成長板の発達調節について
1Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114-2696, USA. kronenberg.henry@mgh.harvard.edu
Nature
|May 16, 2003
まとめ
脊椎動物の骨格は,水母とは異なり,成長のために内分泌骨の形成を利用しています. 最近の進歩は,この骨の発達プロセスにとって重要なシグナル伝達経路と転写因子を明らかにしています.
科学分野:
- 骨格生物学 骨格生物学とは
- 発達生物学 発達生物学とは
- 比較解剖学の比較解剖学について
背景:
- 脊椎動物は,重要な臓器の動きと保護のためのレバーとして機能する骨からなる複雑な骨格を持っています.
- 脊椎動物における骨の発達は,主に軟骨介質を含むプロセスである内軟骨骨化に依存しています.
- 腸内軟骨形成を制御する分子機構の理解において,著しい進展がみられた.
研究 の 目的:
- 脊椎動物における内軟骨骨形成に関する現在の理解を要約します.
- 骨格の発達に関与する重要な信号伝達経路と転写因子を強調する.
- 保存された形成プロセスにもかかわらず,骨の形状と大きさの多様性を強調するために.
主な方法:
- 腸内軟骨化に関する最近の文献のレビュー.
- 信号経路の分析 (Wnt,BMP,FGFなど).
- 重要な転写因子 (Runx2, Sox9など) を特定する.
主要な成果:
- 腸内軟骨化 (endochondral ossification) は,脊椎動物全体で保存されているプロセスであり,多様な骨格構造を生成します.
- 特定のシグナル伝達経路と転写因子は,軟体細胞の分化と骨マトリックス堆積を指揮する.
- これらの分子制御を理解することは,骨格の発達と潜在的な障害を理解するために不可欠です.
結論:
- 脊椎動物の骨格の発達は,複雑な分子シグナリングを含む高度に規制されたプロセスです.
- 腸内軟骨の骨形成に関する継続的な研究は,骨格の進化と病気の洞察を約束します.
- 脊椎動物の特徴的な骨格構造は,水母のような無脊椎動物と比較すると,この特殊な骨の発達の結果である.
関連する概念動画
02:36Cells Coordinate Growth and Proliferation
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
01:24Regulation of Angiogenesis and Blood Supply
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
01:27Growth of Cartilage and Bone Tissue
Chondrocytes form a temporary cartilaginous model by dividing and secreting a thick gel-like extracellular matrix. Once the chondrocytes undergo programmed cell death, osteoblasts enter the site of the cartilaginous model. The process of replacing the temporary cartilaginous model with bone in an ordered manner is called endochondral ossification. In endochondral ossification, not all of the cartilage is replaced by bone tissue. Some cartilage that performs a protective and supportive function...
01:17Hormones and Bone Tissue
The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
01:09Changes in the Appendicular Skeleton with Age
The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
01:24Bone Formation by Endochondral Ossification
Bone formation, or ossification, begins around the sixth to seventh week of embryonic development. Most bones develop from a cartilaginous template through the process of endochondral ossification. Cartilage formation begins when clusters of mesenchymal cells differentiate into chondrocytes. These chondrocytes proliferate rapidly and secrete an extracellular matrix that becomes encased in a membrane called the perichondrium. The resulting cartilage model provides a template that resembles the...