(A) Clustal Omega alignment of the Alx1 sequences from Lytechinus variegatus (LvAlx1), Strongylocentrotus purpuratus (SpAlx1), Eucidaris tribuloides (EtAlx1), Parastichopus parvimensis (PpAlx1), Pati…
(A) Six silent mutations were introduced into the MO target site to generate a MO-resistant Lv-alx1 mRNA (LvAlx1.WT.GFP). Boxed nucleotides indicate changes introduced. A mutant form of …
Each vertical bar indicates the mean percentage of 6a9-positive cells relative to uninjected control embryos, calculated from 80 to 100 embryos. Vertical lines represent standard errors. An average …
(A) Fluorescent images showing expression of LvAlx1.GFP proteins in living embryos at 4 hpf. The dotted line indicates the outline of embryo injected with LvAlx1.3STOPS.GFP, which cannot be …
(A) Constructs generated with different N-terminal deletions and truncations. (B–G) Embryos fixed at the mid-late gastrula stage and labelled with 6a9 antibody. (B’–G’) DIC/fluorescence composite …
(A) Alignment of part of the N-terminal region of Alx1 from L. variegatus (LvAlx1), S. purpuratus (SpAlx1) and E. tribuloides (EtAlx1). Boxed region indicates protein sequences that conform to the …
(A) Constructs generated with different C-terminal deletions and truncations. (B–G) Embryos fixed at the mid-late gastrula stage and labelled with 6a9 antibody. (B’–G’) DIC/fluorescence composite …
(A) Constructs with deletions within the C-terminal region. (B–I) Embryos fixed at the mid-late gastrula stage and labelled with 6a9 antibody. (B’–I’) DIC/fluorescence composite images of the same …
(A) Constructs tested. All mutant constructs contained the homeodomain and Domain 2, both of which were required for PMC specification. (B–G) Embryos fixed at the mid-late gastrula stage and …
(A) Top: Clustal Omega alignment of Alx1 homeodomains from L. variegatus (LvAlx1), S. purpuratus (SpAlx1), E. tribuloides (EtAlx1), P. miniata (PmAlx1), P. parvamensis (PpAlx1), H. sapiens (HsAlx1), …
Embryos were visualized using DIC optics. (A–F) Prism stage embryos (ventral views). Arrowheads indicate spicule primordia. (H–M) Early pluteus stage embryos (posterior views). Arrowheads indicate …
(A) Clustal Omega alignment of the predicted amino acid sequences of LvAlx4 and LvAlx1. (C–I) Embryos fixed at the mid-late gastrula stage and labelled with 6a9 antibody. (C’–I’) DIC/fluorescence …
(A) Three silent mutations (solid boxes) were introduced into the S. purpuratus alx1 translational start site to generate a form of Sp-alx1 mRNA (SpAlx1.WT.GFP) that was resistant to the LvAlx1 MO. …
Left side: molecular phylogeny of echinoderm Alx1 and Alx4 proteins (based on Koga et al., 2016), with a hemichordate as an outgroup. Branch lengths are arbitrary. Right side: intron-exon …
(A) Agarose gel showing different LvAlx1 splice forms. Wild-type LvAlx1 is the predominant splice form throughout embryonic development. MB: mesenchyme blastula; EG: early gastrula; LG: late …
Following gene duplication, the ancestral Lv-alx1 underwent rapid evolution through multiple intron gains and more importantly, acquired Domain 2 through exonization of previously non-coding …