Unprecedented within-species chromosome number cline in the Wood White butterfly Leptidea sinapis and its significance for karyotype evolution and speciation

This study shows that the widespread Eurasian butterfly Leptidea sinapis displays diploid chromosome number ranging from 2n=106 in Spain to 2n=56 in eastern Kazakhstan, resulting in a 6000 km-wide cline that originated recently (8,500 to 31,000 years ago). Excluding polyploidy, this is the widest known within-species chromosome number range for any animal or plant, and it is comparable with the highest known level of within-genus karyotype variability. The discovered cline offers the opportunity to study speciation linked to multiple chromosomal changes, as well as clinal speciation, a process that is theoretically possible but difficult to document.

Reference Article:

Lukhtanov, V.A., Dincă V., Talavera, G., Vila, R. 2011. Unprecedented within-species chromosome number cline in the Wood White butterfly Leptidea sinapis and its significance for karyotype evolution and speciation. BMC Evolutionary Biology 11: 109