Discoordinate expression of pancreatic lipase and two related proteins in the human fetal pancreas

The lipase gene family contains a large number of members. Among the most c losely related are pancreatic triglyceride lipase (PTL) and two pancreatic lipase-related proteins (PLRP1 and PLRP2). Previous studies in rodents demo nstrated divergent temporal expression of the genes encoding these proteins . PLRP1 and PLRP2 were expressed in fetal pancreas, whereas PTL was not exp ressed until pups were several weeks old. To determine whether the human pa ncreas has a similar expression pattern for these genes, we determined the levels of each mRNA in fetal pancreas at various ages. A reverse transcript ase-PCR method was developed and used to quantify the mRNA levels for the t hree species normalized to the mRNA encoding cyclophillin. The mRNA encodin g PLRP1 and PLRP2 was present by 16 wk in the fetal pancreas. In contrast, the mRNA encoding PTL was not present in the fetal pancreas. This pattern o f expression suggests that the genes encoding theses proteins have differen t regulatory elements controlling temporal expression and provides another example of nonparallel expression of genes encoding pancreatic exocrine pro teins.