We uncover that the caudal splanchnic mesoderm (in green) acts as a midline anchor of the heart tube. In Vangl2 and Shroom3 mutants, its bilateral symmetry is disrupted, leading to a rotation of the heart tube and ventricle malposition.

In the dorsal pericardial wall, Vangl2 localises at multicellular junctions and is required for their resolution. This promotes cell rearrangements underlying elongation of the arterial pole of the heart tube.

Paul Palmquist-Gomes, in collaboration with @gaellel.bsky.social, quantified the phenotype of a series of mutants to show that Vangl2 is required in two epithelia adjacent to the heart tube.

She analysed a mouse model of motile ciliopathy to show that the node can be dispensable to establish left-right asymmetry. Stay tuned !

Abnormal D-LOOP are also observed in patients and tend to be associated with poorer prognosis. We reconstruct their developmental revertant trajectory in the mouse. Team work in collaboration with JB Masson and O Raisky.

@audreydsg.bsky.social performed a unique longitudinal analysis of heterotaxy by imaging the same mouse twice, at E9.5 and E18.5. We show that embryonic heart loop shape is a partial predictor of CHD.

We report how ventricle can still change position after heart looping in Nodal mutants, questioning the clinical nomenclature of « D-LOOP ». D-LOOP ventricles at birth can arise from both rightward or leftward embryonic heart looping.

In collaboration with MP Hitz, we identify 6 ultrarare NOTCH3 variants in a cohort of patients with congenital heart defects, reflecting the double role of Notch3 in laterality and heart development

We also show that Notch3 is expressed in the second heart field and required for ventricular and atrial septation, right ventricle wall thickness and the non coronary leaflet of the aortic valve

We identified Notch3 as a new asymmetric gene, amplified by Nodal and a genetic modifier of heart looping defects in Nodal mutants

Is Nodal the only determinant of left-right asymmetry? 🤔 If curious and willing to address the question with lab resources in transcriptomics, mouse genetics and quantitative 3D imaging, please contact me.