The genetics of the sixth and seventh components of complement in the dog: Polymorphism,linkage, locus duplication,and silent alleles

The complement components C6 and C7 exhibit genetic polymorphism in the domestic dog. In the case of C6, there is a single locus with a null allele and two structural alleles; in the case of C7, there are two linked loci, each with three structural alleles. There is a null allele or locus deletion at one of these loci. In all cases, inheritance is autosomal and codominant. The C7 loci are closely linked to each other and to C6. This complex is not close to the dog major histocompatibility complex (MHC) locus.     

Restriction fragment length polymorphism of the murine C4 and Slp genes: two C4 groups.

We have examined the related H-2 genes coding for the fourth component of complement (C4) and the sex-limited protein (Slp) from 30 inbred mouse strains by Southern blot analysis. With four restriction enzymes, 11 RFLP patterns distributed among 26 different H-2 haplotypes have been identified. Strains of the same serologic H-2 haplotype were found to have identical RFLP patterns. It was confirmed that the number of C4-related genes in most haplotypes is two, Slp and C4; but H-2SWI6 (SWI6) and SWI9, which have the same RFLP pattern, have four and Sw7 has five. Although C4 and Slp have many similarities, they also were found to contain distinctive features: relative to Slp, each C4 allele examined has two insertions totaling 1.1 kb located in introns 14 and 15; and each Slp allele examined, excluding hybrids, has a provirus insertion upstream. No other large deletions or insertions were detected. The RFLP patterns are also due to 10 polymorphic restriction sites, which have been placed on standard maps; two are associated with Slp and eight are associated with C4.Sk strains, the only strains that express low serum levels of C4, have the same RFLP phenotype as Sw14, Sw18, and Swx; Sk may have arisen from a recent common ancestor of these strains. Homologous recombination has been important in the formation of existing C4 alleles. However, based on complete linkage disequilibrium between three RFLP internal to C4, the haplotypes have been divided into two groups that may have functional significance.     

Genetic polymorphism of complement C6 and haplotype analysis between C6 and C7 in a Japanese population

Summary Genetic polymorphism of C6 in the Japanese population has been described using polyacrylamide gel isoelectric focusing electrophoresis followed by the electrophoretic blotting technique, and haplotype analysis between C6 and C7 has also been investigated. In 565 plasma samples five different common patterns and three rare variant patterns were observed, and these were controlled by autosomal codominance at a single locus with three common and one rare alleles. These alleles were designated C6^*B, C6^*A, C6^*B2, and C6^*M, and gene frequencies were estimated to be 0.50265, 0.43186, 0.06018, and 0.00531 for C6^*B, C6^*A, C6^*B2, and C6^*M, respectively. It is noteworthy that C6^*B2 has a polymorphic frequency in the Japanese population. The distribution of phenotypes fitted the Hardy-Weinberg equilibrium. Two combinations between C6 and C7 alleles, namely C6B-C7B and C6M-C7B, were shown to be in significant positive linkage disequilibrium. The presence of allelic combinations showing linkage disequilibrium suggests the close proximity between the C6 and C7 loci.     

Genetic polymorphism of the sixth component of complement (C6) in the pig

Summary
Using agarose gel isoelectric focusing and immunoblotting with rabbit anti-rabbit C6, a genetic polymorphism has been found in the sixth component of complement (C6) in six breeds of pigs. The C6 locus was highly polymorphic. Family data indicated that pig C6 pheno-types were inherited by means of five codomonant alleles named C6 ^A, C6 ^B, C6 ^C, C6 ^D and C6 ^E at a single autosomal locus. C6 deficiency in two of 241 individuals tested was found, which suggested the presence of a null allele in pig populations. Marked breed differences among the gene frequencies and heterozygosities at C6 locus were observed.     

Family study on the polymorphisms of the sixth and seventh components (C6 and C7) of human complement: linkage and haplotype analyses

Genetic polymorphisms of the sixth and seventh complement components (C6 and C7) have been studied in Japanese family material using polyacrylamide gel isoelectric focusing followed by immunoblotting. Three common and four rare alleles were observed at the locus for C6. Inheritance of the two rare C6 variants, M11 and B3, was first confirmed. Three common C7 allotypes were classified as C7 1, C7 2, and C7 4, respectively. Linkage analysis confirmed the close linkage between the loci for C6 and C7. The maximum lod score was 8.43 at phi = 0 (95% confidence limits: phi = 0 and phi = .07). No significant linkage disequilibrium was found between C6 and C7 in directly determined haplotypes of unrelated parents.     

