Table 1.

Cyst elements responsible for stress tolerance during diapause and quiescence

Protective element	Characteristics/functions
Shell	Rigid; selective barrier; Arp-CBP-A, Arp-CBP-B, and Arp-CBP-C, and SGEGs are important shell proteins; role in development; protection from UV radiation and other stressors
Trehalose	Non-reducing disaccharide α-d-glucopyranosyl-1-1-α-d-glucopyranoside; prominent in many anhydrobiotic organisms; diapause-specific in Artemia; protects proteins and membranes during desiccation by water replacement and/or vitrification; digested by trehalase; trehalase gene regulated by ArTAP; energy source
LEA proteins	Groups 1 and 3 LEA proteins are found in Artemia; unstructured proteins; prominent in many anhydrobiotic organisms; occur in various cell locations; important in mitochondria; diapause-specific in Artemia; protect proteins and membranes by molecular shielding and/or vitrification during desiccation
Molecular chaperones	sHSPs and artemin; ATP-independent; diapause-specific; very abundant; protect proteins from irreversible denaturation even when ATP is limiting; mediate tolerance to desiccation and freezing; influence embryo development