0000000000634078
AUTHOR
Joaquín Cañizares
Exploiting the diversity of tomato: the development of a phenotypically and genetically detailed germplasm collection
[EN] A collection of 163 accessions, including Solanum pimpinellifolium, Solanum lycopersicum var. cerasiforme and Solanum lycopersicum var. lycopersicum, was selected to represent the genetic and morphological variability of tomato at its centers of origin and domestication: Andean regions of Peru and Ecuador and Mesoamerica. The collection is enriched with S. lycopersicum var. cerasiforme from the Amazonian region that has not been analyzed previously nor used extensively. The collection has been morphologically characterized showing diversity for fruit, flower and vegetative traits. Their genomes were sequenced in the Varitome project and are publicly available (solgenomics.net/projects/…
Mapping of Friedreich's ataxia locus by identification of recombination events in patients homozygous by descent
The Friedreich's ataxia locus (FRDA) maps on chromosome 9q13. Genetic data, obtained from a small number of recombination events, indicated that the FRDA locus might be located centromeric to the D9S15/D9S5 linkage group, the most probable order being cen-FRDA-D9S5-D9S111-D9S15-D9S110-qter. Recently, new centromeric markers have been reported. Analysis of these markers allowed us to localize the recombination breakpoint in some of the recombinant families. However, only one proximal recombination has been found with these markers. To increase the genetic information from FRDA families, we have analyzed the centromeric markers FR1, FR2, FR7, FR8, and FR5 in patients homozygous by descent. Th…
Discovery of a Major QTL Controlling Trichome IV Density in Tomato Using K-Seq Genotyping
[EN] Trichomes are a common morphological defense against pests, in particular, type IV glandular trichomes have been associated with resistance against different invertebrates. Cultivated tomatoes usually lack or have a very low density of type IV trichomes. Therefore, for sustainable management of this crop, breeding programs could incorporate some natural defense mechanisms, such as those afforded by trichomes, present in certain Solanum species. We have identified a S. pimpinellifolium accession with very high density of this type of trichomes. This accession was crossed with a S. lycopersicum var. cerasiforme and a S. lycopersicum var. lycopersicum accessions, and the two resulting F2 …
Haplotype analyses reveal novel insights into tomato history and domestication driven by long-distance migrations and latitudinal adaptations.
Abstract A novel haplotype-based approach that uses Procrustes analysis and automatic classification was used to provide further insights into tomato history and domestication. Agrarian societies domesticated species of interest by introducing complex genetic modifications. For tomatoes, two species, one of which had two botanical varieties, are thought to be involved in its domestication: the fully wild Solanum pimpinellifolium (SP), the wild and semi-domesticated Solanum lycopersicum var. cerasiforme (SLC) and the cultivated S. l. var. lycopersicum (SLL). The Procrustes approach showed that SP evolved into SLC during a gradual migration from the Peruvian deserts to the Mexican rainforests…
Phenotype Correlation and Intergenerational Dynamics of the Friedreich Ataxia GAA Trinucleotide Repeat
Summary The Friedreich ataxia (FA) mutation has recently been identified as an unstable trinucleotide GAA repeat present 7–22 times in the normal population but amplified as many as > 1, 000 times in FA. Since it is an autosomal recessive disease, FA does not show typical features observed in other dynamic mutation disorders, such as genetic anticipation. We have analyzed the GAA repeat in 104 FA patients and 163 carrier relatives previously defined by linkage analysis. The GAA expansion was detected in all patients, most (94%) of them being ho-mozygous for the mutation. We have demonstrated that clinical variability in FA is related to the size of the expanded alleles: milder forms of the …
De novoassembly of the zucchini genome reveals a whole-genome duplication associated with the origin of theCucurbitagenus
Summary The Cucurbita genus (squashes, pumpkins and gourds) includes important domesticated species such as C. pepo, C. maxima and C. moschata. In this study, we present a high-quality draft of the zucchini (C. pepo) genome. The assembly has a size of 263 Mb, a scaffold N50 of 1.8 Mb and 34 240 gene models. It includes 92% of the conserved BUSCO core gene set, and it is estimated to cover 93.0% of the genome. The genome is organized in 20 pseudomolecules that represent 81.4% of the assembly, and it is integrated with a genetic map of 7718 SNPs. Despite the small genome size, three independent lines of evidence support that the C. pepo genome is the result of a whole-genome duplication: the …
Additional file 5: of An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
Phenotypic values of RILs carrying Zucchini and Scallop alleles in the detected QTL regions. Means and standard errors of the phenotypic value of RILs belonging to the alternative allelic classes (Zuchini versus Scallop) for the markers in the LOD peak regions of each significant QTL are shown. Data of the three environments, combined and separate, are shown to validate the effects of the different QTLs (Paip2014, Paip2015, and UPV2015). (DOCX 39 kb)
Friedreich's Ataxia: Autosomal Recessive Disease Caused by an Intronic GAA Triplet Repeat Expansion
International audience; Friedreich's ataxia (FRDA) is an autosomal recessive, degenerative disease that involves the central and peripheral nervous systems and the heart. A gene, X25, was identified in the critical region for the FRDA locus on chromosome 9q13. This gene encodes a 210-amino acid protein, frataxin, that has homologs in distant species such as Caenorhabditis elegans and yeast. A few FRDA patients were found to have point mutations in X25, but the majority were homozygous for an unstable GAA trinucleotide expansion in the first X25 intron.
