A blog with news and curiosity on genomics subjects with a particular interest for topics related to Next Generation Sequencing, Personal Genomics and Bioinformatics. We work at the University of Brescia (Italy) and are new in the field but with a lot of energy to share.
Sunday, 30 September 2012
NGS PubMed Highlights: Puerto Rican Parrot Genome Sequenced
Interestingly the Project also has a Facebook page that I guess was instrumental for the fundraising campaign.
I'm wondering how is the sequence of the FOXP2 Parrot gene (just kidding... or maybe not).
A locally funded Puerto Rican parrot (Amazona vittata) genome sequencing project increases avian data and advances young researcher education
Taras K Oleksyk, Jean-Francois Pombert, Daniel Siu, Anyimilehidi Mazo-Vargas, Brian Ramos, Wilfried Guiblet, Yashira Afanador, Christina T Ruiz-Rodriguez, Michael L Nickerson, David M Logue, Michael Dean, Luis Figueroa, Ricardo Valentin and Juan-Carlos Martinez-Cruzado
GigaScience 2012, 1:14 doi:10.1186/2047-217X-1-14
Published: 28 September 2012
Abstract Background
Amazona vittata is a critically endangered Puerto Rican endemic bird, the only surviving native parrot species in the United States territory, and the first parrot in the large Neotropical genus Amazona, to be studied on a genomic scale.
Findings
In a unique community-based funded project, DNA from an A. vittata female was sequenced using a HiSeq Illumina platform, resulting in a total of ~42.5 billion nucleotide bases. This provided approximately 26.89x average coverage depth at the completion of this funding phase. Filtering followed by assembly resulted in 259,423 contigs (N50 = 6,983 bp, longest = 75,003 bp), which was further scaffolded into 148,255 fragments (N50 = 19,470, longest = 206,462 bp). This provided ~76% coverage of the genome based on an estimated size of 1.58 Gb. The assembled scaffolds allowed basic genomic annotation and comparative analyses with other available avian whole-genome sequences.
Conclusions
The current data represents the first genomic information from and work carried out with a unique source of funding. This analysis further provides a means for directed training of young researchers in genetic and bioinformatics analyses and will facilitate progress towards a full assembly and annotation of the Puerto Rican parrot genome. It also adds extensive genomic data to a new branch of the avian tree, making it useful for comparative analyses with other avian species. Ultimately, the knowledge acquired from these data will contribute to an improved understanding of the overall population health of this species and aid in ongoing and future conservation efforts.
Friday, 28 September 2012
Flash Report: Interesting improvements in Ion performance
Wednesday, 26 September 2012
Exciting news on Ion Semiconductor Sequencing Technology
It's really exciting to see such a rapid increase in performance and accuracy for the Ion Torrent platform. Moreover high multiplexing protocols based on AmpliSeq panels seem to cut cost per sample to a very cheap price!
Tuesday, 25 September 2012
Flash Report: Exclusive deals and discounts: Mexican Dinner for Two, Haircut & Highlights, or ... a DNA test?
I just found this deal on the Italian Groupon site for a DNA test for cellulite (€99, approx. $125). Apparently 19 customers already decided to give it a try. Moved by curiosity I found the web site of the MD offering the test. It is interesting to note that he is also offering, among the others, a Relax DNA test (also called Anti Stress) and a Longevity DNA test. The physician is also President of the Italian Medical Anti-Aging Association. In what appears to be the site of the association, they offer a number of DNA tests (including the ones mentioned above) and they provide a sort of Primer on Genomics stating that "In tutto il genoma abbiamo all'incirca 180.000 geni di lunghezza variabile e molte sequenze di DNA non codificanti" ("in our genome we have approximately 180.000 genes of variable length and several non coding DNA sequences"). The number of genes is even highlighted in bold :-(
I guess I do not need to make any comment.
Monday, 24 September 2012
NGS PubMed Highlights: Oyster genome sequenced!
The oyster genome revealed enrichment in stress-related genes that make this mollusk resistant to environmental stress, and shed light on the complex biological processes implied in the shell formation.
Tuesday, 18 September 2012
Flash Report: Exome sequencing using the Ion Proton™ System
The table below summarizes the results obtained.
Interestingly, at the recent at World 2012 customer conference (13 Sept) Rothberg announced that "Life Technologies has developed Avalanche™, a revolutionary 30-minute emulsion-free template preparation chemistry that will work on all Ion platforms. Dr. Rothberg also announced that Avalanche™ will enable an Ion PIII™ Chip for the Proton, with more than 1.2 billion sensors that will take researchers beyond the $1,000 genome".
