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Cell Division
Dr. Boonsatien Boonsoong
Department of ZoologyFaculty of Science
Kasetsart University
Mitotic Cell Division
Objective
11 ทราบขั้นตอนการแบงเซลลแบบ mitosis เซลลพืช และเซลลสตัว
22 ฝกเตรียมสไลดสด แบบ squash ของรากหอม
Introduction
Cell divisionreproduction
growthCell Cycle
(cell increase in size, produce mRNA, tRNA, ribosome, protein sythesis)
Gap1
Gap2
(DNA duplication)
(cell grows)G0 or Gap0
Cell Cycle Control• Checkpoint Control
Checkpoints are places in the cell cycle where a cell will be stopped so that it can be checked for mistakes. Hey buddy, I don’t
care whatcha say! I am not letting you
through unless your DNA is correct!
Cell Cycle CheckpointsM
G1G2
S
= DNA Damage Checkpoints
= Spindle Checkpoints
= G1 Checkpoint
= G2 Checkpoint
Eukaryotic Cell Cycle
Source: http://www.cellsalive.com/cell_cycle.htm
Cancer and Cell Cycle
Tumor Suppressor Gene
Cell Division
InterphaseInterphase KaryokinesisKaryokinesis CytokinesisCytokinesis
G1 or Gap1
S or Synthesis
G2 or Gap2
• Mitosis or mitotic cell division- somatic cell- 2n 2n (diploid)
• Meiosis or meiotic cell division
- germ cell- 2n n (haploid)
• Occur in late anaphaseor telophase
• Plant cell - cell plate
• Animal cell - cleavage furrow
non-dividing period dividing period
Mitosis• 2n 2n
• Two daughter cells (2n, diploid)
• Somatic cell
• Zygote mitosis
• Animal cell
• Plant cell - meristematic tissue
Mitosis Animations
Source: http://www.cellsalive.com/mitosis.htm
Mitosis
Mitosis Mitosis: Prophase•The nucleolus fadesand chromatincondenses intochromosomes
•Each replicatedchromosomecomprises twochromatids
•Astral microtubule
Mitosis: Metaphase• The spindle fibers aligns all chromosomes in one plane at the center of the cell
• Equatorial plane
• Karyotype studies
Polar microtubule
Kinetochoremicrotubule
Astralmicrotubule
Centriole
Mitosis: Anaphase
• Spindle fibers shorten, the kinetochoresseparate, and one set of chromosomesmove toward each pole
Mitosis: Telophase• The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear
• Cytokinesis
• The nuclei reforming
• Two daughter cells
cell plate
cleavage furrow
Mitosis in animal and plant cellsmiotic cell division
Mitosis in animal cell Squash technique
zone of cell division ~ 3 mm
5% HCl 5 min.
aceto-orcein10 min.
Allium sp. root tip
ลาง HCl ดวยน้ํา 4-5 ครั้ง
2-3 ครั้ง
Squash technique (cont.)
40x 4x
squashซับสีเกาออกหยดสีใหม 1 หยด
mounting
Permanent slides
Whitefish blastula
• Astral microtubule• Polar microtubule• Kinetochore
microtubule• Cytokinesis
Animal celldivision
Fertilized egg of Ascaris sp.
• Astral microtubule• Polar microtubule• Kinetochore
microtubule• Cytokinesis