まとめ
研究者らは,感染したハムスターの脳から,スクレイピー病原体であるPrP 27-30の主要なタンパク質を特定しました. このタンパク質は,哺乳類の単一の遺伝子によってコードされ,感染性スクラピー粒子自体によって運ばれることはありません.
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- スクラピー病は伝染性スポンジ状脳症である.
- 精製されたスクラピー病剤の主要タンパク質はPrP 27-30です.
- PrP 27-30の起源と遺伝的根拠は完全に理解されていません.
研究 の 目的:
- PrP27-30をコードする遺伝子をクローンする.
- 正常な脳とスクレイピーに感染した脳におけるPrP 27-30の遺伝的基礎を調査する.
- PrP 27-30 がスクラピー・プリオン内の核酸によってコードされているかどうかを判断する.
主な方法:
- オリゴヌクレオチドプローブとcDNAライブラリスクリーニングでPrP27-30をクローンする.
- PrP遺伝子を分析するサザン・ブロッティング.
- mRNA分析と,特定の抗血清剤によるウェスタン・ブロッティング.
- プロテインアゼKの消化により,PrPの形態を区別する.
主要な成果:
- PrP 27-30をコードするクローンは,スクラピーに感染したハムスターの脳から分離された.
- サザン・ブロッティングでは,正常なハムスター,マウス,ヒトのDNAと感染したハムスター,マウス,ヒトのDNAに1つのPrP遺伝子が含まれていることが判明しました.
- PrPに関連したmRNAは,正常な脳と感染した脳,および他の組織で同様のレベルに存在していました.
- PrPに関連したタンパク質は,正常な脳と感染した脳の両方の抽出物で検出されましたが,感染した脳におけるプロテアゼKの消化に抵抗したのはPrP 27-30のみでした.
- 浄化されたスクラピー・プリオンには,PrPに関連した核酸は見つかりませんでした.
結論:
- PrP 27-30は単一の宿主遺伝子によってコードされます.
- PrP遺伝子は哺乳類の種にわたって保存されています.
- PrP 27-30は宿主タンパク質であり,スクラピー病原体の核酸によってコード化されていません.
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