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Reader Service No. 553 GENES (Eh DEVELOPMEm

VOLUME 5 NUMBER 2 PAGES 151-330 FEBRUARY 1991

EDITORIAL BOARD [. Adams (Melbourne, Australia) J. Manley (New York, USA) Editors M. Ashbumer (Cambridge, UK) K. Matsubara (Osaka, Japan) T. Grodzicker (Cold Spring Harbor) J. Beckwith (Boston, USA) D. McClay (Durham, USA) N. Hastie (Edinburgh) W. McGinnis (New Haven, USA) W. Bender (Boston, USA) Consultant Editor S. McKnight (Baltimore, USA) P. Berg (Stanford, USA) M. Mathews (Cold Spring Harbor) T. Cech (Boulder, USA) E. Meyerowitz (Pasadena, USA) P. Chambon (Strasbourg, France) N. Murray (Edinburgh, UK) Managing Editor N.-H. Chua (New York, USA) S. Numa (Kyoto, Japan) J. Cuddihy (Cold Spring Harbor) J. Dahlberg (Madison, USA) C. Niisslein-Volhard (Tubingen, FRG) Production E. Davidson (Pasadena, USA) T. Okada (Okazaki, Japan) N. Dumser E. De Robertis (Los Angeles, USA) R. Palmiter (Seattle, USA) C. Kuret H. Diggelmann (Lausanne, Switzerland) U. Pettersson (Uppsala, Sweden) E. Borosky G. Fink (Cambridge, USA) W. Schaffner (Zurich, Switzerland) R. Flavell (Norwich, UK) M. Scott (Stanford, USA) P. Goodfellow (London, UK) L. Shapiro (Stanford, USA) T. Graf (Heidelberg, FRG) D. Solter (Philadelphia, USA) C. Gross (Madison, USA) J. Strathern (Frederick, USA) F. Grosveld (London, UK) S. Tilghman (Princeton, USA) L. Guarente (Cambridge, USA) R. Tjian (Berkeley, USA) W. Herr (Cold Spring Harbor, USA) H. Varmus (San Francisco, USA) J. Hodgkin (Cambridge, UK) E. Wagner (Vienna, Austria) B. Hogan (Nashville, USA) V. Walbot (Stanford, USA) D. Hopwood (Norwich, UK) J. Witkowski (Cold Spring Harbor, R. Horvitz (Cambridge, USA) USA) N. Jones (London, UK)

EDITORIAL OFFICES United States United Kingdom Cold Spring Harbor Laboratory Press MRC Human Genetics Unit Box 100, Bungtown Road Western General Hospital Cold Spring Harbor, New York 11724 Crewe Road Phone 516-367-8492 FAX 516-367-8532 Edinburgh EH4 2XU, UK Phone 031-332-8676 FAX 031-332-7359

GENES «i DEVELOPMENT (ISSN 0890-9369 IS published monthly for $325 tion, University of Sussex, Falmer, Brighton, Sussex BNl 9RH; tele­ (institutional), $98 (individual making personal payment), $70 (Gene- phone 011-44-606755 ext 8240; FAX 011-44-273-678133. tical Society of Great Britain members) by Cold Spring Harbor Labora­ tory Press, Bungtown Road, Cold Spring Harbor, New York 11724, in Claims for missing issues must be received within 4 months of issue association with the Genetical Society of Great Britain. Second-class date. postage is paid at Cold Spring Harbor and additional mailing offices. Change of address Please enclose recent mailing label with address POSTMASTER: Send address changes to Cold Spring Harbor Laboratory change; allow 4 weeks. Press, POB 100, Bungtown Rd., Cold Spring Harbor, New York 11724. Advertising To advertise in Genes &. Development, contact Nancy Subscription Price Orders may be sent to Cold Spring Harbor Labora­ Kuhle, Advertising Manager, Cold Spring Harbor Laboratory Press, Cold tory Press, Fulfillment Department, 10 Skyline Drive, Plainview, NY Spring Harbor, New York 11724; telephone 516-367-8351. 11803-9729. Telephone: Continental US except NY State, 1-800-843- 4388; all other locations, 516-394-1930/1931/1932. FAX 516-349-1946. Photo Copy Authorization to photocopy items for internal or personal Volume 5, 1991, $325, U.S. institutional; $395, R.O.W. institutional. use, or the internal or personal use of specific clients, is granted by Cold Personal subscription rate: $98, U.S.; R.O.W. Price includes surface Spring Harbor Laboratory Press for libraries and other users registered postage for U.S. and airlift for R.O.W. Genetical Society members, with the Copyright Clearance Center (CCC) Transactional Reporting $70.00. All subscriptions are entered for the calendar year and must be Service, provided that the base fee of $1.00 per copy is paid directly to prepaid. Personal subscriptions must be prepaid by personal check, CCC, 21 Congress St., Salem, MA 01970 (0890-9369/91 $1.00 -i- 0.). This credit card, or money order. All checks must be for US dollars and drawn consent does not extend to other kinds of copying, such as copying for on a US bank. Genetical Society members may also subscribe by check, general distribution for advertising or promotional purposes, for creating payable to the Genetical Society, for £35; for airlift add £30. Send to: Dr. new collective works, or for resale. M. Merrick, Treasurer, Genetical Society, AFRC Unit of Nitrogen Fixa­ Copyright © 1991 by Cold Spring Harbor Laboratory Press GENES & DEVELOPMENT February 1991 Contents

