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Sizhong Zhang

Publications and source records attributed to Sizhong Zhang.

15 recordsLinked to original sources
PubMed2003

Molecular cloning and characterization of a mouse spermatogenesis-related ring finger gene znf230.

Complete cDNA of mouse gene znf230 was cloned by rapid amplification of cDNA ends (RACE). This cDNA is 982 base pairs (bp) in length and encodes a 230 amino acids (aa) protein with a ring finger domain at its C-terminus. Ninety-one and 98% nucleotide (nt) and aa sequence identity are observed with its human homolog. Revealed by Northern blot and reverse transcriptase-polymerase chain reaction (RT-PCR), this cDNA is only detected in testicular tissue, whereas the longer transcripts of 2.4 and 4.4kb are ubiquitously expressed. The expression of znf230 in testis is developmentally regulated and first detected at day 6 postnatal (pn). It reaches adult level between day 14 and 21 pn during which round spermatids appear in seminiferous tubule. The protein of znf230 exhibits DNA binding activity and its ring finger domain may function as an activator module in transcription. Therefore, it is postulated that znf230 may function as a testis specific transcription factor during mouse spermatogenesis.

Amino Acid Sequence↗
PubMed2003

A single nucleotide deletion of 293delT in SEDL gene causing spondyloepiphyseal dysplasia tarda in a four-generation Chinese family.

Spondyloepiphyseal Dysplasia Tarda (SEDT; MIM 313400) is a rare genetically heterogeneous disorder of vertebral and epiphyseal growth resulting in disproportionally short-trunked short stature, barrel-shaped chest, and dysplasia of the large joints. It is caused by the mutations of SEDL gene. The distinctive radiological signs and the X-linked mode of inheritance make it easy to diagnose. Here a four-generation Chinese SEDT family has been analyzed and the disease-causing mutation has been found. After polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis and DNA sequencing, a previously unreported deletion of T in exon 5 of SEDL gene (i.e. 293delT) was observed and seven individuals in the family carried the mutation. It results in frameshift and a putative truncated protein with the 97 N-terminal amino acids, and 9 changed amino acids. Therefore, loss of function of the gene could be predicted. However, this mutation has not been detected in 50 age and sex matched unrelated controls.

Adult↗
PubMed2003

[Study on the association of lecithin cholesterol acyltransferase gene polymorphisms with the lipid metabolism in coronary atherosclerotic heart disease].

OBJECTIVE: To examine the distribution of 3 polymorphisms of lecithin cholesterol acyltransferase gene in Chinese population and the association of these polymorphisms with lipid metabolism in patients with atherosclerotic heart disease (CHD). METHODS: Genotypes and frequencies of 3 sites were examined by PCR-restriction fragment length polymorphism technique in 209 unrelated normal control individuals and 203 CHD patients. RESULTS: The observed allele frequencies conform well to Hardy-Weinberg equilibrium. The frequency of 608T allele was significantly higher in controls than that in patients (P=0.034). Compared with the CHD patients without 608T, the CHD patients with 608T exhibited a significant increase in plasma HDL-C concentration (P=0.015). 911T/C and 1188C/T polymorphisms were not found in either group. CONCLUSION: 608T polymorphism of LCAT gene was associated with higher plasma HDL-C level in CHD patients, while 911T/C and 1188C/T polymorphisms maybe very rare in Chinese population.

Alleles↗
PubMed2002

Clustering of variations and haplotype analysis in the highly variable region of exon 11 of BRCA1 in Chinese women with sporadic breast cancer.

