4 research outputs found
Rab-dependent vesicular traffic affects female gametophyte development in Arabidopsis
Eukaryotic cells rely on the accuracy and efficiency of vesicular traffic. In plants, disturbances in vesicular trafficking are well studied in quickly dividing root meristem cells or polar growing root hairs and pollen tubes. The
development of the female gametophyte, a unique haploid reproductive structure located in the ovule, has received
far less attention in studies of vesicular transport. Key molecules providing the specificity of vesicle formation and
its subsequent recognition and fusion with the acceptor membrane are Rab proteins. Rabs are anchored to membranes by covalently linked geranylgeranyl group(s) that are added by the Rab geranylgeranyl transferase (RGT)
enzyme. Here we show that Arabidopsis plants carrying mutations in the gene encoding the β-subunit of RGT
(rgtb1) exhibit severely disrupted female gametogenesis and this effect is of sporophytic origin. Mutations in rgtb1
lead to internalization of the PIN1 and PIN3 proteins from the basal membranes to vesicles in provascular cells of
the funiculus. Decreased transport of auxin out of the ovule is accompanied by auxin accumulation in tissue surrounding the growing gametophyte. In addition, female gametophyte development arrests at the uni- or binuclear
stage in a significant portion of the rgtb1 ovules. These observations suggest that communication between the
sporophyte and the developing female gametophyte relies on Rab-dependent vesicular traffic of the PIN1 and PIN3
transporters and auxin efflux out of the ovule
The natural history and surgical outcome of patients with scimitar syndrome: a multi-centre European study
Treatment decisions in patients with scimitar syndrome (SS) are often challenging, especially in patients with isolated SS who are often asymptomatic and who might be diagnosed accidentally. We queried a large multi-institutional registry of SS patients to evaluate the natural history of this condition and to determine the efficacy of surgical treatment in terms of survival and clinical status