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1.
CD84 is a member of the immunoglobulin gene superfamily (IgSF) with two Ig-like domains expressed primarily on B lymphocytes
and macrophages. Here we describe the cloning of the mouse homologue of human CD84. Mouse CD84 cDNA clones were isolated from
a macrophage library. The nucleotide sequence of mouse CD84 was shown to include an open reading frame encoding a putative
329 amino acid protein composed of a 21 amino acid leader peptide, two extracellular immunoglobulin (Ig)-like domains, a hydrophobic
transmembrane region, and an 87 amino acid cytoplasmic domain. Mouse CD84 shares 57.3% amino acid sequence identity (88.7%,
considering conservative amino acid substitutions) with the human homologue. Chromosome localization studies mapped the mouse
CD84 gene to distal chromosome 1 adjacent to the gene for Ly-9, placing it close to the region where other members of the CD2 IgSF (CD48 and 2B4) have been mapped. Northern blot analysis revealed that the expression of mouse CD84 was predominantly restricted to hematopoietic
tissues. Two species of mRNA of 3.6 kilobases (kb) and 1.5 kb were observed. The finding that the pattern of expression was
restricted to the hematopoietic system and the conserved sequence of the mouse CD84 homologue suggests that the function of
the CD84 glycoprotein may be similar in humans and mice.
Received: 1 July 1998 / Revised: 31 August 1998 相似文献
2.
3.
Polymorphic genotypes of the HRES-1 human endogenous retrovirus locus correlate with systemic lupus erythematosus and autoreactivity 总被引:2,自引:0,他引:2
Claudio Magistrelli Ella Samoilova Rajeev K. Agarwal Katalin Banki Pasquale Ferrante Adrian Vladutiu Paul E. Phillips A. Perl 《Immunogenetics》1999,49(10):829-834
Antinuclear autoantibodies are a hallmark of systemic lupus erythematosus (SLE). Autoantibodies to HRES-1/p28, a 28 000 M
r nuclear protein, commonly occur in patients with SLE. HRES-1 is a single-copy endogenous retroviral element mapped to human Chromosome 1 at q42. A polymorphic Hin dIII site defines two different allelic forms of the genomic locus. The HRES-1/1 probe [5.5 kilobases (kb)] anneals to three
polymorphic fragments and three genotypes can be differentiated: I, 5.5 kb fragment only; II, 3.7 kb and 1.8 kb fragments
only; and III, all three polymorphic fragments. By cloning of the HRES-1 locus from homozygous type I and type II human DNA samples, the polymorphic Hin dIII site was identified as a G to C transition at position 653 of the long terminal repeat region. Family studies showed
that Hin dIII genotypes of the HRES-1 locus are inherited in a Mendelian pattern. The relative frequency of genotype I with respect to genotype III was 3.1-fold
lower in patients with SLE (14 : 40=0.35) in comparison to 100 ethnically matched control donors (47 : 43=1.09;P=0.0084). Frequency of genotype I vs genotype II alleles was lower in SLE (68/52) than in normal donors (137/63;P=0.033), suggesting that a genotype I allele of the HRES-1 locus may be protective against SLE. Western blot seroreactivity with recombinant HRES-1/p28 was noted in 4/14 (29%) of genotype I patients and 13/19 (68%) of genotype III patients (P<0.025). These data raise the possibility that the HRES-1 element or a gene in linkage disequilibrium with this genomic locus may influence autoimmunity in SLE.
Received: 20 February 1999 / Revised: 15 April 1999 相似文献
4.
Theresa L. O’Keefe Gareth T. Williams Sarah L. Davies Michael S. Neuberger 《Immunogenetics》1998,48(2):125-132
CD20 is a hallmark antigen of B lymphocytes. Its expression is restricted to precursor and mature B cells but it is not expressed
on plasma cells. The protein is a membrane-embedded phosphoprotein that appears likely to transverse the membrane four times.
