显示标签为“systems biology”的博文。显示所有博文
显示标签为“systems biology”的博文。显示所有博文

2012年4月18日星期三

enrichment for association between genomic regions and annotations


GREATGenomic Regions Enrichment of Annotations Tool

Analyzing Biological Data Using R: Methods for Graphs and Networks

http://www.springerprotocols.com/Abstract/doi/10.1007/978-1-61779-361-5_19

R is a powerful language and widely used software tool for the analysis and visualization ofdataIts core capabilities can be extended through many different add-on packagesAmongthe many packages are some which offer a broad range of facilities for analyzing statisticalproperties of graphsThis chapter provides a practical tutorial covering the use of R methodsfor graphs and networks to examine biological data and analyze their topological andstatistical properties.

2011年4月10日星期日

how to get the list of genes involved in a biological process

http://biostar.stackexchange.com/questions/7323/how-to-get-the-list-of-genes-involved-in-a-biological-process

how to compare metabolic pathways

http://biostar.stackexchange.com/questions/7403/how-to-compare-metabolic-pathways

here is a good guide on comparing metabolic pathways

2011年4月5日星期二

Evolutionary Systems Biology Lab

Jaume Bertranpetit is the leader of Evolutionary Systems Biology Lab

http://www.ibe.upf-csic.es/ibe/research/research-groups/bertranpetit.html

They have done and are doing many excellent work on human genetics/genomics.

Here is a blog of a member of this lab:
http://bioinfoblog.it/

pajek - network plot

pajek wiki:

http://pajek.imfm.si/doku.php?id=pajek

2011年4月4日星期一

Interactome Networks and its importance

Pascal Braun
http://ccsb.dfci.harvard.edu/web/www/ccsb/publications/2011_papers.html

We recently completed mapping of the first binary interactome network for the reference plant Arabidopsis thaliana. Using tools of graph theory we identify biologically relevant network communities from which a picture of the overall interactome network organization starts to emerge. Combination of interaction and comparative genomics data yielded insights into network evolution, and biological inspection resulted in many hypotheses for unknown proteins and revealed unexpected connectivity between previously studied components of phytohormone signaling pathways.

Interactome Networks and Human Disease
http://www.cell.com/abstract/S0092-8674%2811%2900130-9
Summary

Complex biological systems and cellular networks may underlie most genotype to phenotype relationships. Here, we review basic concepts in network biology, discussing different types of interactome networks and the insights that can come from analyzing them. We elaborate on why interactome networks are important to consider in biology, how they can be mapped and integrated with each other, what global properties are starting to emerge from interactome network models, and how these properties may relate to human disease.

2011年3月31日星期四

Understanding the Evolution of Defense Metabolites in Arabidopsis thaliana Using Genome-wide Association Mapping

http://www.genetics.org/cgi/content/full/185/3/991

With the improvement and decline in cost of high-throughput genotyping and phenotyping technologies, genome-wide association (GWA) studies are fast becoming a preferred approach for dissecting complex quantitative traits. Glucosinolate (GSL) secondary metabolites within Arabidopsis spp. can serve as a model system to understand the genomic architecture of quantitative traits. GSLs are key defenses against insects in the wild and the relatively large number of cloned quantitative trait locus (QTL) controlling GSL traits allows comparison of GWA to previous QTL analyses. To better understand the specieswide genomic architecture controlling plant-insect interactions and the relative strengths of GWA and QTL studies, we conducted a GWA mapping study using 96 A. thaliana accessions, 43 GSL phenotypes, and ~230,000 SNPs. Our GWA analysis identified the two major polymorphic loci controlling GSL variation (AOP and MAM) in natural populations within large blocks of positive associations encompassing dozens of genes. These blocks of positive associations showed extended linkage disequilibrium (LD) that we hypothesize to have arisen from balancing or fluctuating selective sweeps at both the AOP and MAM loci. These potential sweep blocks are likely linked with the formation of new defensive chemistries that alter plant fitness in natural environments. Interestingly, this GWA analysis did not identify the majority of previously identified QTL even though these polymorphisms were present in the GWA population. This may be partly explained by a nonrandom distribution of phenotypic variation across population subgroups that links population structure and GSL variation, suggesting that natural selection can hinder the detection of phenotype–genotype associations in natural populations.

The Complex Genetic Architecture of the Metabolome

The Complex Genetic Architecture of the Metabolome

http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1001198

Understanding how genetic variation can control phenotypic variation is a fundamental goal of modern biology. We combined genome-wide association mapping with metabolomics in the plant Arabidopsis thaliana to explore how species-wide genetic variation controls metabolism. We identified numerous naturally-variable genes that may influence plant metabolism, often clustering in “hotspots.” These hotspots were proximal to selective sweeps, regions of the genome showing decreased diversity possibly from a strong selective advantage of specific variants within the region. This suggests that metabolism may be connected to the selective advantage. Interestingly, metabolite variation in wild Arabidopsis is highly constrained despite the significant genetic variation, thus providing the plant un-sampled metabolic space if the environment shifts. The observed structuring of genetic and metabolic variation suggests individual convergence upon similar phenotypes via different genotypes, possibly intra-specific parallel evolution. This phenotypic convergence couples with a pattern of genotype—phenotype association consistent with metabolite variation largely controlled by numerous small effect genetic variants. This supports the supposition that large magnitude variation is likely unstable in a complex and interconnected metabolism. If this pattern proves generally applicable to other species, it could present a significant hurdle to identifying genes controlling metabolic trait variation via genome-wide association studies.