Meeting Abstract

P2.82  Thursday, Jan. 5  Expression pattern of flamingo during sea urchin early development. OOKA, Shioh*; WANG, Lingyu; WIKRAMANAYAKE, Athula; Univeristy of Miami, FL; Univeristy of Miami, FL; Univeristy of Miami, FL sooka@bio.miami.edu

Wnt signaling pathways are implicated in numerous developmental processes. The Wnt/PCP pathway plays an important role in cell polarity rather than in cell fate decisions. It has been reported that convergent-extension (CE) movements driving gastrulation are regulated by the Wnt/PCP pathway. Flamingo (Fmi) is known as a core member of the Wnt/PCP pathway. It has been reported that Fmi is an atypical cadherin, and that Fmi plays a critical role in CE movements in vertebrates during gastrulation. In addition to the cadherin repeats in extracellular region, Fmi contains a seven-pass transmembrane domain, and a SE/D domain which is highly conserved sequences in the intracellular region. In sea urchin, extension of the archenteron is driven by CE, but molecular mechanisms which regulate this process are not well understood to date. Thus, in the present work, expression pattern of flamingo homolog of the sea urchin, Strongylocentrotus pupuratus (Spfmi), was analyzed during the early development in order to begin to study its role in sea urchin gastrulation. Spfmi mRNA was broadly seen in the unfertilized eggs and cleavage stages. By hatched blastula stage, Spfmi mRNA was restricted to the vegetal plate, which is the region initiating future primary invagination. Subsequently, Spfmi accumulates around the blastopore and the archenteron. These results suggest that Spfmi may play a role in regulating CE during gastrulation. Hence, a morpholino antisense oligonucleotide (MO) against Spfmi was injected into zygotes to investigate how SpFmi is implicated in gastrulation. MO-mediated Spfmi knockdown resulted in failing to elongate the archenteron, suggesting that SpFmi appears to be essential for elongating the archenteron during sea urchin gastrulation.