Its function is unknown although CD20 has been variously proposed to play a role in B-cell activation, proliferation, and calcium transport. A unique homologue
of human CD20 has been described in mouse, which also shows a B-cell-specific pattern of expression. Here we describe the generating of
mice carrying a CD20 gene disruption. So far, we have failed to detect any major effect of the gene disruption on the differentiation and function
of B lymphocytes as judged by the expression of surface markers, antigen receptor signaling, proliferative responses, or calcium
uptake. We did note, however, that the mice homozygous for the gene disruption [generated by intercrossing (129 × C57BL/6)F1
CD20
+/- heterozygotes] showed a substantial depletion of the sub-population of peritoneal B cells that lack expression of the B220
(RA3–6B2) isoform of CD45. The loss of the IgM+ 6B2- peritoneal B cells is not, however, attributable to the CD20 gene disruption itself. Rather, it segregates with a polymorphic difference between the 129 and C57BL/6 strains that is linked
to the CD20 locus which, intriguingly, is itself close to the CD5 gene. This demonstrates that caution must be exercised when comparing the phenotypes of F2 litter-mates generated from crosses between 129 embryonic stem-cell-derived chimeras and mice of other strains.
Received: 23 December 1997 / Revised: 27 January 1998 相似文献
5.
We have mapped the positions in a ∼1.4-Mb region of genomic DNA around the human hprt gene which are accessible in vivo to cleavage by topoisomerase II associated with the nuclear matrix. These positions, which
are interpreted as the boundaries of DNA loop domains, were mapped in K562 cells by examining the truncation of rare-cutter
restriction fragments separated by pulsed field gel electrophoresis after topoisomerase II-mediated cleavage, using seven
linked markers mapped in this region as probes for indirect end-labeling. Eleven cleavage positions were detected and were
interpreted as defining ten loop domains of lengths between 70 and 210 kb (average ∼135 kb); the hprt gene resides in a 150-kb loop domain. Loop domain boundaries coincided with three of the fifteen deletion breakpoints mapped
in a 600-kb sector of this region in human lymphocytes, within the limits of resolution of pulsed field gel electrophoresis;
this correlation was not statistically significant.
Received: 14 June 1998 / Accepted: 4 September 1998 相似文献
6.
7.
K. Erin Lovering Nicholas J. Deacon Claudia A. Mickelson Hilary A. Vaughan Kathleen M. Curnow Ian F. C. McKenzie Mauro S. Sandrin 《Immunogenetics》1987,25(6):391-396
Using DNA from L cells which expressed high levels of the CD7 (Leu-9 or HuLy-m2) antigen obtained after two cycles of transfection, a genomic library was constructed in the lambda phage Charon 4A. Recombinant clones containing the gene coding for this antigen were identified by first screening the library with both the HSVtk gene and a probe detecting the human repetitive (Alu) sequences. DNA from 10 tk+ and 12 Alu+ recombinant clones was used to transfect L cells which were analyzed for the cell-surface expression of CD7 either early (48–72 h posttransfection) or later when hypoxanthine aminopterin thymidine-resistant colonies were obtained. Transfection with either Alu+ or tk+ recombinant phages led to transient early expression of CD7, and stable CD7+ transfectants were also established. Thus the CD7 gene has been isolated in a number of clones in association with either the Alu repetitive sequence or with the HSV-tk gene; the insert size in one of the genomic clones was 13.5 kb. 相似文献
8.
J. Casqueiro O. Ba?uelos S. Gutiérrez M. J. Hijarrubia J. F. Martín 《Molecular & general genetics : MGG》1999,261(6):994-1000
Recombination between direct repeats has been studied in Penicillium chrysogenum using strain TD7-88 (lys− pyr+), which contains two inactive copies of the lys2 gene separated by 4.5 kb of DNA (including the pyrG gene) in its genome. Gene conversion leading to products with the lys+ pyr+ phenotype was observed at a frequency of 1 in 3.2 × 103 viable spores. Two types of deletion events giving rise to lys+ pyr− and lys− pyr− phenotypes were obtained with different frequencies. Southern analysis revealed that gene conversion occurs mainly as a result
of crossing over events that remove the BamHI frameshift mutation present in one of the repeats. In lys− pyr− recombinants, the deletion events do not affect the frameshift mutation in the BamHI site, while lys+ pyr− recombinants showed repair of the BamHI frameshift mutation and the genotype of the parental non-disrupted strain was restored. In summary, deletion events in
P. chrysogenum tend to favor the restoration of the phenotype and genotype characteristic of the parental non-disrupted strain.
