The Cell - Challenges in Delivery of Therapeutic Genomics and Proteomics - page 29

(A) Centrosome (B)

Fragmented
Nuclear envelope

Forming mitotic
spindle

Kinetochore

Kinetochore
microtubules

Intact nuclear envelope

(C) (D)

Daughter
chromosomes

Chromosomes lined at
the equatorial plane

Shortening
kinetochore
microtubule

(E) (F)

Completed
nuclear
envelope

Contractile ring
creating cleavage
furrow

Nuclear envelope
formation initiates

Figure 1.13 Different stages of the M phase: (A) prophase; (B) prometaphase; (C) metaphase;
(D) anaphase; (E) telophase; and (F) cytokinesis.

Telophase
Telophase is marked by the disappearance of kinetochore microtubules and the
arrival of the separated chromatids in the polar region. The nuclear envelope reforms
at the poles, and nucleolus starts to appear ( Fig. 1.1 E). The chromosomes once
again assume the relaxed chromatin form, but the polar microtubules still elongate.
This is the last phase of mitosis.

Cytokinesis
Cytoplasm division by cleavage is initiated during anaphase. In the equatorial plane
of the polar spindle and perpendicular to spindle axis, a cleavage furrow develops by