First published online September 28, 2006
Development 133, 2006e (2006)
© The Company of Biologists Limited
Tinman needed for a good heart
In Drosophila, the NK homeobox gene tinman (tin)
is essential for the specification of cardiac progenitors in the early dorsal
mesoderm. Like its vertebrate counterpart Nkx2.5, tin is also
expressed during cardiac maturation and differentiation. However, its later
role in cardiac development is unclear because tin-null embryos have
no dorsal vessel (the Drosophila equivalent of a heart), and die.
Zaffran et al. now reveal that tin controls the diversification and
differentiation of myocardial cells during the later stages of cardiogenesis,
through regulatory interactions with Dorsocross and other cardiogenic
factors (see p.
4073). The researchers made their discovery by making transgenic fly
lines that expressed tin normally during early heart development, but
that did not express tin in dorsal vessel cardioblasts at later
stages. The dorsal vessel formed in the resulting embryos and was present in
surviving adult flies, but myocardial diversification, differentiation and
remodelling was defective. These findings provide new information about the
molecular pathways that act at later stages of fly, and perhaps also
mammalian, heart development.
Related articles in Development:
- Cardioblast-intrinsic Tinman activity controls proper diversification and differentiation of myocardial cells in Drosophila
- Stéphane Zaffran, Ingolf Reim, Li Qian, Patrick C. Lo, Rolf Bodmer, and Manfred Frasch
Development 2006 133: 4073-4083.
[Abstract]
[Full Text]
