Appendix - CNIC

SCIENTIFIC REPORT ´09 1 Cardiovascular Developmental Biology
Role of new genes
in cardiovacular development
> RESEARCH INTEREST
Head of Laboratory: Juan José Sanz Ezquerro
Predoctoral Researchers: Jesús Chamorro Casanova
Verónica Uribe Sokolov
Masters student: Laura González Calero
Our laboratory combines studies in chick and mouse embryos
with in vitro cell culture strategies to address the role of new
genes in the development of the cardiovascular system and
in particular the morphogenesis of the heart. Our recent work
has examined the role of AT-rich interactive domaincontaining
protein 3B (Arid3b) during heart formation.
Arid3b is a transcription factor of the highly conserved ARID
family, whose members share a common DNA-binding
domain. Arid3b null-mice die early in embryonic
development and their phenotype includes severe defects in
many structures, especially the heart. However, the exact
roles of Arid3b in development remain unclear.
Examination of the pattern of Arid3b expression shows that it
is expressed at early stages of development in the heart tube
Technician: Claudio Badía Careaga
and is later restricted to the myocardium of the outflow tract,
right ventricle, atria and sinus venosus. We are currently
carrying out anatomical, histological, cellular and molecular
analyses to characterize the cardiac defects produced by the
absence of the Arid3b gene. Our results so far identify a
major defect in outflow tract formation in Arid3b knockout
mice.
Our data also indicate that Arid3b regulates the contribution
to the heart of cells from the secondary heart field. We plan
to analyze the cellular basis of these Arid3b functions—for
example its possible involvement in cell migration—and to
identify its molecular targets by microarray analyses.
Proliferation (green labeling by anti-PH3) and apoptosis (red labeling by TUNEL) in Arid3b knockout embryos at E9. At this
stage, embryos show no apparent heart defects, but there is a clear increase in the number of dead cells in cranial
mesenchyme.
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