Expression levels of the putative carbonic anhydrase (SRCA) gene in S. raphanus.

The specimens were cultivated under standard condition (10 mM CaCl2) or at Ca++-depletion condition (1 mM CaCl2). After incubation periods of 3 to 7 d the animals were collected, RNA prepared and the extent of gene expression was quantified by qRT-PCR, as described under “Material and Methods”. Each data point represents the mRNA level of the respective expressed gene normalized to the amount of β-tubulin transcripts, as means ± SD (n = 6).