Ok, this isn't really about the genetics of Glee. What it is really about is the genetic similarities of a group of choral singers.
Why do people sing in groups? Why do some sing in choirs and others not? What makes some people more inclined to participate in group music? After all, singing in a choir is far more than singing by yourself. You have to be willing to work at the pace of the group, be willing to modulate your own music to the needs of the group, and of course...you have to be able to sing.
Is it possible there's something genetic? That's what this study set out to find out. And they took their results, and made MUSIC. Read on and see!
Morley et al. "AVPR1A and SLC6A4 Polymorphisms in Choral Singers and Non-Musicians: A Gene Association Study" PLoS ONE, 2012.
So we know that participation in a choir, at least, a good choir that you have to audition for (and Sci's been in a few of those), requires a certain amount of musical talent, including the ability to carry a tune, read music, sight read music (be able to sing it on sight without playing it out on a piano first), and modulate your own voice volume, pitch, and tone to blend in with a group or stand out as required. While many of these characteristics are associated with all musicians (violins may not use your voice, but they do need to match pitch and tone when necessary), there are other qualities here associated specifically with GROUP music. Working at the pace of the group, responding to the people around you and the conductor, choral music is a very group oriented activity.
So in this study, the authors wanted to take some of the genes that have been previously associated with musical ability, and see how many of them applied specifically to people who sing in groups. Two specific genes were involved. First is the AVPR1A gene, which codes for the vasopressin receptor. The vasopressin receptor is best known for its role in regulation of the water balance in your body, but it is also present in various areas of the brain, where it has roles in behavior (such as in the monogamous behavior of voles). Changes in the promoter region of this gene (which helps control how much of the gene is expressed) have been correlated with test scores for music ability.
The second is the SLC6A4 gene, which codes for the serotonin transporter. Serotonin is a neurotransmitter which has various functions in the body, but which is best known for its role in psychiatric disorders such as depression. Some polymorphisms in the serotonin transporter gene have been associated with scores in music tests, as well as participation in things like creative dance.
What is a polymorphism? This is a case where two or more genotypes for the same region of a gene exist. One person might be A/A, while another is G/G, and another is halfway in between at A/G. There can also be bigger changes in things like repeating sequences of a gene, where the number of repeats varies as a function of genotype. All of these changes can affect how the gene is expressed, in turn affecting various aspects of function and behavior.
The authors wanted to see whether polymorphisms in either of these genes might associate with choral participation. They recruited a bunch of singers (They specified white, why only white?! Probably due to trying to reduce the complexity of the statistics, but I really wish they could have included more ethnicities in the study) from relatively good volunteer choirs, ones you have to really audition for. They recruited the rest of their volunteers from various people at the hospital where the study was being done, specifying only that they have NO participation in music of any kind other than listening to it. They got around 250 in each group with roughly equal gender representation (though a very wide age range), and genotyped them all for different polymorphisms in the vasopressin 1A receptor gene and the serotonin transporter gene.
What they found was that the vasopressin receptor 1A had no real relevance. The choral singers were no more likely to have various combinations of polymorphic alleles (called haplotype blocks) than their non-musical counterparts.
But the serotonin transporter showed more promise. Two polymorphic alleles in the serotonin transporter, the STin2.9 and the STin2.12, were found more often in the choral singers. A third allele, STin2.10, was found LESS often in choral singers and more often in the non-musical group.
So it appears that people who are members of a choir are more likely to have specific alleles of the serotonin transporter (though it is important to note that they are only MORE LIKELY, not all of them have it, and plenty of the non-musical population had it too).
This does leave me with some questions. Vocalists are only one kind of musician, what about intrumentalists, band or symphony vs choir?
What about soloists? People who work on their own?
I am particularly interested in soloists vs group performers. The serotonin transporter has been implicated in many aspects of social behavior, and mutations in the gene have been correlated with autism, obsessive-compulsive disorder, depression, and antidepressant response, as well as cooperation, harm avoidance, and neuroticism. Could this be more to do with the desire for social behavior as opposed to musical ability?
Obviously it takes more than one gene to comprise musical ability, and far more than just one gene to make you likely to sing in a choir. But this study is interesting in attempting to link specific genetics and a tendency toward a specific kind of social, musical activity. And it makes me wonder what other genetics might be out there to predict musical ability, and how they square up with genetics which might make us more or less likely to pursue making music in groups.
And the final result? Well, the result was science, but it was also MUSIC. One of the choirs used in the study, the New London Chamber Choir, used the alleles of their own genomes to create...a new choral piece. You can hear it here, and section of the lyrics is below.
The Other, the unknown. Embedded in
the tinest difference and revealed in song.
The song is beautiful, a wonderful meld of science and art, in an entirely new way! A hybrid of science and song.
Morley, A., Narayanan, M., Mines, R., Molokhia, A., Baxter, S., Craig, G., Lewis, C., & Craig, I. (2012). AVPR1A and SLC6A4 Polymorphisms in Choral Singers and Non-Musicians: A Gene Association Study PLoS ONE, 7 (2) DOI: 10.1371/journal.pone.0031763