Identification of a novel FUT1 allele in a Chinese individual featuring para-Bombay phenotype / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for an individual with a para-Bombay phenotype.@*METHODS@#A proband with mismatched forward and reverse serotypes for the ABO blood group was identified. Weakly expressed ABH blood type antigen on the surface of red blood cells was verified by absorption and release test, and the blood group substances in saliva was detected by sialic acid test. Exons 6 and 7 of the ABO gene and exons of the FUT1 and FUT2 genes were subjected to direct sequencing.@*RESULTS@#The proband was found to be of O type by forward ABO serotyping and AB type by reverse ABO serotyping, though H and substance A and B were detected in her saliva. DNA sequencing revealed that she has harbored c.35C/T, c.328G/A, and c.504delC compound heterozygous variants of the FUT1 gene. Haploid analysis showed that her FUT1 genotype was h328A/h35T+504delC, which has been uploaded to the NCBI website (No. MW323551).@*CONCLUSION@#The para-Bombay phenotype of the proband may be attributed to the novel compound heterozygous variants including c.504delC of the FUT1 gene, which may affect its function by altering the activity of FUT1 glycotransferase.

Serological Identification and FUT1 Gene Mutation Analysis of 8 Individuals with Para-Bombay Phenotypes in Guangxi / 中国实验血液学杂志

OBJECTIVE@#To study the serological characteristics and molecular biological basis of 8 individuals with Para-Bombay phenotypes in Guangxi area.@*METHODS@#Serological tests were used to identify the blood groups of red cells. Molecular biological methods, including PCR-SSP for ABO genotyping and DNA sequencing for FUT1, were used to detect the genotypes of ABO and FUT1 which determined the expression of H antigen.@*RESULTS@#Eight individuals in the study were all the Para-Bombay phenotypes, including 4 cases of B@*CONCLUSION@#There are varieties of molecular genetic mechanisms for Para-Bombay phenotypes. In this study, the FUT1 mutations that cause Para-Bombay phenotypes in Guangxi area are mainly h3, h

Sequence analysis for a case with Para-Bombay AB blood type / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular basis for a rare case with Para-Bombay AB blood type.@*METHODS@#Serological method was used to determine the blood type of the proband. Exons 6 and 7 of the ABO gene and the coding regions of FUT1 and FUT2 genes were analyzed by direct sequencing.@*RESULTS@#Serological results showed that the proband was a Para-Bombay AB subtype. His genotype was determined as ABO*A1.02/B.01. The proband was also found to harbor c.551-552delAG and c.881-882delTT of the FUT1 gene. For his four children, there were three type B and one type A, though the expression of the H type was normal.@*CONCLUSION@#The double deletions in the coding region of the FUT1 gene probably underlay the Para-Bombay blood type in the proband. Carrier of single-strand deletions may have a normal ABO phenotype.

Study on the Identification of Samples Mistyped as O Phenotype and the Strategy of Safe Blood Transfusion / 中国实验血液学杂志

OBJECTIVE@#To investigate the indentification method of samples mistyped as O phenotype and to explore the precision transfusion strategy.@*METHODS@#The blood samples from donors and patients admitted in our center from 2018 to 2019 was collected. The samples with O phenotype suspected subtypes were further determined by tube test, adsorption-elution test, etc. Molecular testing was used to sequence the related blood type genes of the subjects.@*RESULTS@#Among 14 subjects misjudged as O, 11 different genotypes were identified, in which 3 blood donors were Ael02/O02, Bel03/O02, and one para-Bombay with B101/O02 (FUT1: h3h3; FUT2: Se@*CONCLUSION@#The phenotypes of Ael, Bel, Aw and para-Bombay subtypes are easily misjudged as type O. Molecular technology is helpful to identify the genotype of subtypes, and the corresponding transfusion strategies could be reasonably performed.

