Project description:DNA microarrays are two-dimensional arrangements of specific probes deposited on a substrate that have been widely used in gene expression analysis by measuring mRNA accumulation. The use of this type of microarrays involves the synthesis of cDNA, which has to be double stranded (ds) if the microarray probes are of the positive strand. We have used a custom-synthesized non-commercial NimbleGen microarray from melon to evaluate an alternative method of ds cDNA synthesis, which differs substantially in its economical cost relative to a widely recommended method. The results suggested that both methods produce cDNA representative of the melon transcriptome to a similar extent, indicating that the alternative technique provides a cheaper method of ds cDNA synthesis for microarray gene expression assays.
Project description:DNA microarrays are two-dimensional arrangements of specific probes deposited on a substrate that have been widely used in gene expression analysis by measuring mRNA accumulation. The use of this type of microarrays involves the synthesis of cDNA, which has to be double stranded (ds) if the microarray probes are of the positive strand. We have used a custom-synthesized non-commercial NimbleGen microarray from melon to evaluate an alternative method of ds cDNA synthesis, which differs substantially in its economical cost relative to a widely recommended method. The results suggested that both methods produce cDNA representative of the melon transcriptome to a similar extent, indicating that the alternative technique provides a cheaper method of ds cDNA synthesis for microarray gene expression assays. Recently, we have analyzed the transcriptome of melon in response to WMV infection. Cotyledons of two genotypes of melon were virus inoculated and transcriptomic responses to the infection were analyzed by comparing infected and mock inoculated samples at 1, 3, and 7 days post-inoculation (dpi). Three biological replicates were performed for each sample. Double stranded cDNA was obtained with the Double stranded cDNA synthesis kit (Invitrogen, Carlsbad, CA, USA), based on the nick translation approach (Mol. Cell. Biol (1982) 2:161-170; Gene (1983) 25:263-269). Raw and processed microarray data are freely available from GEO database under the accession number GSE30111. By using this set of microarray hybridizations as a reference, RNA corresponding to infected cotyledons replicate 3 at 1 dpi (A1) and replicate 1 at 3 dpi (A2) (GEO accession numbers GSM745566 and GSM745567) were used to perform cDNA synthesis by the alternative method (samples B1 and B2, respectively), based on the SMART approach (BioTechniques (2001) 30:892-897), and microarray data were compared.
Project description:Three RNA viruses-Cucumis melo cryptic virus (CmCV), Cucumis melo amalgavirus 1 (CmAV1), and melon necrotic spot virus (MNSV)-were identified from a melon (Cucumis melo) transcriptome dataset. CmCV has two dsRNA genome segments; dsRNA-1 is 1592 bp in size, containing a conserved RNA-dependent RNA polymerase (RdRp), and dsRNA-2 is 1715 bp in size, and encodes a coat protein (CP). The sequence alignment and phylogenetic analyses of the CmCV RdRp and CP indicated CmCV clusters with approved or putative deltapartitiviruses in well-supported monophyletic clade. The RdRp of CmCV shared an amino acid sequence identity of 60.7% with the closest RdRp of beet cryptic virus 3, and is <57% identical to other partitiviruses. CmAV1 is a nonsegmented dsRNA virus with a genome of 3424 bp, including two partially overlapping open reading frames (ORFs) encoding a putative CP and RdRp. The sequence alignment and phylogenetic analyses of CmAV1 RdRp revealed that it belongs to the genus Amalgavirus in the family Amalgaviridae. The RdRp of CmAV1 shares 57.7% of its amino acid sequence identity with the most closely related RdRp of Phalaenopsis equestris amalgavirus 1, and is <47% identical to the other reported amalgaviruses. These analyses suggest that CmCV and CmAV1 are novel species in the genera Amalgavirus and Deltapartitivirus, respectively. These findings enrich our understanding of new plant dsRNA virus species.
Project description:Total RNA of mice tissues (liver, small intestine, lung and kidney) was extracted using liquid N2 and Trizol. mRNA extracted from total RNA was subjected to double-stranded cDNA synthesis and Illumina stranded paired end library prep for sequencing.
Project description:We report the genome sequence of melon, an important horticultural crop worldwide. We assembled 375 Mb of the double-haploid line DHL92, representing 83.3% of the estimated melon genome. We predicted 27,427 protein-coding genes, which we analyzed by reconstructing 22,218 phylogenetic trees, allowing mapping of the orthology and paralogy relationships of sequenced plant genomes. We observed the absence of recent whole-genome duplications in the melon lineage since the ancient eudicot triplication, and our data suggest that transposon amplification may in part explain the increased size of the melon genome compared with the close relative cucumber. A low number of nucleotide-binding site-leucine-rich repeat disease resistance genes were annotated, suggesting the existence of specific defense mechanisms in this species. The DHL92 genome was compared with that of its parental lines allowing the quantification of sequence variability in the species. The use of the genome sequence in future investigations will facilitate the understanding of evolution of cucurbits and the improvement of breeding strategies.
