scholarly journals Transposable element over-accumulation in autopolyploids results from relaxed purifying selection and provides variants for rapid local adaptation

2019 ◽  
Author(s):  
P. Baduel ◽  
L. Quadrana ◽  
B. Hunter ◽  
K. Bomblies ◽  
V. Colot

AbstractPolyploidization is frequently associated with increased transposable element (TE) content. However, what drives TE dynamics following whole genome duplication (WGD) and the evolutionary implications remain unclear. Here, we leveraged whole-genome resequencing data of ∼300 individual Arabidopsis arenosa plants, a well characterized natural diploid-autotetraploid species, to address these questions. Based on 43,176 polymorphic TE insertions we detected in these genomes, we demonstrate that relaxed purifying selection rather than transposition bursts is the main driver of TE over-accumulation after WGD. Furthermore, the increased pool of TE insertions in tetraploids is especially enriched within or near abiotic and biotic stress response genes. Notably, we uncovered one such insertion in a major flowering-time repressor gene and found that the resulting allele is specific to the rapid-cycling tetraploid lineage that colonized mainland railways. Together, our findings indicate that tetrasomy by itself leads to an enhanced tolerance to accumulating genic TE variants, some of which can potentially contribute to local adaptation.

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Pierre Baduel ◽  
Leandro Quadrana ◽  
Ben Hunter ◽  
Kirsten Bomblies ◽  
Vincent Colot

AbstractPolyploidization is frequently associated with increased transposable element (TE) content. However, what drives TE dynamics following whole genome duplication (WGD) and the evolutionary implications remain unclear. Here, we leverage whole-genome resequencing data available for ~300 individuals of Arabidopsis arenosa, a well characterized natural diploid-autotetraploid plant species, to address these questions. Based on 43,176 TE insertions we detect in these genomes, we demonstrate that relaxed purifying selection rather than transposition bursts is the main driver of TE over-accumulation after WGD. Furthermore, the increased pool of TE insertions in tetraploids is especially enriched within or near environmentally responsive genes. Notably, we show that the major flowering-time repressor gene FLC is disrupted by a TE insertion specifically in the rapid-cycling tetraploid lineage that colonized mainland railways. Together, our findings indicate that tetrasomy leads to an enhanced accumulation of genic TE insertions, some of which likely contribute to local adaptation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luciano Calderón ◽  
Nuria Mauri ◽  
Claudio Muñoz ◽  
Pablo Carbonell-Bejerano ◽  
Laura Bree ◽  
...  

AbstractGrapevine cultivars are clonally propagated to preserve their varietal attributes. However, genetic variations accumulate due to the occurrence of somatic mutations. This process is anthropically influenced through plant transportation, clonal propagation and selection. Malbec is a cultivar that is well-appreciated for the elaboration of red wine. It originated in Southwestern France and was introduced in Argentina during the 1850s. In order to study the clonal genetic diversity of Malbec grapevines, we generated whole-genome resequencing data for four accessions with different clonal propagation records. A stringent variant calling procedure was established to identify reliable polymorphisms among the analyzed accessions. The latter procedure retrieved 941 single nucleotide variants (SNVs). A reduced set of the detected SNVs was corroborated through Sanger sequencing, and employed to custom-design a genotyping experiment. We successfully genotyped 214 Malbec accessions using 41 SNVs, and identified 14 genotypes that clustered in two genetically divergent clonal lineages. These lineages were associated with the time span of clonal propagation of the analyzed accessions in Argentina and Europe. Our results show the usefulness of this approach for the study of the scarce intra-cultivar genetic diversity in grapevines. We also provide evidence on how human actions might have driven the accumulation of different somatic mutations, ultimately shaping the Malbec genetic diversity pattern.


BMC Genomics ◽  
2011 ◽  
Vol 12 (1) ◽  
Author(s):  
Paul Stothard ◽  
Jung-Woo Choi ◽  
Urmila Basu ◽  
Jennifer M Sumner-Thomson ◽  
Yan Meng ◽  
...  

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 959
Author(s):  
Alexander Igoshin ◽  
Nikolay Yudin ◽  
Ruslan Aitnazarov ◽  
Andrey A. Yurchenko ◽  
Denis M. Larkin

Despite the economic importance of creating cold resilient cattle breeds, our knowledge of the genetic basis of adaptation to cold environments in cattle is still scarce compared to information on other economically important traits. Herein, using whole-genome resequencing of animals showing contrasting phenotypes on temperature maintenance under acute cold stress combined with the existing SNP (single nucleotide polymorphism) functional annotations, we report chromosomal regions and candidate SNPs controlling body temperature in the Siberian cattle populations. The SNP ranking procedure based on regional FST calculations, functional annotations, and the allele frequency difference between cold-tolerant and cold-sensitive groups of animals pointed to multiple candidate genes. Among these, GRIA4, COX17, MAATS1, UPK1B, IFNGR1, DDX23, PPT1, THBS1, CCL5, ATF1, PLA1A, PRKAG1, and NR1I2 were previously related to thermal adaptations in cattle. Other genes, for example KMT2D and SNRPA1, are known to be related to thermogenesis in mice and cold adaptation in common carp, respectively. This work could be useful for cattle breeding strategies in countries with harsh climates, including the Russian Federation.


2021 ◽  
Author(s):  
Yifei Jiang ◽  
Huaiyong Luo ◽  
Bolun Yu ◽  
Yingbin Ding ◽  
Yanping Kang ◽  
...  

Abstract Cultivated peanut (Arachis hypogaea L.) is rich in edible oil and protein, which is widely planted around the world as an oil and cash crop. However, aflatoxin contamination seriously affects the quality safety of peanut, hindering the development of peanut industry and threatening consumers’ health. Breeding peanut varieties with resistance to Aspergillus flavus infection is important for control the aflatoxin contamination, and understanding of the genetic basis of resistance is vital to its genetic enhancement. In this study, we report the QTL mapping of resistance to A. flavus infection of a well-known resistant variety J11. A recombination inbred line (RIL) population was constructed by crossing a susceptible variety Zhonghua 16 and J11. Through whole-genome resequencing, a genetic linkage map was constructed with 2,802 recombination bins and an average inter-bin distance of 0.58 cM. Combined with phenotypic data of infection index in four consecutive years, six novel resistant QTLs were identified and they explained 5.03-10.87% phenotypic variances. The favorable alleles of five QTLs were from J11 while that of one QTL were from Zhonghua 16. The pyramiding of these favorable alleles significantly improved the resistance to A. flavus infection. These results could contribute greatly to understanding of genetic basis of A. flavus resistance and could be meaningful in further resistance improvement in peanut.


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