Polymorphism in BoLA-DRB3 exon 2 correlates with resistance to persistent lymphocytosis caused by bovine leukemia virus.

The relationship between polymorphism of the bovine lymphocyte Ag (BoLA)-DRB3 gene and resistance and susceptibility to persistent lymphocytosis (PL) caused by bovine leukemia virus (BLV) was investigated. Exon 2 of the BoLA-DRB3 gene was cloned from animals with BoLA haplotypes previously found to be associated with resistance and susceptibility to PL. Sequence analysis revealed the presence of the amino acids Glu-Arg (ER) at putative Ag binding residues 70 and 71 only in BoLA haplotypes associated with resistance to PL.

Order of bovine DRB3, DYA, and PRL determined by sperm typing.

The order and recombination fractions (theta) between the bovine major histocompatibility complex DRB3, DYA, and prolactin (PRL) genes were determined by typing of 254 sperm from a triply heterozygous bull. A recently developed method, primer extension preamplification (PEP), was used to amplify the bovine sperm genome prior to amplification of specific loci by the polymerase chain reaction (PCR). At least 28 copies of the DRB3, PRL, or DYA gene were obtained from 50 cycles of PEP.

Lipid mixing is mediated by the hydrophobic surfactant protein SP-B but not by SP-C.

Pulmonary surfactant contains two families of hydrophobic proteins, SP-B and SP-C. Both proteins are thought to promote the formation of the phospholipid monolayer at the air/fluid interface of the lung. The excimer/monomer ratio of pyrene-labeled PC fluorescence intensities was used to investigate the capacity of the hydrophobic surfactant proteins, SP-B and SP-C, to induce lipid mixing between protein-containing small unilamellar vesicles and pyrene-PC-labeled small unilamellar vesicles.

Close linkage between bovine prolactin and BoLA-DRB3 genes: genetic mapping in cattle by single sperm typing.

The major histocompatibility complex and prolactin (PRL) genes are syntenic in humans and cattle but the genetic distance between these loci has not been determined for either species. In this study, the sperm typing technique was used to measure the recombination frequency between the bovine lymphocyte antigen (BoLA)-DRB3 and PRL loci. A total of 300 sperm were typed from one doubly heterozygous bull for segregation of DRB3 and PRL alleles.

Extensive polymorphism of the BoLA-DRB3 gene distinguished by PCR-RFLP.

A polymerase chain reaction (PCR)-based method is described for typing of alleles of the bovine lymphocyte antigen (BoLA)-DRB3 gene. A total of 30 DRB3 alleles were distinguished by digestion of PCR amplification products of BoLA-DRB3 exon 2 with RsaI, BstYI and HaeIII (PCR-RFLP). All restriction fragment patterns, with the exception of one HaeIII pattern, were consistent with restriction sites that were found among 14 previously sequenced DRB3 alleles.

Surfactant protein composition of lamellar bodies isolated from rat lung.

Lamellar bodies isolated from rat lung contain all three classes of surfactant proteins, SP-A, SP-B and SP-C, as determined by immunoblot analysis. The amounts of the surfactant proteins present in lamellar bodies, determined by sandwich e.l.