調査地点のサンゴ礁

A）ヒトデの後期原腸胚の口陥部で働く遺伝子。これらの多くはシュペーマン・オーガナイザー（形成体）で発現する。(B) 脊索動物の背側構造（脊索と底板）で発現する遺伝子群（左）と水腔動物の口陥部分（Aの波線部で横断図）で発現する遺伝子群（右）の比較。相同遺伝子が数多く発現することから、水腔動物の口陥部分は脊索動物の背側構造部分と相同と言える。

The scientists took a local flight to Fakarava airport where they boarded a boat to Taiaro Atoll. Both Fakarava and Taiaro are part of the Tuamotu Archipelago, which includes the largest chain of atolls in the world.

 A diver secures a buoy to measure the temperature. Credit: Pascal Kobeh

Atolls are ring-shaped islands that form in the tropics and subtropics from the buildup of coral reefs atop an underwater landmass. The shape of the island usually forms a lagoon. The lagoons are often connected to the outside ocean by passes but Taiaro Atoll, located in French Polynesia, is unique. Its lagoon is fully enclosed. With a temperature of around 0.5-1.0°C warmer than the surrounding ocean, this lagoon provides scientists with a natural laboratory to answer questions about climate change and evolution. Credit: Pascal Kobeh

脊索動物（ヒトを含む）の背側神経系を作りだす遺伝子はイトマキヒトデ（水腔動物の中の棘皮動物）の繊毛帯を作り出すように働いている。つまり、この二つの領域は相同であることが分かる。