Genetic variation of the sixth component of complement (C6) in the Manx shearwater (Puffinus p. puffinus)

A polymorphism in the sixth complement component (C6) has been investigated by isoelectric focusing. The results indicate that C6 is coded by genes at a single autosomal locus. Six structural alleles have been identified, a null allele is also postulated. Five island colonies of Shearwater were investigated, two alleles C6 A and C6 B predominate in all sites. The ability of rabbit C5 and C7 to combine successfully with avian C6 indicates the functional sites of these molecules are highly conserved.     

Genetic variation of the sixth component of complement (C6) in the Manx shearwater (Puffinus p. puffinus)

A polymorphism in the sixth complement component (C6) has been investigated by isoelectric focusing. The results indicate that C6 is coded by genes at a single autosomal locus. Six structural alleles have been identified, a null allele is also postulated. Five island colonies of Shearwater were investigated, two alleles C6 A and C6 B predominate in all sites.
The ability of rabbit C5 and C7 to combine successfully with avian C6 indicates the functional sites of these molecules are highly conserved.     

中国广东省四个民族C6别型遗传特点——附三个新的罕见变异型报道

应用等电聚焦-免疫印迹法调查了广东省四个民族(汉、苗、黎和回族)C6遗传多态性。广州地区汉族C6等位基因频率分别为:C6*A0.4225,C6*B0.5288,C6*B2 0.0387和C6*R(M91,M92,M11,B21)0.0100。海南岛三个少数民族C6遗传特点与广州汉族相似,均处于Hardy-Weinberg平衡状态。共发现五个罕见基因的杂合子,其中三个等位基因为首次报道。     

Polymorphism of the sixth component of complement (C6) in the dog

Isoelectric focusing was used to identify five alleles at the locus determining the production of the sixth component of complement (C6) in the dog. Four of these alleles,C6 ¹, C6², C6⁴,andC6 ⁵,were studied in family pedigrees and shown to be inherited in a codominant autosomal fashion. All alleles except forC6 ⁴occurred commonly in the multiple breeds tested. This investigation was supported by Grant HL 17265 awarded by the National Institute of Heart, Lung, and Blood Diseases, DHEW, and by Grants CA 18105 and CA 31787 awarded by the National Cancer Institute.     

Induction of β(A4)-amyloid in primates by injection of Alzheimer’s disease brain homogenate

Amyloid plaques, associated with argyrophilic dystrophic neurites, and cerebral amyloid angiopathy (CAA), but no neurofibrillary tangles, were found in the brains of three middle-aged marmoset monkeys that had been injected intracerebrally (ic) 6–7 yr earlier with brain tissue from a patient with early-onset Alzheimer’s disease. Such changes were not found in the brains of three age-matched control marmosets. Immunochemically the amyloid plaques and CAA stained with antibody to β(A4)-protein. The plaques and CAA displayed dichroic birefringence when stained with Congo red and viewed under polarized light. β(A4)-amyloid plaques and CAA were also found in the brain of one of two marmosets injectd ic 6 yr previously with brain tissue from a patient with prion disease with concomitant β(A4)-amyloid plaques and CAA. An occasional β(A4)-amyloid plaque was found in the brains of two of four marmosets injected ic >4.5 yr previously with brain tissue from three elderly patients, two of whom had suspected (but untransmitted) CJD. No β(A4)-amyloid plaques or CAA were found in six marmosets who were older than the injected animals, in four marmosets that had not developed spongiform encephalopathy (SE) having been injected several years previously with human brain tissue from three younger patients with suspected or atypical prion disease, or in 10 younger marmosets who had undergone various neurosurgical procedures. Seventeen marmosets injected in the same way with brain tissue from patients or animals with SE developed SE 17–49 mo after injection. These results suggest that β(A4)-amyloidosis is a transmissible process comparable to the transmissibility of SE.     

Genetic polymorphism of the sixth component of complement (C6) in dogs

Using agarose gel isoelectric focusing and immunoblotting with rabbit anti-rabbit C6, a genetic polymorphism was found in the sixth component of complement (C6) in 18 Asian native breeds or populations and three European breeds of dog. The C6 locus was highly polymorphic. The phenotype distribution data indicated that dog C6 phenotypes were controlled by seven codominant alleles, C6 ^A, C6 ^B, C6 ^C, C6 ^D, C6 ^E, C6 ^F and C6 ^G, at a single autosomal locus. Breed differences were observed among the gene frequencies, especially between Asian and European breeds. Two gene flows from the adjacent areas into Japanese native dogs were postulated.     

