Characterization of the Mouse Collectin Gene Locus

Three of the four known mouse collectin genes have been mapped to chromosome 14. To further characterize the spatial relationship of these genes, a bacterial artificial chromosome (BAC) library of mouse chromosome 14 was screened using mouse surfactant protein (SP)-A and -D complementary DNAs (cDNAs). One large clone hybridized to both SP-A and SP-D cDNAs and was found by polymerase chain reaction (PCR) to contain sequences from one of the mouse mannose-binding lectin genes (Mbl1). We used Southern mapping and subcloning of overlapping restriction fragments to characterize the gene locus. Mapping was confirmed by fluorescent in situ hybridization of fiber-stretched BAC DNA and by Southern hybridization of restriction endonuclease–digested and PCR-amplified genomic DNA. We found that the SP-A, Mbl1, and SP-D genes reside contiguously within a 55-kb region. The SP-A and Mbl1 genes are in the same 5′ to 3′ orientation and 16 kb apart. The SP-D gene is in the opposite orientation to the two other collectin ge...