Flash Report: The Giants' Wedding
Complete Genomics’s sequencing technology gives results slower than that of Illumina, however comparative studies have shown that the technology BGI is acquiring is more accurate than Illumina’s. The purchase may also reduce BGI’s dependence on sequencer-maker Illumina.
More details about the takeover at Bloomberg Businessweek.
Monday, 17 September 2012
Rapid development of clinical and diagnostic applications for NGS benchtop sequencers
However, the use of target resequencing and WES has demonstrated to be a powerful tool in molecular diagnosis and mutation discovery. Several papers have been published reporting the identification of new mutations for known syndromes as well as for new rare diseases. Some interesting examples are: - - the use of WES to identify molecular defects in Usher syndrome; (SOLiD, GAIIx and 454 GS FLX)
- the application of 454 technology for the dignosis of inherited retinal degeneration;
- a novel mutation identified in CUL7 gene in a patient with an undiagnosed growth disorder (HiSeq 2000);
- application of WES in a consaguineous family that lead to the identification of mutations in GTDC2 gene as cause of Walker-Warburg Syndrome (HiSeq 2000);
- identification of KCNQ2 defects as cause of Ohtahra syndrome, a kind of neonatal epileptic encephalopathy (HiSeq 2000);
- identification of the molecular defect in the calcium channel gene CACNA1S in a children with atypical episodic muscle weakness (HiSeq 2000);
- discover of compound heterozygous mutations in the PKHD1 gene as cause of recessive polycystic kydney disease (HiSeq 2000);
- identification of missense mutations in SLC29A3 gene as cause of Dysisteosclerosis (HiSeq 2000), a peculiar form of ostepetrosis;
- study on a large family affected by essential tremor neudegenerative syndrome that revealed defects in the FUS gene (SOLiD);
- discovery of ANK3 mutations as associated with autism syndrome applying WES to a cohort of about 60 individuals (GAIIx).
These publications indicate that Illumina HiSeq sequencers dominate the NGS arena by now. We are curious to see if something is going to change with the capillary installation of Ion Proton sequencers.
A case worth mentioning is for sure cystic fibrosis, a disease caused by impairment of the CFTR gene with more than 1000 mutations identified so far. Even if a major percentage of cases are due to a restricted set of about 20 mutations, the possibility to quickly sequence the entire gene would simplify and speed-up the molecular diagnosis, particularly for ethnic groups with a high prevalence of rare mutations. In the past year some paper came out describing the application of Ion Torrent PGM sequencer for a quick and rapid detection of CFTR mutations and the set-up of a diagnostic protocol based on this NGS platform (see a recent example here). Recently, the University of Medicine and Dentistry of New Jersey's, Institute for Genomic Medicine (IGM), has announced that this procedure has been adopted as the standard diagnostic test for Cystic Fibrosis. A multiplexing protocol on a 316 chips allows to lower the cost of the analysis of a DNA samples at $200. This analysis looks at the 1,000 most relevant mutations identified so far providing an 98% detection rate, a remarkable improvement over the 88% obtained with the previous protocol. IGM also offers a complete mitochondrial DNA analysis for about $500 and revealed the intention to expand the NGS based diagnostic protocols to other frequently asked tests.
The diagnostic applications also represent a top priority for the NGS leader companies. Illumina has recently announced its new TruSight kits for the MiSeq (see also a post on GenomeWeb) which are targeted to various genetic disease such as autism, cardiomyopathies and pediatric inherited diseases. To complete the offer they also include a sort of Exome kit that covers all the genes reported in the Human Gene Mutation Database. Four months ago Life Technologies has presented its AmpliSeq kit on Inherited disease and with the AmpliSeq Designer they provide a tool for customer tailored target resequencing. Both companies also sell solutions targeted to the analysis of cancer genes, which is another diagnostic area with a tremendous expansion.
For sure NGS has enormously boosted the development of sequencing applications for diagnostic testings as well as the discovery of novel functional variants, opening the path leading to the long waited Personal Genomics and Personal Medicine.
Tuesday, 11 September 2012
Flash Report: we certainly do not want to miss the avalanche of new data from the ENCODE Project
Flash Report: Wanna win a complete Illumina MiSeq system?
You have time until October 15, 2012. You just need to fill out a form available at this address.
