クテノフォア Mnemiopsis leidyi のゲノムと,細胞型進化に対するその影響
Joseph F Ryan1, Kevin Pang, Christine E Schnitzler
1Genome Technology Branch, Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Science (New York, N.Y.)
|December 17, 2013
まとめ
クテノフォア (コムゼリー) のゲノム配列解析は,彼らが最も初期の動物の系統であり,スポンジより前のものである可能性があることを明らかにしました. これは,以前の進化モデルに異議を唱え,神経や筋肉のような複雑な細胞タイプの独立した進化を示唆しています.
科学分野:
- * 進化生物学について
- * ゲノミクスについて
- * 海洋生物学について
背景:
- * 初期の動物の進化を理解するには,基礎系統の洞察が必要です.
- *クテノフォア (コムゼリー) は,系統遺伝関係の解明の鍵である.
- *以前の仮説では,スポンジを他のすべての動物の姉妹グループとした.
研究 の 目的:
- *クテノフォア Mnemiopsis leidyi.のゲノムをシーケンシングし,組み立て,注釈する.
- *他のすべての動物の姉妹系統を決定するために,系統解析を行う.
- * 神経細胞と筋肉細胞を含む細胞の進化的起源を調査する.
主な方法:
- * Mnemiopsis leidyi.の全ゲノムシーケンシングとアセンブリについて
- * アミノ酸の位置と遺伝子の含有量の両方を用いた系統遺伝学分析.
- * 比較ゲノミクスを用いて,遺伝子ファミリーや細胞型特異遺伝子を特定する.
主要な成果:
- * 系統遺伝学的分析は,クテノフォアが他のすべての動物の姉妹系統であることを支持し,伝統的なスポンジ姉妹仮説に異議を唱える.
- * Mnemiopsis leidyiのゲノムには,双極性メソダーマ細胞タイプに特有の多くの遺伝子が欠けていて,独立した進化を示唆しています.
- * Mnemiopsis の神経遺伝子のセットは,スポンジに匹敵し,スポンジの潜在的神経系喪失を示しています.
結論:
- *スポンジではなく,クテノフォアは,最も初期の分岐する動物の系統を表している可能性があります.
- * 神経や筋肉のような複雑な細胞タイプの進化は,異なる系統で独立して起こった.
- *この研究は,細胞タイプの著しい損失および/または増加を含む,初期の動物の進化を理解するための新しい枠組みを提供します.
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