Received: 9 November 1998 / Accepted: 14 April 1999 相似文献
9.
Genes of the major histocompatibility complex (MHC) are exceptionally polymorphic due to the combined effects of natural and
sexual selection. Most research in wild populations has focused on the second exon of a single class II locus (DRB), but complete gene sequences can provide an illuminating backdrop for studies of intragenic selection, recombination, and
organization. To this end, we characterized class II loci in the banner-tailed kangaroo rat (Dipodomys spectabilis). Seven DRB-like sequences (provisionally named MhcDisp-DRB*01 through *07) were isolated from spleen cDNA and most likely comprise ≥5 loci; this multiformity is quite unlike the situation
in muroid rodents such as Mus, Rattus, and Peromyscus. In silico translation revealed the presence of important structural residues for glycosylation sites, salt bonds, and CD4+
T-cell recognition. Amino-acid distances varied widely among the seven sequences (2–34%). Nuclear DNA sequences from the Disp-DRB*07 locus (∼10 kb) revealed a conventional exon/intron structure as well as a number of microsatellites and short interspersed
nuclear elements (B4, Alu, and IDL-Geo subfamilies). Rates of nucleotide substitution at Disp-DRB*07 are similar in both exons and introns (π = 0.015 and 0.012, respectively), which suggests relaxed selection and may indicate that this locus is an expressed pseudogene.
Finally, we performed BLASTn searches against Dipodomys ordii genomic sequences (unassembled reads) and find 90–97% nucleotide similarity between the two kangaroo rat species. Collectively,
these data suggest that class II diversity in heteromyid rodents is based on polylocism and departs from the muroid architecture.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession numbers EU817477–EU817485. 相似文献
10.
Mazaheri Z Movahedin M Rahbarizadeh F Amanpour S 《In vitro cellular & developmental biology. Animal》2011,47(8):521-525
Bone morphogenetic protein (BMP)-4 has a crucial role on primordial germ cells (PGCs) development in vivo which can promote
stem cell differentiation to PG-like cells. In this study, we investigated the expression of Mvh as one of the specific genes
in primordial germ cells after treatment with different doses of BMP4 on bone mesenchymal stem cells (BMSCs)-derived PGCs.
Following isolation of BMSCs from male mouse femur and tibia, cells were cultured in medium for 72 h. Passage 4 murine BMSCs
were characterized by CD90, CD105, CD34, and CD45 markers and osteo-adipogenic differentiation. Different doses of BMP4 (0,
0.01, 0.1, 1, 5, 25, 50, and 100 ng/ml) were added to BMSCs for PGCs differentiation during 4-days culture. Viability percent,
proliferation rates, and expression of Mvh gene were analyzed by RT-qPCR. Data analysis was done with ANOVA test. CD90+, CD105+, CD34−, and CD45− BMSCs were able to differentiate to osteo-adipogenic lineages. The results revealed that proliferation rate and viability
percent were raised significantly (p ≤ 0.05) by adding 1, 5, 25 ng/ml of BMP4 and there were decreased to the lowest rate after adding 100 ng/ml BMP4 (p ≤ 0.05). There were significant up regulation (p ≤ 0.05) in Mvh expression between 25, 50, and 100 ng/ml BMP4 with other doses. So the selective dose of BMP-4 for treatment
during 4-day culture was 25 ng/ml. The results suggest that addition of 25 ng/ml BMP4 had the best effects based on gene-specific
marker expression. 相似文献
11.