Serological and molecular biological analysis of an individual with para-Bombay blood group due to homozygous c.948C>A variant of FUT1 gene / 中华医学遗传学杂志

OBJECTIVE@#To study the serological, molecular and genetic characteristics of an individual with para-Bombay blood group.@*METHODS@#Serological method was used to detect the presence of A, B, H antigens in red blood cells and saliva, and Sanger sequencing was used to analyze the FUT1 gene of the proband and her family members. Genetic mechanism of the blood group was analyzed by pedigree analysis.@*RESULTS@#Forward and reverse typing of the ABO blood group were inconsistent for the proband. A, B and H antigens were not found on erythrocytes, while B and H antigens were found in saliva, in addition with unexpected antibodies. The proband was found to have a genotype of ABO*B.01/ABO*O.01.04 caused by homozygous variant of c.948C>A (p.Tyr316Ter) of the FUT1 gene.@*CONCLUSION@#A novel para-Bombay blood group was identified, which was due to the missense variant of c.948C>A in the coding region of the FUT1 gene, which has probably resulted in inability to synthesis active H antigen transferase.

Molecular characterization of a recombination allele of ABO blood group / 中华医学遗传学杂志

OBJECTIVE@#To analyze the molecular characteristics of a recombinant allele of the ABO blood group.@*METHODS@#The ABO phenotype was determined with the tube method. The coding regions of the ABO and FUT1 genes were analyzed by PCR-sequence based typing. The ABO alleles of the proband were determined by allele-specific primer sequencing. The full sequences of the ABO gene of the proband and her mother were determined through next generation sequencing.@*RESULTS@#The red blood cells of the proband did not agglutinate with anti-H, and the sequence of the FUT1 gene was homozygous for c.551_552delAG.The proband was thereby assigned as para-Bombay. Bi-directional sequencing also found that she was heterozygous for c.261G/del,467C>T,c.526C>G,c.657C>T,c.703G>A,c.796C>A,c.803G>C and c.930G>A of the coding regions of the ABO gene. Allele-specific primer sequencing also found her to carry a ABO*A1.02 allele and a recombinant allele from ABO*O.01.01 and ABO*B.01. The recombination site was located between nucleotide c.375-269 and c.526, and the allele was maternally derived.@*CONCLUSION@#An recombinant allele of the ABO gene has been identified, which has originated from recombination of ABO*O.01.01 with the ABO*B.01 allele.

Analysis of two novel variants of FUT1 gene in a Chinese family with para-Bombay phenotype / 中华医学遗传学杂志

OBJECTIVE@#To study rare para-Bombay blood type Bm@*METHODS@#ABO and H phenotype of the proband and her pedigree were determined with serological methods. The ABO genotype was analyzed by polymerase chain reaction-sequence specific primer(PCR-SSP). The full coding region of alpha-l,2 fucosyltransferase (FUT1) gene of the pedigree was analyzed by polymerase chain reaction and direct sequencing of the amplified fragments. The haplotype of the FUT1 gene were analyzed by cloning sequencing.@*RESULTS@#The rare para-Bombay blood type Bm@*CONCLUSION@#Two new alleles of FUT1 gene (h

Identification of a novel FUT1 allele of para-Bombay phenotype / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular basis for an individual with para-Bombay phenotype of the H blood group.@*METHODS@#Intron 5 to 3'-UTR of the ABO gene and exon 4 of the FUT1 gene were amplified with PCR and subjected to direct sequencing. Mutations of the FUT1 gene were identified by TOPO cloning sequencing.@*RESULTS@#Direct sequencing showed that her ABO genotype was B101/O01. TOPO cloning sequencing found that this individual had three mutations of the FUT1 gene, including an heterozygous AG deletion (CAGAGAG→CAGAG) at position 547 to 552, and two C→T mutations at positions 35 (C35T) and 293 (C293T) on the other homologous chromosome. The two alleles comprised a new recombination of mutations c.35T>C and c.293C>T, and the sequence has been submitted to NCBI (No. MG597611).@*CONCLUSION@#A novel combination of FUT1 alleles with c.35 C>T and c.293C>T has been identified in an individual with para-Bombay phenotype.