New NGS site: Genomics Law Report
We added the link to an interesting (and somehow unsettling) web site in the list of external resources of genomics news (it's on the right side of our blog page).
Friday, 7 September 2012
PubMed Highlight: NGS in molecular diagnosis of Usher syndrome
Molecular diagnosis of usher syndrome: application of two different next generation sequencing-based procedures.
Source
Cluster in Biomedicine (CBM) scrl - Genomics, Area Science Park, Basovizza, Trieste, Italy.
Abstract
Usher syndrome (USH) is a clinically and genetically heterogeneous disorder characterized by visual and hearing impairments. Clinically, it is subdivided into three subclasses with nine genes identified so far. In the present study, we investigated whether the currently available Next Generation Sequencing (NGS) technologies are already suitable for molecular diagnostics of USH. We analyzed a total of 12 patients, most of which were negative for previously described mutations in known USH genes upon primer extension-based microarray genotyping. We enriched the NGS template either by whole exome capture or by Long-PCR of the known USH genes. The main NGS sequencing platforms were used: SOLiD for whole exome sequencing, Illumina (Genome Analyzer II) and Roche 454 (GS FLX) for the Long-PCR sequencing. Long-PCR targeting was more efficient with up to 94% of USH gene regions displaying an overall coverage higher than 25×, whereas whole exome sequencing yielded a similar coverage for only 50% of those regions. Overall this integrated analysis led to the identification of 11 novel sequence variations in USH genes (2 homozygous and 9 heterozygous) out of 18 detected. However, at least two cases were not genetically solved. Our result highlights the current limitations in the diagnostic use of NGS for USH patients. The limit for whole exome sequencing is linked to the need of a strong coverage and to the correct interpretation of sequence variations with a non obvious, pathogenic role, whereas the targeted approach suffers from the high genetic heterogeneity of USH that may be also caused by the presence of additional causative genes yet to be identified.
Wednesday, 5 September 2012
PubMed Highlight: A tale of three next generation sequencing platforms: comparison of Ion Torrent, Pacific Biosciences and Illumina MiSeq sequencers
A tale of three next generation sequencing platforms: comparison of Ion Torrent, Pacific Biosciences and Illumina MiSeq sequencers.
Source
Wellcome Trust Sanger Institute, Hinxton, UK. mq1@sanger.ac.uk.
Abstract
ABSTRACT:
BACKGROUND:
Next generation sequencing (NGS) technology has revolutionized genomic and genetic research. The pace of change in this area is rapid with three major new sequencing platforms having been released in 2011: Ion Torrent's PGM, Pacific Biosciences' RS and the Illumina MiSeq. Here we compare the results obtained with those platforms to the performance of the Illumina HiSeq, the current market leader. In order to compare these platforms, and get sufficient coverage depth to allow meaningful analysis, we have sequenced a set of 4 microbial genomes with mean GC content ranging from 19.3 to 67.7%. Together, these represent a comprehensive range of genome content. Here we report our analysis of that sequence data in terms of coverage distribution, bias, GC distribution, variant detection and accuracy.
RESULTS:
Sequence generated by Ion Torrent, MiSeq and Pacific Biosciences technologies displays near perfect coverage behaviour on GC-rich, neutral and moderately AT-rich genomes, but a profound bias was observed upon sequencing the extremely AT-rich genome of Plasmodium falciparum on the PGM, resulting in no coverage for approximately 30% of the genome. We analysed the ability to call variants from each platform and found that we could call slightly more variants from Ion Torrent data compared to MiSeq data, but at the expense of a higher false positive rate. Variant calling from Pacific Biosciences data was possible but higher coverage depth was required. Context specific errors were observed in both PGM and MiSeq data, but not in that from the Pacific Biosciences platform.
CONCLUSIONS:
All three fast turnaround sequencers evaluated here were able to generate usable sequence. However there are key differences between the quality of that data and the applications it will support.
Monday, 3 September 2012
A couple of interesting summer papers...
The first one is a study showing how NGS can be a useful and powerful method to improve diagnosis in syndromes with complex clinical presentation. The second paper illustrates the use of Solid and IonTorrent NGS platforms in diagnostic routine for the screening of BRCA mutations.
Exploring the utility of Whole-Exome Sequencing as a diagnostic tool in a child with Atypical Episodic Muscle Weakness.
Clin Genet. 2012 Aug 17
J Mol Diagn. 2012 Aug 22.