Single-nucleotide polymorphisms in porcine mannan-binding lectin A.
The MBL1 and MBL2 genes encode mannan-binding lectins (MBL) A and C, respectively, that are collagenous lectins (collectins) produced mainly by the liver. Several single-nucleotide polymorphisms (SNPs) in the human MBL2 gene are responsible for various innate immune dysfunctions due to abnormal structure or expression of human MBL-C. The MBL1 gene encodes MBL-A, which has bacteria-binding properties in pigs and rodents but is mutated to a pseudogene in humans and chimpanzees. In these studies, we surveyed both porcine MBL genes for SNPs that might impair disease resistance. Single-strand conformational polymorphism (SSCP) analysis of MBL cDNAs from porcine liver revealed three SNPs within the coding region of MBL1 in various breeds of pigs. One nonsynonymous SNP that substituted cysteine for glycine in the collagen-like domain of pig MBL-A was found by a multiplex PCR test in all European pig breeds examined, with allele frequencies ranging from 1.4 to 46.4%. No SNPs were identified in the coding region of porcine MBL2 but the expression of MBL-C in the liver was widely variable in comparison to the expression of MBL-A, GAPDH, PigMAP, and haptoglobin. These results indicate that some pigs have a miscoding defect in MBL-A and a possible expression defect in MBL-C, which are analogous to coding and promoter polymorphisms that affect human MBL-C.
Lillie
Brandon N
BN
Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Keirstead
Natalie D
ND
Squires
E James
EJ
Hayes
M Anthony
MA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D008099:Liver / Q000378:metabolism; D037601:Mannose-Binding Lectin / Q000235:genetics*; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D018807:Polymorphism, Single-Stranded Conformational; D016415:Sequence Alignment; D034421:Sus scrofa / Q000235:genetics / Q000276:immunology*
D037601:Mannose-Binding Lectin