據(jù)9月25日的《科學(xué)》雜志報(bào)道說,幫助君王蝶遷徙的24小時(shí)不停走動(dòng)的"時(shí)鐘"在太陽(yáng)于天空中移動(dòng)的時(shí)候一直處于運(yùn)行狀態(tài);與過去人們所以為的不同,,該"時(shí)鐘"位于這種蝴蝶的觸須之中,而非其腦中,。君王蝶在其秋季的從北美不同地區(qū)遷徙到墨西哥的過程中,,它們會(huì)利用太陽(yáng)的位置來計(jì)算它們應(yīng)該前去的地方,并在一天的過程中,,隨著太陽(yáng)位置的改變,,其內(nèi)置的"時(shí)鐘"會(huì)校正它們所做的計(jì)算。 君王蝶在其腦中確實(shí)也有一個(gè)生物鐘,。人們一般假設(shè)這一生物鐘是該蝴蝶巡航時(shí)的主要計(jì)時(shí)裝置,。但在50年前的某些觀察表明,該蝴蝶的觸須起著更為重要的作用,。
為了研究這一問題,,Christine Merlin及其同僚用手術(shù)方法切除了某些君王蝶的觸須,并將這些蝴蝶栓住,,接著將它們放在一個(gè)飛行模擬器中在戶外飛行,。 這些蝴蝶失去了它們正常的西南方向的導(dǎo)向,即使它們腦中的時(shí)鐘分子仍然能夠顯示正常的時(shí)間,。 進(jìn)一步的實(shí)驗(yàn)包括了將其它君王蝶的觸須用黑色或透明的瓷漆覆蓋,。這些實(shí)驗(yàn)表明,該蝴蝶觸須中的生物鐘提供了主要的以太陽(yáng)為羅盤導(dǎo)向的定時(shí)機(jī)制,。 正如一則相關(guān)的Perspective所提出的,,人們對(duì)君王蝶觸須中的生物鐘與腦中的生物鐘之間的聯(lián)系之確切的性質(zhì)仍然不清楚。 Merlin及其共同作者說,,其它用太陽(yáng)來導(dǎo)航的昆蟲可能也以同樣的方法來使用其觸須,。(生物谷Bioon.com)
生物谷推薦原始出處:
Science 25 September 2009:DOI: 10.1126/science.1176221
Antennal Circadian Clocks Coordinate Sun Compass Orientation in Migratory Monarch Butterflies
Christine Merlin, Robert J. Gegear, Steven M. Reppert*
During their fall migration, Eastern North American monarch butterflies (Danaus plexippus) use a time-compensated Sun compass to aid navigation to their overwintering grounds in central Mexico. It has been assumed that the circadian clock that provides time compensation resides in the brain, although this assumption has never been examined directly. Here, we show that the antennae are necessary for proper time-compensated Sun compass orientation in migratory monarch butterflies, that antennal clocks exist in monarchs, and that they likely provide the primary timing mechanism for Sun compass orientation. These unexpected findings pose a novel function for the antennae and open a new line of investigation into clock-compass connections that may extend widely to other insects that use this orientation mechanism.
1 Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.