分子生物学 Molecular Biology 先進理工学科 2年生必修科目・自己紹介担当：瀧真清・予習：副教材（カラー版）のパスワード：biology URL: http://tkl.pc.uec.ac.jp/ ・授業：副教材（白黒版）は、授業当日にも紙で配布します。 1 成績評価方法・基準 • 方法：期末テスト 50% 中間テスト 30% 小テスト・出席 20% • 合格の最低基準： 1）細胞の種類・構造・役割 2）遺伝子と蛋白質との関係 3）多細胞生物における遺伝子の役割を理解していること。 • テストは、教科書に書かれている内容から出します。 2 • 副教材は、理解を補助する役割（位置づけ） •教科書：コア講義・分子生物学（田村隆明著、裳華房） •参考書： 1. アメリカ版大学生物学の教科書第3巻分子生物学（D・サダヴァ等著、講談社ブルーバックス） 2. よくわかる分子生物学の基本としくみ（井出利憲著、秀和システム） 3. ゆかいな生物学（フランク・H・ヘプナー著、黒田玲子訳、朝倉書店） 4. 細胞の分子生物学, 第5版. Bruce Alberts著/ 中村桂子, 松原謙一監訳. ニュートンプレス, 2010. (Molecular Biology of the Cellの和訳) Harvard Medical School, Caltechその他で使われている本教科書から抜き出して副教材とします。 3 スライドの復習・発展学習のために図の出典を明記しますので、適宜図書館等で参照ください。本日の内容： ★生物とは？？生物の特徴（の基本）： ① 自己増殖能を持つ。 ② 遺伝現象を示す。 ③ 柔らかく水を含む細胞からなる。 ★分子生物学の概念：分子生物学では、全ての生物をたった3種類に分類する。分類基準は、細胞や分子の(ミクロな)形態であり、肉眼で見える生物の（マクロな）形態ではない。 4 教科書 1.2.1 卵細胞の遺伝情報が、多細胞生物の個体の性質を決めるミクロマクロ 5 Figure 1-1 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 教科書 1.2.2 分子生物学における生物の分類：生物を外見ではなく、遺伝子（DNAプログラム）の類似性によって分類する。とうもろこしぞうりむしみどりむし 6 Figure 1-21 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 表 1.1 コレラ菌（原核生物；核を持たない生物）原形質膜細胞壁鞭毛リボソーム（蛋白質合成装置） 7 Figure 1-18a Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 表 1.1 出芽酵母（真核生物）： ↓核（DNAを閉じ込める場所）ミトコンドリア分子生物学の視点では、パン酵母も人間も同じ分類に入る。 8 Figure 1-42 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 真核生物のDNA：核内でヒストン蛋白質に巻きついて圧縮されている。 9 Figure 4-31 Molecular Biology of the Cell (© Garland Science 2008) 表 1.1 真核生物の染色体：教科書 1.2.2 表 1.1 「1本鎖DNA－蛍光物質結合体」を用いた染色体の蛍光染色 Figure 4-10 Molecular Biology of the Cell (© Garland Science 2008) 10 紡錘体微少管は緑、セントロメアは赤、染色体DNAは青に染色 Figure 9-15 Molecular Biology of the Cell (© Garland Science 2008) 教科書11 1.2.2 表 1.1 によって揺れる生物の定義教科書 1.3.2 発展 →真核生物と同じ特徴。「ヒトの起源」仮説も？出典：2013.09.23 朝日新聞 12 Science, 2013年7月号 12.1 Cell Compartments: High voltage electron microscopy allows three-dimensional imaging of a segment of this insulin secreting pancreatic cell. Relatively thick slices of the cell are viewed in the microscope from different angles, which allows us to reconstruct a three-dimensional image. Stepping through the image from the top reveals the complexity of cell structure. Focusing on the Golgi apparatus, individual membranes can be traced, and we can appreciate the size and shape of various compartments. Using these outlines, a computer can construct a three-dimensional model of the entire segment. Here we see the stacks of the Golgi apparatus, each traced in a different color. The cis Golgi, where proteins are first delivered to the organelle, is light blue and the trans Golgi network, where they exit, is light blue. Shown in dark blue are the secretory vesicles into which insulin gets packaged after leaving the trans Golgi network. Many little transport vesicles, shown in white, surround the Golgi apparatus. They transport cargo between the cisternae or back to the endoplasmic reticulum. When all the other organelles are combined into a single image, we can see the incredible crowding of organelles in the cytosol. Here, mitochondria and microtubules are colored green. Endoplasmic reticulum and ribosomes are shown in yellow. The purple organelles are probably endosomes. Given this apparent clutter, one cannot help but wonder how all these components work in synchrony to allow the cell to achieve its tasks. 教科書13 1.3.2 図 1.3 謎多きミトコンドリア Figure 1-33 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 教科書 141.3.2e 図 1.3 謎多きミトコンドリア古代の真核生物膜真核生物のできあがり？核古細菌？原核生物？ Figure 1-34 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 教科書 1.3.2e 15 図 1.3, p.8コラム 14.1 Tomogram of Mitochondrion A mitochondrion contained in a one-half micrometer thick section of chicken brain is viewed with a high voltage electron microscope. When the section is tilted in the microscope, it can be viewed from many different angles, and a large amount of three-dimensional detail becomes apparent. Images from such a series of tilted views can be used to calculate a three-dimensional reconstruction, or tomogram, of the mitochondrion. The tomogram of the same tissue slice is shown here as a series of stacked images. The movie steps through the images one by one, from the bottom of the stack, to the top, and back. This allows us to trace individual membranes in three-dimensions. To create a three-dimensional model, membranes in an individual slice of the tomogram are traced. In this case the inner membrane is traced in light blue, where it parallels the outer membrane, and traced in yellow, where it folds into the cristae that protrude into the mitochondrial interior. The tracings from all sections are then modeled as three-dimensional surfaces, and displayed as a three-dimensional model by a computer program. Such a model can now be viewed from any angle. In this view, only four cristae are shown and the others are omitted. The cristae are colored differently and show the variety of shapes and connections to the inner membrane in a single mitochondrion. The model also shows the reconstitution of the outer mitochondrial membrane, represented in dark blue, as well as two fragments of endoplasmic reticulum. Regions of such close proximity between the two organelles are quite frequently seen in cells. Note that there is no continuity between the mitochondrial and endoplasmic reticulum membranes. Lipids are thought to be shuttled between the two organelles by special carrier proteins that operate in this gap. 教科書 161.3.2e 図 1.3 謎多き葉緑体植物細胞？さらにそこに、光合成細菌？ Figure 1-36 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 葉緑体？教科書 171.3.4 図 1.3 葉緑体クロロフィル分子を含む膜内膜外膜植物細胞 Figure 1-35 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 教科書 181.3.4 図 1.3 教科書 1.3.3 1.1 Keratocyte Dance Keratocytes, found on the scales of fish, are specialized for very rapid motility in order to heal scratches. 1.2 Crawling Amoeba This single-celled amoeba crawls around by using actin polymerization to push out pseudopods, or false feet, to explore new territory. At the same time, organelles move in complex patterns within the cell. 1.3 Swimming Eutreptiella Some cells use rather peculiar ways to move, such as this eutreptiella flagellate, which uses both flagella and pronounced cell shape changes to swim. 19 教科書 1.3.3 16.11 Beating Heart Cell Single heart muscle cells spontaneously contract when grown in cell culture. This cell is grown on a flexible rubber substratum. Each time the cell contracts, it pulls on the substratum which becomes wrinkled. Although individual heart cells can beat with their own rhythms, they are coordinated in an intact heart so that all cells beat synchronously. 20 単細胞生物 Figure 1-17 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 教科書 211.3.5 図 1.4 （モデル）多細胞生物ショウジョウバエ（モデル動物）線虫（モデル動物）シロイヌナズナ（モデル植物） Figure 1-46 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 教科書 221.3.6 本日のまとめ：生物の基本単位ー細胞真核生物ならほとんど皆同じ 23 Figure 1-30 Molecular Biology of the Cell, Fifth Edition (© Garland Science 2008) 分子生物学の基本的な考え方：細胞とは生物の最小単位である（非常に複雑）。生物は分子（化学物質；特に蛋白質などの有機化合物）からなる。分子同士は集まってシステム（分子ナノマシン）を形成している。それらは、遺伝子(DNA)によってプログラムされている。 24