Comparative population genetic study of two oligophagous insects associated with the same hosts

Lung Cancer and Pulmonary Tuberculosis - A Comparative Population-Genetic StudySeveral host genes proven to contribute to active tuberculosis (TB) and some of the localized major susceptibility loci, which influence lung cancer (LC) risk, are of considerable scientific interest, but do not confer high enough risk to be clinically relevant. Assuming that these diseases are genetically controlled, we hypothesized that retreat from optimal homozygosity level, as well as a changed variability among the patients, could be the populationgenetic parameter for prediction of illness. We performed a homozygous-recessive-characters (HRCs) test based analysis of the presence, distribution and individual combination of 23 selected genetically-controlled morpho-physiological traits in groups of LC patients, patients with pulmonary TB and healthy control subjects. This study showed: i) a statistically significant difference of the middle values of genetic homozygosity between both patients groups and the control group, ii) differences in the type of distribution, and iii) differences in the presence of certain individual combinations of such traits. The frequency of blood group O was significantly decreased in the TB group compared to the general population. According to their population-genetic structure, LC patients, TB patients and healthy controls represent three different groups. The retreat from optimal homozygosity level towards decrease that we found in both LC and TB patients support the influence of a dominant factor in development of these diseases.

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Population genetic structure of a major reef-building coral species Acropora downingi in northeastern Arabian Peninsula

Coral Reefs ◽

10.1007/s00338-021-02158-y ◽

2021 ◽

Author(s):

Felipe Torquato ◽

Jessica Bouwmeester ◽

Pedro Range ◽

Alyssa Marshell ◽

Mark A. Priest ◽

...

Keyword(s):

Population Structure ◽

Genetic Study ◽

Persian Gulf ◽

Population Genetic ◽

Coral Species ◽

Arabian Peninsula ◽

Ecological Speciation ◽

Population Genetic Study ◽

Sea Of Oman ◽

Neutral Markers

AbstractCurrent seawater temperatures around the northeastern Arabian Peninsula resemble future global forecasts as temperatures > 35 °C are commonly observed in summer. To provide a more fundamental aim of understanding the structure of wild populations in extreme environmental conditions, we conducted a population genetic study of a widespread, regional endemic table coral species, Acropora downingi, across the northeastern Arabian Peninsula. A total of 63 samples were collected in the southern Arabian/Persian Gulf (Abu Dhabi and Qatar) and the Sea of Oman (northeastern Oman). Using RAD-seq techniques, we described the population structure of A. downingi across the study area. Pairwise G’st and distance-based analyses using neutral markers displayed two distinct genetic clusters: one represented by Arabian/Persian Gulf individuals, and the other by Sea of Oman individuals. Nevertheless, a model-based method applied to the genetic data suggested a panmictic population encompassing both seas. Hypotheses to explain the distinctiveness of phylogeographic subregions in the northeastern Arabian Peninsula rely on either (1) bottleneck events due to successive mass coral bleaching, (2) recent founder effect, (3) ecological speciation due to the large spatial gradients in physical conditions, or (4) the combination of seascape features, ocean circulation and larval traits. Neutral markers indicated a slightly structured population of A. downingi, which exclude the ecological speciation hypothesis. Future studies across a broader range of organisms are required to furnish evidence for existing hypotheses explaining a population structure observed in the study area. Though this is the most thermally tolerant acroporid species worldwide, A. downingi corals in the Arabian/Persian Gulf have undergone major mortality events over the past three decades. Therefore, the present genetic study has important implications for understanding patterns and processes of differentiation in this group, whose populations may be pushed to extinction as the Arabian/Persian Gulf warms.

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