What is "polycystine"

Polycystine \Pol`y*cys"tine\, a. (Zo["o]l.) Pertaining to the Polycystina. -- n. One of the Polycystina.

a. (context zoology English) Pertaining to the Polycystina. n. 1 (context zoology English) One of the Polycystina. 2 (context biochemistry English) a homopolymer of the amino acid cystine.

The polycystines are a group of radiolarian protists. They include the vast majority of the fossil radiolaria, as their skeletons are abundant in marine sediments, making them one of the most common groups of microfossils. These skeletons are composed of opaline silica. In some it takes the form of relatively simple spicules, but in others it forms more elaborate lattices, such as concentric spheres with radial spines or sequences of conical chambers.