Posterior hoxa genes expression during zebrafish bony fin ray development and regeneration suggests their involvement in scleroblast differentiation.
Inhibition of BMP signaling during zebrafish fin regeneration disrupts fin growth and scleroblast differentiation and function.
Figure 21 shows a scleroblast with a large space that had been occupied by a spicule.
The cells beneath the pinacoderm differentiate to scleroblasts that form triradiate spicules.
Scleroblasts characteristically have multivesicular bodies.
Examination of a large number of electron micrographs revealed that the flagellated cells become the three principal cell types of juvenile sponges--that is, pinacocytes, scleroblasts, and choanocytes.
et spiculogenese chez une eponge siliceuse.
These cells, known as scleroblasts, are responsible for the synthesis and deposition of the lepidotrichial extracellular matrix in the region turned to the basal layer, and therefore between the row of scleroblasts and the basal layer of the epidermis.
With six days of regeneration, scleroblasts migrated to the other side of the hemisegment of the regenerating lepidotrichia and were interposed between the epidermis and the hemisegment, maintaining the disposition of a single layer of cells involving, this time, both sides of the lepidotrichial hemisegment and started to secrete extracellular matrix to the hemisegment direction.
The migration of scleroblasts to the other side of the hemisegment of the regenerating lepidotrichia, responsible for the growth in width of the hemisegment, initiated only on the tenth day after amputation and the nucleation centre formation, that is, the beginning of calcium salts deposition in the lepidotriquial matrix happened around the twelfth day of regeneration for the treated group with doses of 20 and 30 mg.
Sclerite formation occurs within vacuoles of scleroblasts
(Dunkelberger and Watabe, 1974; Kingsley and Watabe, 1982) where the sclerites develop as an aggregate of calcite fibers, which are laid in concentric layers.
Around the base of the pillar bridges are some scleroblasts
that are not in immediate contact with the ligament.