SummaryTwo cDNAs (At.EIF4E1 and At.EIF4E2) encoding, respectively, the eukaryotic initiation factors eIF4E and eIF(iso)4E of Arabidopsis thaliana were isolated by complementation of a Saccharomyces cerevisiae conditional mutant. The deduced amino acid sequences of the proteins are homologous to those from monocotyledonous plants, yeast and mammals. The corresponding genes were identified in YAC clones mapping to chromosome IV (At.EIF4E1) and to chromosome V (At.EIF4E2). The yeast strain complemented by At.EIF4E2 grew poorly compared with an isogenic strain expressing At.EIF4E1. Northern and in situ hybridization analysis show that both Arabidopsis At.EIF4E1 and At.EIF4E2 mRNAs are differentially accumulated in plant tissues. The At.EIF4E1 mRNA is expressed in all tissues except in the cells of the specialization zone of the roots; the At.EIF4E2 mRNA is particularly abundant in floral organs and in young developing tissues. This work further demonstrates an association between a high level of EIF4E mRNAs and cell proliferation and suggests that the plant eIF4E isoforms may have distinct functions in cell development and metabolism.

No abstract

No abstract

Ramón y Cajal's studies in the field of neuroscience provoked a radical change in the course of its history. For this reason he is considered as the father of modern neuroscience. Some of his original preparations are housed at the Cajal Museum (Cajal Institute, CSIC, Madrid, Spain). In this article, we catalogue and analyse more than 4,500 of Cajal's histological preparations, the same preparations he used during his scientific career. Furthermore, we catalogued Cajal's original correspondence, both manuscripts and personal letters, drawings and plates. This is the first time anyone has compiled an account of Cajal's enormous scientific production, offering some curious insights into his work and his legacy.

Dendritic spines receive the majority of excitatory connections in the central nervous system, and, thus, they are key structures in the regulation of neural activity. Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest. Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies. Here, we present original results obtained from high-quality images of Cajal's histological preparations, stored at the Cajal Museum (Instituto Cajal, CSIC), obtained using extended focus imaging, three-dimensional reconstruction, and rendering. Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.