Tissue-specific expression of two Artemia franciscana sarco/endoplasmic reticulum Ca-ATPase isoforms.

The sarco/endoplasmic reticulum Ca-ATPase (SERCA) gene from Artemia franciscana is transcribed into two mRNAs that code for two different enzyme isoforms. We investigated the tissue-specific expression of each mRNA by in situ hybridization of larval tissue sections. One of the isoforms is expressed in the muscle fibers of the appendages. The other isoform is generally expressed throughout all tissues of the larvae. The tissue distribution of these two isoforms is very similar to the one described for the two homologous isoforms generated from the vertebrate SERCA 2 gene, and shows the evolutionarily conserved nature of their tissue-specific expression.