Chloroquine efficacy for Plasmodium vivax in Myanmar in populations with high genetic diversity and moderate parasite gene flow

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.

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Range reduction of the Oblong Rocksnail, Leptoxis compacta, shapes riverscape genetic patterns

10.1101/2020.05.12.090662 ◽

2020 ◽

Author(s):

Aaliyah D. Wright ◽

Nicole L. Garrison ◽

Ashantye’ S. Williams ◽

Paul D. Johnson ◽

Nathan V. Whelan

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Human Impacts ◽

Isolation By Distance ◽

Extinction Risk ◽

River System ◽

High Genetic Diversity ◽

Range Contraction ◽

Genetic Patterns ◽

Cahaba River

AbstractMany freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Leptoxis compacta does not display an isolation by distance pattern, contrasting patterns seen in many riverine taxa. Our findings also indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.

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Range reduction of Oblong Rocksnail, Leptoxis compacta, shapes riverscape genetic patterns

PeerJ ◽

10.7717/peerj.9789 ◽

2020 ◽

Vol 8 ◽

pp. e9789

Author(s):

Aaliyah D. Wright ◽

Nicole L. Garrison ◽

Ashantye’ S. Williams ◽

Paul D. Johnson ◽

Nathan V. Whelan

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Human Impacts ◽

Isolation By Distance ◽

Extinction Risk ◽

River System ◽

High Genetic Diversity ◽

Range Contraction ◽

Genetic Patterns ◽

Cahaba River

Many freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Our findings indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.

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The Sri Lankan paradox: high genetic diversity in Plasmodium vivax populations despite decreasing levels of malaria transmission – ERRATUM

Parasitology ◽

10.1017/s0031182014000444 ◽

2014 ◽

Vol 141 (7) ◽

pp. 891-891

Keyword(s):

Genetic Diversity ◽

Plasmodium Vivax ◽

Malaria Transmission ◽

Sri Lankan ◽

High Genetic Diversity

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Gene flow from multiple sources maintains high genetic diversity and stable population history of Common MoorhenGallinula chloropusin China

Ibis ◽

10.1111/ibi.12579 ◽

2018 ◽

Vol 160 (4) ◽

pp. 855-869 ◽

Cited By ~ 4

Author(s):

Luzhang Ruan ◽

Wei Xu ◽

Yuqing Han ◽

Chaoying Zhu ◽

Bicai Guan ◽

...

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Population History ◽

Stable Population ◽

Multiple Sources ◽

High Genetic Diversity ◽

History Of

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Gene flow between diploid and tetraploid junipers - two contrasting evolutionary pathways in two Juniperus populations

BMC Evolutionary Biology ◽

10.1186/s12862-020-01688-3 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Perla Farhat ◽

Sonja Siljak-Yakovlev ◽

Nicolas Valentin ◽

Carlos Fabregat ◽

Silvia Lopez-Udias ◽

...

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Ploidy Level ◽

High Genetic Diversity ◽

Iberian Range ◽

In The Wild ◽

Evolutionary Pathways

Abstract Background Gene flow and polyploidy have been found to be important in Juniperus evolution. However, little evidence has been published elucidating the association of both phenomena in juniper taxa in the wild. Two main areas were studied in Spain (Eastern Iberian Range and Sierra de Baza) with both diploid and tetraploid taxa present in sympatry. Gene flow and ploidy level were assessed for these taxa and the resulted offspring. Results Twenty-two allo-triploid hybrids between J. sabina var. sabina and J. thurifera were found in the Eastern Iberian Range population. However, in the Sierra de Baza population no triploids were found. Instead, 18 allo-tetraploid hybrids between two tetraploid taxa: J. sabina var. balkanensis and J. thurifera were discovered. High genetic diversity was exhibited among the tetraploid hybrids at Sierra de Baza, in contrast to the genetically identical triploid hybrids at the Eastern Iberian Range; this suggests meiotic difficulties within the triploid hybrids. In addition, unidirectional gene flow was observed in both studied areas. Conclusion Polyploidy and hybridization can be complementary partners in the evolution of Juniperus taxa in sympatric occurrences. Juniperus was shown to be an ideal coniferous model to study these two phenomena, independently or in concert.

