The MolBio Carnival is here!

The fifth issue of the MolBio carnival is here! We've got loads of great entries in this edition, all focusing on the mysterious world inside cells, so take some time out to take a look and comment on them. The inside of cells is such a fascinating place to explore - and many of these posts were written by the people whose job it is to explore them. I've used a fairly broad interpretation of molecular biology, so in this carnival you'll see everything from the atomic details of protein interactions, to the (comparatively) far bigger world of bacterial colonies in the gut.

All good explorations should start with a map - and you don't get much better than the truly gorgeous pictures spotlighted by E. Campbell of the HighMag Blog. This beautiful picture shows a cell with the actin-binding proteins stained purple in order to see how they interact with a mutant actin motor.

Once we head inside the cell, we can start to explore the many complex and fascinating interactions that help to control it. While the DNA might encode all the information needed to create cellular proteins, it isn't just the DNA that is responsible for cellular behaviour, as explained by Christopher Dieni in "How I Learned to Stop Worrying and Love Epigenetics" (which comes second place in the Lab Rat award for best post name). As well as proteins, DNA expression is also controlled by fragments of RNA, explained beautifully clearly by student blogger Khalil A. Cassimally who looks into whether miRNA might be used to control cocaine addiction. And while we're at the level of molecular interactions for cellular control, we can look at control mechanisms for protein folding as well, as the Computational Biology blog takes us through the consequences of entanglement during protein folding.

Picture from Robert Ezra showing protein (green) binding to DNA (gold)

But the cell does not consist solely of DNA and proteins - it also relies on metabolites such as sugars and fats. These metabolites pass through a complex series of reactions in order to convert them to energy, and research on how these reactions occur and are controlled has been going on for many years. Sigmabioblogs has a wonderful interview with the biolegend Dr. Donald Nicholson, who is now over 80 years old and has been working on metabolic pathways for pretty much his entire life! On the subject of nutrients, there is also a great bilingual post on Knedliky about how flavour-enhancers work at a molecular level.

These small and focused intramolecular reactions aren't just used to control the cell, but also to control far bigger systems, or cell-cell interactions and communication. Memoirs of a Defective Brain explains how the bacteria Strep pyogenes uses intramolecular interactions to prevent the immune system recognising an infection. His post "The SpyCEP who cleaved me" not only wins the Lab Rat award for best post name, but also features the BEST diagram I've ever seen for explaining the subtle and complex interactions between cells of the immune system:

While we're on the theme of bacteria (yay!) we'll head over to the stomach. James, of (currently...) Disease of the Week, has written a great two part series on those bacteria in our gut, focusing on the question of how they actually get into our gut, and what they do when they get there. Part 1 deals with babies, and Part 2 with adults. There's also a lovely post from Lucas Brouwers, of Thoughtomics, which looks at the evolution of cyanobacterial toxins - and why a bacteria that lived millions of years before humans were even thought of would need to produce such a powerful neurotoxin.

And lets not forget the plants! They rely on intracellular interactions as much as any other organism. There's an old (but very good) post from Denim and Tweed about how nitrogen fixing bacteria made the leap from being intracellular parasites to mutualistic helpers. We've also got a post from It Takes 30 - about how sex is specified in plants. Unlike humans, who rely on chromosomes, hormones, and a whole host of social norms and pressures to distinguish the sexes, plants might need no more than a single amino acid insertion.

Those are basically just brightly painted sexual organs on display

We'll finish the exploration on a slightly larger, but no less fascinating level, the reproductive systems of marsupials by the amazing piratey Captain Skellet. By labelling gene markers for the development of organs researchers have come to the (not unexpected) conclusion that marsupials are Just Weird, and no one is quite sure why...

The next edition of the MolBio carnival will be hosted at PHASED, so if you've missed out this time, go submit your posts here by the 3rd of January. Blog carnivals are a great way to share information and to get new readers, so it's highly recommended!