From Nervous Mice to Neurotic Humans

While the study of anxiety in mice using QTLs is both ground-breaking and remarkable, the reality is that the ultimate goal is to understand the genetic basis of such traits in humans. Similar techniques have been used to narrow down the QTLs and have led to some very interesting discoveries.
Five loci have been identified that affect anxiety related traits, however some of these acted only in males or females. This indicates that gender must be taken into account when considering such traits.
Some of the loci discovered in humans seem to relate specifically to fairly narrowly defined disorders such as panic disorders and phobias. Other sites however were linked to panic disorder and neuroticism but not to agoraphobia or simple phobias, traits which would appear to be related.
One of the five loci in mouse that was linked to anxiety was mapped to a region homologous to the loci 14p in humans which has been linked predominately to phobias. This suggests that the information from mouse QTL studies could be used to discover loci in humans and further our knowledge of disorders such as anxiety and phobias.

Eleanor McDonald
40855130

References

Mackay, Trudy. (2004) Complementing complexity, Nature Genetics, Vol 36, Number 11, 1145-7

Villafuerte, S and Burmeister, (2003) M. Untangling genetic networks of panic, phobia, fear and anxiety. Genome Biology, Vol 4, Issue 8, Article 224

“EMO” mice shed light on human neuroticism

In our human-centric way, one of the biggest questions in modern genetics is what makes us act the way we do? Understanding the genetic basis of human behaviour is a major goal for many scientists, but an important (and difficult) first step is the successful mapping of the genes underlying quantitative trait loci (QTLs) known to contribute to complex phenotypes such as neuroticism. This trait is of particular interest due to its association with many psychiatric disorders including depression and anxiety. A QTL shown to influence neuroticism has been located on human chromosome 1, but just how do we set about finding the genes responsible for regulating this trait?

That’s where the more genetically tractable model organisms come in. By successfully studying QTLs for the quantitative trait, "emotionality" (determined by a quantitative “EMO” score), and subsequently the putative genes, in mice, the human genome can potentially be analysed to see if any of the candidate mouse genes correlate with any of similar function and location in humans.

Validating this comparison, studies show that the mouse EMO QTL is one of the few behavioural QTLs which correlate to human QTL. Further evidence suggesting the comparison between mice and humans is fair includes functional and anatomical similarities between the emotion centres of the brain, and some identical pharmacological treatments for anxiety.

So, by studying mice before humans, we may be able to gain valuable insight into the genetic basis of traits such as neuroticism and emotionality.

Written by: 41203970

References:
1. Willis-Owen, S.A.G. & Flint, J. (2007), Identifying the genetic determinants of emotionality in humans: insights from rodents. Neuroscience and Behavioural Reviews, 31, 115-124.
2. Fullerton, J., Cubin, M., Tiwari, H., Wang, C., Bomhra, A., Davidson, S., Miller, S., Fairburn, C., Goodwin, G., Neale, M.C., Fiddy, S., Mott, R., Allison, D.B. & Flint, J. (2003), Linkage analysis of extremely discordant and concordant sibling pairs identifies quantitative-trait loci that influence variation in the human personality trait neuroticism. Am. J. Hum. Genet., 72, 879-890.
3. Mackay, T.F.C. (2004), Complementing complexity. Nature Genetics, 36(11), 1145-1147.