Related Experiment Video
Updated: Aug 1, 2026
07:47
Microscopy of Fission Yeast Sexual Lifecycle
Published on: March 9, 2016
Mitosis in the cellular slime mold Polysphondylium violaceum
The Journal of Cell Biology
|February 1, 1975
Summary
This study details the unique mitosis process in Polysphondylium violaceum, highlighting a persistent nuclear envelope and extranuclear spindle pole bodies (SPBs). These findings offer insights into microtubule dynamics during cell division.
Area of Science:
- Cell Biology
- Microbiology
- Mycology
Background:
- Polysphondylium violaceum is a model organism for studying cellular processes.
- Understanding mitosis is crucial for comprehending cell division and genetics.
Purpose of the Study:
- To elucidate the intricate mechanisms of mitosis in Polysphondylium violaceum.
- To characterize the behavior of nuclear structures and microtubules during cell division.
Main Methods:
- Culturing of Polysphondylium violaceum myxamebas in liquid medium.
- High-resolution electron microscopy for ultrastructural analysis.
- Observation of mitotic stages, including prophase, metaphase, anaphase, and telophase.
Main Results:
- Mitosis features a persistent nuclear envelope, extranuclear spindle pole bodies (SPBs), and a spatially separated central spindle.
- SPBs originate from an electron-opaque body and migrate to opposite poles, facilitating microtubule organization.
- Chromosomes exhibit amphitelic orientation at metaphase, with distinct kinetochores and nucleoli dispersion.
Conclusions:
- The observed mitotic process in P. violaceum is distinct, with unique SPB dynamics and nuclear envelope behavior.
- The study provides a detailed ultrastructural account of microtubule organization and chromosome segregation.
- Findings contribute to understanding the diversity of mitotic mechanisms across eukaryotes.
Related Concept Videos
02:03Mitosis and Cytokinesis
In eukaryotes, the cell division cycle is divided into distinct, coordinated cellular processes that include cell growth, DNA replication/chromosome duplication, chromosome distribution to daughter cells, and finally, cell division. The cell cycle is tightly regulated by its regulatory systems as well as extracellular signals that affect cell proliferation.
The processes of the cell cycle occur over approximately 24 hours (in typical human cells) and in two major distinguishable stages. The...
The processes of the cell cycle occur over approximately 24 hours (in typical human cells) and in two major distinguishable stages. The...
01:57Meiosis II
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing...
02:13Determining the Plane of Cell Division
Positioning the cell division plane is a critical step during development and cell differentiation, particularly during mitosis when the plane is essential for determining the size of the two daughter cells. The cell division plane is perpendicular to the plane of chromosome segregation, but different types of organisms have different cell division mechanisms to suit their morphology and function.
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division starting...
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division starting...
01:59The Phragmoplast
Cell division is essential for organismal growth and development. In animal cells, the central spindle and its associated proteins form the midbody, a structure that has an essential role in cytokinesis. In plants, the central spindle, along with the microtubules, actin, and other cell components, matures into the phragmoplast, which is necessary for cytokinesis. Unlike the stationary midbody, the phragmoplast expands centrifugally, eventually leading to the formation of the new cell wall.
The...
The...
02:02Meiosis II
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
01:35Mitosis and Cytokinesis
In eukaryotes, the cell division cycle is divided into distinct, coordinated cellular processes that include cell growth, DNA replication/chromosome duplication, chromosome distribution to daughter cells, and finally, cell division. The cell cycle is tightly regulated by its regulatory systems as well as extracellular signals that affect cell proliferation.
The processes of the cell cycle occur over approximately 24 hours (in typical human cells) and in two major distinguishable stages. The...
The processes of the cell cycle occur over approximately 24 hours (in typical human cells) and in two major distinguishable stages. The...