|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Development, Vol 125, Issue 22 4439-4449, Copyright © 1998 by Company of Biologists
JOURNAL ARTICLES |
Y Fu, W Yan, TJ Mohun and SM Evans
Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0613C, USA.
Tinman is a Drosophila homeodomain protein that is required for formation of both visceral and cardiac mesoderm, including formation of the dorsal vessel, a heart-like organ. Although several vertebrate tinman homologues have been characterized, their requirement in earliest stages of heart formation has been an open question, perhaps complicated by potential functional redundancy of tinman homologues. We have utilized a novel approach to investigate functional redundancy within a gene family, by coinjecting DNA encoding dominantly acting repressor derivatives specific for each family member into developing Xenopus embryos. Our results provide the first evidence that vertebrate tinman homologues are required for earliest stages of heart formation, and that they are required in a functionally redundant manner. Coinjection of dominant repressor constructs for both XNkx2-3 and XNkx2-5 is synergistic, resulting in a much higher frequency of mutant phenotypes than that obtained with injection of either dominant repressor construct alone. Rescue of mutant phenotypes can be effected by coinjection of either wild-type tinman homologue. The most extreme mutant phenotype is a complete absence of expression of XNkx2-5 in cardiogenic mesoderm, an absence of markers of differentiated myocardium, and absence of morphologically distinguishable heart on the EnNkxHD-injected side of the embryo. This phenotype represents the most severe cardiac phenotype of any vertebrate mutant yet described, and underscores the importance of the tinman family for heart development. These results provide the first in vivo evidence that XNkx2-3 and XNkx2-5 are required as transcriptional activators for the earliest stages of heart formation. Furthermore, our results suggest an intriguing mechanism by which functional redundancy operates within a gene family during development. Our experiments have been performed utilizing a recently developed transgenic strategy, and attest to the efficacy of this strategy for enabling transgene expression in limited cell populations within the developing Xenopus embryo.
This article has been cited by other articles:
![]() |
K. Nagao, Y. Taniyama, T. Kietzmann, T. Doi, I. Komuro, and R. Morishita HIF-1{alpha} Signaling Upstream of NKX2.5 Is Required for Cardiac Development in Xenopus J. Biol. Chem., April 25, 2008; 283(17): 11841 - 11849. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Karamboulas, G. D. Dakubo, J. Liu, Y. De Repentigny, K. Yutzey, V. A. Wallace, R. Kothary, and I. S. Skerjanc Disruption of MEF2 activity in cardiomyoblasts inhibits cardiomyogenesis J. Cell Sci., October 15, 2006; 119(20): 4315 - 4321. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. N. Olson Gene regulatory networks in the evolution and development of the heart. Science, September 29, 2006; 313(5795): 1922 - 1927. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. F. M. MOORMAN and V. M. CHRISTOFFELS Cardiac Chamber Formation: Development, Genes, and Evolution Physiol Rev, October 1, 2003; 83(4): 1223 - 1267. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Dentice, C. Morisco, M. Vitale, G. Rossi, G. Fenzi, and D. Salvatore The Different Cardiac Expression of the Type 2 Iodothyronine Deiodinase Gene between Human and Rat Is Related to the Differential Response of the dio2 Genes to Nkx-2.5 and GATA-4 Transcription Factors Mol. Endocrinol., August 1, 2003; 17(8): 1508 - 1521. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Zaffran and M. Frasch Early Signals in Cardiac Development Circ. Res., September 20, 2002; 91(6): 457 - 469. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. G. Bruneau Transcriptional Regulation of Vertebrate Cardiac Morphogenesis Circ. Res., March 22, 2002; 90(5): 509 - 519. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Yang, M. M. Lu, L. Zhang, J. A. Whitsett, and E. E. Morrisey GATA6 regulates differentiation of distal lung epithelium Development, January 5, 2002; 129(9): 2233 - 2246. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Jamali, P. J. Rogerson, S. Wilton, and I. S. Skerjanc Nkx2-5 Activity Is Essential for Cardiomyogenesis J. Biol. Chem., November 2, 2001; 276(45): 42252 - 42258. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Liang, R. J. Wiese, O. F. Bueno, Y.-S. Dai, B. E. Markham, and J. D. Molkentin The Transcription Factor GATA4 Is Activated by Extracellular Signal-Regulated Kinase 1- and 2-Mediated Phosphorylation of Serine 105 in Cardiomyocytes Mol. Cell. Biol., November 1, 2001; 21(21): 7460 - 7469. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Palmer, N. Groves, A. Schindeler, T. Yeoh, C. Biben, C.-C. Wang, D. B. Sparrow, L. Barnett, N. A. Jenkins, N. G. Copeland, et al. The Small Muscle-specific Protein Csl Modifies Cell Shape and Promotes Myocyte Fusion in an Insulin-like Growth Factor 1-dependent Manner J. Cell Biol., May 21, 2001; 153(5): 985 - 998. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Marvin, G. Di Rocco, A. Gardiner, S. M. Bush, and A. B. Lassar Inhibition of Wnt activity induces heart formation from posterior mesoderm Genes & Dev., February 1, 2001; 15(3): 316 - 327. [Abstract] [Full Text] |
||||
![]() |
D. Smith, C Nielsen, C. Tabin, and D. Roberts Roles of BMP signaling and Nkx2.5 in patterning at the chick midgut-foregut boundary Development, January 9, 2000; 127(17): 3671 - 3681. [Abstract] [PDF] |
||||
![]() |
M. Rones, K. McLaughlin, M Raffin, and M Mercola Serrate and Notch specify cell fates in the heart field by suppressing cardiomyogenesis Development, January 9, 2000; 127(17): 3865 - 3876. [Abstract] [PDF] |
||||
![]() |
K Gajewski, N Fossett, J. Molkentin, and R. Schulz The zinc finger proteins Pannier and GATA4 function as cardiogenic factors in Drosophila Development, January 12, 1999; 126(24): 5679 - 5688. [Abstract] [PDF] |
||||
![]() |
R. Schwartz and E. Olson Building the heart piece by piece: modularity of cis-elements regulating Nkx2-5 transcription Development, January 10, 1999; 126(19): 4187 - 4192. [Abstract] [PDF] |
||||
![]() |
M. Su, M Fujioka, T Goto, and R Bodmer The Drosophila homeobox genes zfh-1 and even-skipped are required for cardiac-specific differentiation of a numb-dependent lineage decision Development, January 6, 1999; 126(14): 3241 - 3251. [Abstract] [PDF] |
||||
![]() |
Q. Liang, L. J. De Windt, S. A. Witt, T. R. Kimball, B. E. Markham, and J. D. Molkentin The Transcription Factors GATA4 and GATA6 Regulate Cardiomyocyte Hypertrophy in Vitro and in Vivo J. Biol. Chem., August 3, 2001; 276(32): 30245 - 30253. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Phiel, V. Gabbeta, L. M. Parsons, D. Rothblat, R. P. Harvey, and K. M. McHugh Differential Binding of an SRF/NK-2/MEF2 Transcription Factor Complex in Normal Versus Neoplastic Smooth Muscle Tissues J. Biol. Chem., September 7, 2001; 276(37): 34637 - 34650. [Abstract] [Full Text] [PDF] |
||||