Holcombe RF Jacobson J Dakhil SR Stewart RM Betzing KS Kannan K Macdonald JS 《Cancer immunology, immunotherapy : CII》1999,48(9):533-539
Levamisole (LMS), utilized in the adjuvant treatment of patients with stage III colon cancer, is immunomodulatory. To determine
whether alterations in immune parameters before, during and after 12 months of 5FU/LMS therapy correlate with disease-free
survival, 38 patients enrolled on Southwest Oncology Group (SWOG) protocol 8899 received extensive lymphocyte phenotypic analysis
prior to therapy and 3, 6, 12 and 15 months after treatment initiation. The median follow-up of patients is 41 months. Significant
increases in the proportion and total number of CD56+ natural killer cells were seen, starting at 3 months and continuing until 15 months (P < 0.001). Increases in the total numbers of cells expressing CD25 (interleukin-2 receptor), VLA4 and the combinations of CD4:
CD45RA and CD4:CDw29 were not evident during therapy but were seen at 15 months (P < 0.05: CD25, CD4:CDw29, CD4:CD45RA; P < 0.001: VLA4). Low levels of CD8+ cells prior to treatment initiation and after 3 months of therapy correlated with early relapse within the first year of
5FU/LMS treatment. Patients who have remained disease-free (n = 22, median follow-up 45 months) demonstrated increases in the total numbers of CD8+, CD25+, CD56+, VLA4+, CD4: CDw29 and CD4:CD45RA cells, primarily at 15 months. In contrast, patients who relapsed had decreased numbers of CD8+, CD4:CDw29, CD4: CD45RA and VLA4+ cells and minimal increases in CD56+ and CD25+ cells. Statistically significant differences between the late-relapse group and the group remaining disease-free were seen
for CD25+, CD4: CD45RA and CD4:CDw29 cells at the 15-month assay time (P = 0.0276, P = 0.0349, P = 0.0178 respectively). In conclusion, multiple alterations in lymphocyte phenotype, with increases in the proportion and total
number of cells involved in cell-mediated immune responses, were seen during and especially following completion of therapy
with 5FU/LMS. Many of these changes are significantly associated with clinical outcome and may be useful for risk stratification
of stage III colon cancer patients following completion of adjuvant therapy.
Received: 9 July 1999 / Accepted: 11 August 1999 相似文献
12.
The expression of monocyte cell-surface receptors represents one index of immune dysfunction, which is common with aging.
Although mouse models of aging are prevalent, monocyte subset assessment is rare. Our purpose was to compare cell receptor
expression on classic (CD115+/Gr-1high) and non-classic (CD115+/Gr-1low) monocytes from 80- or 20-week-old CD-1 mice. Three-colour flow cytometry was used to determine the concentration of monocyte
subsets and their respective cell-surface expression of TLR2, TLR4, CD80, CD86, MHC II and CD54. These receptors were selected
because they have been previously associated with altered monocyte function. Data were analysed with independent t-tests; significance was set at P < 0.05. Old mice had a greater concentration of both classic (258%, P = 0.003) and non-classic (70%, P = 0.026) monocytes. The classic : non-classic monocyte ratio doubled in old as compared with that in young mice (P = 0.006), indicating a pro-inflammatory shift. TLR4 (↓27%, P = 0.001) and CD80 (↓37%, P = 0.004) were decreased on classic monocytes from old as compared with those from young mice. TLR2 (↑24%, P = 0.002) and MHCII (↓21%, P = 0.026) were altered on non-classic monocytes from old as compared with those from young mice. The increased classic : non-classic
monocyte ratio combined with changes in the cell-surface receptor expression on both monocyte subsets is indicative of immune
dysfunction, which may increase age-associated disease risk. 相似文献
13.
Brady MS Lee F Petrie H Eckels DD Lee JS 《Cancer immunology, immunotherapy : CII》2000,48(11):621-626
Purpose: Most melanoma cell lines express HLA class II antigens constitutively or can be induced to do so with interferon γ (IFNγ).
