Identification of the building blocks of ventricular septation in monitor lizards (Varanidae)
Language English Country Great Britain, England Media electronic
Document type Journal Article, Research Support, Non-U.S. Gov't, Video-Audio Media
PubMed
31285354
DOI
10.1242/dev.177121
PII: dev.177121
Knihovny.cz E-resources
- Keywords
- Evolution, Heart, Lizard, Ventricular septum,
- MeSH
- Time-Lapse Imaging MeSH
- Echocardiography veterinary MeSH
- Embryo, Nonmammalian MeSH
- Homeodomain Proteins genetics physiology MeSH
- Lizards embryology genetics MeSH
- Ventricular Septum diagnostic imaging embryology MeSH
- Evolution, Molecular MeSH
- T-Box Domain Proteins genetics physiology MeSH
- Heart Ventricles diagnostic imaging embryology MeSH
- Heart Atria diagnostic imaging embryology MeSH
- Myosin Heavy Chains genetics metabolism MeSH
- Gene Expression Regulation, Developmental MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Video-Audio Media MeSH
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Homeodomain Proteins MeSH
- T-Box Domain Proteins MeSH
- T-box transcription factor 5 MeSH Browser
- Myosin Heavy Chains MeSH
Among lizards, only monitor lizards (Varanidae) have a functionally divided cardiac ventricle. The division results from the combined function of three partial septa, which may be homologous to the ventricular septum of mammals and archosaurs. We show in developing monitors that two septa, the 'muscular ridge' and 'bulbuslamelle', express the evolutionarily conserved transcription factors Tbx5, Irx1 and Irx2, orthologues of which mark the mammalian ventricular septum. Compaction of embryonic trabeculae contributes to the formation of these septa. The septa are positioned, however, to the right of the atrioventricular junction and they do not participate in the separation of incoming atrial blood streams. That separation is accomplished by the 'vertical septum', which expresses Tbx3 and Tbx5 and orchestrates the formation of the electrical conduction axis embedded in the ventricular septum. These expression patterns are more pronounced in monitors than in other lizards, and are associated with a deep electrical activation near the vertical septum, in contrast to the primitive base-to-apex activation of other lizards. We conclude that evolutionarily conserved transcriptional programmes may underlie the formation of the ventricular septa of monitors.
References provided by Crossref.org
"Form follows function": the developmental morphology of the cardiac atria
The changing morphology of the ventricular walls of mouse and human with increasing gestation
Hemodynamics During Development and Postnatal Life
Low incidence of atrial septal defects in nonmammalian vertebrates
