チャンネルキャットフィッシュの嗅覚受容体をコードする遺伝子のファミリー

J Ngai¹, M M Dowling, L Buck

¹Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, College of Physicians and Surgeons, Columbia University, New York, New York 10032.

Cell

|March 12, 1993

まとめ

ネズミと似たキャットフィッシュの嗅覚受容体は,遺伝子が少ないが多様性が高い. それぞれのニューロンは,独特の受容体のサブセットを表現し,脳の匂いの差別を可能にします.

科学分野:

嗅覚神経生物学について
ゲノミクスゲノミクスとは
進化生物学の進化生物学について

背景:

魚の嗅覚システムは,匂いを研究するための簡素化されたモデルを提供します.
嗅覚受容体 (ORs) は,匂いを検知するのに極めて重要です.
ORの多様性と表現を理解することは,嗅覚処理の鍵です.

研究の目的:

カットフィッシュの嗅覚受容体遺伝子を特定し,特徴づけること.
カットフィッシュのORレパートリーを形作る進化的圧力を調査する.
個々の嗅覚ニューロンにおけるORの発現パターンを探求する.

主な方法:

キャットフィッシュの嗅覚受容体ファミリーの遺伝子識別と配列決定.
進化的選択を検出するための系統遺伝分析と核酸配列分析.
嗅覚ニューロンの受容体発現を決定するためのインシットウ・ハイブリダイゼーションまたは同様の技術.

主要な成果:

ネズミのオルファクトリー受容体遺伝子の家族を特定し,ネズミのオルファクトリー受容体遺伝子の同質性を示した.
キャットフィッシュのORレパートリーは,哺乳類の同類動物よりも著しく小さい.
キャットフィッシュのOR遺伝子,特にオドラント結合領域に作用するDarwinian選択の正の証拠.
それぞれの嗅覚ニューロンは,異なる嗅覚受容体の小さな,ユニークなサブセット (0.5%~2%の合計) を表現します.

結論:

キャットフィッシュは独特の嗅覚受容体システムを持ち,多様性に対する進化的適応があります.
限られた受容体レパートリーとユニークなニューロン発現は,匂い知覚のための組み合わせコード化戦略を示唆しています.
このニューロンのアイデンティティメカニズムは,キャットフィッシュの脳が活性化ニューロンパターンに基づいてさまざまな匂いを区別することを可能にする可能性があります.

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