Evaluation of changes in drug susceptibility and population genetic structure in Haemonchus contortus following worm replacement as a means to reverse the impact of multiple-anthelmintic resistance on a sheep farm

Pinus occidentalis is the dominant species of forest ecosystems in the Dominican Republic, located between 200 and 3000 meters above sea level, with extensive and overexploited natural populations. However, over the years, various restoration plans have been performed, which could affect the genetic structure of P. occidentalis. Despite being the species with the highest occurrence in the Dominican forests, there is no existing information on genetic structure and molecular characterization among natural populations with limited information on both phenological and productive characterization. In this study, the genetic structure, diversity, and gene flow of the five P. occidentalis natural populations of the Dominican Republic were determined using microsatellite markers. A total of 145 individuals were genotyped with eight polymorphic chloroplastic microsatellites, producing an average of 41 haplotypes with high genetic diversity across populations (HE = 0.90). Significant population genetic structure was found between populations (FST = 0.123). These results reflect the impact of reforestation programs on natural populations and diluting the natural genetic signature. Analysis of population genetic data is, therefore, crucial for the breeding and conservation programs of P. occidentalis in the country.

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Contrasting patterns of population genetic structure of Fasciola hepatica from cattle and sheep: Implications for the evolution of anthelmintic resistance

Infection Genetics and Evolution ◽

10.1016/j.meegid.2011.10.010 ◽

2012 ◽

Vol 12 (1) ◽

pp. 45-52 ◽

Cited By ~ 26

Author(s):

Román Vilas ◽

Severo Vázquez-Prieto ◽

Esperanza Paniagua

Keyword(s):

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Fasciola Hepatica ◽

Anthelmintic Resistance ◽

Cattle And Sheep

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Analyses multivariées de descendances de rétrocroisements et mise en évidence de distorsions de ségrégation de caractères quantitatifs chez le mil (Pennisetum typhoides (Burm.) Stapf et Hubb.)

Genome ◽

10.1139/g88-070 ◽

1988 ◽

Vol 30 (3) ◽

pp. 411-422 ◽

Cited By ~ 5

Author(s):

A. Sarr ◽

J. Pernès

Keyword(s):

Multivariate Analysis ◽

Genetic Structure ◽

Pearl Millet ◽

Population Genetic Structure ◽

Population Genetic ◽

Pollen Competition ◽

Statistical Methodology ◽

Pennisetum Typhoides ◽

Differential Transmission ◽

The Impact

Evidence for self-pollination predominance and pollen competition was derived from certain genotypes of pearl millet (Pennisetum typhoides). In the present study, the impact of such phenomena was analyzed, using F2 and backcross lineages resulting from crosses between two millet lines, namely Ligui and Massue. Four backcross families were involved: BC1a (Ligui ♂ × F1), BC1b (F1 ♂ × Ligui), BC2a (Massue ♂ × F1), BC2b (F1 ♂ × Massue). Concatenating the multivariate analysis methods allowed the division of each family into subgroups of affinities. This procedure resulted in disclosing a distortion of the global segregation in favor of the Ligui parent. To explain such distortions, a model including gametic and gametophytic selections is proposed. Besides the utilized statistical methodology, which might prove very effective in sorting out backcross lineages early in selection programs, implications of character differential transmission at the level of population genetic structure are discussed.Key words: Pennisetum typhoides, intergametophytic competitions, segregation distortion.

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The impact of successive mass selection on population genetic structure in the Pacific oyster (Crassostrea gigas) revealed by microsatellite markers

Aquaculture International ◽

10.1007/s10499-017-0196-0 ◽

2017 ◽

Vol 26 (1) ◽

pp. 113-125 ◽

Cited By ~ 5

Author(s):

Jingxiao Zhang ◽

Qi Li ◽

Qingzhi Wang ◽

Rihao Cong ◽

Jianlong Ge ◽

...

Keyword(s):

Genetic Structure ◽

Microsatellite Markers ◽

Population Genetic Structure ◽

Crassostrea Gigas ◽

Population Genetic ◽

Pacific Oyster ◽

Mass Selection ◽

The Pacific ◽

The Impact

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Centennial clonal stability of asexual Daphnia in Greenland lakes despite climate variability

10.1101/2020.07.22.208553 ◽

2020 ◽

Author(s):

Maison Dane ◽

N. John Anderson ◽

Christopher L. Osburn ◽

John K. Colbourne ◽

Dagmar Frisch

Keyword(s):

Genetic Structure ◽

Population Genetic Structure ◽

Environmental Conditions ◽

Population Genetic ◽

Environmental Variability ◽

Arctic Lakes ◽

Ice Age ◽

Genotypic Differences ◽

Polar Regions ◽

The Impact

AbstractClimate and environmental condition drive biodiversity at many levels of biological organisation, from populations to ecosystems. Combined with palaeoecological reconstructions, palaeogenetic information on resident populations provides novel insights into evolutionary trajectories and genetic diversity driven by environmental variability. While temporal observations of changing genetic structure are often made of sexual populations, little is known about how environmental change affects the long-term fate of asexual lineages. Here, we provide information on obligately asexual, triploid Daphnia populations from three Arctic lakes in West Greenland through the past 200-300 years to test the impact of a changing environment on the temporal and spatial population genetic structure. The contrasting ecological state of the lakes, specifically regarding salinity and habitat structure may explain the observed lake-specific clonal composition over time. Palaeolimnological reconstructions show considerable environmental fluctuations since 1700 (the end of the Little Ice Age), but the population genetic structure in two lakes was almost unchanged with at most two clones per time period. Their local populations were strongly dominated by a single clone that has persisted for 250-300 years. We discuss three possible explanations for the apparent population genetic stability: (1) the persistent clones are general purpose genotypes that thrive under broad environmental conditions, (2) clonal lineages evolved subtle genotypic differences that are unresolved by microsatellite markers, or (3) epigenetic modifications allow for clonal adaptation to changing environmental conditions. Our results will motivate research into the mechanisms of adaptation in these populations, as well as their evolutionary fate in the light of accelerating climate change in the polar regions.

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