Showing posts with label phylogeny. Show all posts
Showing posts with label phylogeny. Show all posts

Tuesday, June 19, 2018

MICROBE 2018 recap - Bioinformatics - PhaME: from Reads to Genomes to SNP phylogenies and more...

Karen Davenport, LANL:
From Raw Reads to  Trees: Whole Genome Single Nucleotide Polymorphisms Phylogenetics Across the Tree of Life


This presentation may win for longest title.

So Los Alamos National Laboratories (LANL) puts out lots of different bioinformatics tools with their more well known tools, from my perspective, being PhaME (bioRxiv paper), EDGE (NAR paper) and GOTTCHA (NAR paper). 

I was a part of a group from WRAIR that tested their EDGE platform when it was originally being developed. While it has a lot of good software integrations (packaging up of open source software for pathogen detection, surveillance and other analyses), for me, 'black box' bioinformatics solutions always have their caveats. I see these 'all-in-one' answers as exploratory tools that require validation at the very least with other pipelines. Additionally, with the large software packages like EDGE, if there is no comprehensive manual or links to manuals of programs integrated into the system then I am suspicious of the 'default' settings and why they were set in that way. I've have had many a reviewer ask for justifications on my data analysis set ups and if you cannot justify your settings (default or not) then you don't understand what the analysis is really doing to your data. Perhaps I just have an innate distrust of machine default outputs.

To LANL and the EDGE team's credit this is posted on their readthedocs site for EDGE:
"While the design of EDGE was intentionally done to be as simple as possible for the user, there is still no single ‘tool’ or algorithm that fits all use-cases in the bioinformatics field. Our intent is to provide a detailed panoramic view of your sample from various analytical standpoints, but users are encouraged to have some insight into how each tool or workflow functions, and how the results should best be interpreted." 
Like they read my mind...this is good advice for any tool(s) that you use.

Thursday, January 17, 2013

Blog Series: WoG, Cesky Krumlov: Day 10: How beavers and black queens teach us about Metagenomics...

Robert Beiko
Dalhousie University
Halifax, Nova Scotia, Canada

Topic: Metagenomics

So the term 'metagenomics' was coined by Jo Handelsman in 1998. Metagenomics describes the functional and sequence based analysis of the collective microbial genomes contained in an environmental sample.
  • This rather 'pure' definition excludes PCR based metagenomic studies as they only provide information about one gene.
The beaver gut is an example of a microbial community hard at work digesting the wood the beaver eats. Unfortunately, as I learned anew today...that microbial community is apparently also nom-i-licious and also gets digested at some point. Sucks to be them. But given turnover the cycle continues, the wood is digested and the balance of nature maintained. Still sucks to be a bacterium in the beaver gut...I gotta say.

Metagenomics asks two essential questions:
  1. Who is there?
  2. What are they doing?