Animal cloning technology with somatic cells provides an alternative tool to conventional methods for producing transgenic animals. Gene targeting in animals is made feasible using somatic cells with homologous recombination procedure that is a major technique in embryonic stem cells for knocking-out genes. Homologous recombination events in somatic cells are relatively inefficient as compared to those in ES cells, suggesting the need for establishment of efficient gene targeting system in somatic cells. To investigate the efficiency of positive and negative selection for gene targeting in pig fetal fibroblast cells, pig alpha-1,3-galactosyl transferase (13-GT) gene was used for gene targeting. The neomycin phosphotransferase (Neo(r)) and herpes simplex virus-thymidine kinase (HSV-tk) genes were used as positive and negative selection markers in this experiment. Following transfection with targeting DNA construct, the pig fetal fibroblast cells were selected against resistance of G418 and gancyclovir. In DMEM medium containing 5 to 10% serum, Pig fetal fibroblast cells failed to proliferate during drug selection. Increasing serum concentration to 15% of medium yielded less senescent colonies of pig fetal fibroblast cells following drug selection that allowed enough cell colonies to screen genomic DNA. The frequency of gene targeting in pig fetal fibroblast cells with double drug selection was more than 10-fold efficient compared to that with G418 single selection. Double selection method with Neo' and HSV-tk genes could be useful for gene targeting in somatic cells for production of cloned animals carrying targeted endogenous genes.
Animals ; Fibroblasts ; Galactosyltransferases/*genetics/*metabolism ; *Gene Targeting ; Genetic Vectors/genetics ; Polymerase Chain Reaction ; Swine/*embryology/genetics

OBJECTIVETo study the molecular genetic basis for p phenotype.

METHODSRed blood cell phenotype of the proband was characterized by standard serological technique. Exon 3 of the alpha (1,4) galactosyltransferase gene was amplified by polymerase chain reaction from genomic DNA of the proband. The amplified PCR products were excised and purified from agarose gels and direct sequenced.

RESULTSHomozygous single nucleotide G deletion at position 300 or 301 was found in the proband, which caused a reading frame shift at codon 101,resulting in a premature stop at codon 113. Parents of the proband were heterozygous carriers.

CONCLUSIONA novel single guanosine deletion at position 300 or 301 of alpha (1,4) galactosyltransferase gene was determined, which may be one facet of the molecular basis for p phenotype.

Galactosyltransferases ; genetics ; Gene Deletion ; Humans ; Male ; Phenotype ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide

OBJECTIVETo explore the molecule basis of a p blood group in a patient with gastric carcinoma.

METHODSThe p phenotype was determined with serological method. Inheritance of the p phenotype was investigated by pedigree analysis. Sequence of α-1,4- galactosyltransferase (A4GALT) gene was determined by Sanger method.

RESULTSThe proband and his younger brother were both determined to have a p phenotype. Two homozygous variations, c.343A>T (AAA>TAA) and c.903C>G (CCC>CCG), have been detected in exon 3 of the A4GALT gene. Among these, c.343 A>T (AAA>TAA) was a novel mutation, which has resulted in a termination codon, with which no normal product of the gene can be produced. c.903C>G was determined to be a polymorphism.

CONCLUSIONA novel c.343A>T mutation in the A4GALT gene probably underlies the p phenotype, to which a Genbank access number KC202808 has been assigned.

Blood Group Antigens ; genetics ; Galactosyltransferases ; genetics ; Humans ; Male ; Middle Aged ; Mutation ; Pedigree ; Phenotype ; Polymorphism, Genetic ; Stomach Neoplasms ; blood ; genetics

