12 research outputs found
Identification of and partial characterization of platelet vitronectin: evidence for complex formation with platelet-derived plasminogen activator inhibitor-1
Identification of and partial characterization of platelet vitronectin: evidence for complex formation with platelet-derived plasminogen activator inhibitor-1
Line of sight waypoint guidance for a container ship based on frequency domain identification of Nomoto model of vessel
Consecutive Production of Hydroalcoholic Extracts, Carbohydrates Derivatives and Silica Nanoparticles from Equisetum arvense
Manufacture of Mesoporous Silicon from Living Plants and Agricultural Waste: An Environmentally Friendly and Scalable Process
Dynamics of spicule production in marine sponge Hymeniacidon perlevis during in vitro cell culture and seasonal development in the field
To characterize the formation of silica spicules, the dynamics of spiculogenesis of an intertidal marine sponge Hymeniacidon perlevis (Montagu 1818) (Porifera: Demospongiae) were investigated by measuring the gene expression of silicatein (the enzyme responsible for spicule silicification) and the dimensional changes of spicules during the developmental process of individual sponges and in cell cultures of primmorphs of archaeocyte-dominant cell populations. The different developmental stages of spicules were documented by time-lapse microscopy and observed by transmission electron microscopy during a 1-month culture period. During its annual life cycle, H. perlevis has four different developmental stages: dormancy, resuscitation, bloom, and decline. Field-grown individual sponge samples at different stages were collected over 7 months (March to September 2005). The dimensions of the silica spicules from these samples were microscopically measured and statistically analyzed. This analysis and the material properties of the spicules allowed them to be classified into four groups representing the different developmental stages of spiculogenesis. Silicatein expression in the bloom stage was more than 100 times higher than that in the other stages and was correlated with the spicule developmental stage. The trend of spicule formation in field-grown sponges was consistent with the trend in cell culture. A new parameter, the maturation degree (MD) of spicules (defined as the ratio of actual to theoretical silica deposition of mature spicules), was introduced to quantify spicule development. Silica spiculogenesis during H. perlevis development was delineated by comparing MD and silicatein expression