Low variation in the polymorphic Clock gene poly-Q region despite population genetic structure across barn swallow (Hirundo rustica) populations.
Dor R, Lovette IJ, Safran RJ, Billerman SM, Huber GH, Vortman Y, Lotem A, McGowan A, Evans MR, Cooper CB, Winkler DW. Low variation in the polymorphic Clock gene poly-Q region despite population genetic structure across barn swallow (Hirundo rustica) populations. PLoS One. 2011; 6(12):e28843.