Clock gene variation in Tachycineta swallows

ROI DOR; CAREN COOPER; IRBY J. LOVETTE; VIVIANA MASSONI; FLORENCIA BULIT; LILJESTHROM MARCELA; DAVID W. WINKLER

Ecology and Evolution

Allen Moore, University of Georgia, USA

Lugar: Georgia; Año: 2011

2045-7758

Many animals use photoperiod cues to synchronize reproduction with environmentalconditions and thereby improve their reproductive success. The circadianclock, which creates endogenous behavioral and physiological rhythms typicallyentrained to photoperiod, is well characterized at the molecular level. Recent workprovided evidence for an association between Clock poly-Q length polymorphismand latitude and, within a population, an association with the date of laying and thelength of the incubation period. Despite relatively high overall breeding synchrony,the timing of clutch initiation has a large impact on the fitness of swallows in thegenus Tachycineta.We compared length polymorphism in the Clock poly-Q regionamong five populations from five different Tachycineta species that breed acrossa hemisphere-wide latitudinal gradient (Fig. 1). Clock poly-Q variation was notassociated with latitude; however, there was an association between Clock poly-Qallele diversity and the degree of clutch size decline within breeding seasons. Wedid not find evidence for an association between Clock poly-Q variation and dateof clutch initiation in for any of the five Tachycineta species, nor did we found arelationship between incubation duration and Clock genotype. Thus, there is nogeneral association between latitude, breeding phenology, and Clock polymorphismin this clade of closely related birds.