A study of the Spec1 gene encoding a major calcium-binding protein in the embryonic ectoderm of the sea urchin

The Spec1 and Spec2 gene family is expressed exclusively in the aboral ectoderm of the sea urchin, Strongylocentrotus purpuratus, and encodes a number of calcium-binding proteins belonging to the troponin C-calmodulin-myosin light chain superfamily. A study of the structure and expression of the Spec1 gene is presented. Genomic clones have been isolated that comprise a 60 kb region of the S. purpuratus genome and include the Spec1 gene. There is a single polymorphic Spec1 gene in the sea urchin genome. This gene is 10.3 kb in length and contains six exons. S;In a separate study, two oligonucleotide probes were developed that are complementary to the nucleotides encoding the third calcium-binding domain of members of the troponin C superfamily. These probes are of general use in detecting and isolating genes that are members of this superfamily. An analysis of the evolution in gene structure of members of the troponin C superfamily is presented.;Microinjection experiments of Spec1/CAT fusion constructs into single-cell sea urchin embryos were performed to determine which cis sequences associated with the Spec1 gene are biologically important for proper temporal and spatial expression. Evidence presented here suggests that there are sequences important for the level of Spec1 gene transcription located between 500 and 2000 base pairs upstream from the initiation of Spec1 gene transcription. The presence or absence of a portion of the RST repeat element in constructs containing transcription from the construct.