Vegetal plate specification was assessed in S. purpuratus embryos after micromere deletions at the 4th, 5th and 6th cleavages, by assaying expression of the early vegetal plate marker Endo 16, using whole-mount in situ hybridization. After 4th cleavage micromere deletions, the embryos typically displayed weak Endo16 expression in relatively few cells of the lineages that normally constitute the...

The animal plate of the sea urchin embryo becomes the apical organ, a sensory structure of the larva. In the absence of vegetal signaling, an expanded and unpatterned apical organ forms. To investigate the signaling that restricts the size of the animal plate and patterns neurogenesis, we have expressed molecules that regulate specification of ectoderm in embryos and chimeras. Enhancing oral ec...

We have used whole amount in situ hybridization to analyze the patterns of expression of two genes, S9 and actin CyIIa, during the development of the sea urchin, Strongylocentrotus purpuratus. We demonstrate that at the late blastula stage, these two mRNAs are expressed specifically by cells of the vegetal plate. Their domains of expression, however, are different. S9 mRNA is broadly distribute...

The unfertilized ascidian egg displays a visible polar organization along its animal-vegetal axis. In particular, the myoplasm, a mitochondria-rich subcortical domain inherited by the blastomeres that differentiate into muscle cells, is mainly situated in the vegetal hemisphere. We show that, in the unfertilized egg, this vegetal domain is enriched in actin and microfilaments and excludes micro...

We performed some experiments to investigate the temporal and spatial details of the dorsal induction exerted by dorsal vegetal cells in Xenopus embryo. Two dorsal vegetal cells (D1 cells) were transplanted into the ventral vegetal region of a recipient at the 32-cell stage. At various times after transplantation, the ventral animal-equatorial part was explanted and cultured. The explants isola...

The paper employed Remote sensing data in a multi-decadal assessment of vegetal to urban land cover transition along Lagos-Ibadan expressway. forty-year commenced 1980 and ended 2020. Landsat imageries acquired for the respective periods were subjected supervised classification. Results reveal massive conversion vegetated areas into built-up areas. became pronounced from second decade with 30,2...

J TORRA*, A CIRUJEDA , J RECASENS*, A TABERNER* & S B POWLES§ *Departament d Hortofructicultura, Botànica i Jardineria, ETSEA, Universitat de Lleida, Lleida, Spain, Unidad de Sanidad Vegetal, CITA, Diputación General de Aragón, Zaragoza, Spain, Servei de Sanitat Vegetal, Unitat de Malherbologia, Departament d Agricultura, Ramaderia i Pesca, Generalitat de Catalunya, Lleida, Spain, and §Western ...

Specification of the dorsoventral axis is a subject of great importance in amphibian embryogenesis. We have found that cytoplasm of the vegetal dorsal cells of a 16-cell embryo of Xenopus laevis, when injected into the ventral vegetal cells of a recipient at the same stage, can induce formation of a second axis. In the present experiments,using the same assay procedure, we found that the cytopl...