Affiliation:
1. Department of Zoology, Graduate School of Science, Kyoto University, Sakyo,Kyoto 606-8502, Japan
2. CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 333-0012,Japan
Abstract
Understanding the molecular basis of heart development is an important research area, because malformation of the cardiovascular system is among the most frequent inborn defects. Although recent research has identified molecules responsible for heart morphogenesis in vertebrates, the initial specification of heart progenitors has not been well characterized. Ascidians provide an appropriate experimental system for exploring this specification mechanism, because the lineage for the juvenile heart is well characterized,with B7.5 cells at the 110-cell stage giving rise to embryonic trunk ventral cells (TVCs) or the juvenile heart progenitors. Here, we show that Cs-Mesp, the sole ortholog of vertebrate Mesp genes in the ascidian Ciona savignyi, is specifically and transiently expressed in the embryonic heart progenitor cells (B7.5 cells). Cs-Mesp is essential for the specification of heart precursor cells, in which Nkx, HAND and HAND-like (NoTrlc) genes are expressed. As a result, knockdown of Cs-Mesp with specific morpholino antisense oligonucleotides causes failure of the development of the juvenile heart. Together with previous evidence obtained in mice, the present results suggest that a mechanism for heart specification beginning with Mespthrough Nkx and HAND is conserved among chordates.
Publisher
The Company of Biologists
Subject
Developmental Biology,Molecular Biology
Reference47 articles.
1. Andree, B., Duprez, D., Vorbusch, B., Arnold, H. H. and Brand,T. (1998). BMP-2 induces ectopic expression of cardiac lineage markers and interferes with somite formation in chicken embryos. Mech. Dev.70,119-131.
2. Azumi, K., Takahashi, H., Miki, Y., Fujie, M., Usami, T.,Ishikawa, H., Kitayama, A., Satou, Y., Ueno, N. and Satoh, N.(2003). Construction of a cDNA Microarray Derived from the Ascidian Ciona intestinalis.Zool. Sci.20,1223-1229.
3. Chiba, S., Satou, Y., Nishikata, T. and Satoh, N.(1998). Isolation and characterization of cDNA clones for epidermis-specific and muscle-specific genes in Ciona savignyiembryos. Zool. Sci.15,239-246.
4. Corbo, J. C., Levine, M. and Zeller, R. W.(1997). Characterization of a notochord-specific enhancer from the Brachyury promoter region of the ascidian, Ciona intestinalis.Development124,589-602.
5. Corbo J. C., Di Gregorio, A. and Levine, M.(2001). The ascidian as a model organism in developmental and evolutionary biology. Cell.106,535-538.
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