Apparent dissociation of photoperiodic time measurement between vernal migration and breeding under dim green light conditions in Gambel＇s white-crowned sparrow Zonotrichia leucophrys gambelii  

作　　者：Gang WANG Marilyn RAMENOFSKY John C. WINGFIELD 

机构地区：[1]Department of Biology, University of Washington, Seattle, WA 98195, USA [2]Department of Neurobiology Physiology Behavior, University of California, Davis, CA 95616, USA. [3]Shannxi Institute of Zoology & Northwest Institute of Endangered Zoological Species, Xian 710032, Shaanxi, China.

出　　处：《Current Zoology》2013年第3期349-359,共11页动物学报（英文版）

摘　　要：In seasonally breeding birds, the annual cycle of photoperiod is a principal environmental cue for temporal arrange- ment of different life-history stages, such as migration and breeding. In the past, most research has focused on the mechanisms of photoperiodic control of breeding with less attention paid to migration. In Gambel＇s white-crowned sparrow Zonotrichia leuco- phrys gambelii （GWCS）, photoreceptors for induction of breeding are known to reside in the basal hypothalamus. However, it is unknown whether the sites of photoperiodic reception for vernal migration are the same as those for breeding. Therefore, we hy- pothesized that they may be controlled separately. In this study, we exposed photosensitive GWCSs to low-penetration green light （wavelength at 510 nm） under a regime of 1 lux during the day and 〈0.1 lux at night, and switched the photoperiodic conditions from short day （10 h daytime） to long day （18 h daytime）. The results showed that the experimental birds developed traits associ- ated with vernal migration including mass increase, fat deposition and migratory restlessness behavior when transferred from short day to long day green light cycles, while control birds maintained continuously on short day green light conditions did not ex- press any migration related characteristics. Neither experimental nor control groups showed gonadal recrudescence trader either green light cycles. In support of our hypothesis, we were able to apparently dissociate the photoperiodic responses regulating vernal migra- tion and breeding, which suggests separate mechanisms of photoperiodic time measurement. Such distinct photoperiodic mechanisms may drive the free-tuned temporal arrangement of the two life history stages.

关 键 词：Gambel＇s white-crowned sparrow Vernal migration Gonadal recrudescence Photoperiodic time measurement 

分 类 号：S723.33[农业科学—林木遗传育种] S965.325[农业科学—林学]