Monday, February 8, 2010

Guest hosts for PoW during February

Frequent readers of this blog, will be acquainted with our weekly series "Picks of the Week"(PoW), in which we select stand-out molbio-related blog posts aggregated to ResearchBlogging the week before.

After this long year, I've decided to take some time off during February, and due to the success this series has had, I wanted to keep things rolling while I'm away (I may not actually be "away" per se, but I want to take some time off to do some other stuff). So, what better way to keep PoW going than inviting fellow bloggers to host PoW during February?

I invited a few of the ones that are generally part of PoW (and are among my twitter friends ;-) and many were eager to participate!

So, I'm pleased to present this week's "Picks of the Week", hosted by none other than LabRat, a fellow science blogger who has been selected for PoW many times now.

This week's title?


Check it out now!!


(If you want to guest host PoW anytime during the year, just send me an email!)

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Monday, February 1, 2010

GWAS under attack?, historical evolutionary constraints, and a lot more, in my picks of the week from RB

Another week has gone by and some very interesting molbio blog posts have been aggregated to Researchblogging.org. Every week [see my opening post on the matter], I'll select some blog posts I consider particularly interesting in the field of molecular biology [see here to get a sense of the criteria that will be used], briefly describe them and list them here for you to check out.

This week's Picks encompass posts from both last week and the week before, as last week no Picks were posted. Also, this will be the last "Picks of the Week" till March (written by me), as I'm sort of going on vacation (at the very least, I'm going to take some time off from the lab).

Note that I'm only taking into consideration the molbio-related blog posts aggregated under "Biology".

Congratulations to everyone who got their post selected.

1) Drug-induced side effects resulting from secondary targets are an important limitation in drug development. Indeed, “one third of potential therapeutic compounds fail in clinical trials or are later removed from the market due to unacceptable side effects often caused by off-target binding”.
Sometimes, however, a compound binding multiple targets or sites (“polypharmacology”) can be an advantage: a single drug could be used for the treatment of two or three different diseases. Also,

The rational design of drugs that act via polypharmacological mechanisms can produce compounds that exhibit increased therapeutic potency and against which resistance is less likely to develop
Thus, having a way to predict and identify secondary targets of known molecules, is something useful. Iddo Friedberg at Byte Size Biology discusses a recent paper published in PLoS Computational Biology reporting:

a multidimensional strategy for the identification of secondary targets of known small-molecule inhibitors in the absence of global structural and sequence homology with the primary target protein.
Using this approach, the authors predicted a few secondary targets for a compound that inhibits a protein responsible for RNA processing in Trypanosoma brucei and validated some of them.

2) The early atmosphere, the one who witnessed the origin of life, differs greatly from the one present today, the former probably being characterized by very little oxygen and an abundance of carbon dioxide.
The rise of atmospheric oxygen, as stated by Sessions et al., “was an epic event for both the biosphere and geosphere, and paved the way for the evolution of animal life” [Current Biology, 19:R567-R574].

LabRat describes the atmospheric scenery where this marvellous phenomenon took place, billions of years ago, and speculates on the time it took multicellularity to arise from the “blob phase”.

3) After some hard and arduous work, Psi Wavefunction at Skeptic Wonder, a blogger who usually surprises us with fantastic stories from the bizarre and ever-surprising world of protists, now unveils her very own tree of Eukaryotes based on an impressive body of work. You should definitely check it out!

From the post, here’s one of the blogger’s reasons for composing this tree…

Remember how I often refer to the Keeling et al 2005 tree when pointing out where some obscure organism lies on the 'map'? Well, that tree is 5 years out of date now. In fields like molecular biology and genomics, a lot can change in five years; compounded with how the protistan phylogeny was still in murky, squishy swamp of a mess only about 10-15 years ago, the current tree is far from static.

4) A recent study using two vertebrate species (zebrafish and mouse), suggests that genes expressed early during development have a more dramatic effect when knocked out or mutated, and also are more likely to revert to single copy after whole genome duplication, than genes expressed late.

It then appears that constraints are high in early stages of vertebrate development, and that the timing of expression during development, constrains a gene’s "evolvability”

Lucas Brouwers at Thoughtomics comments on a recent paper addressing the following question: are these developmental and genomic constraints associated to the age of origin of the corresponding genes?

5) There has been a lot of fuzz regarding a new paper published in PLoS Biology recently that, according to “various articles around the internet”, supposedly undermines GWAS studies. But does it really?