基于SSR标记探讨三种金花茶植物的遗传多样性和遗传结构

薄叶金花茶、小花金花茶和小瓣金花茶是三种濒危金花茶植物,为了解珍稀濒危植物遗传多样性和遗传结构,该研究利用微卫星标记对他们的7个种群共184个个体进行了遗传多样性和遗传结构分析。结果表明:11个位点共检测到等位基因92个。在物种水平上,小瓣金花茶平均等位基因数(N_A)为3.9、有效等位基因数(N_E)为2.328、观测杂合度(H_o)为0.520、期望杂合度(H_e)为0.501,高于薄叶金花茶和小花金花茶。在种群水平上,有效等位基因数(N_E)在1.788～2.466之间,期望杂合度(H_e)在0.379～0.543之间;种群间遗传分化系数(FST)在0.143 7～0.453 3之间,种群间基因流(N_m)在0.301 5～1.488 9之间。AMOVA分子变异分析显示65.72%的变异存在于种群内。三种金花茶具有较低水平的遗传多样性和高水平的种群间遗传分化。STRUCTURE和PCoA种群遗传结构分析结果将取样种群分为2组,即薄叶金花茶和小花金花茶大部分个体分为一组,小瓣金花茶大部分个体分为一组。现存所有种群应根据实际情况尽快采取就地保护或迁地保护措施。     

Role of CYP2C9 and CYP2C19 polymorphisms in patients with atherosclerosis

The arachidonic acid metabolizing CYP enzymes with prominent roles in vascular regulation are epoxygenases of the two gene family which generate epoxyeicosatrienoic acids. Carriers of CYP2C9 mutant alleles exhibit a diminished CYP2C9 metabolic capacity leading to decreased endothelium-derived hyperpolarizing factors (EDHF) synthesis and an increased risk for atherosclerosis. We investigated whether the polymorphisms of CYP2C9/19 are related with atherosclerosis. We examined 108 patients having angioraphically > or =70 coronary artery narrowing and 90 healthy controls. CYPC2C9/19*2 and CYP2C9/19*3 alleles were investigated in both patients and controls by a real time PCR instrument. There was no significant difference in the distribution of the CYP2C9*2/*3 alleles between cases and the controls. We found that smoker patients having CYP2C9*2 heterozygote genotype have 3.7-fold risk of developing atherosclerosis. CYP2C19*3 heterozygote alleles are more frequent in patients than in controls (10.2%, 5.6% respectively) and it is related with a three-fold risk of atherosclerosis (odds ratio (OR) = 3.75, confidence interval (CI) = 0.75-18.65). It becomes clear that cigarette smoking can cause almost all major diseases prevalent today, such as cancer or heart disease. This inter-subject variability in cigarette-induced pathologies is partly mediated by genetic variants of genes that may participate in detoxification processes, e.g., cytochrome P450 (CYP), cellular susceptibility to toxins, such as p53, or disease development such as atherosclerosis.     

Studies of esterase 6 in Drosophila melanogaster. I. The genetics of a posttranslational modification

A locus has been found, an allele of which causes a modification of some allozymes of the enzyme esterase 6 in Drosophila melanogaster. There are two alleles of this locus, one of which is dominant to the other and results in increased electrophoretic mobility of affected allozymes. The locus responsible has been mapped to 3-56.7 on the standard genetic map (Est-6 is at 3-36.8). Of 13 other enzyme systems analyzed, only leucine aminopeptidase is affected by the modifier locus. Neuraminidase incubations of homogenates altered the electrophoretic mobility of esterase 6 allozymes, but the mobility differences found are not large enough to conclude that esterase 6 is sialylated.This work was supported by NIH Grant No. GM23706 and PHS Grant SO7RR7031 to Rollin C. Richmond and by NIH Genetics Training Grant No. 82 to Indiana University.     

Genetic analysis of strains C57BL/6J and BALB/cJ for Ath-1, a gene determining atherosclerosis susceptibility in mice

We previously reported that mice have at least one major gene determining atherosclerosis susceptibility, Ath-1. Susceptible alleles of Ath-1 are found in strain C57BL/6J and are associated with relatively low levels of high-density lipoprotein cholesterol (HDL-C) when these mice are fed an atherogenic diet. Resistant alleles of Ath-1 are found in strains C3H/HeJ and BALB/cJ and are associated with relatively high levels of HDL-C. Data reported earlier from the set of seven recombinant inbred (RI) strains, derived from C57BL/6By and BALB/cBy, showed that these parental strains differed at Ath-1. However, due to the limited number of RI strains, it was not possible to determine with certainty whether Ath-1 was the only major gene determining atherosclerosis susceptibility in these two strains or to determine its map position accurately. In this report, examination of F1, F2, and backcross progeny from a cross between C57BL/6J and BALB/cJ demonstrates that Ath-1 is the major gene determining atherosclerotic lesion formation and HDL-C levels in female mice. The data from male animals suggest that environmental factors or modifying genes also influence male HDL-C levels and thus partly obscure the Ath-1 phenotype. HDL-C levels in F1 progeny resemble the BALB/c parent. The data from the cross provide confirmatory evidence that Ath-1 is linked to Alp-2 on chromosome 1 with a map distance of 4.8 +/- 2.3 (SE). Combining these data with a previous cross between strain C57BL/6 and strain C3H/HeJ gives a map distance between Ath-1 and Alp-2 of 4.9 +/- 1.8 based on 7 crossovers found among 144 tested chromosomes.     

