Search results for " embryogenesis"
showing 10 items of 79 documents
Holm Oak Quercus ilex L.
2018
The holm oak is an evergreen tree species representative of Mediterranean forests. The largest populations of this species are in the Iberian Peninsula, forming the tree cover of an agro-silvo-pastoral system called “dehesa” in Spain and “montado” in Portugal. The high ecological and economic value of the species is of interest for rural development. The main current product are the acorns used for feeding Iberian black pigs, which are the basis of an important gastronomic industry. In addition, several bioactive compounds with new potential industrial applications in nutrition, pharmacology and cosmetics have been identified in acorns of oak species. Plantations with holm oak seedlings myc…
On the Establishment of Polarity in Polychaete Eggs
1990
The study of Spiralian development began about a hundred years ago when Whitman (1878) published a description of the development of the leech, Clepsine marginata. Subsequently, Spiralian development became popular because the developmental fate of each individual blastomere can be determined precisely from the cell lineage. About the turn of the century several extensive papers describing the cell lineages of various molluscs (e.g. Blochmann, 1881, 1883; Kofoid, 1895; Conklin, 1897; Wierzejski 1905) and annelids (e.g. Wilson, 1892; Mead, 1897; Woltereck, 1904) appeared. From these studies it became clear that the general principles of mollusc and annelid development (and to a much lesser d…
Quantitative analysis of cellular differentiation during early embryogenesis ofPlatynereis dumerilii.
1990
As in many spiralian embryos with unequal cleavage, cleavage inPlatynereis follows an invariant pattern. Preceding each cleavage the cytoplasm is reorganized, allowing the spiral cleavage mode to produce cells with different cytoplasmic composition. The fertilized egg undergoes a dramatic ooplasmic segregation after the completion of the cortical reaction. As a consequence, a plug of clear cytoplasm becomes located at the animal pole. Once the four quadrants of the embryo have been established, the cleavage sequence of the D quadrant differs clearly from that of the other three quadrants. The results presented here suggest that differential distribution of the clear cytoplasm governs this s…
Early embryo achievement through isolated microspore culture in citrus clementina hort. Ex tan., cvs. 'Monreal Rosso' and 'nules'
2015
10 p.-5 fig.-3 tab.
Morphogenesis in leaf and single-cell cultures of mature Juniperus oxycedrus
1996
Single cells were mechanically isolated from leaf-derived callus of mature Juniperus oxycedrus L. These cells divided and gave rise to callus when plated on medium containing growth regulators. Best plating efficiency was obtained on a modified Schenk and Hildebrandt medium supplemented with 0.6 micro M 2,4-dichlorophenoxyacetic acid and 100 mg l(-1) casein hydrolyzate. Although single-cell-derived callus showed poor morphogenic potential, both adventitious shoots and embryogenic tissues differentiated from the callus. We also achieved induction of somatic embryogenesis in leaf explants of mature J. oxycedrus trees cultured in the presence of 6.0 or 10.0 micro M 2,4-dichlorophenoxyacetic ac…
Early in vitro development of isolated microspores of four Sicilian olive cultivars.
2015
Nowadays there is a great interest in the advancement of the studies on gametic embryogenesis in olive, as a method for obtaining homozygous material, due to the enormous effort and relevance in its genome sequencing and gene mapping. In this study, in vitro isolated microspore culture of four Sicilian olive cultivars (‘Biancolilla napoletana’, ‘Nocellara del Belice’, ‘Tonda Iblea’ and ‘Verdello’) has been carried out, investigating the influence of two polyamines (putrescine and spermidine) and of two medium compositions on pollen embryogenesis induction. During in vitro development, different structural features have been observed: uninucleated microspores, with no development, binucleate…
Expression profiling of glial genes during Drosophila embryogenesis
2006
AbstractIn the central nervous system of Drosophila, the induction of the glial cell fate is dependent on the transcription factor glial cells missing (gcm). Though a considerable number of other genes have been shown to be expressed in all or in subsets of glial cells, the course of glial cell differentiation and subtype specification is only poorly understood. This prompted us to design a whole genome microarray approach comparing gcm gain-of-function and, for the first time, gcm loss-of-function genetics to wildtype in time course experiments along embryogenesis. The microarray data were analyzed with special emphasis on the temporal profile of differential regulation. A comparison of bo…
Effect of methyl jasmonate in gene expression, and in hormonal and phenolic profiles of holm oak embryogenic lines before and after infection with Ph…
2022
The dieback syndrome affecting Quercus ilex and other oak species impels the search for tolerant plant genotypes, as well as methods of plant immunization against such infections. Elicitation treatments can be an effective strategy to activate plant defense response and embryogenic lines represent a promising tool to generate new tolerant genotypes and also to study early markers involved in defense response. The aim of the presented work was to investigate changes in gene expression, and in hormonal and phenolic profiles induced in three holm oak embryogenic lines (ELs) elicited with methyl jasmonate (MeJA) before and after infection with the oomycete Phytophthora cinnamomi, which is the m…