Conversaciones sobre la economía política : en las cuales se esplican [sic] de un modo simple y familiar los elementos de esta ciencia

Copia digital : Biblioteca de Asturias "Ramón Pérez de Ayala" : Biblioteca Pública Estatal de Oviedo, 201

The immunological synapse: a focal point for endocytosis and exocytosis

There are many different cells in the immune system. To mount an effective immune response, they need to communicate with each other. One way in which this is done is by the formation of immunological synapses between cells. Recent developments show that the immune synapse serves as a focal point for exocytosis and endocytosis, directed by centrosomal docking at the plasma membrane. In this respect, formation of the immunological synapse bears striking similarities to cilia formation and cytokinesis. These intriguing observations suggest that the centrosome may play a conserved role in designating a specialized area of membrane for localized endocytosis and exocytosis

Expansion of Signal Transduction Pathways in Fungi by Extensive Genome Duplication

International audienceno abstrac

Genome evolution in the allotetraploid frog Xenopus laevis

To explore the origins and consequences of tetraploidy in the African clawed frog, we sequenced the Xenopus laevis genome and compared it to the related diploid X. tropicalis genome. We characterize the allotetraploid origin of X. laevis by partitioning its genome into two homoeologous subgenomes, marked by distinct families of ???fossil??? transposable elements. On the basis of the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor species diverged around 34 million years ago (Ma) and combined to form an allotetraploid around 17-18 Ma. More than 56% of all genes were retained in two homoeologous copies. Protein function, gene expression, and the amount of conserved flanking sequence all correlate with retention rates. The subgenomes have evolved asymmetrically, with one chromosome set more often preserving the ancestral state and the other experiencing more gene loss, deletion, rearrangement, and reduced gene expression.ope

Conversations on vegetable physiology : comprehending the elements of botany, with their application to agriculture, vol.2/ Marcet

304 hal.; 22 cm

Conversations on Chemistry in which the Elements of that Science are familiarly explained and illustrated by Experiments

[s.c.

Conversations on vegetable physiology : comprehending the elements of botany, with their application to agriculture, vol.2/ Marcet

304 hal.; 22 cm

Conversations on vegetable physiology : comprehending the elements of botany, with their application to agriculture, vol.1/ Marcet

286 hal.; 21 cm