Distribution of ORM1, C6, C7 and APO C-II allele frequencies in populations from mainland Italy and Sardinia.

The genetic variation of the human plasma proteins ORM1, C6, C7 and APO C-II was investigated by isoelectric focusing followed by immunoblotting in populations from mainland Italy and Sardinia. The frequencies of ORM1*1 were 0.621 and 0.564, while those of C6*A were 0.657 and 0.706 on mainland Italy and in Sardinia, respectively. In the Roman sample, 8 heterozygotes with C6 variant alleles were encountered, while none were observed in Sardinians. For C7 and APO C-II a number of heterozygotes with the rare alleles C7*2 and APO C-II*2 were found, but their frequency did not reach polymorphic levels in either population. The two populations showed a significant difference in the gene frequencies distribution for ORM1.     

Genetic polymorphism of the sixth component (C6) of rat complement

The complement protein C6 has been shown to be genetically polymorphic in the rat. Isoelectric focusing of plasma samples from 19 inbred strains demonstrated two electrophoretically distinguishable migration patterns, each consisting of three bands. Breeding studies with the use of the BN and DA strains showed that the C6 patterns were inherited in a manner consistent with the co-dominant autosomal expression of two alleles (C6 A and C6 B). The distribution of the C6 alleles in a backcross mating was compared with eight independently segregating marker genes: RT1.A, RT2, Gdc -1, Igk-1, Hbb, Svp-1, Fh-1, and Es-6. There was no detectable linkage between C6 and any of these eight loci.     

Ly-6A.2 and Ly-6E.1 molecules are antithetical and identical to MALA-1

Rat monoclonal antibodies YE3/19.1, defining the murine-activated lymphocyte antigen MALA-1, and D7, detecting an Ly-6 locus-controlled antigen, bound highly purified Ly-6E.1. On western blots of lymphocyte surface proteins which had been solubilized and electrophoretically separated in octylglucoside, they detected bands which comigrated with Ly-6A.2 or Ly-6E.1 antigens. On cells or in an immunoassay they blocked alloantibodies against Ly-6A.2 or Ly-6E.1. The tissue distribution of MALA-1 also correlated with Ly-6A.2 or Ly-6E.1. Upon octylglucoside or sodium dodecyl sulfate-polyacrylamide gel electrophoresis, these antigens displayed similar sizes. Thus, Ly-6A.2 and Ly-6E.1 are most likely products of alternate alleles. Electrophoretic analysis showed a similar size and charge for Ly-6A.2, Ly-6B.2, Ly-613.2, and Ly-27.2. Ly-6C.2 and Ly-28.2 appeared to be identical, and were similar in size to Ly-6A.2, but they differed in charge and in intrachain disulfide constraints. Since Ly-613.2 and Ly-27.2 may represent the same or different epitopes on the Ly-6A.2 molecule, the previously postulated five Ly-6-like antigens that were thought to be separable on the basis of tissue distribution, may represent no more than three separate proteins which can be assigned to one of two distinct categories by electrophoretic mobility in gels containing octylglucoside.     

Differences among captive callitrichids in the digestive responses to dietary gum

Although many members of the Callitrichidae, a monophyletic family of small, New World monkeys, have been observed to feed on plant exudates, available field data support the generalization that pygmy and common marmosets (Cebuella pygmaea and Callithrix jacchus) feed on gums to a greater extent than most other callitrichids. Because microbial fermentation is required for vertebrates to digest gums, gum-feeding primates may react differently to dietary gum from their relatives that eat little gum. To test this hypothesis, digestion trials were conducted on animals from the two marmoset species, two tamarin species (Saguinus fuscicollis and S. oedipus), and a species of lion tamarin (Leontopithecus rosalia). These species span the range of body sizes within the Callitrichidae. All animals were fed two variations of a homogeneous diet, which differed only in that gum arabic was added to one. Transit time of digesta (TFA) and digestive efficiency (as measured by the coefficients of apparent digestibility of dry matter and energy [ADDM and ADE, respectively]) were compared between diets for each individual. As predicted, the digestive responses of marmosets differed from the responses of the other study species. In marmosets, TFA tended to be longer when gum was added to the diet, while TFA did not change in the other three species. Digestive efficiency decreased in tamarins and lion tamarins with the addition of gum to the diet; marmoset digestive efficiency was unaffected by diet. The results of this research are consistent with the hypothesis that marmosets have digestive adaptations that aid in the digestion of gum that other callitrichids lack. © 1996 Wiley-Liss, Inc.