Expression of actin isoforms in Artemia

Complementary DNA clones have been isolated from the crustacean Artemia that code for four different actin isoforms. The nucleotide sequence of these clones has been determined. The four clones are about 80% identical in their translated regions but unrelated in their untranslated regions. The cloned Artemia actins are very similar in their deduced amino acid sequences to other invertebrate actins, especially in the amino terminal region. The analyses of the steady-state levels of actin mRNAs during Artemia development has shown a parallel increase in the levels of all four mRNAs between five and ten hours of development. Whole-mount embryo hybridizations have shown that one of the clones codes for a muscular actin isoform while the other three clones code for cytoplasmic isoforms.