Studies on mutations of BRCA1 gene in Oriental populations, especially in Chinese are sparse. To evaluate the contribution of BRCA1 mutations to sporadic breast cancer in Chinese, mutations in exon 11 from nucleotide positions 3533 to 3682(U14680), a highly variable region of BRCA1 gene, were screened by single-strand conformation polymorphism (SSCP) and DNA sequencing in 329 genomic DNAs from 95 Chinese women with sporadic breast cancer, 29 with benign breast disease and 50 controls. As results, 6 single nucleotide changes were found, and 5 of them (3545A>G, 3551G>T, 3607C>T, 3646T>A and 3661T>C) were newly discovered. The 3545A>G and 3607C>T were germline variations, and the other 3 were somatic variations. In addition, four new haplotypes were defined. Since these newly discovered nucleotide changes were only detected in patients, our results suggest that BRCA1 may also play a role in the development of sporadic breast cancer in Chinese populations.

Adolescent↗
PubMed2002

Molecular characterization of the TCP11 gene which is the human homologue of the mouse gene encoding the receptor of fertilization promoting peptide.

A human testis-specific gene was isolated by subtractive hybridization between the cDNA pools of adult and fetal testes, followed by rapid amplification of cDNA ends (RACE). This gene sequence is highly homologous to a large portion of the mouse Tcp11 gene which is important in sperm function because it encodes the receptor for fertilization-promoting peptide (FPP). The gene was mapped to human chromosome band 6p21 by fluorescence in-situ hybridization. The 9 exon gene spans a 22.8 kp genomic DNA sequence. The mature processed message encodes a 441 amino acid protein that is highly homologous to the mouse 566 amino acid protein after the first 142 amino acids. Results of Northern blot and RT-PCR analyses of RNA extracted from human tissues revealed that the gene is only expressed in fertile adult testes, but not in azoospermic testes, fetal testes nor in other human tissues. Taken together, our results along with the mouse Tcp11 function suggest that TCP11 gene is important in sperm function and fertility.

Amino Acid Sequence↗
PubMed2002

Novel mutations of PKD1 gene in Chinese patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common disease in China. The major gene responsible for ADPKD, PKD1, has been fully characterized and shown to encode an integral membrane protein, polycystin 1, which is thought to be involved in cell-cell and cell-matrix interaction. Until now, 82 mutations of PKD1 gene have been reported in European, American, and Asian populations. However, there has been no report on mutations of the PKD1 gene in a Chinese population. METHODS: Eighty Chinese patients in 60 families with ADPKD were screened for mutations in the 3' region of the PKD1 gene using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA-sequencing techniques. RESULTS: Three mutations were found. The first mutation is a 12593delA frameshift mutation in exon 45, and the polycystin change is 4129WfsX4197, 107 amino acids shorter than the normal polycystin (4302aa). The second mutation is a 12470InsA frameshift mutation in exon 45, producing 4088DfsX4156, and the predicted protein is 148 amino acids shorter than the normal. The third one is a 11151C-->T transition in exon 37 converting Pro3648 to Leu. In addition, nine DNA variants, including IVS44delG, were identified. CONCLUSIONS: Three mutations in Chinese ADPKD patients are described and all of them are de novo mutations. Data obtained from mutation analysis also suggests that the mutation rate of the 3' single-copy region of PKD1 in Chinese ADPKD patients is very low, and there are no mutation hot spots in the PKD1 gene. Mutations found in Chinese ADPKD patients, including nucleotide substitution and minor frameshift, are similar to the findings reported by other researchers. Many mutations of the PKD1 gene probably exist in the duplicated region, promoter region, and the introns of PKD1.

Amino Acid Sequence↗
PubMed2002

A novel allele in the promoter of the hepatic lipase is associated with increased concentration of HDL-C and decreased promoter activity.

