There's one question about animal behaviour that's always puzzled me and I would be really interested in your thoughts on it.

We know that genes are translated into proteins, and we also know that genes influence behaviour, sometimes leading to complex behaviours such as mating rituals, migrations etc. What I would like to know is how do proteins do this? Have there been any studies looking at the mechanism by which proteins influence behaviour or is it just too complex for us to understand?

That's a big question and there is so much research its hard to know where to start! Have a look here to get you started..

http://en.wikipedia.org/wiki/Behavioural_genetics

In general terms, yes, it's complicated but statistical genetics approaches provide us with loads of evidence that aspects of behaviour (aggressiveness, mating preference) are heritable (i.e. influenced by genes). Given that knowledge we can then set about trying to pinpoint genes or regions of the genome that contribute to behavioural variation in just the same way as we would any other type of trait (e.g. height).

As for the role of proteins, consider as a thought example, the role of neurotransmitters and hormones in mediating behaviour. For instance an external stimulus that triggers cortisol release may result in fight/flight behaviour. These systems rely on receptor proteins located in cell membranes that bind to the signalling chemicals. Thus, genetic variation can translate in to variation in binding protein structure and therefore function. ultimately this could translate into behavioural variation.

In addition to controlling neurotransmitters and their receptors, genes and the proteins they encode are also the determinants for how the brain is wired up during development. Migrating neurons and growing axons find where they are supposed to go by detecting extracellular cues which are, mostly, proteins that come from other cells. A mutation that changes where and when these proteins are expressed can lead to changes in how neurons connect to each other which in turn can lead to variations in personality, cognitive abilities, etc.

In my field of research there is quite a 'famous' example of how a gene may change behaviour. The distribution of vasopressin and oxytocin receptors in the brain can exhibit profound species differences; e.g., the montane and prairie vole have strikingly different patterns in vasopressin V1a receptor expression. It has been shown that vasopressin is important for affiliative behaviour, such that this ‘neuro’hormone increases olfactory investigation and grooming (towards a female) in the highly social, ‘monogamous’ male prairie vole but not in the relatively asocial, ‘promiscous’ male montane vole. If you engineer a mouse (relatively ‘promiscuous’) to express a prairie vole-like V1a receptor distribution in the brain (e..g., by introducing the prairie vole V1a receptor gene into the mouse) then this animal has pro-social response to vasopressin, i.e., behaves more like a ‘monogamous’ animal!

This does not mean that only the V1a receptor is responsible for pro-social behaviour (or for example, that generating a prairie vole-like brain distribution in a mouse has not altered other genes and/or neural wiring) but it does seem to suggest that changes in the (pattern of) expression of a single gene can influence some types of behaviour.

See - http://www.ncbi.nlm.nih.gov/pubmed/10466725

Last edited by Steve Lolait (13th Feb 2016 10:33:43)