Enzyme polymorphism in Schistosoma mattheei from cattle in the Eastern Transvaal Lowveld

ABSTRACTEnzyme electrophoresis was conducted on 10 Schistosoma mattheei adult worm samples, comprising 270 individuals, collected from cattle in the Eastern Transvaal Lowveld. Glucose-6-phosphate dehydrogenase (G6PDH) was studied in all the samples and phosphoglucomutase (PGM) and malate dehydrogenase (MDH) in five populations each. Only one population was polymorphic for G6PDH. In this population, in addition to the allele found in all the other samples, a second allele occurred with a similar Rf value to S. haematobium. The two alleles were in Hardy-Weinberg equilibrium. MDH-1 exhibited two alleles. However, these alleles were not in equilibrium. In certain populations, heterozygotes occurred together with homozygotes of one of the alleles only. PGM was monomorphic in all the populations studied.

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Enzyme electrophoresis, 18S rRNA sequences, and levels of phylogenetic resolution among several species of freshwater planarians (Platyhelminthes, Tricladida, Paludicola)

Canadian Journal of Zoology ◽

10.1139/z92-199 ◽

1992 ◽

Vol 70 (7) ◽

pp. 1425-1439 ◽

Cited By ~ 14

Author(s):

M. Riutort ◽

K. G. Field ◽

J. M. Turbeville ◽

R. A. Raff ◽

J. Baguña

Keyword(s):

18S Rrna ◽

Taxonomic Status ◽

Sister Group ◽

Genetic Distances ◽

Enzyme Polymorphism ◽

The Other ◽

Enzyme Electrophoresis ◽

The Family ◽

Phylogenetic Resolution ◽

Rrna Sequences

Enzyme polymorphism and 18S rRNA sequences have been used to measure genetic distances between several species of Platyhelminthes belonging to different taxa including freshwater and parasitic forms. We have used these data to address unresolved phylogenetic and taxonomic problems with this group at several different levels ranging from phylum to subgenus. The main conclusions supported by the data seem to be the following: (i) 18S rRNA data strongly suggest that the Platyhelminthes are monophyletic, being a sister-group to the other Eubilateria; a similar conclusion applies to the Paludicola as to the rest of Platyhelminthes studied; (ii) 18S rRNA and enzyme data indicate that the family Dugesiidae of the Paludicola is monophyletic with respect to the other two families, Planariidae and Dendrocoelidae; and (iii) the subgenus Schmidtea of the genus Dugesia is monophyletic with respect to the other two subgenera of Dugesia, Dugesia and Girardia. Other aspects of the relationships of subgenera and families could not be satisfactorily resolved, but point to new problems that should be addressed in future studies, namely the taxonomic status of the family Planariidae and the relationships between the genera and subgenera of the family Dugesiidae.

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Genetic Differentiation among Populations of the Northern Redbelly Dace (Phoxinus eos) in Ontario

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-122 ◽

1994 ◽

Vol 51 (6) ◽

pp. 1218-1228 ◽

Cited By ~ 4

Author(s):

C. Anna Toline ◽

Allan J. Baker

Keyword(s):

Gene Flow ◽

Genetic Differentiation ◽

Fish Species ◽

Protein Electrophoresis ◽

The Other ◽

Population Divergence ◽

Average Heterozygosity ◽

Weinberg Equilibrium ◽

Hardy Weinberg Equilibrium ◽

Population Substructuring

Eighteen populations of northern redbelly dace (Phoxinus eos) from three regions in Ontario were examined genetically using protein electrophoresis. Differentiation among regions was greater (FST = 0.100) than within them (FST = 0.045–0.064), suggesting that levels of gene flow are high enough to prevent differentiation through drift only within regions. Levels of heterozygosity, percent polymorphic loci, and number of alleles per locus are high relative to other fish species, which suggests that populations of dace in this study have not been subject to severe bottlenecks. Thus, population divergence has apparently occurred gradually over the last 10 000 yr. Average heterozygosity was not correlated with pond area. Thus, populations in Algonquin Park are not more prone to the effects of drift than those in the other two regions. Populations from the Sudbury region were genetically differentiated from those in Algonquin Park and from near Kingston, a result consistent with the historical biogeography of Ontario. Despite relatively high levels of heterozygosity, observed levels in this study deviated significantly from those expected from Hardy–Weinberg equilibrium. The breeding biology of P. eos and other fish suggests that our results may be explained by the presence of population substructuring in the localities sampled.

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Reported CCR5-∆32 deviation from Hardy-Weinberg equilibrium is explained by poor genotyping of rs62625034

10.1101/791517 ◽

2019 ◽

Cited By ~ 1

Author(s):

Yosuke Tanigawa ◽

Manuel A. Rivas

Keyword(s):

Hiv Infection ◽

Chemokine Receptor ◽

Survival Probability ◽

Gene Editing ◽

Nature Medicine ◽

The Other ◽

Ccr5 Chemokine Receptor ◽

Weinberg Equilibrium ◽

Ethical Concerns ◽

Hardy Weinberg Equilibrium

AbstractIn the fall of 2018, news broke about a researcher from China who had used CRISPR gene editing to cause human babies to have a deletion in the CCR5 chemokine receptor, making them resistant to HIV infection. One of the numerous ethical concerns about this study is that the deletion may have other effects. Subsequently, Nature Medicine published a Brief Communications from Wei and Nielsen concluding that homozygotes for the CCR5-∆32 deletion have a survival probability to age 76 of 83.5% compared to 86.5% and 86.4% for the heterozygotes and the other homozygote, respectively, and that observed departures from Hardy Weinberg proportions also support selection operating on this allele1. In the study, Wei and Nielsen used a proxy variant, rs62625034 in their analysis. Here, we report that the reported CCR5-∆32 deviation from Hardy-Weinberg equilibrium (HWE) inferred by Wei and Nielsen can be explained by poor genotyping of rs62625034, the variant used for their analysis.

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Genetic Variation and Immunochemical Properties of L-Malate : NAD+ Oxidoreductase Isozymes in the Bandicoot, Isoodon macrourus.

Australian Journal of Biological Sciences ◽

10.1071/bi9740677 ◽

1974 ◽

Vol 27 (6) ◽

pp. 677

Author(s):

RS Holmes ◽

JL VandeBerg ◽

G Gordon

Keyword(s):

Genetic Variation ◽

Genetic Polymorphism ◽

Malate Dehydrogenase ◽

Gene Frequencies ◽

Weinberg Equilibrium ◽

Hardy Weinberg Equilibrium ◽

Nad Oxidoreductase

A genetic polymorphism for the soluble isozyme (MDH-A2) of malate dehydrogenase (L-malate : NAD+ oxidoreductase; EC 1.1.1.37) was found in a Townsville-Inkerman population of short-nosed bandicoots, 1. macrourus. The enzyme seems to be inherited in a normal autosomal codominant manner. The gene frequencies for the MDH-A and MDH-A' alleles were O' 82 and 0�18 respectively. The genotypic frequencies indicated that the population was in Hardy-Weinberg equilibrium. None of 22 pouch young from seven litters expressed a phenotype inconsistent with its mother's genotype, assuming autosomal co dominance. Other populations of I. macrourus and of the long-nosed bandicoot (Perameles nasuta) exhibited only the MDH-A allele. Homologous relationships of bandicoot MDH-A2 and MDH-B2 isozymes to those of other vertebrates were established by immunochemical studies.

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