lab 9 cell division mitosis - kasetsart...

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