OBJECTIVE: To explore the molecular basis for an individual with Ax28 phenotype of the ABO subtype. METHODS: The ABO group antigens on red blood cells of the proband were identified by monoclonal antibodies. The ABO antibody in serum was detected by standard A, B, O cells. Exons 1 to 7 of the ABO gene were respectively amplified by PCR and directly sequenced. Amplicons for exons 5 to 7 were also sequenced after cloning. RESULTS: Weakened A antigen was detected on red blood cells from the proband. Both anti-A and anti-B antibodies were detected in the serum. Heterozygous 261G/del was detected in exon 6, while heterozygous 467C/T and 830T/C were detected in exon 7 by direct DNA sequencing. After cloning and sequencing, two alleles (O01 and Ax28) were obtained. Compared with A102, the sequence of Ax28 contained one nucleotide changes (T to C) at position 830, which resulted in amino acid change (Val to Ala) at position 277. CONCLUSION The novel mutation c.830T>C of the galactosaminyltransferase gene may give rise to the Ax28 phenotype.
ABO Blood-Group System ; genetics ; Alleles ; Amino Acid Substitution ; Exons ; Galactosyltransferases ; genetics ; Genotype ; Humans ; Phenotype ; Polymorphism, Single Nucleotide ; Sequence Deletion

OBJECTIVETo investigate the molecular genetic basis of the Bw variant and identify novel alleles at ABO locus in Chinese Han population.

METHODSSerological techniques were performed to characterize erythrocyte phenotype of a proband. Mutations of the ABO gene were screened by polymerase chain reaction, reverse transcription-polymerase chain reaction and DNA sequencing.

RESULTSThe proband was identified as Bw phenotype by serological technology and family study. A novel Bw variant allele was identified in the gDNA and cDNA. The novel allele was observed a missense mutation (278 C to T) at the exon 6 which resulted in an amino acid substitution (P93L) compared with B101 allele. The 278 C to T was the first report mutation position in exon 6 among Bw alleles, so the P93L amino acid substitution was different from others Bw variants which had amino acid substitutions in a conserved functional domain reported previously.

CONCLUSIONA novel Bw allele (278 C to T) responsible for Bw variant is reported in Chinese population.

ABO Blood-Group System ; genetics ; Alleles ; Amino Acid Substitution ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; DNA Mutational Analysis ; Exons ; Galactosyltransferases ; genetics ; Humans ; Male ; Mutation, Missense

OBJECTIVETo explore genetic background of a pedigree with a rare p phenotype from Guangdong province.

METHODSThe rare p phenotype was identified by a conventional serologic method. With genomic DNA of proband and family members extracted, exon 3 of alpha-(1,4)galactosyltransferase (A4GALT) gene was amplified with PCR and analyzed by direct sequencing. The mutation found in the pedigree was screened in a normal population using direct sequencing.

RESULTSThe proband and 4 family members with the rare p phenotype have all carried a point mutation c.100G>A (p.Val34Ile) in combination with a deletion-insertional mutation c.418_428del11ins34(p.Gln139Trpfs*72), which renders a compound mutation of A4GALT gene. One family member with P2 phenotype has carried a same heterozygous mutation. Of the 100 healthy donors, 5 have carried a heterozygous point mutation c.100G>A, and none carried the deletion-insertional mutation c.418_428del11ins34.

CONCLUSIONThe rare p phenotype of the pedigree has resulted from a compound mutation of the A4GALT gene, which is in keeping with a recessive inheritance pattern of the p phenotype.

Adult ; Base Sequence ; Blood Grouping and Crossmatching ; Exons ; Female ; Galactosyltransferases ; genetics ; Genotype ; Humans ; Mutation ; P Blood-Group System ; genetics ; immunology ; Pedigree ; Phenotype

OBJECTIVETo delineate serological features and genetic basis for a rare p phenotype of P1Pk blood group system found in a Chinese individual.

METHODSSerological assaying was carried out for a proband with unexpected antibody found in his serum using specific antibodies and panel cells. Coding regions and flanking introns of α 1,4-galactosyltransferase gene (A4GALT) associated with the p phenotype were screened with polymerase chain reaction and DNA sequencing.

RESULTSA rare p phenotype of the P1Pk blood group system has been identified with red blood cells from the proband, whose serum contained anti-Tja antibody which can agglutinate and hemolyze with other common red blood cells. Other members of the proband's family were all normal with P1 or P2 phenotype. DNA sequencing has identified in the proband a homozygous 26 bp deletion at position 972 to 997 of the A4GALT gene. The deletion has caused a shift of the reading frame, resulting in a variant polypeptide chain with additional 83 amino acid residues compared with the wild-type protein. Other family members were either heterozygous for above deletion or non-deleted.

