Phylogenetic comparison of lcp1 first exon size and
discovery of several evolutionarily-conserved regions (ECRs).
A. Comparative size of the lcp1 first
intron in selected vertebrate genomes. 5’UT1 = purple; protein-coding
regions = green.
B. mVISTA alignment of the lcp1 first
intron in the amazon molly, stickleback, and pla-tyfish reveals 4 evolutionarily
conserved regions (> 50% similarity), labeled ECR1 through ECR4.
C. Spliced ESTs show an intronic ‘foothill’
(orange arrow) adjacent to the canonical exon boundary, indicating
transcriptional activity. These foothill ESTs are stage-specific to shield or
segmentation stage embryos (see Table
3).
D. A CAGE-seq cluster active between sphere and somite
stages suggests a devel-opmentally-regulated alternative transcriptional start
site (TSS) approximately 500 bp upstream of the canonical exon boundary.
E&F. Activating histone modifications (H3K4me3 and
H3K27ac) overlap the ESTs and the CAGE-seq cluster. These ontogenetic marks
appear in only a narrow stage-specific window, from dome through shield.
5’
UTR = 5’ untranslated region; ECR =
evolutionarily conserved region; lcp1 =
L-plastin.