We have previously demonstrated that peptide-specific CD4+ T cells proliferate in response to HLA-class-II-antigen-mediated peptide presentation by melanoma cells in vitro and produce
interleukin-10 (IL-10) and (IFNγ). We asked whether the responding T cells kill the tumor cells and, if so, whether direct
cell contact was required. Methods: Two HLA class II+ melanoma cell lines derived from metastases were co-cultured with a human CD4+ T cell clone specific for influenza hemagglutinin peptide (HA). T cells, melanoma, and HA were co-cultured for 48 h. Melanoma
cells with and without HA and/or T cells served as controls. After 36 h, the medium was removed for cytokine analysis by enzyme-linked
immunosorbent assay (ELISA). Twelve hours later non-adherent cells were washed away and the adherent melanoma cells were trypsinized
and counted. Dual-chamber culture plates were used to determine whether cell contact and/or exposure to cytokine were required
for tumor cell death. Results: Melanoma cell counts were over 80% lower in wells containing T cells than in wells with melanoma and peptide alone (P < 0.05). ELISA of supernatants revealed production of IFNγ and IL-10 by the responding T cells. Direct T cell contact with
tumor cells was not required for tumor cell death, as melanoma cells were killed when they shared medium but had no contact
with T cells responding to peptide presentation by HLA-class-II-antigen-positive melanoma cells in a separate chamber. Blocking
antibody to IFNγ but not IL-10 prevented melanoma cell death at levels of cytokine similar to that present in co-culture assays.
Conclusions: Peptide-specific CD4+ T cells kill melanoma cells in vitro when they recognize peptide presented by the tumor cell in the context of HLA class
II antigen. Direct cell contact is not required, suggesting that it is a cytokine-mediated event. Immunotherapy, using primed
CD4+ T cells and peptide, may be beneficial in patients whose tumors express HLA class II antigens or can be induced to do so
with IFNγ.
Received: 1 July 1999 / Accepted: 17 September 1999 相似文献
14.
Intracellular cytokine profile of T cells from children with acute lymphoblastic leukemia 总被引:12,自引:0,他引:12
Zhang XL Komada Y Chipeta J Li QS Inaba H Azuma E Yamamoto H Sakurai M 《Cancer immunology, immunotherapy : CII》2000,49(3):165-172
Purpose: During an ongoing immune response, cytokines produced by T helper types 1 (Th1) and 2 (Th2) together with T cytotoxic types
1 (Tc1) and 2 (Tc2) are critical to the effectiveness of that response. Dysregulated expansion of one or the other subset
may contribute to the impaired function of the T-cell-mediated immune system in cancer patients. In the present study we have
investigated whether such dysregulation might exist in children with acute lymphoblastic leukemia (ALL). Methods: We analyzed 61 blood samples from 45 children with B cell precursor ALL and 16 healthy children. Interleukin(IL)-2, IL-4,
and interferon γ (IFNγ) production of their respective purified CD4+ and CD8+ T cells were assessed at the single-cell level by intracellular-cytokine-staining flow cytometry. Results: At the time of diagnosis, IL-2-producing cell populations in CD4+ and CD8+ T cells were reduced below the normal range in 31 of 44 (70.5%) and 23 of 38 (60.5%) cases respectively. Similarly, IFNγ-producing
cell populations in CD4+ and CD8+ T cells decreased in 17 of 44 (38.6%) and 18 of 38 (47.4%) cases respectively. Conversely cell populations capable of IL-4
production in CD4+ and CD8+ T cell subsets were increased in 13 of 30 (43.3%) and 15 of 30 (50.0%) cases respectively. Therefore, the Th1-to-Th2 and
Tc1-to-Tc2 ratios (1.6 ± 2.2 and 7.7 ± 6.7 respectively) were significantly lower in peripheral blood T cells of ALL patients
(n = 30) than those (6.0 ± 2.9 and 20.1 ± 10.3 respectively) in 15 healthy controls (P < 0.0001). Although both CD45RA+/CD4+ and CD45RA+/CD8+ cells significantly increased in 43 ALL patients (P < 0.05), there existed no apparent correlation between CD45 isoform expression and cytokine (IL-2 and IFNγ) production. Interestingly,
the ability to produce both IL-2 and IFNγ was recovered in 8 cases examined, after complete remission had been achieved. Conclusion: These observations suggest that, in both CD4+ and CD8+ T cells of ALL patients, there is a dysregulation in the functionality of Th1 (Tc1) and Th2 (Tc2) cells with a gross reduction
of Th1 (Tc1) cell populations and an expansion in Th2 (Tc2).