CONCLUSIONA 26 bp deletion at position 972 to 997 of the A4GALT gene has been identified in a Chinese individual with p phenotype.

ABO Blood-Group System ; genetics ; Alleles ; Base Sequence ; Galactosyltransferases ; genetics ; Genetic Association Studies ; Genotype ; Humans ; Male ; Molecular Sequence Data ; Pedigree ; Phenotype ; Sequence Deletion

OBJECTIVETo study the effect of 905A to G mutation of α -1,3 galactosyltransferase of ABO gene on B antigen expression.

METHODSThree samples were diagnosed as B subgroup by serological test. Genotyping and sequencing were performed with polymerase chain reaction-sequence specific primer (PCR-SSP), direct sequencing and gene dones of exons 6 and 7 of the ABO locus.

RESULTSThe sequence of B allele has differed from that of regular B101 allele with a 905A to G missense mutation in exon 7, which resulted in an amino acid substitution (D302G) in all of the three B subgroup samples.

CONCLUSION905A to G mutation can reduce the expression of B antigen.

ABO Blood-Group System ; genetics ; Alleles ; Amino Acid Substitution ; Base Sequence ; Female ; Galactosyltransferases ; genetics ; Genotype ; Humans ; Male ; Molecular Sequence Data ; Mutation, Missense

OBJECTIVETo gain an insight into the molecular genetic basis of Bw subgroup of ABO blood group system.

METHODSThree Bw phenotypes were confirmed by standard serological techniques. The enhancer, promoter and exons 1-7 including flanking introns of ABO gene were amplified and directly sequenced after PCR amplified fragments being purified by gel. Exons 6 and 7 were also sequenced after pcDNA3.1 (-) vector transformation. The sequence specific primer-polymerase chain reaction was performed to confirm the mutations detected by sequencing in this study.

RESULTSGenotypes of three individuals were Bw/O by direct sequencing, there were G deletion heterozygous at position 261 and C/T heterozygous at position 721. A normal O allele was confirmed by cloning sequencing and 721 C>T mutation of the alpha 1, 3 galactosyltransferase (B allele) gene was also observed, which caused amino acid 241 Arg>Trp substitution. This mutation was not detected in 140 random samples by PCR-SSP.

CONCLUSIONThe mutation of 721C>T in the alpha 1, 3 galactosyltransferase gene may be one of the molecular genetic bases of Bw phenotype.

ABO Blood-Group System ; genetics ; Alleles ; Base Sequence ; DNA Mutational Analysis ; Exons ; Female ; Galactosyltransferases ; genetics ; Genotype ; Humans ; Introns ; Male ; Molecular Sequence Data ; Point Mutation ; Polymerase Chain Reaction

OBJECTIVETo analyze a sample with ABO subgroup using serological and molecular methods.

METHODSThe ABO phenotype of the sample was determined with a tube method, and the activity of glycosyltransferases was determined with an uridine diphosphate galactose transferring method. The ABO gene of the propositus was identified by PCR with sequence-specific primers (PCR-SSP). In addition, exons 6 and 7 of the ABO gene were cloned and sequenced.

RESULTSNeither A nor B antigen was identified in the propositus, despite that its anti-B antibody was found to be attenuated. No activity of α -1, 3-D-galactosyltransferase was detected in the serum. The presence of B and O alleles were confirmed by PCR-SSP, and a novel mutation (562C to T) of the exon 7 was confirmed by sequencing, which has led to an amino acid substitution (Arg to Cys) at position 188. The genotype of the propositus was determined as Bnew/O.

CONCLUSIONA novel B allele has been identified, which was named as Bw39 by the Blood Group Antigen Gene Mutation Database (BGMUT).

ABO Blood-Group System ; genetics ; Adult ; Alleles ; Amino Acid Substitution ; Base Sequence ; Exons ; Galactosyltransferases ; genetics ; Humans ; Male ; Molecular Sequence Data ; Point Mutation