Hepatic lipase (HL) is a lipolytic enzyme involved in the metabolism of plasma lipoproteins, especially HDLs. Association of the polymorphisms in the promoter region of the LIPC gene to post-heparin plasma HL activity and the plasma HDL-C concentration has been investigated thoroughly, but to date little is known about this in the Chinese. In the present study, we analyzed the polymorphisms in the promoter region of LIPC gene in Chinese patients with coronary artery disease (CAD) using denaturing high performance liquid chromatography (DHPLC) and DNA sequencing. As the result, a novel single nucleotide polymorphism -586T-to-C was identified and no linkage of this variant with other polymorphisms in the promoter was found. Compared with the nonsymptomatic control subjects, excess of carriers of the -586T/C substitution were detected in the CAD patients (43% vs. 31%, chi(2) = 4.597, degree of freedom = 2, P = 0.032). The -586C allele carriers in the CAD patients had a significantly higher HDL-C level than the noncarriers (1.13 +/- 0.24 mmol/l vs. 0.91 +/- 0.14 mmol/l, P < 0.05). To test the functionality of this substitution, luciferase-reporter assays was performed in HepG2 cells. Promoter activity of the -586C construct was decreased 2-fold than the -586T construct. Our studies suggest that a T-to-C substitution at -586 of the LIPC promoter is associated with a lowered HL activity and that this variation may contribute to the increased plasma HDL-C concentration in the Chinese.

Adult↗
PubMed2002

[Polymorphisms of four microsatellite markers tightly linked with polycystic kidney disease 2 gene in Chinese].

OBJECTIVE: To investigate the polymorphisms of four microsatellites, D4S1534, D4S1563, D4S423 and D4S414, which are tightly linked to polycystic kidney disease 2 (PKD2) gene, and hence to provide a basis for studying the heterogeneity of adult polycystic kidney disease (APKD). METHODS: An analysis on the DNA of some unrelated Chinese people was performed using polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining. RESULTS: In Chinese Hans, there are 11 alleles of D4S1534, and their sizes are 142-162 bp 14 alleles of D4S1563, 205-235 bp 17 alleles of D4S423, 103-135 bp; and 15 alleles of D4S414, 236-264 bp. The polymorphism information contents of the four microsatellites are 0.872, 0.844, 0.921 and 0.871 respectively. CONCLUSION: In the Chinese Han people studied above, the four microsatellite markers that have many alleles are highly polymorphic genetic markers and may serve as the data of population genetics, suggesting that all four microsatellites could be used in studies on heterogeneity of APKD, linkage analysis of APKD and forensic personal identification.

Alleles↗
PubMed2002

[Fluorescence probe two-hybridization technique and its application in medical genechips].

OBJECTIVE: To establish a new nucleic acid hybridization detection technique which may be used in medical genechips. METHODS: The specific DNA fragment was detected by sequential two hybridization of fluorescence probe with template DNA and fixed DNA probe. RESULTS: Fluorescence probe two-hybridization (FPTH) was applied to genechips for the detection of sex-transmitted pathogens from culture strains, and the results showed that the values of fluorescence density of the positive groups decreased remarkably when compared with those of the negative group. Both the sensitivity and specificity for detecting clinical samples are higher than 90%. There is no need of any additional reagent in hybridization procedure, and the hybridization detection can be accomplished in 40 minutes. CONCLUSION: The FPTH technique is rapid, simple and reliable, it can also make the clinical detection process completely automatic and integrative.

DNA Probes↗
PubMed2002

Typing Y chromosome STR haplotypes using redesigned primers.

A panel of Y-specific STR loci, including DYS19, DYS389, DYS390, DYS391, DYS392, and DYS393 was analyzed using horizontal nondenaturing polyacrylamide gel electrophoresis with a discontinuous buffer system (horizontal disk-PAGE). In order to obtain correct results for the larger DYS389 and DYS392 alleles, it was necessary to design new primers that bind closer to the repeat region and lead to a significant reduction of the amplified fragment size. Using the modified primer sets the horizontal disk-PAGE results were consistent with a nondenaturing approach using fluorescent primers and a 377 automated sequencer. The modified procedure also amplifies the second repeat stretch at the duplicated DYS389 locus as a single fragment, which results in an immediate allele identification. The results indicate that horizontal disk-PAGE with silverstaining is a simple approach to type the recommended Y-specific STR markers.