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Pollen-mediated gene flow ensures connectivity among spatially discrete sub-populations of Phalaenopsis pulcherrima, a tropical food-deceptive orchid

BMC Plant Biology ◽

10.1186/s12870-019-2179-y ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 2

Author(s):

Zhe Zhang ◽

Stephan W. Gale ◽

Ji-Hong Li ◽

Gunter A. Fischer ◽

Ming-Xun Ren ◽

...

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Polynomial Regression ◽

Genetic Erosion ◽

Population Level ◽

Hainan Island ◽

Paternity Analysis ◽

Genetic Structuring ◽

Long Distance ◽

High Genetic Diversity

Abstract Background Gene flow in plants via pollen and seeds is asymmetrical at different geographic scales. Orchid seeds are adapted to long-distance wind dispersal but pollinium transfer is often influenced by pollinator behavior. We combined field studies with an analysis of genetic diversity among 155 physically mapped adults and 1105 F1 seedlings to evaluate the relative contribution of pollen and seed dispersal to overall gene flow among three sub-populations of the food-deceptive orchid Phalaenopsis pulcherrima on Hainan Island, China. Results Phalaenopsis pulcherrima is self-sterile and predominantly outcrossing, resulting in high population-level genetic diversity, but plants are clumped and exhibit fine-scale genetic structuring. Even so, we detected low differentiation among sub-populations, with polynomial regression analysis suggesting gene flow via seed to be more restricted than that via pollen. Paternity analysis confirmed capsules of P. pulcherrima to each be sired by a single pollen donor, probably in part facilitated by post-pollination stigma obfuscation, with a mean pollen flow distance of 272.7 m. Despite limited sampling, we detected no loss of genetic diversity from one generation to the next. Conclusions Outcrossing mediated by deceptive pollination and self-sterility promote high genetic diversity in P. pulcherrima. Long-range pollinia transfer ensures connectivity among sub-populations, offsetting the risk of genetic erosion at local scales.

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The Sri Lankan paradox: high genetic diversity in Plasmodium vivax populations despite decreasing levels of malaria transmission

Parasitology ◽

10.1017/s0031182013002278 ◽

2014 ◽

Vol 141 (7) ◽

pp. 880-890 ◽

Cited By ~ 39

Author(s):

SHARMINI GUNAWARDENA ◽

MARCELO U. FERREIRA ◽

G. M. G. KAPILANANDA ◽

DYANN F. WIRTH ◽

NADIRA D. KARUNAWEERA

Keyword(s):

Genetic Diversity ◽

Sri Lanka ◽

Plasmodium Vivax ◽

Malaria Transmission ◽

Population Size ◽

Effective Population Size ◽

Allele Frequency Distribution ◽

Effective Population ◽

High Genetic Diversity ◽

Mode Shift

SUMMARYHere we examined whether the recent dramatic decline in malaria transmission in Sri Lanka led to a major bottleneck in the local Plasmodium vivax population, with a substantial decrease in the effective population size. To this end, we typed 14 highly polymorphic microsatellite markers in 185 P. vivax patient isolates collected from 13 districts in Sri Lanka over a period of 5 years (2003–2007). Overall, we found a high degree of polymorphism, with 184 unique haplotypes (12–46 alleles per locus) and average genetic diversity (expected heterozygosity) of 0·8744. Almost 69% (n = 127) isolates had multiple-clone infections (MCI). Significant spatial and temporal differentiation (FST = 0·04–0·25; P⩽0·0009) between populations was observed. The effective population size was relatively high but showed a decline from 2003–4 to 2006–7 periods (estimated as 45 661 to 22 896 or 10 513 to 7057, depending on the underlying model used). We used three approaches – namely, mode-shift in allele frequency distribution, detection of heterozygote excess and the M-ratio statistics – to test for evidence of a recent population bottleneck but only the low values of M-ratio statistics (ranging between 0·15–0·33, mean 0·26) were suggestive of such a bottleneck. The persistence of high genetic diversity and high proportion of MCI, with little change in effective population size, despite the collapse in demographic population size of P. vivax in Sri Lanka indicates the importance of maintaining stringent control and surveillance measures to prevent resurgence.

