Genetic variability and demographic history of Heliothis virescens (Lepidoptera: Noctuidae) populations from Brazil inferred by mtDNA sequences

AbstractIntra- and inter-population genetic variability and the demographic history of Heliothis virescens (F.) populations were evaluated by using mtDNA markers (coxI, coxII and nad6) with samples from the major cotton- and soybean-producing regions in Brazil in the growing seasons 2007/08, 2008/09 and 2009/10. AMOVA indicated low and non-significant genetic structure, regardless of geographical scale, growing season or crop, with most of genetic variation occurring within populations. Clustering analyzes also indicated low genetic differentiation. The haplotype network obtained with combined datasets resulted in 35 haplotypes, with 28 exclusive occurrences, four of them sampled only from soybean fields. The minimum spanning network showed star-shaped structures typical of populations that underwent a recent demographic expansion. The recent expansion was supported by other demographic analyzes, such as the Bayesian skyline plot, the unimodal distribution of paired differences among mitochondrial sequences, and negative and significant values of neutrality tests for the Tajima's D and Fu's FS parameters. In addition, high values of haplotype diversity (Ĥ) and low values of nucleotide diversity (π), combined with a high number of low frequency haplotypes and values of θπ<θW, suggested a recent demographic expansion of H. virescens populations in Brazil. This demographic event could be responsible for the low genetic structure currently found; however, haplotypes present uniquely at the same geographic regions and from one specific host plant suggest an initial differentiation among H. virescens populations within Brazil.

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Population Genetic Structure and Genetic Diversity in Twisted-Jaw Fish, Belodontichthys truncatus Kottelat & Ng, 1999 (Siluriformes: Siluridae), from Mekong Basin

International Journal of Zoology ◽

10.1155/2017/5976421 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Surapon Yodsiri ◽

Komgrit Wongpakam ◽

Adisak Ardharn ◽

Chadaporn Senakun ◽

Sutthira Khumkratok

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Demographic History ◽

Hydropower Plant ◽

Mekong River ◽

Demographic Expansion ◽

High Genetic Diversity ◽

History Analysis ◽

History Of ◽

Important Food Source

The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.

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Genetic structure of the grey side-gilled sea slug (Pleurobranchaea maculata) in coastal waters of New Zealand

10.1101/239855 ◽

2017 ◽

Author(s):

Yeşerin Yıldırım ◽

Marti J. Anderson ◽

Selina Patel ◽

Craig D. Millar ◽

Paul B. Rainey

Keyword(s):

New Zealand ◽

Genetic Structure ◽

Sequence Data ◽

Demographic History ◽

Population Expansion ◽

Haplotype Network ◽

Founding Population ◽

Mtdna Sequence ◽

Expansion Time ◽

History Of

AbstractPleurobranchaea maculatais a rarely studied species of the Heterobranchia found throughout the south and western Pacific – and recently recorded in Argentina – whose population genetic structure is unknown. Interest in the species was sparked in New Zealand following a series of dog deaths caused by ingestions of slugs containing high levels of the neurotoxin tetrodotoxin. Here we describe the genetic structure and demographic history ofP. maculatapopulations from five principle locations in New Zealand based on extensive analyses of 12 microsatellite loci and theCOIandCytBregions of mitochondrial DNA (mtDNA). Microsatellite data showed significant differentiation between northern and southern populations with population structure being associated with previously described regional variations in tetrodotoxin concentrations. However, mtDNA sequence data did not support such structure, revealing a star-shaped haplotype network with estimates of expansion time suggesting a population expansion in the Pleistocene era. Inclusion of publicly available mtDNA sequence from Argentinian sea slugs did not alter the star-shaped network. We interpret our data as indicative of a single founding population that fragmented following geographical changes that brought about the present day north-south divide in New Zealand waters. Lack of evidence of cryptic species supports data indicating that differences in toxicity of individuals among regions are a consequence of differences in diet.

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The Genetic History of France

10.1101/712497 ◽

2019 ◽

Author(s):

Aude Saint Pierre ◽

Joanna Giemza ◽

Matilde Karakachoff ◽

Isabel Alves ◽

Philippe Amouyel ◽

...

Keyword(s):

Genetic Structure ◽

Demographic History ◽

Migration Routes ◽

Effective Population ◽

Genetic Studies ◽

Independent Population ◽

Genome Wide Data ◽

Population Sizes ◽

History Of ◽

Exhaustive Study

ABSTRACTThe study of the genetic structure of different countries within Europe has provided significant insights into their demographic history and their actual stratification. Although France occupies a particular location at the end of the European peninsula and at the crossroads of migration routes, few population genetic studies have been conducted so far with genome-wide data. In this study, we analyzed SNP-chip genetic data from 2 184 individuals born in France who were enrolled in two independent population cohorts. Using FineStructure, six different genetic clusters of individuals were found that were very consistent between the two cohorts. These clusters match extremely well the geography and overlap with historical and linguistic divisions of France. By modeling the relationship between genetics and geography using EEMS software, we were able to detect gene flow barriers that are similar in the two cohorts and corresponds to major French rivers or mountains. Estimations of effective population sizes using IBDNe program also revealed very similar patterns in both cohorts with a rapid increase of effective population sizes over the last 150 generations similar to what was observed in other European countries. A marked bottleneck is also consistently seen in the two datasets starting in the fourteenth century when the Black Death raged in Europe. In conclusion, by performing the first exhaustive study of the genetic structure of France, we fill a gap in the genetic studies in Europe that would be useful to medical geneticists but also historians and archeologists.

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Population Genetic Structure of the Invasive Spotted Alfalfa Aphid Therioaphis trifolii (Hemiptera: Aphididae) in China Inferred From Complete Mitochondrial Genomes

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.759496 ◽

2021 ◽

Vol 9 ◽

Author(s):

Xinzhi Liu ◽

Shuhua Wei ◽

Zhenyong Du ◽

Jia He ◽

Xinyue Zhang ◽

...

Keyword(s):

Invasive Species ◽

Genetic Structure ◽

Population Genetic ◽

High Throughput Sequencing ◽

Demographic History ◽

Complete Mitochondrial Genome ◽

Haplotype Diversity ◽

Evolutionary Process ◽

Invasion History ◽

Ecosystem Integrity

Biological invasions represent a natural rapid evolutionary process in which invasive species may present a major threat to biodiversity and ecosystem integrity. Analyzing the genetic structure and demographic history of invaded populations is critical for the effective management of invasive species. The spotted alfalfa aphid (SAA) Therioaphis trifolii is indigenous in the Mediterranean region of Europe and Africa and has invaded China, causing severe damages to the alfalfa industry. However, little is known about its genetic structure and invasion history. In this study, we obtained 167 complete mitochondrial genome sequences from 23 SAA populations across China based on high-throughput sequencing and performed population genetic and phylogenomic analyses. High haplotype diversity and low nucleotide diversity were found in SAA populations in China with distinct genetic structures, i.e., all populations diverged into three phylogenetic lineages. Demographic history analyses showed a recent expansion of the SAA population, consistent with the recent invasion history. Our study indicated that SAA may have invaded through multiple introduction events during commercial trades of alfalfa, although this needs further validation by nuclear markers.

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