Expression of Ikaros and FUT4 in Children's Acute Lymphoblastic Leukemia and Their Relationship / 中国实验血液学杂志

OBJECTIVE@#To explore the possible molecular mechanism of Ikaros regulation on FUT4 expression by analyzing the correlation of the functional state of Ikaros with level of FUT4 expression, so as to provide the theoretical basis for personalized treatment in children with ALL.@*METHODS@#The subtypes of Ikaros were identified by nested PCR and sequencing. The expression level of FUT4 was detected by quantitative PCR and analyzed by ΔΔCt method in the early stage of treatment, remission and relapse of ALL.@*RESULTS@#Ik1 and Ik2 were the main functional subtypes, and the dominant negative Ikaros was Ik6; the Ik6 was detected in 23 patients with ALL. It was found that 2.73% patients expressing Ik6 alone and 18.18% patients with heterozygous expression were detected. The expression of FUT4 in the newly diagnosed ALL was higher than that in the control group, and the functional Ikaros negatively correlated with the FUT4 expression(r=-0.6329).@*CONCLUSION@#Dominant negative Ikaros closely correlated with the relapse of acute lymphoblastic leukemia in children. The functional Ikaros negatively correlated with FUT4 expression. Ikaros inhibit the transcriptional activity of FUT4, that may be the molecular mechanism of Ikaros regulating the expression of FUT4.

Gene expression profiling reveals upregulated FUT1 and MYBPC1 in children with pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is associated with high risk of epithelial atypical growth and malignant transformation of the bile duct or gallbladder. However, overall changes in genetic expression have not been examined in children with PBM. Genome-wide expression was analyzed using peripheral blood samples from 10 children with PBM and 15 pediatric controls. Differentially expressed genes (DEGs) were identified using microarray. Bioinformatics analysis was conducted using Gene Ontology and KEGG analyses. The top 5 in the up-regulated genes in PBM were verified with qRT-PCR. Receiver operator characteristic curve analysis was conducted to evaluate the predictive accuracy of selected genes for PBM. The microarray experiments identified a total of 876 DEGs in PBM, among which 530 were up-regulated and the remaining 346 were down-regulated. Verification of the top 5 up-regulated genes (TYMS, MYBPC1, FUT1, XAGE2, and GREB1L) by qRT-PCR confirmed the up-regulation of MYBPC1 and FUT1. Receiver operating characteristic curve analysis suggested that FUT1 and MYBPC1 up-regulation could be used to predict PBM, with the area under the curve of 0.873 (95%CI=0.735−1.000) and 0.960 (95%CI=0.891−1.000), respectively. FUT1 and MYBPC1 were up-regulated in children with PBM, and could be used as potential biomarkers for PBM.

Study of a case with homozygous 35C>T and 658C>T mutations of FUT1 gene leading to a para-Bombay phenotype / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular mechanism for a case with para-Bombay phenotype caused by α-1,2-fucosyltransferase (FUT1) gene mutations.</p><p><b>METHODS</b>Blood phenotype of the propositus was determined by standard serological testing. Polymerase chain reaction-sequence specific primer (PCR-SSP) and direct sequencing of PCR product were used to analyze its ABO genotype. The PCR product of FUT1 gene was sequenced and analyzed.</p><p><b>RESULTS</b>The phenotype of the propositus was initially detected as para-Bombay A type. Direct sequencing of ABO gene showed that the genotype of the proband was A101/O01 (261G/del), which was consistent with the result of PCR-SSP. Two homo-mutations, 35C>T and 658C>T, were detected in the FUT1 gene by sequencing, and the genotype was determined as h(35T+658T)/h(35T+658T).</p><p><b>CONCLUSION</b>h(35T+658T)/h(35T+658T) is responsible for the para-Bombay phenotype of the propositus. The genotype is rare even in para-Bombay populations.</p>