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Genetic diversity and conservation of the endemic tuco-tuco Ctenomys ibicuiensis (Rodentia: Ctenomyidae)

Journal of Mammalogy ◽

10.1093/jmammal/gyaa119 ◽

2020 ◽

Author(s):

Mayara Delagnelo Medeiros ◽

Daniel Galiano ◽

Bruno Busnello Kubiak ◽

Paula Angélica Roratto ◽

Thales Renato Ochotorena de Freitas

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Environmental Changes ◽

Isolation By Distance ◽

Conservation Status ◽

Significant Risk ◽

Structured Populations ◽

Small Range ◽

High Genetic Diversity ◽

Landscape Modification

Abstract Endemic, small range species are susceptible to environmental changes and landscape modification. Understanding genetic diversity and distributional patterns is important for implementation of effective conservation measures. In this context, genetic diversity was evaluated to update the conservation status of an endemic tuco-tuco, Ctenomys ibicuiensis. Phylogeographic and population genetic analyses of mitochondrial DNA and microsatellite loci were carried out using 46 individuals sampled across the species’ distribution. Ctenomys ibicuiensis presented moderate to high genetic diversity and highly structured populations with low levels of gene flow and isolation by distance. Anthropogenic landscape changes threaten this restricted-range tuco-tuco. Considering its limited geographic distribution and highly structured populations with low gene flow, we consider C. ibicuiensis to be at significant risk of extinction.

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Genetic diversity, natural selection and haplotype grouping of Plasmodium vivax Duffy-binding protein genes from eastern and western Myanmar borders

Parasites & Vectors ◽

10.1186/s13071-019-3803-2 ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Yubing Hu ◽

Lin Wang ◽

Huguette Gaelle Ngassa Mbenda ◽

Myat Thu Soe ◽

Chunyun Yu ◽

...

Keyword(s):

Genetic Diversity ◽

Natural Selection ◽

Genetic Differentiation ◽

Plasmodium Vivax ◽

Binding Protein ◽

Duffy Binding Protein ◽

High Genetic Diversity ◽

Low Level ◽

Malaria Epidemiology ◽

Greater Mekong Subregion

Abstract Background Merozoite proteins of the malaria parasites involved in the invasion of red blood cells are selected by host immunity and their diversity is greatly influenced by changes in malaria epidemiology. In the Greater Mekong Subregion (GMS), malaria transmission is concentrated along the international borders and there have been major changes in malaria epidemiology with Plasmodium vivax becoming the dominant species in many regions. Here, we aimed to evaluate the genetic diversity of P. vivax Duffy-binding protein gene domain II (pvdbp-II) in isolates from the eastern and western borders of Myanmar, and compared it with that from global P. vivax populations. Methods pvdbp-II sequences were obtained from 85 and 82 clinical P. vivax isolates from the eastern and western Myanmar borders, respectively. In addition, 504 pvdbp-II sequences from nine P. vivax populations of the world were retrieved from GenBank and used for comparative analysis of genetic diversity, recombination and population structure of the parasite population. Results The nucleotide diversity of the pvdbp-II sequences from the Myanmar border parasite isolates was not uniform, with the highest diversity located between nucleotides 1078 and 1332. Western Myanmar isolates had a unique R391C mutation. Evidence of positive natural selection was detected in pvdbp-II gene in P. vivax isolates from the eastern Myanmar area. P. vivax parasite populations in the GMS, including those from the eastern, western, and central Myanmar as well as Thailand showed low-level genetic differentiation (FST, 0.000–0.099). Population genetic structure analysis of the pvdbp-II sequences showed a division of the GMS populations into four genetic clusters. A total of 60 PvDBP-II haplotypes were identified in 210 sequences from the GMS populations. Among the epitopes in PvDBP-II, high genetic diversity was found in epitopes 45 (379-SIFGT(D/G)(E/K)(K/N)AQQ(R/H)(R/C)KQ-393, π = 0.029) and Ia (416-G(N/K)F(I/M)WICK(L/I)-424], Ib [482-KSYD(Q/E)WITR-490, π = 0.028) in P. vivax populations from the eastern and western borders of Myanmar. Conclusions The pvdbp-II gene is genetically diverse in the eastern and western Myanmar border P. vivax populations. Positive natural selection and recombination occurred in pvdbp-II gene. Low-level genetic differentiation was identified, suggesting extensive gene flow of the P. vivax populations in the GMS. These results can help understand the evolution of the P. vivax populations in the course of regional malaria elimination and guide the design of PvDBP-II-based vaccine.

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