Homeodomain factor Nkx2-5 controls left/right asymmetric expression of bHLH gene eHand during murine heart development
- Author(s)
- Biben, C; Harvey, RP;
- Details
- Publication Year 1997-06-01,Volume 11,Issue #11,Page 1357-1369
- Journal Title
- GENES & DEVELOPMENT
- Publication Type
- Journal Article
- Abstract
- One of the first morphological manifestations of left/right (L/R) asymmetry in mammalian embryos is a pronounced rightward looping of the linear heart tube. The direction of looping is thought to be controlled by signals from an embryonic L/R axial system. We report here that morphological L/R asymmetry in the murine heart first became apparent at the linear tube stage as a leftward displacement of its caudal aspect. Beginning at the same stage, the basic helix-loop-helix (bHLH) factor gene eHand was expressed in a strikingly left-dominant pattern in myocardium, reflecting an intrinsic molecular asymmetry. In hearts of embryos lacking the homeobox gene Nkx2-5, which do not loop, left-sided eHand expression was abolished. However, expression was unaffected in Sc1(-/-) hearts that loop poorly because of hematopoietic insufficiency, and was right-sided in hearts of inv/inv embryos that display situs inversus. The data predict that eHand expression is enhanced in descendants of the left heart progenitor pool as one response to inductive signaling from the L/R axial system, and that eHand controls intrinsic morphogenetic pathways essential for looping. One aspect of the intrinsic response to L/R information falls under Nkx2-5 homeobox control.
- Publisher
- COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT
- Keywords
- EMBRYONIC HEART; MOUSE EMBRYOS; TRANSCRIPTION FACTOR; CHICK HEART; DIFFERENTIATION; EMBRYOGENESIS; DROSOPHILA; INDUCTION; MESODERM; ENDODERM
- Publisher's Version
- https://doi.org/10.1101/gad.11.11.1357
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 1997-06-01 12:00:00