Association of inflammatory bowel disease with the polymorphisms and haplotypes of fucosyltransferase 3 gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of inflammatory bowel disease with polymorphisms and haplotypes of Fucosyltransferase 3 (FUT3) gene.</p><p><b>METHODS</b>A total of 389 patients with ulcerative colitis (UC), 274 patients with Crohn's disease (CD), and 492 controls were collected. Three single nucleotide polymorphisms (SNPs) of the FUT3 gene (rs28362459, rs3745635 and rs3894326) were determined by direct sequencing. Linkage disequilibrium and haplotype analysis were performed using a Haploview 4.2 software.</p><p><b>RESULTS</b>Compared with the controls, the allele and genotype distributions of FUT3 gene did not significantly differ between the UC and CD groups (all P>0.05). By stratified analysis, the mutant allele (A) and genotype (GA+AA) of the FUT3 gene (rs3745635) were significantly increased in the UC group with distal colitis compared with the controls (P<0.01, P<0.05, respectively). The mutant allele (G) and genotype (TG+GG) of the FUT3 gene (rs28362459) as well as the mutant allele (A) of FUT3(rs3745635) were significantly increased in patients with ileocolonic CD and ileal CD as compared with the controls (P<0.05, P<0.01, P<0.05, respectively). The frequency of mutant allele (G) of FUT3(rs28362459) was higher in stricturing CD patients than in the controls (P<0.05). In addition, the three polymorphic loci of FUT3 gene were shown in complete linkage disequilibrium [rs3894326/rs3745635 (D'=1.0, r2=0.017), rs3894326/rs28362459 (D'=0.937, r2=0.311), rs3745635/rs28362459 (D'=0.944, r2=0.448)]. However, the frequency of each haplotype was not significantly different between the UC and CD groups compared with the controls (all P>0.05).</p><p><b>CONCLUSION</b>FUT3 (rs3745635) mutation may increase the risk of distal colitis. FUT3 (rs28362459 and rs3745635) mutations may engender the increased risk of ileocolonic and ileal CD. Moreover, FUT3 (rs28362459) polymorphism may influence the incidence of stricturing CD.</p>

Formation of para-Bombay phenotype caused by homozygous or heterozygous mutation of FUT1 gene / 中国实验血液学杂志

This study was aimed to explore the molecular mechanisms for para-Bombay phenotype formation. The H antigen of these individuals were identified by serological techniques. The full coding region of alpha (1, 2) fucosyltransferase (FUT1) gene of these individuals was amplified by high-fidelity polymerase chain reaction (PCR). PCR product was identified by TOPO cloning sequencing. Analysis and comparison were used to explore the mechanisms of para-bombay phenotype formation in individuals. The results indicated that the full coding region of FUT1 DNA was successfully amplified by PCR and gel electrophoresis. DNA sequencing and analysis found that h1 (547-552delAG) existed in one chromosome and h4 (35C > T) existed in the other chromosome of NO.1 individual. Meantime, h1 (547-552delAG) was found in two chromosomes of NO.2 and NO.3 individual. It also means that FUT1 gene of NO.1 individual was h1h4 heterozygote, FUT1 gene of NO.2 and NO.3 individuals were h1h1 homozygote. It is concluded that homozygous and heterozygous mutation of FUT1 gene can lead to the formation of para-Bombay phenotype.

Effect of α -1,2 fucosyltransferase gene 682A> G and 547_552delAG mutations on the activity of fucosyltransferase / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the effect of α -1,2 fucosyltransferase (FUT1) gene 682A> G and 547_552delAG mutations on the expression of FUT1 mRNA and activity of α -1,2 fucosyltransferase.</p><p><b>METHODS</b>Recombinant expression vectors of FUT1 682A> G and FUT1 547_552delAG were constructed and transfected into COS-7 cells for stable expression screening. Expression of FUT1 mRNA was determined using real-time quantitative PCR. The activity of FUT1 was measured with high-performance liquid chromatography.</p><p><b>RESULTS</b>Stably transfected COS-7 cells with wild type FUT1, FUT1 682A> G and FUT1 547_552delAG were respectively obtained. The FUT1 mRNA level of transfected cells with 682A> G and 547_552delAG recombination vectors have measured 101.69% and 102.79% compared with that of wild type FUT1 transfected cells. A specific protein band with about 46 kD was confirmed in the 682A> G transfected cell lysates by SDS-PAGE electrophoresis and Western blotting with 6× His Tag antibody. Similar protein was not identified in the 547_552delAG cells lysates. Enzymes activity of FUT1 682A> G has measured 61.01% compared with wild type FUT1 protein, whilst the activity of FUT1 547_557delAG was completely abolished.</p><p><b>CONCLUSION</b>FUT1 682A> G and 547_552delAG mutations do not affect the transcript efficiency, although various mutations have different impact on the enzyme's activity.</p>

