Pancreatic lipase mrna isolated from female mouse lacrimal glands

Purpose: To identify molecular differences in the expression patterns of mRNAs between the lacrimal glands of males and females, we employed differential display analysis. Method; We isolated poly(A)+ RNA from the lacrimal glands of male and female adult Swiss Webster mice, reverse transcribed the RNA, amplified the cDNA with multiple sets of primers using the polymerase chain reaction (PCR), and compared the resultant DNA fragments from males and females on 6% polyacrylamide, silver stained gels. We re-amplified the differentially expressed DNA fragments using PCR, subcloned and sequenced the DNA. We labeled the subcloned DNA with 32P and hybridized the DNA to Northern blots of lacrimal gland RNA isolated from male and female Swiss Webster and Skh-1 mice. Results; One primer combination consistently produced a prominent product of 240 bases (clone Y2) from female infraorbital and exorbital lacrimal gland RNA, but not from male lacrimal gland RNA. BLAST data base comparisons of the clone Y2 DNA sequence indicated 92% identity with the 3' end of rat pancreatic lipase (GenBank, RNLIPRNA), a triacylglycerol lipase. Clone Y2 exhibited only 62% identity with the 3' end coding region of mouse cylotoxic T lymphocyte lipase (GenBank, MUSCTLL). Labeled clone Y2 DNA hybridized to a 1.9kb band in Northern blots of female lacrimal gland RNA from Swiss Webster and Skh-1 mice, and to pancreatic RNA from both males and females. Clone Y2 did not hybridize detectably to RNA from male lacrimal glands. Conclusions: The mRNA for the lipolytic enzyme pancreatic lipase is expressed in the lacrimal glands of female mice. If the lacrimal glands secrete pancreatic lipase into the tears, this enzyme mav modifv tear film lioids at the lioid/aaueous interface.