Received: 12 November 1999 / Accepted: 2 January 2000 相似文献
15.
Aarnink A Garchon HJ Puissant-Lubrano B Blancher-Sardou M Apoil PA Blancher A 《Immunogenetics》2011,63(2):95-102
While the number of peripheral blood T lymphocytes and of their two main subsets (CD4+CD8− and CD4−CD8+) varies little in
a given healthy individual, substantial variation is observed between individuals. It was proposed that these counts could
be influenced by MHC polymorphisms because of the well-established role of MHC molecules in thymic T lymphocyte maturation
and presentation of antigenic peptides to peripheral T lymphocytes. To test this hypothesis, we have chosen the crab-eating
macaque (Macaca fascicularis), an animal model phylogenetically close to man. We selected the Philippine macaque population because of a restriction of
the MHC polymorphism in this islander population. Peripheral blood lymphocytes were counted with an automated analyzer and
T lymphocyte subsets were assessed by immunolabeling and flow cytometry. The MHC polymorphism was investigated in 200 unrelated
subjects using 14 microsatellites markers distributed across the MHC and the DRB locus that was genotyped by denaturing gradient gel electrophoresis and sequencing. All markers were in Hardy–Weinberg equilibrium.
Allelic associations were tested with the UNPHASED software. We revealed a significant influence of the MHC class II region
on CD4+ T lymphocyte blood count with the largest effect associated with a two-locus haplotypes combining the DRACA allele 274 and the DRB haplotype #8a (p < 8 × 10−7). Our data should stimulate a similar association study of the CD4+ T cell counts in humans. 相似文献
16.
V. I. Loginov D. S. Khodyrev I. V. Pronina A. V. Malyukova T. P. Kazubskaya V. D. Ermilova R. F. Gar’kavtseva E. R. Zabarovskii E. A. Braga 《Molecular Biology》2009,43(6):1014-1018
Earlier, methylation of a CpG island in the SEMA3B gene (3p21.31) was observed in cell lines of small-cell and non-small-cell lung carcinoma. According to NCBI (Build 36),
that island belonged to intron 1 of the gene. Our study concerns the methylation of two CpG islands, promoter and intronic,
in the SEMA3B gene in patients with clear cell renal cell carcinoma (RCC). Methylation-specific PCR and bisulfite sequencing revealed a
high frequency of methylation in the promoter CpG island (34/61, 56%) and somewhat lower, in the intronic (17/48, 35%). A
significant inverse correlation was found between the SEMA3B mRNA level and methylation of the promoter CpG island in RCC (P < 0.05 according to Fisher’s exact test). The intronic island showed no such correlation. Thus, we suggest that the methylation
of the promoter CpG island contributes to the inactivation of the SEMA3B suppressor gene in RCC tissue. 相似文献
17.
Ursula Grohmann Maria Laura Belladonna Roberta Bianchi Ciriana Orabona Silvia Silla Giuseppe Squillacioti Maria Cristina Fioretti Paolo Puccetti 《Cancer immunology, immunotherapy : CII》1999,48(4):195-203
Nonameric P815AB, a cytotoxic-T-lymphocyte-defined minimal core peptide encoded by the murine mastocytoma gene P1A, fails to initiate CD4+ cell-dependent reactivity in vivo to class-I-restricted epitopes when mice are administered peptide-pulsed dendritic cells.
