MORPHOGENESIS IN STENTOR
V A N C E T A R T A R f
Department of Zoology, University of Washington, Seattle, U.S.A.
I. Introduction
1
I I . Development of New Individuals in Stentor
2
A. The Normal Form
2
B. Origin of Two Stentors from One in Division
3
C. Reorganization of an Individual
4
D. Regeneration
4
I I I . Adjustment of Proportionality and Arrangement of Parts
7
IV. Relation of Cell Elaborations to the Cortical Pattern
9
A. Induction of Membranellar Bands
9
B. Induction of Mouthparts Formation
11
V. Activation and Inhibition of Primordium Formation in Development
12
VI. Upper and Lower Limits to Size of Organizational Mass
14
A. Lower Limits
14
B. Upper Limits
15
VII. Reconstitution of Minced Stentor
17
VIII. Nucleocytoplasmic Interaction
18
A. Cytoplasmic Differentiation without Nuclear Differentiation
18
B. Necessity of the Nucleus for Primordium Formation and Development
19
C. Nuclear Behaviour Governed by the Cytoplasm
20
D. Chimeras
21
IX. Conclusions
22
References
25
I. Introduction
Ciliate protozoa of the genus Stentor have proved to be the most operable of all cells. We can now perform many of the classical experiments
of grafting, transplantation, and transposition on a unicellular organism
whose form should be completely definable and capable of total surveillance in any experimental situation. The mode of morphogenesis,
analysable by such interferences, will be simple and specialized because
it involves neither cellularization nor intercellular relationships; but
since the problem of the development of form is still so much a mystery
we should look for clues in any direction. Whether by contrast or comparison, ciliate studies may supply such hints. Using as our example the
large and exquisite species S. coeruleus, we shall describe the form and
f This investigation was supported by research grant C-3637 from the National Cancer
Institute, U.S. Public Health Service.
1
V A N C E T A R T A R f
Department of Zoology, University of Washington, Seattle, U.S.A.
I. Introduction
1
I I . Development of New Individuals in Stentor
2
A. The Normal Form
2
B. Origin of Two Stentors from One in Division
3
C. Reorganization of an Individual
4
D. Regeneration
4
I I I . Adjustment of Proportionality and Arrangement of Parts
7
IV. Relation of Cell Elaborations to the Cortical Pattern
9
A. Induction of Membranellar Bands
9
B. Induction of Mouthparts Formation
11
V. Activation and Inhibition of Primordium Formation in Development
12
VI. Upper and Lower Limits to Size of Organizational Mass
14
A. Lower Limits
14
B. Upper Limits
15
VII. Reconstitution of Minced Stentor
17
VIII. Nucleocytoplasmic Interaction
18
A. Cytoplasmic Differentiation without Nuclear Differentiation
18
B. Necessity of the Nucleus for Primordium Formation and Development
19
C. Nuclear Behaviour Governed by the Cytoplasm
20
D. Chimeras
21
IX. Conclusions
22
References
25
I. Introduction
Ciliate protozoa of the genus Stentor have proved to be the most operable of all cells. We can now perform many of the classical experiments
of grafting, transplantation, and transposition on a unicellular organism
whose form should be completely definable and capable of total surveillance in any experimental situation. The mode of morphogenesis,
analysable by such interferences, will be simple and specialized because
it involves neither cellularization nor intercellular relationships; but
since the problem of the development of form is still so much a mystery
we should look for clues in any direction. Whether by contrast or comparison, ciliate studies may supply such hints. Using as our example the
large and exquisite species S. coeruleus, we shall describe the form and
f This investigation was supported by research grant C-3637 from the National Cancer
Institute, U.S. Public Health Service.
1