the sika populations of the subregions of Kladská, Žlutice, and Lány. The NeighborNet network clearly separated the seven red and sika deer sampling populations according to the geography. The knowledge gained from the evaluated data is applicable in hunting management to reduce hybridization with the European deer.

scholarly journals Allelic diversity of merozoite surface protein genes (msp1 and msp2) and clinical manifestations of Plasmodium falciparum malaria cases in Aceh, Indonesia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Kurnia Fitri Jamil ◽  
Nandha Rizki Pratama ◽  
Sylvia Sance Marantina ◽  
Harapan Harapan ◽  
Muhammad Riza Kurniawan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Liver Function ◽  
Severe Malaria ◽  
Clinical Manifestation ◽  
Allelic Diversity ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Malaria Control Programme ◽  
Co Morbidity ◽  
Aceh Province

Abstract Background The malaria control programme in Indonesia has successfully brought down malaria incidence in many parts in Indonesia, including Aceh Province. Clinical manifestation of reported malaria cases in Aceh varied widely from asymptomatic, mild uncomplicated to severe and fatal complications. The present study aims to explore the allelic diversity of merozoite surface protein 1 gene (msp1) and msp2 among the Plasmodium falciparum isolates in Aceh Province and to determine their potential correlation with the severity of malaria clinical manifestation. Methods Screening of over 500 malaria cases admitted to the hospitals in 11 districts hospital within Aceh Province during 2013–2015, identified 90 cases of P. falciparum mono-infection without any co-morbidity. The subjects were clinically phenotyped and parasite DNA was extracted and polymerase chain reaction (PCR) amplified for the msp1 and msp2 allelic subfamilies. Results Analysis of clinical manifestation revealed that fever-chill is the most frequent symptom. Based on WHO criteria showed 19 cases were classified as severe and 71 as mild malaria. Analysis of msp1 gene revealed the presence of K1 allele subfamily in 34 subjects, MAD20 in 42 subjects, RO33 in 1 subject, and mixed allelic of K1 + MAD20 in 5 subjects, K1 + RO33 in 4 subjects, and MAD20 + RO33 in 4 subjects. Analysis of msp2 gene revealed 34 subjects carried the FC27 allelic subfamily, 37 subjects carried the 3D7 and 19 subjects carried the mixed FC27 + 3D7. Analysis of multiplicity of infection revealed that msp1 alleles is slightly higher than msp2 with the mean of MOI were 2.69 and 2.27, respectively. Statistical analysis to determine the association between each clinical manifestation and msp1 and msp2 alleles revealed that liver function abnormal value was associated with the msp2 mixed alleles (odds ratio (OR):0.13; 95%CI: 0.03–0.53). Mixed msp1 of K1 + RO33 was associated with severe malaria (OR: 28.50; 95%CI: 1.59–1532.30). Conclusion This study found a strong association between severe malaria in Aceh with subjects carrying the msp1 mixed alleles of K1 and RO33. The liver function abnormal value associated with the msp2 mixed allelic subfamilies. Further study in different geographic areas is recommended.

THE GEOGRAPHICAL DISTRIBUTION OF ALLELIC DIVERSITY, A PRACTICAL MEANS OF PRESERVING AND USING MINOR ROOT CROP GENETIC RESOURCES

2005 ◽  
Vol 41 (4) ◽  
pp. 475-489 ◽  
Author(s):  
VINCENT LEBOT ◽  
ANTON IVANCIC ◽  
KUTTOLAMADATHIL ABRAHAM
Keyword(s):  
Genetic Resources ◽  
Geographical Distribution ◽  
Allelic Diversity ◽  
Core Sample ◽  
Ex Situ ◽  
Breeding Strategies ◽  
Current Conservation ◽  
Crop Genetic Resources ◽  
Root Crop

This paper addresses the preservation and use of minor root crop genetic resources, mostly aroids and yams. Conservation is fraught with difficulty: ex situ collections are expensive to maintain and methods for on-farm conservation have not been studied. Conventional breeding strategies present serious limitations when applied to these species. Furthermore, the evaluation and distribution of improved material are as problematical as its conservation. The similarities shared by these species regarding their domestication, breeding constraints and improvement strategies as well as farmers' needs, are briefly reviewed. Based on these biological constraints, we propose a practical alternative to current conservation and breeding strategies. This approach focuses on the geographical distribution of allelic diversity rather than localized ex situ and/or in situ preservation of genotypes. The practical steps are described and discussed. First, a core sample representing the useful diversity of the species is assembled from accessions selected for their diverse and distant geographic origins, wide genetic distances, quality, agronomic performances and functional sexuality. Second, the geographical distribution of this core sample, in vitro via a transit centre, allows the direct use of selected genotypes by farmers or for breeding purposes. Third, the distribution of genes is realized in the form of clones resulting from segregating progenies and, fourth, farmers select clones with local adaptation.

Use of half-tetrad analysis to discriminate between two types of 2n egg formation in a potato haploid

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Joanna E. Werner ◽  
David S. Douches ◽  
Rosanna Freyre
Keyword(s):  
Solanum Tuberosum L ◽  
2N Gametes ◽  
Breeding Value ◽  
Tetrad Analysis ◽  
Recombination Rates ◽  
First Division Restitution ◽  
Egg Formation ◽  
Second Division Restitution ◽  
2N Eggs ◽  
Tetraploid Progeny

The ratio of the first division restitution (FDR) to second division restitution (SDR) 2n eggs was estimated in 4182t, a haploid (2n = 2x = 24) of Solanum tuberosum L. that produces 2n eggs by the two modes. The segregation of three genes previously mapped relative to their centromeres, Pgm-2 (2.0 cM), Mdh-1 (33.5 cM), and 6-Pgdh-3 (30.1 cM) was analyzed in the tetraploid offspring of a 2x × 4x cross. Based on the segregation of the Pgm-2 locus, 39.7% of the progeny originated from FDR 2n eggs and 60.3% from SDR. Segregation patterns of the two distal loci within the FDR-derived 4x subpopulation indicated that the gene–centromere recombination rate during megasporogenesis was significantly reduced for Mdh-1 when compared with a previous estimate during microsporogenesis. In the SDR-derived 4x subpopulation, the gene–centromere recombination rates for Mdh-1 and 6-Pgdh-3 were not significantly different from previous estimates. Tetraploid progeny generated from one 2x × 4x cross where the 2x parent produces 2n gametes by two modes can be used to make an unbiased comparison of the potential breeding value of FDR and SDR gametes.Key words: potato, megasporogenesis, first division restitution, second division restitution, isozyme.

MHC class II DR allelic diversity in bighorn sheep

Gene ◽  
2012 ◽  
Vol 506 (1) ◽  
pp. 217-222 ◽  
Author(s):  
Renuka Subramaniam ◽  
Stephen N. White ◽  
Lynn M. Herrmann-Hoesing ◽  
Subramaniam Srikumaran
Keyword(s):  
Mhc Class Ii ◽  
Allelic Diversity ◽  
Bighorn Sheep ◽  
Class Ii
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