DNA Primers↗
PubMed2002

Relationship between a novel polymorphism of lipoprotein lipase gene and coronary heart disease.

OBJECTIVE: To investigate polymorphisms in the gene for lipoprotein lipase (LPL) in Chinese populations with coronary heart disease (CHD) and to inquire into the relationship between these polymorphisms in LPL gene and CHD. METHODS: Genomic DNA was extracted from patients with CHD and normal control subjects using a salting out method. The entire coding region and flanking sequences of all coding exons of the LPL gene were amplified by PCR technique and PCR products were detected by denaturing high-performance liquid chromatography (DHPLC) and sequenced with a dideoxy terminal termination method. RESULTS: A novel polymorphic site, G830A, that is within the fifth exon of the LPL gene was found. The 192 codon CGA was changed into CAA and resulted in the substitution of glutamine for arginine. Between the control and CHD groups, chi-square test showed no significant difference in the frequencies of the A/A genotype and A allele (P > 0.05). However, the frequencies of A/A genotype and A allele (0.653 and 0.786) in CHD patients with high plasma triglyceride/lowed plasma high density lipoprotein cholesterol were higher than those (0.415 and 0.642) in CHD patients without hyperlipidemia (P < 0.05). CONCLUSION: No direct association was found between the LPL Arg192-->Gln substitution polymorphism and CHD, but there is a significant positive correlation between the A/A genotype of the LPL gene and CHD associated with high triglyceride/lowed high density lipoprotein cholesterol. This study may provide new data for exploring the molecular mechanism of CHD.

Alleles↗
PubMed2002

[A study of the relationship between MICA gene and systemic lupus erythematosus].

OBJECTIVE: To investigate the relationship between major histocompatibility complex class I chain-related A(MICA) gene and systemic lupus erythematosus (SLE). METHODS: The alleles and frequencies of exons 4 and 5 of MICA gene were determined in 70 cases of SLE and 152 controls of Yunnan Hans by STR genotyping, polymerase chain reaction, single strand conformation polymorphism and bidirection DNA sequencing. RESULTS: Five alleles of exon 5 and 10 alleles of exon 4 were found in this study. The frequency of each allele was determined in patients and controls. There was no significant difference between the two groups in exons 4 and 5 of MICA gene. CONCLUSION: Exons 4 and 5 of MICA were not related to SLE in Yunnan Hans.

Alleles↗
PubMed2002

[Nested coamplification polymerase chain reaction].

OBJECTIVE: To develop a simple and reliable method for intensifying the hybridization signals of gene chips. METHODS: The authors added EDTA and another FAM-labeled probe to the normal PCR products, denatured the mixture by heat, and then let the mixture hybridize with the fastened probes on the chip. RESULTS: With the use of EDTA and another FAM-labeled probe, the hybridization signals increased by 6 times or greater. CONCLUSION: Adding EDTA and another probe to the normal PCR products is a simple and efficient method to intensify the hybridization signal of chips.

Base Sequence↗
PubMed2002

[The relationship between haplotypes of angiotensinogen gene and essential hypertension].

OBJECTIVE: To investigate the relationship between the polymorphism of angiotensinogen gene (AGT) and the risk for hypertension in a Chinese population. METHODS: Three polymorphisms of AGT gene were analyzed in 335 patients with documented essential hypertension and 196 control subjects by using PCR-restriction fragment length polymorphism. Expectation maximization(EM) algorithm was then used for pairwise linkage disequilibrium test and haplotype analysis of AGT polymorphisms. RESULTS: Linkage disequilibrium between M235T and A-20C, between M235T and A-6G, between A-20C and A-6G was observed (P<10(-4)). The case-control analysis revealed that the frequency of T235 is significantly higher in essential hypertension patients than in control subjects. But all haplotype frequencies showed no significant difference between the patient and control groups. CONCLUSION: No association was noted between the haplotypes of AGT gene and hypertension in tested people, but T235 allele might play an important role in increased risk for essential hypertension.

Alleles↗