The only real solid claim in the paper is that, if you do not include rare SNPs in your genome-wide association study, and rare SNPs of large effect are contributing to disease, then you will sometimes pick up more common SNPs as associated, because they are in Linkage Disequilibrium with the rare SNPs.
[…]
The paper makes no attempt to say whether this IS happening, just says that it CAN happen, and that we should be AWARE of it.
Luke Jostins at Genetic Interference takes a critical stand against this paper and makes some interesting points, particularly in the comments section.

I have a lot of issues with this paper, but I will be brief and stick to my main objection; the authors attempt to demonstrate that common associations can be caused by sets of rare variants, and in doing so inadvertantly show they most of them are not.[my emphasis]

That's it for this week. Stay tuned for more MolBio Research Highlights!

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ResearchBlogging.orgSome of the articles discussed in this week's selected posts:

Durrant, J., Amaro, R., Xie, L., Urbaniak, M., Ferguson, M., Haapalainen, A., Chen, Z., Di Guilmi, A., Wunder, F., Bourne, P., & McCammon, J. (2010). A Multidimensional Strategy to Detect Polypharmacological Targets in the Absence of Structural and Sequence Homology PLoS Computational Biology, 6 (1) DOI: 10.1371/journal.pcbi.1000648

Falkowski PG (2006). Evolution. Tracing oxygen's imprint on earth's metabolic evolution. Science (New York, N.Y.), 311 (5768), 1724-5 PMID: 16556831

KEELING, P., BURGER, G., DURNFORD, D., LANG, B., LEE, R., PEARLMAN, R., ROGER, A., & GRAY, M. (2005). The tree of eukaryotes Trends in Ecology & Evolution, 20 (12), 670-676 DOI: 10.1016/j.tree.2005.09.005

Milinkovitch, M., Helaers, R., & Tzika, A. (2009). Historical Constraints on Vertebrate Genome Evolution Genome Biology and Evolution, 2010, 13-18 DOI: 10.1093/gbe/evp052

Dickson, S., Wang, K., Krantz, I., Hakonarson, H., & Goldstein, D. (2010). Rare Variants Create Synthetic Genome-Wide Associations PLoS Biology, 8 (1) DOI: 10.1371/journal.pbio.1000294


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Monday, January 25, 2010

The Top 20 most bizarre experiments of all time

A postdoc in my lab just send me this list. Check the original site here.


To research my new book, Elephants on Acid, I scoured scientific archives searching for the most bizarre experiments of all time — the kind that are mind-twistingly, jaw-droppingly strange... the kind that make you wonder, "How did anyone ever conceive of doing such a thing?"

Listed below are twenty of these experiments.

#1: Elephants on Acid (Published in no other than Science)
#2: Obedience
#3: Demikhov’s Two-Headed Dogs
#4: The Initiation of Heterosexual Behavior in a Homosexual Male
#5: The Isolated Head of a Dog
#6: Human-Ape Hybrid
#7: The Stanford Prison Experiment
#8: Facial expressions while decapitating a rat
#9: The Vomit-Drinking Doctor
#10: Beneficial Brainwashing
#11: Monkey-Head Transplant
#12: The Remote-Controlled Bull
#13: The Ape and the Child
#14: “My Fingernails Taste Terribly Bitter”
#15: The Electrification of Human Corpses
#16: Seeing Through Cat’s Eyes
#17: Stimuli Eliciting Sexual Behavior in Turkeys
#18: “Would You Go To Bed With Me Tonight?”
#19: Shock the Puppy
#20: Heartbeat At Death

[Image taken for the original website]


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Monday, January 18, 2010

Protein dancing partners, yeast as our allies, and more, in my Picks of the Week from RB

Another week has gone by and some very interesting molbio blog posts have been aggregated to Researchblogging.org. Every week [see my opening post on the matter], I'll select some blog posts I consider particularly interesting in the field of molecular biology [see here to get a sense of the criteria that will be used], briefly describe them and list them here for you to check out.

Note that I'm only taking into consideration the molbio-related blog posts aggregated under "Biology".

Congratulations to everyone who got their post selected.

1) By making use of what was known about the galactose-mediated induction of gene expression in yeast (one of the earliest model systems for studying transcriptional regulation), and of studies showing the modular nature of the DNA-binding and activation domains of transcriptional activators, the Fields lab published in 1989 the first report of the yeast two-hybrid system, an approach for assessing protein-protein interactions in vivo. LabRat describes, in very simple terms, the logic behind this technique, in light of a recent review which discusses recent modifications this system has suffered in the last few years in order for it to be a more powerful source of biological information.

2) The genomes of humans and chimpanzees, as a whole, are practically identical: indeed, as stated in the article reporting the initial sequence of the chimpanzee genome, "nearly all of the bases are identical by descent and sequences can be readily aligned except in recently derived, large repetitive regions".

