Direct somatic embryogenesis was induced in root tissues of the Cichorium hybrid '474' (C. intybus L. var. sativum x C. endivia L. var. latifolia). Addition of beta-D-glucosyl Yariv reagent (betaGlcY), a synthetic phenylglycoside that specifically binds arabinogalactan-proteins (AGPs), to the culture medium blocked somatic embryogenesis in a concentration-dependent manner with complete inhibition of induction occurring at 250 microM betaGlcY. The AGP-unreactive alpha-D-galactosyl Yariv reagent had no biological activity in this system. Upon transfer of 250 microM betaGlcY-treated roots to control conditions, somatic embryogenesis was recovered with a time course similar to that of control roots. The betaGlcY penetrated roots and bound abundantly to developing somatic embryos, to the root epidermis and the stele. Immunofluorescence and immunogold labelling using monoclonal antibodies (JIM13, JIM16 and LM2) revealed that AGPs were localised in the outer cell walls peripheral cells of the globular embryo. A spatio-temporal expression of AGPs appeared to be associated with differentiation events in the somatic embryo during the transition from the globular stage to the torpedo stage. To verify betaGlcY specificity, molecules that bound betaGlcY were extracted from treated conditioned medium and identified as AGPs by using the same monoclonal antibodies. In addition, AGPs were found to be abundantly present in the medium during embryogenic culture. All of these results establish the implication of AGPs in embryo development, and their putative role in somatic embryogenesis is discussed.

This study identified candidate genes deregulated in CTNNB1-mutated adrenocortical tumors that may lead to a better understanding of the role of the Wnt-β-catenin pathway in adrenocortical tumorigenesis.

SummaryAdrenocortical tumours (ACT), which include adenomas, carcinomas and adrenal hyperplasia, may be associated with genetic syndromes, such as Li–Fraumeni syndrome, Beckwith–Wiedemann syndrome, multiple endocrine neoplasia type 1, familial adenomatous polyposis and Carney complex. Genetic defects have been found to be responsible for the disease in most of these syndromes, allowing genetic counselling to affected patients and family members. Here, we summarize the clinical criteria of these hereditary syndromes and briefly describe the genetic alterations related to them. In addition, we discuss the involvement of various genetic defects in the development of sporadic adrenocortical tumours.

The present study reports, for the first time, that AXIN2 genetic defects may be found in adrenocortical tumors. However, the functional consequence of this genetic alteration remains to be determined.