Meeting Abstract

SICB+    The involvement of a phosphate transporter in crayfish molt and mineralization Shaked, SA*; Abehsera, S; Weil, S; Aflalo, ED; Eichler, J; Ohana, E; Sagi, A; Ben-Gurion University of the Negev; Ben-Gurion University of the Negev; Ben-Gurion University of the Negev; Ben-Gurion University of the Negev; Ben-Gurion University of the Negev; Ben-Gurion University of the Negev shaiavsh@post.bgu.ac.il

In vertebrates, a significant component of the mineralization mechanism includes the transport of phosphate by SLC20 proteins, which are Na+-coupled phosphate cotransporters. On the contrary, the mechanism of phosphate transport for skeletal biomineralization in invertebrates has remained to be elucidated. In this study, a molt-related transcriptomic library and a novel binary patterning approach were exploited to reveal an SLC20 transport protein exhibiting molt-related expression in the crayfish Cherax quadricarinatus. Functional genomic experiments using RNAi demonstrated that the newly found Cq-SLC20 phosphate transporter is responsible for the transport of phosphate to the mineralization site of amorphous calcium carbonate (ACC) in the gastroliths (transient storage organs of minerals which are formed during the molt cycle of C. quadricarinatus). The in-vitro assay showed increased crystallinity in gastroliths following SLC20 silencing, confirming the hypothesis of phosphate involvement in the stabilization of amorphous calcium carbonate (ACC) phases. In invertebrates, such as crustaceans, whose exoskeletons are composed mostly of calcium carbonate, phosphate also plays a role in the mineralization of various skeletal structures, including the stabilization of amorphous calcium salt phases. The discovery of the involvement of the Cq-SLC20 transport protein in the active transport of phosphate ions and skeletal mineralization of an invertebrate demonstrates the conservation of skeletal phosphate transportation tools from early arthropods to mammals, representing an important link in the evolutionary history of phosphate biominerals.