Nucleus and Mitosis VIBS 443602 Structure pancreatic acinar

Nucleus and Mitosis VIBS 443/602

Structure: pancreatic acinar cells Identification: nucleus, nucleolus, heterochromatin 1. Heterochromatin 2. Nucleus 3. Nucleolus

158 Pancreas

32409

32409 Nuclei with nucleoli

Structure: electron micrograph of hepatocyte (EM 5) Identification: nuclear envelope, inner and outer membrane, nuclear pores 1. Nuclear envelope 2. Heterochromatin 3. Euchromatin 4. Nuclear pore

EM 2 b cytoplasm nucleus

Structure: electron micrograph of stomach (EM 15) Identification: honeycomb nucleolus called nucleonema 1. Nucleus 2. Nucleonema

$Structure: freeze etched of small lymphocyte (EM 6) Identification: fracture plane at one of$

Structure: freeze etched of small lymphocyte (EM 6) Identification: fracture plane at one of the nuclear pores jumped from the outer to the inner membrane of the nuclear envelope 1. Inner nuclear membrane 2. Outer nuclear membrane 3. Nuclear pores

102 Mitosis anaphase

102 Mitosis - metaphase

102 Mitosis - anaphase

Three major events ORIENTATION in mitosis ALIGNMENT SEGREGATION

CHROMOSOME MOVEMENT Three contributions 3 Astral microtubules 1 2

Structure: intestinal absorptive cells Identification: nucleus, nucleolus 1. Nuclei 2. Nucleoli 152 201

201 Intestine crypt mitotic activity. 1. Brush border 2. Interphase nucleus 3. Anaphase 4. Artifact

152 duodenum

148

148

148 Ileum

32409

32409 Cells in mitosis

EM 10 f: Arteriolar wall; 30, 000 x. 1. Apical caveolae 2. Collagen 3. Dense bodies 4. Elastic fiber 5. Endothelial cell 6. Nuclear pore 7. RER

EM 19 c: Sertoli cell; 13, 300 x. 1. Golgi 2. Heterophagic vacuole 3. Lipid droplet 4. Microtubule 5. Nuclear pores (cross-section) 6. Sertoli cell 7. Synaptoneural complex

Colchicine treatment – chromosomes do not separate and NE forms around each chromosome due to breakdown of MT. 1. Multinucleated cell

Cytochalasin B treatment – chromosomes separate into two normal size nuclei, but the cytoplasm does not split in two Cytochalasin B treatment-breaks down microfilaments-nucleus activity but cells do not undergo cytokinesis 1. Binucleated cell 2. Nucleolus

EVENTS IN MITOSIS CYTOKINESIS

Nucleus and Mitosis