Presence and localization of chitinase in Hydra and Podocoryne (Cnidaria, Hydrozoa)

Abstract

The presence of chitinase was checked in three species of Hydrozoa by incubating y-chitin-red (Hackmann and Goldberg, '64) with crude extracts of entire polyps or parts of them. When the substrate is lytically degraded it releases its soluble red dye the quantities of which were spectrophotometrically (A = 510 nm) determined. Crude extracts of entire polyps of Hydra attenuata Pall., H. circurncincta M. Sch., and Podocoryne carnea M. Sars all contained active chitinase. A more detailed localization which was studied in H. attenuata revealed that the enzyme is confined to the endoderm of the body column and that it is absent in the ectoderm and in the tentacles which contain the stenotele nematocysts. Therefore, it is very unlikely that enzymatic action of chitinase aids the nematocyst in boring holes in the cuticule of the prey.

A transcriptional time-course analysis of oral vs. aboral whole-body regeneration in the Sea anemone Nematostella vectensis

“…This group contained mostly chitinase genes, as well as von willebrand factor d and egf domain-containing genes that are also predicted to be secreted and to harbor a chitin binding domain found in animal chitinases. These enzymes have been reported to be expressed in the endoderm of the body column of three Hydra species [ 84 ] and were suggested to function in prey digestion. The first cnidarian chitinase that was cloned and studied in the hydroid Hydractinia , was rather found to be highly expressed in the ectodermal layers of the stolons of the colonies and of the basal (aboral) part of the polyps, and is proposed to act in immunological protection of the latter from chitinous pathogens [ 85 ].…”

Glycogen Synthase Kinase 3β Inhibitor Delivered by Chitosan Nanocapsules Promotes Safe, Fast, and Efficient Activation of Wnt Signaling In Vivo

“…Overall, chitosan has been shown to be degraded by enzymes such as chitinases and chitosanases, as well as other enzymes such as chitobiases and lysozime Daphnia magna) or Artermia salina nauplii (under laboratory conditions), both possessing a chitin skeleton. , Actually, the presence of chitinase activity has been reported to be confined to the endoderm of the body column in Hydra . Interestingly, our data reported in Figure S3A demonstrate that the Hydra -conditioned medium does not induce release of the encapsulated dye, thus suggesting that capsule degradation may occur by enzymatic activity at the animal cell surface and not by secreted enzymes.…”

“…63,64 Actually, the presence of chitinase activity has been reported to be confined to the endoderm of the body column in Hydra. 65 Interestingly, our data reported in Figure S3A demonstrate that the Hydra-conditioned medium does not induce release of the encapsulated dye, thus suggesting that capsule degradation may occur by enzymatic activity at the animal cell surface and not by secreted enzymes. Therefore, even though we did not investigate further this aspect of cargo relief mechanisms, Nile red discharge may occur through nanocapsule degradation/erosion mediated by chitinases or other enzymatic activities available at the epithelial cell layer, including membranes, glycocalyx, and associated bacteria (see Figure S5).…”

Exoskeletons of Bougainvilliidae and other Hydroidolina (Cnidaria, Hydrozoa): structure and composition

“…Chitin synthetase (Chs) is found in Hydractinia echinata ( Mali et al, 2004 ). Chitinase is restricted to the gastrodermis of the hydrocaulus and absent in the epidermis and tentacles of Podocoryna carnea (accepted as Hydractinia carnea ) and Hydra attenuata (accepted as Hydra circumcincta ) ( Klug et al, 1984 ). Phenoloxidase, produced in epidermal cells of Laomedea flexuosa , is involved in cross-linking of perisarc components ( Knight, 1970 ; Kossevitch, Herrmann & Berking, 2001 ).…”