Genomic variation in tomato, from wild ancestors to contemporary breeding accessions
[EN] Background: Domestication modifies the genomic variation of species. Quantifying this variation provides insights into the domestication process, facilitates the management of resources used by breeders and germplasm centers, and enables the design of experiments to associate traits with genes. We described and analyzed the genetic diversity of 1,008 tomato accessions including Solanum lycopersicum var. lycopersicum (SLL), S. lycopersicum var. cerasiforme (SLC), and S. pimpinellifolium (SP) that were genotyped using 7,720 SNPs. Additionally, we explored the allelic frequency of six loci affecting fruit weight and shape to infer patterns of selection. Results: Our results revealed a pat…
The transcriptome of Spodoptera exigua larvae exposed to different types of microbes.
We have obtained and characterized the transcriptome of Spodoptera exigua larvae with special emphasis on pathogen-induced genes. In order to obtain a highly representative transcriptome, we have pooled RNA from diverse insect colonies, conditions and tissues. Sequenced cDNA included samples from 3 geographically different colonies. Enrichment of RNA from pathogen-related genes was accomplished by exposing larvae to different pathogenic and non-pathogenic microbial agents such as the bacteria Bacillus thuringiensis, Micrococcus luteus, and Escherichia coli, the yeast Saccharomyces cerevisiae, and the S. exigua nucleopolyhedrovirus (SeMNPV). In addition, to avoid the loss of tissue-specific …
Additional file 2: of An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
Average percentage of genome covered with the GBS reads with a read depth from > 1 to > 20. (PPTX 713 kb)
Evidence for a common origin of most Friedreich ataxia chromosomes in the Spanish population
Haplotype analysis is a powerful approach to understand the spectrum of mutations accounting for a disease in a homogeneous population. We show that haplotype variation for 10 markers linked to the Friedreich ataxia locus (FRDA) argues in favor of an important mutation homogeneity in the Spanish population, and positions the FRDA locus in the region where it has been recently isolated. We also report the finding of a new single nucleotide polymorphism called FAD1. The new marker shows a very strong linkage disequilibrium with Friedreich ataxia (FA) in both the Spanish and French populations. suggesting the existence of an ancient and widespread FRDA mutations. Inclusion of FAD1 in the exten…
An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
[EN] Background: Cucurbita pepo is a cucurbit with growing economic importance worldwide. Zucchini morphotype is the most important within this highly variable species. Recently, transcriptome and Simple Sequence Repeat (SSR)- and Single Nucleotide Polymorphism (SNP)-based medium density maps have been reported, however further genomic tools are needed for efficient molecular breeding in the species. Our objective is to combine currently available complete transcriptomes and the Zucchini genome sequence with high throughput genotyping methods, mapping population development and extensive phenotyping to facilitate the advance of genomic research in this species. Results: We report the Genoty…
Additional file 1: of An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
Phenotyped traits in the RIL population. (DOCX 13 kb)
Tirant is a new member of the gypsy family of retrotransposons in Drosophila melanogaster.
