Porcine luteal cells express monocyte chemoattractant protein-1 (MCP-1): analysis by polymerase chain reaction and cDNA cloning.

RT PCR employing poly(A+)RNA from porcine luteal cells and a combination of primers designed from the known bovine MCP-1 cDNA identified the luteal cells as a source of MCP-1. This finding is corroborated by results from Northern analysis using total RNA from luteal cells. To characterize the complete porcine MCP-1 cDNA, poly (A+)RNA was isolated from porcine corpus luteum, transcribed into cDNA and the latter cloned into the expression vector lambda Uni-ZapXR. A digoxigenin-labeled DNA probe of 375 bp was obtained by PCR and employed to screen the library. From the positive clones pMCP5, pMCP7 and pMCP10, the clone pMCP5 was selected and both strands of the cDNA insert were sequenced. The cDNA insert was 742 bp long, with an open reading frame (ORF) encoding a protein of 99 amino acid residues which by comparison with known amino acid sequences of MCPs yielded highest identities with MCP-1 sequences. We therefore assume that pMCP5 encodes the amino acid sequence for porcine MCP-1.