microtubule organizing center

Examples of microtubule organizing center in the following topics:

• Centrosome

  • The centrosome is an organelle that is the main microtubule organizing center of the animal cell and a regulator of cell-cycle progression.
  • In cell biology, the centrosome is an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell as well as a regulator of cell-cycle progression.
  • Fungi and plants use other MTOC structures to organize their microtubules.
  • Unlike centrioles, centrosomes are required for survival of the organism.
  • Microtubules are anchored at the centrosomes.

• Intermediate Filaments and Microtubules

  • As their name implies, microtubules are small hollow tubes.
  • Microtubules are the largest element of the cytoskeleton.
  • In animal cells, the centrosome is the microtubule-organizing center.
  • This is an appropriate name because a single flagellum or cilium is made of a ring of nine microtubule doublets surrounding a single microtubule doublet in the center .
  • This transmission electron micrograph of two flagella shows the 9 + 2 array of microtubules: nine microtubule doublets surround a single microtubule doublet.

• Comparing Plant and Animal Cells

  • While both animal and plant cells have microtubule organizing centers (MTOCs), animal cells also have centrioles associated with the MTOC: a complex called the centrosome.
  • The centrosome is a microtubule-organizing center found near the nuclei of animal cells.
  • Each centriole is a cylinder of nine triplets of microtubules.
  • Each centriole is a cylinder made up of nine triplets of microtubules.
  • Nontubulin proteins (indicated by the green lines) hold the microtubule triplets together.

• Replicative Cycle of Influenza A

  • It is known that virions converge to the microtubule organizing center, interact with acidic endosomes, and finally enter the target endosomes for genome release.

• Characteristics of Eukaryotic Cells

  • Because a eukaryotic cell's nucleus is surrounded by a membrane, it is often said to have a "true nucleus. " Organelles (meaning "little organ") have specialized cellular roles, just as the organs of your body have specialized roles.
  • In prokaryotes, DNA is organized into a single circular chromosome.
  • The centrosome is a microtubule-organizing center found near the nuclei of animal cells while lysosomes take care of the cell's digestive process.

• Binary Fission

  • Binary fission is the method by which prokaryotes produce new individuals that are genetically identical to the parent organism.
  • For unicellular organisms, cell division is the only method used to produce new individuals.
  • In unicellular organisms, daughter cells are individuals.
  • A septum is formed between the nucleoids, extending gradually from the periphery toward the center of the cell.
  • FtsZ proteins can form filaments, rings, and other three-dimensional structures that resemble the way tubulin forms microtubules, centrioles, and various cytoskeletal components.

• The Mitotic Phase and the G0 Phase

  • Microtubules that will eventually form the mitotic spindle extend between the centrosomes, pushing them farther apart as the microtubule fibers lengthen.
  • The proteins of the kinetochore attract and bind mitotic spindle microtubules.
  • Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached.
  • There, the vesicles fuse and coalesce from the center toward the cell walls; this structure is called a cell plate.
  • A cell plate formed by the fusion of the vesicles of the phragmoplast grows from the center toward the cell walls and the membranes of the vesicles fuse to form a plasma membrane that divides the cell in two.

• Meiosis I

  • The centrosomes, which are the structures that organize the microtubules of the meiotic spindle, also replicate.
  • Microtubules grow from centrosomes placed at opposite poles of the cell.
  • The microtubules move toward the middle of the cell and attach to one of the two fused homologous chromosomes at the kinetochores.
  • In anaphase I, the microtubules pull the attached chromosomes apart.
  • In some organisms, the chromosomes decondense and nuclear envelopes form around the chromatids in telophase I.

• Development of Nervous Tissue

  • In vertebrates, the first sign of the nervous system is the appearance of a thin strip of cells along the center of the back, called the neural plate .
  • In the early 20th century, a set of famous experiments by Hans Spemann and Hilde Mangold showed that the formation of nervous tissue is "induced" by signals from a group of mesodermal cells called the organizer region.
  • As shown in a 2008 study, one factor common to all bilateral organisms (including humans) is a family of secreted signaling molecules called neurotrophins which regulate the growth and survival of neurons.
  • Because neurotrophins have now been identified in both vertebrate and invertebrates, this evidence suggests that neurotrophins were present in an ancestor common to bilateral organisms and may represent a common mechanism for nervous system formation.
  • F-Actin in red, Microtubules in green.

• Fluorescence Microscopy

  • Staining organisms with these special dyes reduces the non-specific autofluorescence that some organisms can emit.
  • Cells or organisms stained with fluorochromes appear colored against a dark background when fixed on a glass slide .
  • Nuclei are stained blue with DAPI, microtubules are stained green by an antibody bound to FITC and actin filaments are labelled red with phalloidin bound to TRITC.