関連する実験動画
Updated: Jul 12, 2026

09:47
Microdissection of Black Widow Spider Silk-producing Glands
Published on: January 11, 2011
デヴォン時代のスピンネレット:クモとシルクの使用に関する初期の証拠
まとめ
蜘蛛の糸の生産に関する最古の証拠は,デボニアン期の化石化したスピナーレットが発見されました. この発見は,クモの起源とシルク生産の起源を何百万年も後退させます.
科学分野:
- パレオントロジー・パレオントロジー
- アラクロノジー アラクロノジー
- 進化生物学の進化生物学について
背景:
- 初期のクモ (Araneae) の化石記録は稀で,決定的な特徴が欠けていることが多い.
- クモに由来する以前のデボニアン期の化石は,クモの重要な特徴の欠如のために疑問視されています.
研究 の 目的:
- 糸を生産する構造を持つ最も古い蜘蛛の化石の発見を報告するために.
- この古代のシルク生産アラクニドの系統的位置を決定するために.
主な方法:
- 中部デボニアン時代の岩石から化石化したスピナーレットの古生物学的発掘と分析.
- 化石化したスピゴットと現存する蜘蛛のサブオーダーとの比較形質学的分析.
主要な成果:
- 約3億8,500万~3億8,800万年前の,ほぼ完全な蜘蛛のスパイネレットは,ニューヨーク州ギルボアの近くで発見された.
- この化石は,オピストソーマル・スパイゴットからシルクが生産された最古の証拠であり,クモとしての地位を確認しています.
- スパイゴットの形態学は,メソテラとオピストテラの両方との親和性を示し,スパイダークラード内の基礎位置を示唆しています.
結論:
- この発見は,クモとシルク生産に関する以前に認められた証拠よりもかなり前のものです.
- この化石は,クモの初期の進化と多様化に関する重要な洞察を提供します.
- 系統遺伝学的な配置からすると,メソテラ (Mesothelae) またはオピストホテラ (Opisthothelae) と呼ばれる他のすべてのクモの姉妹群を代表している可能性があることが示唆される.
関連する概念動画
Spindle Assembly
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
Generation of Straight or Branched Actin Filaments
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Spin–Spin Coupling Constant: Overview
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must have a...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must have a...
The Fossil Record
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
The Mitotic Spindle
The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
Adaptability of Cytoskeletal Filaments
The cytoskeleton is a complex dynamic structure performing varied functions based on cellular requirements. The adaptability of the individual filaments in the cytoskeleton determines their ability to perform various functions within the cell. It can undergo rapid reorganization during processes like cell division or remain stable for several hours as in the interphase. The adaptability of these filaments depends on stringent regulatory mechanisms. The microfilament and microtubules of the...
