Further study on a BF silent allele

Tokunaga, Katsushi; Omoto, Keiichi; Yukiyama, Y; Sakurai, Michiyo; Saji, Hiroo; Maruya, Etsuko

doi:10.1007/bf00291408

Cited by 17 publications

(5 citation statements)

References 10 publications

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“…In contrast to the situation with C2, total deficiency of Factor B has not been seen, suggesting that it may be lethal, and reports of heterozygous deficiency are also rare, However, in two recent studies a heterozygous deficiency of Factor B was described which was thought to be due to a haemolytically inactive gene product (Mauff et al 1980, Suciu-Foca et al 1980, while in a third the existence of a silent allele was indicated (Tokunaga et al 1984).…”

Section: Introductionmentioning

confidence: 98%

The Structure and Genetics of the C2 and Factor B Genes

Campbell

1985

Immunological Reviews

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This review summarises our current knowledge of the genetic organisation, structure and polymorphism of the loci for the complement proteins, C2 and Factor B--class III gene products of the major histocompatibility complex. cDNA probes specific for C2 and Factor B have been used to screen cosmid libraries of human genomic DNA, and this has allowed isolation and characterisation of the corresponding genes. Southern blot analysis of the cosmid clones and of uncloned genomic DNA has shown that there are single C2 and Factor B loci that are less than 500 bp apart. Molecular mapping has revealed that the C2 gene spans approximately 18 kb of DNA. This is in marked contrast to the Factor B gene which is 6 kb in length. The entire gene structure of the Factor B gene has been determined and the interesting features of this gene which have emerged from an examination of the intron-exon boundaries are discussed. C2 and Factor B are polymorphic and structural variants have been detected by differences in charge. The degree of polymorphism at the C2 and Factor B loci has been examined by Southern blot analysis of restriction digests of genomic DNA. Three DNA polymorphisms have been identified in the C2 gene. These polymorphisms subdivide the common allelic variant of C2 (C2C) and reveal that there is much greater variability at the C2 locus than that detected by protein typing. It is suggested that these DNA polymorphisms may serve as useful markers in the genetic analysis of diseases that are related to the major histocompatibility complex.

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Section: Introductionmentioning

confidence: 98%

The Structure and Genetics of the C2 and Factor B Genes

Campbell

1985

Immunological Reviews

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“…A number of studies on BF polymorphism in many ethnic groups in the world has been reported so far. Al though several rare variants including a silent allele [12,13] and some aberrant var iants [14,15] have been disclosed, no var iant like F025, which migrates between F and S, has been reported yet. The F025 variant was stable in repeatable studies.…”

Section: Resultsmentioning

confidence: 99%

A New BF Variant (F025)

Suzuki¹,

Matsumoto²

1986

Hum Hered

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“…Heterozygous factor B deficiency and the presence of a factor B null allele BF*Q0 (frequency in population < 0.001) in several healthy kindreds has been reported on the basis of unusual segregation patterns of the factor B electrophoretic variants and low factor B levels in serum [43][44][45]. Based on immunochemical and functional studies, non-functional factor B alleles (BF*FO.55 and BF*FM, gene frequency 0.001) have also been described only in the heterozygous state [46][47][48].…”

Section: Discussionmentioning

confidence: 99%

Mice Deficient for the Complement Factor B Develop and Reproduce Normally

et al. 1998

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Pekna M, Hietala MA, Landin A, Nilsson AK, Lagerberg C, Betsholtz C, Pekny M. Mice Deficient for the Complement Factor B Develop and Reproduce Normally. Scand J Immunol 1998;47:375-380 Factor B is an essential component of the complement cascade which forms the C3 and C5 convertase of the alternative pathway. Factor B cleavage products also function as cofactors in antibody-independent monocyte-mediated cytotoxicity, macrophage spreading, plasminogen activation and proliferation of B lymphocytes. Several healthy kindreds heterozygous for the factor B null or non-functional allele have been reported but the absence of homozygous factor B deficiency in humans or in animals has been speculated to be caused by the lethality of the phenotype. Here we report the generation of factor B-deficient mice by gene targeting in vivo. These mice were born at the expected Mendelian ratio and they both develop and breed normally in a conventional animal facility. These mice represent a model of complete alternative pathway deficiency. This model enables the dissection of the complement cascade in vivo and the elucidation of the relative contribution of this complement pathway in the various physiological and pathological phenomena ascribed to the complement system.

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Further study on a BF silent allele

Cited by 17 publications

References 10 publications

The Structure and Genetics of the C2 and Factor B Genes

The Structure and Genetics of the C2 and Factor B Genes

A New BF Variant (F025)

Mice Deficient for the Complement Factor B Develop and Reproduce Normally

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