トリースピン・スティクルバックの主要な装甲遺伝子に対する自然選択

Rowan D H Barrett¹, Sean M Rogers, Dolph Schluter

¹Zoology Department and Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada. rbarrett@zoology.ubc.ca

Science (New York, N.Y.)

|August 30, 2008

まとめ

選択により,淡水に適応した三脊椎スティックルバック魚の低プレートアレルが好まれました. 縮小した横板に結びついたこのアレルは,おそらく成長の利点を提供し,一世代に渡ってその頻度の増加を促した.

科学分野:

進化生物学の進化生物学について
遺伝学遺伝学とは
エコロジーエコロジーエコロジー

背景:

適応的進化は,自然選択によって引き起こされる遺伝子周波数の変化を伴う.
Ectodysplasin遺伝子のローカスは,三脊椎のスティックバック魚の横板の発達に影響を与えます.
誘導性アレル (低) 還元プレート番号は,海洋の祖先から生まれた淡水スティックルバックの集団で繰り返し現れる.

研究の目的:

選択が三脊椎のスティックルバックのEctodysplasinロカスに及ぼす影響を実験的に推定する.
淡水環境の植民期における適応の遺伝的メカニズムを理解する.

主な方法:

祖先 (完全) と派生 (低) のエクトディスプラシンアレルの両方を運ぶ海洋スティックルバック魚は,淡水池に移植されました.
ゲノタイプ頻度は1世代にわたってモニタリングされ,アレル流行の変化を追跡しました.

主要な成果:

横板の縮小に関連した低アルレルは,淡水環境で頻度が増加しました.
この増加は,横板が発達した後に観察され,成長に関連している可能性が高いフィットネス優位性を示唆しています.
異なった選択圧力は,幼虫の段階で観察され,フィットネスの優位性は,魚の生涯にわたって変化した.

結論:

Ectodysplasin locusは,スティックルバックの淡水適応過程で選択されている.
観察されたアレル頻度の変化は,低アレルによる幼虫後の発達による成長の利点を示唆しています.
複雑な選択パターンは,プレオトロピーや,遺伝的位置を結びつける選択を示唆する可能性があります.

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