A recent report suggests this scenery dramatically changes when only the Y chromosomes are the subject of comparison. Apparently, there have been stark changes between the chimp and human Y chromosomes, particularly due to gene loss in the chimp, gene gain in the human and rearrangements of large portions of the chromosome.

"Thirty percent of our Y-chromosome sequences have no counterpart in the chimpanzee. As the authors say that's the sort of divergence you'd expect to see between humans and chickens, which are separated by 310 million years of evolution not humans and chimps which only split 6 million years ago!"
The Atavism discusses this article from an evolutionary point of view, commenting on possible mechanisms that could account for the amazing evolutionary rate the Y chromosome displays, compared to the rest of the genome.

"So, the burning question is what is behind that evolutionary rate? There is probably no single answer to that question but it's safe to assume it results from some of the unique features of the Y-chromosome; a lack of genetic recombination, the presence of those large repetitive sections of DNA and the preponderance of male specific genes"
3) In a sort of shameless self-promotion, I’d also like to highlight the two-article series on Yeast Recombinational cloning (YRC), an alternative to “classic cloning”, posted on our blog last week. These posts have been widely read, so I decided to select them for this week’s picks.

So, what is YRC?
"Just to refresh your memory, and in a nutshell, the idea is to co-transform the DNA segment to be cloned into yeast along with the linearized target plasmid, provided that this DNA segment bears homology to defined plasmid sequences. By homologous recombination, yeast machinery will directly “ligate” your DNA segment into the linearized vector."
The first post explains the methodology and how it relates to my own research, and the second one, explains how we get the resulting plasmid out of yeast in order to transform our model organism of choice.
This is way cheaper than using In Fusion ;-)


That's it for this week. Stay tuned for more MolBio Research Highlights!

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ResearchBlogging.orgSome of the articles discussed in this week's selected posts:

Brückner A, Polge C, Lentze N, Auerbach D, & Schlattner U (2009). Yeast two-hybrid, a powerful tool for systems biology. International journal of molecular sciences, 10 (6), 2763-88 PMID: 19582228

Hughes, J., Skaletsky, H., Pyntikova, T., Graves, T., van Daalen, S., Minx, P., Fulton, R., McGrath, S., Locke, D., Friedman, C., Trask, B., Mardis, E., Warren, W., Repping, S., Rozen, S., Wilson, R., & Page, D. (2010). Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content Nature DOI: 10.1038/nature08700

Oldenburg KR, Vo KT, Michaelis S, & Paddon C (1997). Recombination-mediated PCR-directed plasmid construction in vivo in yeast. Nucleic acids research, 25 (2), 451-2 PMID: 9016579


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Sunday, January 17, 2010

Chile has a new President

Sebastián Piñera Echeñique has been elected President of Chile, for the period 2010-2014.

He represents the "Coalition for Change", an alliance that has embodied the Opposition for the last 20 years and finally gets a chance to hold office, supporting one of the most important aspects of the political dimension of democracy: the alternation of power.

Let's hope his administration is a successful one and that it can lead Chile to a period of growth and stability.

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BioKM Webinar

As my readers (and twitter followers) may remember, a few months ago I was a runner up in the BioKM Twitter challenge, which got me a one year account at BioKM and a great t-shirt, which some may recognize, as I wore it to the lab last Thursday.

So, what is BioKM anyway?

In a nutshell, BioKM is an online lab management solution geared towards academic research labs.

Do you want to know a little more? Do you want to see if BioKM can help you organize your projects and experiments? Sign up for their free webinar next Thursday and see for yourself!
Avi Wener will review the laboratory management system and explain its benefits as well as demonstrate its ease of use.




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Research Blogging Awards 2010

Research Blogging Awards 2010Directly from its website:

Seed Media Group’s Research Blogging Awards honor the outstanding bloggers who discuss peer-reviewed research. With nearly 1,000 blogs registered at ResearchBlogging.org and 8,500 posts about peer-reviewed journal articles collected, it is time to recognize the best of the best.

Any blog that discusses peer-reviewed research is eligible for nomination, and the winners will be determined by votes from their peers in the Research Blogging community. All finalists will be highlighted on ResearchBlogging.org, and winners will receive cash prizes totaling $2000.

We've been a part of RB for some time now (our first post at RB was on January 29th, 2009) and our posts, either discussing stand-out papers in molecular biology or highlighting the best molbio posts aggregated to RB, have been a success. For example, last week, our two posts aggregated to RB were the most viewed ones under "Biology".
As I've mentioned before, our blog differs from most science-themed blogs as it is written by scientists for scientists, and we are very pleased with how this whole project has developed.

Please support MolBio Research Highlights by nominating us in any category you feel we fit in.

More info here.


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