Assessment of allelic variation in serpin gene (Srp5B) in Indian wheats

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

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Genetic diversity of high and low molecular weight glutenin subunits in Saharan bread and durum wheats from Algerian oases

Czech Journal of Genetics and Plant Breeding ◽

10.17221/105/2011-cjgpb ◽

2012 ◽

Vol 48 (No. 1) ◽

pp. 23-32 ◽

Cited By ~ 11

Author(s):

I. Bellil ◽

M. Chekara Bouziani ◽

D. Khelifi

Keyword(s):

Genetic Diversity ◽

Molecular Weight ◽

Durum Wheat ◽

Bread Wheat ◽

Allelic Variation ◽

Low Molecular Weight ◽

Glutenin Subunits ◽

Lmw Glutenin Subunits ◽

Genotypic Identification ◽

Diversity Studies

Saharan wheats have been studied particularly from a botanical viewpoint. Genotypic identification, classification and genetic diversity studies to date were essentially based on the morphology of the spike and grain. For this, the allelic variation at the glutenin loci was studied in a set of Saharan bread and durum wheats from Algerian oases where this crop has been traditionally cultivated. The high molecular weight and low molecular weight glutenin subunit composition of 40 Saharan bread and 30 durum wheats was determined by SDS-PAGE. In Saharan bread wheats 32 alleles at the six glutenin loci were detected, which in combination resulted in 36 different patterns including 17 for HMW and 23 for LMW glutenin subunits. For the Saharan durum wheats, 29 different alleles were identified for the five glutenin loci studied. Altogether, 29 glutenin patterns were detected, including 13 for HMW-GS and 20 for LMW-GS. Three new alleles were found in Saharan wheats, two in durum wheat at the Glu-B1 and Glu-B3 loci, and one in bread wheat at the Glu-B1 locus. The mean indices of genetic variation at the six loci in bread wheat and at the five loci in durum wheat were 0.59 and 0.63, respectively, showing that Saharan wheats were more diverse. This information could be useful to select Saharan varieties with improved quality and also as a source of genes to develop new lines when breeding for quality.

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Microsatellite and Chromosome Evolution of Parthenogenetic Sitobion Aphids in Australia

Genetics ◽

10.1093/genetics/144.2.747 ◽

1996 ◽

Vol 144 (2) ◽

pp. 747-756 ◽

Cited By ~ 4

Author(s):

Paul Sunnucks ◽

Phillip R England ◽

Andrea C Taylor ◽

Dinah F Hales

Keyword(s):

Sexual Reproduction ◽

Chromosome Evolution ◽

Genetic Recombination ◽

Allelic Variation ◽

Repeat Unit ◽

Chromosomal Evolution ◽

Microsatellite Variation ◽

Wide Range ◽

Sexual Recombination ◽

Minimum Numbers

Abstract Single-locus microsatellite variation correlated perfectly with chromosome number in Sitobion miscanthi aphids. The microsatellites were highly heterozygous, with up to 10 alleles per locus in this species. Despite this considerable allelic variation, only seven different S. miscanthi genotypes were discovered in 555 individuals collected from a wide range of locations, hosts and sampling periods. Relatedness between genotypes suggests only two successful colonizations of Australia. There was no evidence for genetic recombination in 555 S. miscanthi so the occurrence of recent sexual reproduction must be near zero. Thus diversification is by mutation and chromosomal rearrangement alone. Since the aphids showed no sexual recombination, microsatellites can mutate without meiosis. Five of seven microsatellite differences were a single repeat unit, and one larger jump is likely. The minimum numbers of changes between karyotypes corresponded roughly one-to-one with microsatellite allele changes, which suggests very rapid chromosomal evolution. A chromosomal fission occurred in a cultured line, and a previously unknown chromosomal race was detected. All 121 diverse S. near fragariae were heterozygous but revealed only one genotype. This species too must have a low rate of sexual reproduction and few colonizations of Australia.

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Synonymous single nucleotide polymorphism in arsenic (+3) methyltransferase of the Western mosquitofish (Gambusia affinis) and its gene expression among field populations

Ecotoxicology ◽

10.1007/s10646-021-02376-8 ◽

2021 ◽

Author(s):

Daesik Park ◽

Catherine R. Propper ◽

Guangning Wang ◽

Matthew C. Salanga

Keyword(s):

Gene Expression ◽

Sequence Variation ◽

Allelic Variation ◽

Arsenic Concentration ◽

Gambusia Affinis ◽

Contamination Level ◽

Water Medium ◽

Single Nucleotide ◽

Wide Range ◽

High Arsenic

AbstractNaturally occurring arsenic is toxic at extremely low concentrations, yet some species persist even in high arsenic environments. We wanted to test if these species show evidence of evolution associated with arsenic exposure. To do this, we compared allelic variation across 872 coding nucleotides of arsenic (+3) methyltransferase (as3mt) and whole fish as3mt gene expression from three field populations of Gambusia affinis, from water sources containing low (1.9 ppb), medium-low (3.3 ppb), and high (15.7 ppb) levels of arsenic. The high arsenic site exceeds the US EPA’s Maximum Contamination Level for drinking water. Medium-low and high populations exhibited homozygosity, and no sequence variation across all animals sampled. Eleven of 24 fish examined (45.8%) in the low arsenic population harbored synonymous single nucleotide polymorphisms (SNPs) in exons 4 and/or 10. SNP presence in the low arsenic population was not associated with differences in as3mt transcript levels compared to fish from the medium-low site, where SNPs were noted; however, as3mt expression in fish from the high arsenic concentration site was significantly lower than the other two sites. Low sequence variation in fish populations from sites with medium-low and high arsenic concentrations suggests greater selective pressure on this allele, while higher variation in the low population suggests a relaxed selection. Our results suggest gene regulation associated with arsenic detoxification may play a more crucial role in influencing responses to arsenic than polymorphic gene sequence. Understanding microevolutionary processes to various contaminants require the evaluation of multiple populations across a wide range of pollution exposures.

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