TISSUE-SPECIFIC EXPRESSION OF 2 ARTEMIA-FRANCISCANA SARCO ENDOPLASMIC-RETICULUM CA-ATPASE ISOFORMS

The sarco/endoplasmic reticulum Ca-ATPase (SERCA) gene from Artemia fr anciscana is transcribed into two mRNAs that code for two different en zyme isoforms. We investigated the tissue-specific expression of each mRNA by in situ hybridization of larval tissue sections. One of the is oforms is expressed in the muscle fibers of the appendages. The other isoform is generally expressed throughout all tissues of the larvae. T he tissue distribution of these two isoforms is very similar to the on e described for the two homologous isoforms generated from the vertebr ate SERCA 2 gene, and shows the evolutionarily conserved nature of the ir tissue-specific expression.