>>13947559>>13947566>>13947698>2/2"the outline of the membranes, fine threads inside the lumen, the baseplate, and a thinfilm surrounding the CaCO3 crystals. The CAP is a highly complex soluble acidic
polysaccharide containing at least 13 different monosaccharide residues, including
uronic acids, mono- and dimethylated sugars, and sulfate esters (Fichtinger-
Schepman et al. 1981). It has been shown that this CAP can inhibit crystal growth
(Borman et al. 1982) and influence crystal morphology by site-specific attachment to
crystallographic steps (Henriksen et al. 2004). It is therefore thought that this
polysaccharide has a regulatory function in the inhibition, termination, and therefore
modeling of crystal growth. The regulation of coccolith shape is also thought to be
dependent on the morphology of the membrane of the coccolith vacuole. Using
various inhibitors, Langer et al. (2010) experimentally demonstrated that cytoskeletal
microtubules and actin filaments play a role in coccolith morphogenesis in
E. huxleyi, presumably by determining the shape of the coccolith vesicle. After it
is completed, the coccolith is transported to the cell membrane and exuded to the
extracellular coccolith cover. In the motile scale-bearing form of E. huxleyi, the
scales are formed in the Golgi apparatus, but do not calcify, although a cv-rb system
is present (Klaveness 1972)."
