“…Activated Pmar1 in turn inhibits the transcriptional repressor HesC, resulting in derepression of the major skeletogenic TFs, including Alx1, Ets1 and Tbr Revilla-i-Domingo et al, 2007). The transcriptional activation of these skeletogenic TFs triggers specification of the large micromeres to become PMCs (Khaner and Wilt, 1991;Koga et al, 2010;Sharma and Ettensohn, 2010;Damle and Davidson, 2011;Sharma and Ettensohn, 2011;Lyons et al, 2014;Saunders and McClay, 2014). Alx1, which belongs to the evolutionarily conserved Cart1/Alx3/Alx4 family of Paired-class homeodomain proteins, plays a central role in the skeletogenesis of sea urchins and vertebrates (Ettensohn et al, 2003;Uz et al, 2010;Damle and Davidson, 2011;McGonnell et al, 2011;Dee et al, 2013).…”