Genetic analysis of an individual with para-Bombay phenotype / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study genetic characteristics of an individual with para-Bombay phenotype and her family members.</p><p><b>METHODS</b>ABO and H antigens were detected with routine serological techniques.The entire coding region of FUT1 gene was amplified by polymerase chain reaction (PCR). PCR products was purified with enzymes digestion and directly sequenced.</p><p><b>RESULTS</b>The RBCs of the proband did not agglutinate with H antibody. The proband therefore has a para-Bombay phenotype (Bmh). Direct sequencing indicated the FUT1 sequence of the proband contained a homozygous 547-552 del AG and heterozygous 814A>G mutation, which gave rise to two haplotypes of 547-552delAG, 547-552delAG and 814A>G. The ABO blood type of the proband' s mother and sisters were all B.Sequencing of the FUT1 gene has found heterozygous 547-552 del AG, 814A>G mutations in the mother and elder sister, and heterozygous 547-552 del AG mutation in her younger sister. The FUT1 547-552 del AG and 814 A>G mutations of the proband were inherited from her mother.</p><p><b>CONCLUSION</b>A complex mutation of the FUT1 gene consisting of 547-55 del AG and 814 A>G has been identified in an individual with para-Bombay phenotype.</p>

Distribution specificity of human fucosyltransferase 5 and its expression and localization in spermatids / 法医学杂志

OBJECTIVE@#To investigate distribution specificity of human fucosyltransferase 5 (FUT5) as well as its expression and localization in spermatids.@*METHODS@#Human semen, vaginal swab, saliva and venous blood from healthy individuals were collected. The spermatids were isolated and the spermatid membrane protein was then extracted. Expression levels of FUT5 from human spermatid membrane, seminal plasma, vaginal fluid, saliva and serum were detected by immunoblotting technique. The expression and localization of FUT5 in spermatids were analyzed by immunofluorescent method.@*RESULTS@#Immunoblotting technique showed that FUT5 was expressed on spermatid membranes and in serum, but not in seminal plasma, vaginal fluid and saliva. The expressed FUT5 on spermatids was mostly localized on head of spermatids by fluorescent microscopy, suggesting that there was certain amount of FUT5 on human spermatid membrane, and the spermatids might be isolated from mixed stains with vaginal fluid by antigen-antibody reaction.@*CONCLUSION@#Human FUT5 shows a characteristic distribution specificity, and this feature may be used for identification of mixed stain involved in criminal sexual offence in future forensic practice.

Generation of glyco-engineered BY2 cell lines with decreased expression of plant-specific glycoepitopes

Plants are known to be efficient hosts for the production of mammalian therapeutic proteins. However, plants produce complex N-glycans bearing β1,2-xylose and core α1,3-fucose residues, which are absent in mammals. The immunogenicity and allergenicity of plant-specific Nglycans is a key concern in mammalian therapy. In this study, we amplified the sequences of 2 plant-specific glycosyltransferases from Nicotiana tabacum L. cv Bright Yellow 2 (BY2), which is a well-established cell line widely used for the expression of therapeutic proteins. The expression of the endogenous xylosyltranferase (XylT) and fucosyltransferase (FucT) was downregulated by using RNA interference (RNAi) strategy. The xylosylated and core fucosylated N-glycans were significantly, but not completely, reduced in the glycoengineered lines. However, these RNAi-treated cell lines were stable and viable and did not exhibit any obvious phenotype. Therefore, this study may provide an effective and promising strategy to produce recombinant glycoproteins in BY2 cells with humanized N-glycoforms to avoid potential immunogenicity.

