Table Of ContentPhotograph by Ruth Mayerson Gilbert
DANIEL MAZIA
ICN-UCLA Symposia on Molecular and Cellular Biology
Volume XII, 1978
CELL REPRODUCTION:
IN HONOR OF
DANIEL MAZIA
edited by
ELLEN R. DIRKSEN
Department of Anatomy
University of California, Los Angeles
Los Angeles, California
DAVID M. PRESCOTT
Department of Molecular, Cellular, and Developmental Biology
University of Colorado
Boulder, Colorado
C. FRED FOX
Department of Microbiology and Molecular Biology Institute
University of California, at Los Angeles
Los Angeles, California
ACADEMIC PRESS New York San Francisco London 1978
A Subsidiary of Harcourt Brace Jovanovich, Publishers
ACADEMIC PRESS RAPID MANUSCRIPT REPRODUCTION
Proceedings of the ICN-UCLA 1978 Spring Symposia on Molecular and
Cellular Biology held in Keystone, Colorado, March 1978
COPYRIGHT © 1978, BY ACADEMIC PRESS, INC.
ALL RIGHTS RESERVED.
NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR
TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC
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ACADEMIC PRESS, INC.
Ill Fifth Avenue, New York, New York 10003
United Kingdom Edition published by
ACADEMIC PRESS, INC. (LONDON) LTD.
24/28 Oval Road, London NW1 7DX
Dirksen et al.
Library of Congress Cataloging in Publication Data
Main entry under title:
Cell reproduction.
(ICN-UCLA symposia on molecular and cellular
biology ; v. 12)
Proceedings of a symposium held Mar. 19-24,
1978 in Keystone, Colo.
Includes index.
1. Cell cycle—Congresses. 2. Cellular
control mechanisms—Congresses. 3. Cell
proliferation—Congresses. 4. Mazia, Daniel,
Date I. Mazia, Daniel, Date II. Dirksen,
Ellen R. III. Prescott, David M., Date
IV. Fox, C.Fred. V. Series.
QH605.2.C44 574.8'762 78-14051
ISBN 0-12-217850-5
PRINTED IN THE UNITED STATES OF AMERICA
Preface
In March 1978, a symposium entitled "Cell Reproduction," was held in
Keystone, Colorado to honor Daniel Mazia. This volume represents the pro-
ceedings of this meeting. In planning this conference, we, the organizers,
invited former and present graduate students, postdoctoral fellows, and as-
sociates of Daniel Mazia, as well as colleagues whose works derive from
similar scientific lineage.
In organizing this symposium, several methods of formal presentation as
well as the usual informal discussions, made possible by the comfortable
setting at Keystone, were utilized. There were five morning plenary ses-
sions, each focusing on a major research area and involving a total of 18
speakers. On the first three evenings, nine separate workshops were held in
which 36 participants presented their current work, after which there was a
general discussion of the topic of the workshop. In addition, 85 abstracts
were contributed for poster presentations, which were held during the late
afternoons. And, finally, Daniel Mazia, in a special session, presented a bril-
liant synthesis of all the scientific threads that began in his laboratory and
united those of us present.
This conference and the volume it has generated are truly unique, since
few biologists anywhere have produced so many disciples as to fill a week-
long conference with reports of their current research. It is noteworthy to
mention that most of the areas of research that were discussed at the confer-
ence and appear in this volume had their origins in Dan Mazia's laboratory,
having been stimulated by his thinking, his intuition, and his philosophical
approach to science. The impetus and enthusiasm for science, in general,
and cell biology in particular, that he has imparted to those of us who were
fortunate to have had our beginnings in his laboratory have been enduring.
Few biologists have a comparable record of accomplishment in the teaching
and training of scientists; and many of those he trained are now among the
XII PREFACE
major contributors to cell research. Through his own research as well, Dan
Mazia has had a profound impact on our understanding of the structure and
workings of the cell. Thus, this volume represents a tribute to Daniel
Mazia's extraordinary contributions as teacher, scientist, and friend.
Acknowledgments
Many people worked extremely hard to make this meeting possible and a
success. From start to finish, Fran Stusser was involved in the planning and
implementation of the program. To her, in particular, we owe a considerable
debt. We also wish to thank her able staff for the many chores done during
the two years it took to bring the idea of this symposium to fruition. Peter
Linsley and Sidney Suggs are to be commended for their excellent work in
handling the various visual aids during the meeting. Everything possible was
done by the symposium staff to facilitate communication among the par-
ticipants during the meeting, and for this we are grateful.
Photographs: Joyce Ellis and Ellen Dirksen
(First row) Kiefer, Wolfe, Dirksen, Fulton/ Bryan
(Second row) Perry, Prescott/ Mitchison, Petzelt/ Harris
(Third row) Runnstrom-Reio, Mazia/ Hinegardner/ Zimmerman
(Fourth row) Wilson/ Wahrman/ Brinkley/ Swift
(First row) Went, Dan/ Paweletz/ de Terra
(Second row) Gontcharoff, Murphy/ Porter/ Sakai
(Third row) Ezell, Clarke/ Jensen, Cande/ Candelas/ Rustad
(Fourth row) Sluder, Ellis/ Schatten/ Gelfant
(First row) Hayashi, Rebhun/ Child/ James
(Second row) Zeuthen/ Burns, Inoue/ Margolis/ Bücher
(Third row) Goldstein/ Epel/ Bibring/ Rosenbaum, Lederberg
(Fourth row) Blumenthal/ Weisenberg/ Warner/ Vacquier
CELL REPRODUCTION
ORIGIN OF TWONESS IN CELL REPRODUCTION
Daniel Mazia
Department of Zoology, University of California,
Berkeley, California 9^720
ABSTRACT The concept of the cell cycle is reconsidered.
Without rejecting the supposedly typical sequence of
phases as a useful calendar, the cycle is described as
a bicycle with a Reproductive Wheel and a Growth Wheel.
From this point of view, it is seen that the turn of the
Reproductive Wheel is inherently rapid and that the re-
gulation of real cycles should be viewed in terms of
processes on the Growth Wheel which retard the Reproduc-
tive Wheel. In free-running cycles, the initiation of
chromosome replication depends on the final stages of
decondensation of the chromosomes after mitosis. The
chromosome cycle runs through the whole cell cycle;
chromosomes continue to decondense after telophase; they
reach maximum de con den sat ion at the onset of chromosome
replication and recondense as they replicate. Condensa-
tion during mitosis only representsthe final orders of
folding or coiling of the chromosomes. This older spe-
culation is now well-supported by facts. Given repli-
cated chromosomes, the second problem of making two cells
from one is bipolarization, the establishment of mitotic
poles. The older hypothesis that bipolarization results
from the reproduction, splitting and pushing-apart of
sister mitotic centers, probably by elongation of micro-
tubules, is reexamined. The case considered in detail
is the induction of mitotic centers in parthenogeneti-
cally-activated eggs, about which some new research is
reported. In its ideal untrammeled form , the reproductive
cycle of the cell consists of: (l) a continuous cycle
of decondensation and condensation of the chromosomes ,
with replication governed by the last stage of deconden-
sation and (2) the reproduction of the mitotic centers
with bipolarization following the splitting-apart of
sister centers.
"Work by the author was supported by NIH grant GM-13882.
Copyright© 1978 by Academic Press, Inc.
1 All right of reproduction in any form reserved.
ISBN 0-12-217850-5
