Molecular characterization of murine pancreatic phospholipase A(2)

The pancreatic secretory phospholipase A(2) (sPLA(2)IB) is considered to be a digestive enzyme, although it has several important receptor-mediated fu nctions. In this study, using the newly isolated murine sPLA(2)IB cDNA clon e as a probe, we demonstrate that in addition to the pancreas, the sPLA(2)I B mRNA was expressed in extrapancreatic organs such as the liver, spleen, d uodenum, colon, and lungs. We also demonstrate that sPLA(2)IB mRNA expressi on was detectable from the 17(th) day of gestation in the developing mouse fetus, coinciding with the time of completion of differentiation of the pan creas. Furthermore, the mRNA expression pattern of sPLA(2)IB was distinct f rom those of sPLA(2)IIA and cPLA(2) in various tissues examined. The murine sPLA(2)IB gene structure is well conserved, consistent with findings in ot her mammalian species, and this gene mapped to the region of mouse chromoso me 5P1-G1.1. Taken together, our results suggest that sPLA(2)IB plays impor tant roles both in the pancreas and in extrapancreatic tissues and that in the mouse, its expression is developmentally regulated.