LIMホメオボックス遺伝子Lhx9は,マウスの性腺形成に不可欠である
O S Birk1, D E Casiano, C A Wassif
1Laboratory of Mammalian Genes and Development, National Institute of Child Health and Human Development, NIH, Bethesda, Maryland 20892, USA.
Nature
|March 8, 2000
まとめ
LIMホメオボックス遺伝子Lhx9は,マウスの性腺発育に不可欠です. 欠乏すると,性腺の形成が妨げられ,雄マウスは雌として発達し,ヒトの性腺発現に役割があることを示唆する.
科学分野:
- 発達生物学 発達生物学とは
- 遺伝学 遺伝学とは
- 生殖生物学 生殖生物学
背景:
- 哺乳類の性腺 (卵巣と丸) は,泌尿器官の脊から発達する.
- 性別決定には,テストステロンやアンチムレリアンホルモンなどのホルモンが含まれており,それは丸によって生成されます.
- LIMホメオボックス遺伝子Lhx9は,胚の発達に役割を果たしています.
研究 の 目的:
- 哺乳類の性腺発達におけるLhx9遺伝子の機能を調査する.
- 性腺の形成と分化におけるLhx9の役割を決定する.
- Lhx9変異とヒトの性腺発現との潜在的な関連性を調査する.
主な方法:
- 胚の発達中のマウスの泌尿器官の脊椎におけるLhx9遺伝子発現を研究した.
- 機能的なLhx9.9が欠けているマウスを生成し,分析した.
- Lhx9欠乏胚における生殖細胞の移動,体細胞の増殖,性腺の形成を評価した.
- Lhx9変異体におけるステロイド生成因子1 (Sf1) の発現を調べました.
主要な成果:
- Lhx9のトランスクリプトは,初期の泌尿器内脊椎に存在し,その後は,発達中の性腺のインタースティシャル領域に存在します.
- Lhx9欠乏症のマウスは正常な生殖細胞の移動を示しているが,体細胞の増殖が欠如しているため,分離性性腺を形成することができない.
- 遺伝的に男性であるLhx9欠乏症のマウスは,フェノタイプ的に女性であり,テストステロンとアンチムレリアンホルモンが欠けている.
- Lhx9-欠乏性生殖器の脊椎では,重要な性腺生成遺伝子Sf1の発現が著しく低下しています.
- Lhx9ミュータントは,他の主要な発達異常は示さない.
結論:
- Lhx9は体細胞の増殖と性腺の形成に不可欠です.
- Lhx9は,Sf1より上流に発達カスケードで作用し,性腺生成を調節する.
- Lhx9の変異は,ヒトにおける単離性ゴナダルの発現の原因である可能性があります.
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