In this paper, we propose a consensus sequence for a putative complete Tirant retrotransposon. Several defective copies, as well as relevant sequences available in databases have been analyzed. The putative complete Tirant element is 8533 bp long, and presents all the structural features of a retroviruslike transposable element of the gypsy family. It contains three ORFs (open reading frames) that encode putative products resembling the retroviral Gag, Pol, and Env proteins. Southern blot analyses show that complete and defective Tirant elements are widespread in Drosophila melanogaster. The different hybridization patterns observed in several natural populations of this species suggest tha…
dfh is a Drosophila homolog of the Friedreich's ataxia disease gene
Abstract A putative Drosophila homolog of the Friedreich's ataxia disease gene (FRDA) has been cloned and characterized; it has been named Drosophila frataxin homolog (dfh). It is located at 8C/D position on X chromosome and is spread over 1 kb, a much smaller genomic region than the human gene. Its genomic organization is simple, with a single intron dividing the coding region into two exons. The predicted encoded product has 190 amino acids, being considered a frataxin-like protein on the basis of the sequence and secondary structure conservation when compared with human frataxin and related proteins from other eukaryotes. The closest match between the Drosophila and the human proteins in…
Additional file 4: of An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
a) LOD peaks of the QTLs identified in the RIL population for vine, flowering and fruit traits. Lines represent the thresholds p 0.01 and 0.05. Results of CIM analysis with a 20 cM windows are shown for each trait. First box show QTL results with data from all the environments and the other three boxes show the QTL results for single environments Paip2014, Paip2015 and UPV2015. b) Means and errors of the phenotype of alternative allelic classes, homozygous Zucchini (AA) and homozygous Scallop (BB), are shown for each QTL, calculated with the full set of data and with the data form each environment separately. c) Genetic correlations (r x,y) between locations for each trait (*p
Genotype and phenotype analysis of Friedreich's ataxia compound heterozygous patients
Friedreich's ataxia is caused by mutations in the FRDA gene that encodes frataxin, a nuclear-encoded mitochondrial protein. Most patients are homozygous for the expansion of a GAA triplet repeat within the FRDA gene, but a few patients show compound heterozygosity for a point mutation and the GAA-repeat expansion. We analyzed DNA samples from a cohort of 241 patients with autosomal recessive or isolated spinocerebellar ataxia for the GAA triplet expansion. Patients heterozygous for the GAA expansion were screened for point mutations within the FRDA coding region. Molecular analyses included the single-strand conformation polymorphism analysis, direct sequencing, and linkage analysis with FR…
ABCC transporters mediate insect resistance to multiple Bt toxins revealed by bulk segregant analysis
[EN] Background: Relatively recent evidence indicates that ABCC2 transporters play a main role in the mode of action of Bacillus thuringiensis (Bt) Cry1A-type proteins. Mapping of major Cry1A resistance genes has linked resistance to the ABCC2 locus in Heliothis virescens, Plutella xylostella, Trichoplusia ni and Bombyx mori, and mutations in this gene have been found in three of these Bt-resistant strains. Results: We have used a colony of Spodoptera exigua (Xen-R) highly resistant to a Bt commercial bioinsecticide to identify regions in the S. exigua genome containing loci for major resistance genes by using bulk segregant analysis (BSA). Results reveal a region containing three genes fro…
Additional file 6: of An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
List of genes underlying the significant QTLs involved in vine, flowering and fruit traits variation annotated in the last version of the C. pepo genome (v 3.2) available [13]. (XLSX 146 kb)
Additional file 3: of An SNP-based saturated genetic map and QTL analysis of fruit-related traits in Zucchini using Genotyping-by-sequencing
a) Genetic map developed using the GBS approach with the RIL population derived from the cross Zucchini x Scallop. The genetic and physical position of each of the the 7,718 SNP markers (in the C. pepo genome version 3.2) is indicated and the flanking sequenced of each SNPs is also included. b) Physical position and annotation (in the C. pepo genome version 3.2) of the SNPs that showed statistically significant distorted segregation. Chi-square p-values were corrected for multiple testing using Benjamini and Yekutieli correction [36]. Distorted SNPs are integrated with the 7,718 non-distorted SNPs used for the map construction for which the genetic position is also indicated. c) Main region…