In situ immunolocalization of tubulin revealed that important rearrangements occur during all the early symbiotic steps in the Medicago/R. meliloti symbiotic interaction. Microtubular cytoskeleton (MtC) reorganizations were observed in inner tissues, first in the pericycle and then in the inner cortex where the nodule primordium forms. Subsequently, major MtC changes occurred in outer tissues, associated with root hair activation and curling, the formation of preinfection threads (PITs) and the initiation and the growth of an infection network. From the observed sequence of MtC changes, we propose a model which aims to better define, at the histological level, the timing of the early symbiotic stages. This model suggests the existence of two opposite gradients of cell differentiation controlling respectively the formation of division centers in the inner cortex and plant preparation for infection. It implies that (i) MtC rearrangements occur in pericycle and inner cortex earlier than in the root hair, (ii) the infection process proceeds prior to the formation of the nodule meristem, (iii) the initial primordium prefigures the future zone II of the mature nodule and (iv) the nodule meristem derives from the nodule primordium. Finally, our data also strongly suggest that in alfalfa PIT differentiation, a stage essential for successful infection, requires complementary signaling additional to Nod factors.
Refined analysis of early symbiotic steps of the Rhizobium-Medicago interaction in relationship with microtubular cytoskeleton rearrangements
A.C. Timmers, M.C. Auriac, G. Truchet; Refined analysis of early symbiotic steps of the Rhizobium-Medicago interaction in relationship with microtubular cytoskeleton rearrangements. Development 15 August 1999; 126 (16): 3617–3628. doi: https://doi.org/10.1242/dev.126.16.3617
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Our successful webinar series continues in 2021, with early-career researchers presenting their papers and a chance to virtually network with the developmental biology community afterwards. Here, Iva Kelava discusses the insights of human cortical organoids into the role of sex hormones in the developing human brain.
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The people behind the papers - Vincent Mouilleau, Célia Vaslin and Stéphane Nedelec
First authors, Vincent Mouilleau and Célia Vaslin, and their supervisor Stéphane Nedelec, talk about their latest work on HOX regulation, its potential clinical impact and where the story will take the Nedelec lab.
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The Immune System in Development and Regeneration
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