Project description:Heterosis is the superiority of an F1 hybrid over its parents. Since this phenomenon is still unclear in melon, a half diallel experiment based on eight genetically distant breeding lines was conducted in six environments of Central Italy, assessing commercially important traits: yield, total soluble solids (TSS), and days to ripening (DTR). To estimate the additive (general combining ability; GCA) and the non-additive gene effects (specific combining ability; SCA), yield was analyzed by Griffing's methods two and four, and the results were compared to the GGE (Genotype plus Genotype by Environment interaction) biplot methodology; TSS and earliness were evaluated only by Griffing's method four. Overall, GCAs were significantly more relevant than SCAs for all examined traits. Least square means (LsM), mid-parent heterosis (MPH), best-parent heterosis (BPH), as well as Euclidean and Mahalanobis' distances were calculated and compared with the genetic distance (GD). As a few correlations were found statistically significant (only for TSS), it was difficult to predict the value of a hybrid combination only by knowing the genetic distance of its parents. Despite this, heterosis was observed, indicating either the presence of epistatic effects (additive × additive interactions) and/or an underestimate of SCAs embedded within Griffing's method. The significant Env × Entries source of variation suggests development of hybrids in specific environments. The results are discussed with a breeding perspective.
Project description:BackgroundMelon (Cucumis melo L.) is a highly diverse species that is cultivated worldwide. Recent advances in massively parallel sequencing have begun to allow the study of nucleotide diversity in this species. The Sanger method combined with medium-throughput 454 technology were used in a previous study to analyze the genetic diversity of germplasm representing 3 botanical varieties, yielding a collection of about 40,000 SNPs distributed in 14,000 unigenes. However, the usefulness of this resource is limited as the sequenced genotypes do not represent the whole diversity of the species, which is divided into two subspecies with many botanical varieties variable in plant, flowering, and fruit traits, as well as in stress response. As a first step to extensively document levels and patterns of nucleotide variability across the species, we used the high-throughput SOLiD™ system to resequence the transcriptomes of a set of 67 genotypes that had previously been selected from a core collection representing the extant variation of the entire species.ResultsThe deep transcriptome resequencing of all of the genotypes, grouped into 8 pools (wild African agrestis, Asian agrestis and acidulus, exotic Far Eastern conomon, Indian momordica and Asian dudaim and flexuosus, commercial cantalupensis, subsp. melo Asian and European landraces, Spanish inodorus landraces, and Piel de Sapo breeding lines) yielded about 300 M reads. Short reads were mapped to the recently generated draft genome assembly of the DHL line Piel de Sapo (inodorus) x Songwhan Charmi (conomon) and to a new version of melon transcriptome. Regions with at least 6X coverage were used in SNV calling, generating a melon collection with 303,883 variants. These SNVs were dispersed across the entire C. melo genome, and distributed in 15,064 annotated genes. The number and variability of in silico SNVs differed considerably between pools. Our finding of higher genomic diversity in wild and exotic agrestis melons from India and Africa as compared to commercial cultivars, cultigens and landraces from Eastern Europe, Western Asia and the Mediterranean basin is consistent with the evolutionary history proposed for the species. Group-specific SNVs that will be useful in introgression programs were also detected. In a sample of 143 selected putative SNPs, we verified 93% of the polymorphisms in a panel of 78 genotypes.ConclusionsThis study provides the first comprehensive resequencing data for wild, exotic, and cultivated (landraces and commercial) melon transcriptomes, yielding the largest melon SNP collection available to date and representing a notable sample of the species diversity. This data provides a valuable resource for creating a catalog of allelic variants of melon genes and it will aid in future in-depth studies of population genetics, marker-assisted breeding, and gene identification aimed at developing improved varieties.
Project description:The tracks show enrichment of RNA sequence tags mapped to the mouse genome generated by high throughput sequencing (RNA-Seq). Double stranded cDNA was synthesized from enriched RNA that was obtained after depletion of ribosomal RNA. Pieces of cDNA, 300-350 nucleotides in length, were PCR amplified, adapter ligated, and sequenced on an Illumina HiSeq sequencer. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Cells were grown according to the approved ENCODE cell culture protocols (http://hgwdev.cse.ucsc.edu/ENCODE/protocols/cell). Total RNA was extracted using RNeasy Mini Kit (74104, Aiagen), following the manufacturer's protocol. Ribosomal RNA was removed from total RNA using the Ribo-ZeroTM Gold Kits (MRZG126, Epicentre). Double-stranded cDNA synthesis was performed on the rRNA depleted RNA using random primers and the SuperScript double-stranded cDNA synthesis kit (11917-010, Life Tech). After first strand cDNA synthesis, NucAway Spin Column (Ambion cat. 100070-30) was used to remove dNTPs. In the second strand cDNA synthesis reaction, dTTP in the dNTP mix was substituted with dUTP. After end repair and addition of 'A' base to 3' end, illumina paired-end adapter was ligated to Double-stranded cDNA library. After gel size selection of adapter ligated cDNA (300-350), Uracil-N-Glycosylase (UNG: Applied Biosystems) was used to digest the second strand cDNA (Parkhomchuk et al. , 2009). PCR amplified adapter ligated cDNA was sequenced using Illumina HiSeq. Sequence reads of 2x101 nt long with 0-2 mismatches were mapped to the mouse genome (version mm9) using the BWA aligner, version 0.5.7. The signal height corresponds to the number of overlapping fragments at each nucleotide position in the genome.