Research papers Cellular localization and cell cycle regulation by a temperature-sensitive p53 protein 151 Jesse Martinez, Ingo Georgoff, Joanne Martinez, and Arnold J. Levine

A central role for chromosome breakage in gene amplification, deletion formation, and 160 amplicon integration Brad Windle, Bruce W. Draper, Yuxin Yin, Stephen O'Gorman, and Geoffrey M. Wahl

Retinoic acid modifies mesodermal patterning in early Xenopus embryos 175 A. Ruiz i Altaba and T. Jessell

A unique zinc finger protein is associated preferentially with active ecdysone-responsive loci 188 in Drosophila Sally A. Amero, Sarah C.R. Elgin, and Ann L. Beyer

Analysis of arginine-rich peptides from the HIV Tat protein reveals unusual features of 201 RNA-protein recognition Barbara J. Calnan, Sara Biancalana, Derek Hudson, and Alan D. Frankel

The role of branchpoint and 3'-exon sequences in the control of balanced splicing of avian 211 retrovirus RNA Xiang-Dong Fu, Richard A. Katz, Anna Marie Skalka, and Tom Maniatis

Two distinct destabilizing elements in the c-fos message trigger deadenylation as a first step in 221 rapid mRNA decay Ann-Bin Shyu, Joel G. Belasco, and Michael E. Greenberg

The protein-coding region of c-myc mRNA contains a sequence that specifies rapid mRNA 232 turnover and induction by protein synthesis inhibitors Ron Wisdom and William Lee

Occlusion of the HIV poly(A) site 244 Caroline Weichs an der Glon, Joan Monks, and Nick J. Proudfoot

Activation and repression of transcription by the gap proteins hunchback and Kriippel in 254 cultured Drosophila cells Ping Zuo, Dusan Stanojevic, John Colgan, Kyuhyung Han, Michael Levine, and James L. Manley

Autoregulation of a segmentation gene in Drosophila: combinatorial interaction of the 265 even-skipped homeo box protein with a distal enhancer element Jin Jiang, Timothy Hoey, and Michael Levine

High-affinity binding sites for the Deformed protein are required for the function of an 278 autoregulatory enhancer of the Deformed gene Michael Regulski, Scott Dessain, Nadine McGinnis, and William McGinnis Illegitimate recombination in plants: a model for T-DNA integration 287 Godelieve Gheysen, Raimundo Villarroel, and Marc Van Montagu

Identification of functional domains in the maize transcriptional activator CI: comparison of 298 wild-type and dominant inhibitor proteins Stephen A. Goff, Karen C. Cone, and Michael E. Fromm

An arginine to lysine substitution in the bZIP domain of an opaque-2 mutant in maize 310 abolishes specific DNA binding Milo J. Aukerman, Robert J. Schmidt, Benjamin Burr, and Frances A. Burr

Characterization of a gene controlling heterocyst differentiation in the cyanobacterium 321 Anabaena 7120 William J. Buikema and Robert Haselkorn

Cover Filaments of the cyanobacterium Anabaena 7120 containing extra copies of the hetR gene. Heterocysts appear frequently in pairs rather than as the single cells characteristic of the wild-type organism. (For details, see Buikema and Kaselkom, p. 322).