Study on the expression stability of mutant alpha-1,2 fucosyltransferase gene 293C to T and 658C to T in eukaryotic cells / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish the eukaryotic cell expression system for the alpha-1,2 fucosyltransferase gene FUT1 293C to T and 658C to T mutations and explore the mechanism of FUT1 mutations resulting in the reduced expression of H antigen.</p><p><b>METHODS</b>Genomic DNAs were extracted from individuals with para-Bombay phenotype and full coding region of FUT1 was amplified. The amplification fragments were ligated with pcDNA3.1 plasmid to construct the recombinant expression vectors. The recombinant plasmids were transfected into the COS-7 cells using lipofectamine transfection reagent and stable expression screening was performed. FUT1 mRNA expression was determined by real-time quantitative PCR. The activity of enzyme was measured by high performance liquid chromatography. Expressed protein was identified by SDS-PAGE and Western blotting.</p><p><b>RESULTS</b>pcDNA3.1-FUT1 wildtype, pcDNA3.1-FUT1 293C to T and pcDNA3.1-FUT1 658C to T recombinant vectors were constructed, respectively. COS-7 cells with stable expression of FUT1 were obtained through recombinant plasmid transfection and screening with G418. The FUT1 mRNA level of transfected cells with 293C to T and 658C to T recombinant vectors reached 97.10% and 104.74% of the wildtype FUT1 transfected cell. A specific protein band with about 46 000 was confirmed in the transfected cell lysates by SDS-PAGE electrophoresis and Western blotting with 6×His Tag antibody. The wildtype FUT1 transfected cell lysates can catalyze the enzymatic reaction, while the enzyme activity of cell lysates from 293C to T and 658C to T were abolished.</p><p><b>CONCLUSION</b>The results suggested that the 293C to T and 658C to T mutations of FUT1 gene did not affect the RNA and protein expression levels, but the enzyme activity of cells with FUT1 mutations was significantly decreased which resulted in the reduced expressin of H antigen.</p>

The balance between GMD and OFUT1 regulates Notch signaling pathway activity by modulating Notch stability

The Notch signaling pathway plays an important role in development and physiology. In Drosophila, Notch is activated by its Delta or Serrate ligands, depending in part on the sugar modifications present in its extracellular domain. O-fucosyltransferase-1 (OFUT1) performs the first glycosylation step in this process, O-fucosylating various EGF repeats at the Notch extracellular domain. Besides its O-fucosyltransferase activity, OFUT1 also behaves as a chaperone during Notch synthesis and is able to down regulate Notch by enhancing its endocytosis and degradation. We have reevaluated the roles that O-fucosylation and the synthesis of GDP-fucose play in the regulation of Notch protein stability. Using mutants and the UAS/Gal4 system, we modified in developing tissues the amount of GDP-mannose-deshydratase (GMD), the first enzyme in the synthesis of GDP-fucose. Our results show that GMD activity, and likely the levels of GDP-fucose and O-fucosylation, are essential to stabilize the Notch protein. Notch degradation observed under low GMD expression is absolutely dependent on OFUT1 and this is also observed in Notch Abruptex mutants, which have mutations in some potential O-fucosylated EGF domains. We propose that the GDP-fucose/OFUT1 balance determines the ability of OFUT1 to endocytose and degrade Notch in a manner that is independent of the residues affected by Abruptex mutations in Notch EGF domains.

Mutational analysis for FUT1 gene in two cases with para-Bombay blood type / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study two cases of rare para-Bombay blood types Bmh and Amh in order to determine clinical strategies of blood transfusion.</p><p><b>METHODS</b>ABO blood type was determined with serological assays. The samples were also genotyped with polymerase chain reaction-sequence specific primer (PCR-SSP) for potential mutations in α-1,2-fucosyltransferase gene (FUT1). The results were verified with direct sequencing.</p><p><b>RESULTS</b>Two rare para-Bombay blood types, namely Bmh and Amh, were identified by serological method, with one being BO1 which contained a FUT1 allele 547-548delAG deletion (h1h1), and another being A205O2 which contained FUT1 allele a 547-548delAG deletion and a FUT1 allele 658C/T missense mutation (h1h3).</p><p><b>CONCLUSION</b>FUT1 allele 547-548delAG deletion and 658C>T missense mutation in part form the molecular basis of para-Bombay blood types. As Bmh and Amh contain anti-HI in sera, great attention should be paid to avoid adverse reaction of blood transfusion in clinics.</p>