Effective immunization requires T helper effects, such as those mediated by coimmunization with class-II-restricted (helper)
peptides or by the use of recombinant interleukin-12 (rIL-12). Although P815AB does possess class-II-restricted epitopes,
they are likely suboptimal, resulting in poor affinity and/or stability of MHC/P815AB complexes and inadequate activation
of the antigen-presenting cell function of dendritic cells. The present study has examined a series of longer, P815AB-centered
peptides (11–14 amino acids in length, all P1A-encoded) for their ability to initiate CD4+ and CD8+ cell-mediated responses to the nonamer in vivo, their ability to bind class II MHC in vitro, and their ability to assemble
class II molecules stably. By means of a class-I-restricted skin test assay in mice receiving peptide-pulsed dendritic cells,
we found that a 12-mer and a 13-mer effectively immunized against the core P815AB peptide, and that this correlated with IL-2
production in vitro by CD4+ cells in response to the nonamer. In vitro studies, involving affinity-purified class II molecules, showed that the capacity
to assemble class II molecules stably, more than the affinity for class II MHC, correlated with the ability of the different
P815AB peptides to prime the host to the core peptide seen by the T cells.
Received: 25 February 1999 / Accepted: 14 April 1999 相似文献
18.
Shiina T Shimizu C Oka A Teraoka Y Imanishi T Gojobori T Hanzawa K Watanabe S Inoko H 《Immunogenetics》1999,49(5):384-394
Class I genomic clones of the quail (Coturnix japonica) major histocompatibility complex (MhcCoja) were isolated and characterized. Two clusters spanning the 90.8 kilobase (kb) and 78.2 kb class I gene regions were defined
by overlapping cosmid clones and found to contain at least twelve class I loci. However, unlike in the chicken Mhc, no evidence for the existence of any Coja class II gene was obtained in these two clusters. Based on comparative analysis of the genomic sequences with those of the
cDNA clones, Coja-A, Coja-B, Coja-C, and Coja-D (Shiina et al. 1999), these twelve loci were assigned to represent one Coja-A gene, two Coja-B genes (Coja-B1 and -B2), four Coja-C genes (Coja-C1-C4), four Coja-D genes (Coja-D1-D4), and one new Coja-E gene. A class I gene-rich segment of 24.6 kb in which five of these genes (Coja-B1, -B2, -D1, -D2 and -E) are densely packed were sequenced by the shotgun strategy. All of these five class I genes are very compact in size [2089
base pairs (bp)–2732 bp] and contain no apparent genetic defect for functional expression. A transporter associated with the
antigen processing (TAP) gene was identified in this class I gene-rich segment. These results suggest that the quail class I region is physically
separated from the class II region and characterized by a large number of the expressible class I loci (at least seven) in
contrast to the chicken Mhc, where the class I and class II regions are not clearly differentiated and only at most three expressed class I loci so far
have been recognized.
Received: 9 March 1998 / Revised: 12 October 1998 相似文献
19.
20.
Elaine K. Lau Nahid Tayebi Loring J. Ingraham Suzanne L. Winfield V. Koprivica Deborah L. Stone Ari Zimran Edward I. Ginns E. Sidransky 《Human genetics》1999,104(4):293-300
Gaucher disease, an inherited glycolipid storage disorder, is caused by a deficiency of the catabolic enzyme glucocerebrosidase
(EC 3.2.1.45). The gene for human glucocerebrosidase is located on chromosome 1q21 and has a highly homologous pseudogene
situated 16 kb downstream. We report two novel polymorphic sequences in the glucocerebrosidase gene region: the first consists
of a variable number of dinucleotide (CT) repeats located 3.2 kb upstream from the glucocerebrosidase gene, and the second
is a tetranucleotide (AAAT) repeat found between the glucocerebrosidase gene and its pseudogene, 9.8 kb downstream from the
functional gene. These polymorphic sequences, along with a previously reported PvuII polymorphism in intron 6 of the glucocerebrosidase gene, were analyzed in patients with Gaucher disease (n=106) and in two normal control populations, one of Ashkenazi Jewish ancestry (n=72) and the second comprising non-Jewish individuals (n=46). In these samples, strong linkage disequilibrium was found between mutations N370S, c.84–85insG, and R463C and specific
haplotypes; no significant linkage disequilibrium was found when examining haplotypes of patients with the L444P mutation.
Studies of these polymorphic sites in several instances also led to the recognition of genotyping errors and the identification
of unusual recombinant alleles. These new polymorphic sites provide additional tools for mutational screening and founder
effect studies of Gaucher disease.
Received: 5 December 1998 / Accepted: 14 January 1999 相似文献