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Many studies have show that the structurally polymorphic Alu insertion within HLA class I region are useful tools for investigating the origin, evolution and recombination of HLA class I progenitor haplotypes and gene diversity in different ethnic populations. In the present study, we determined the frequencies of HLA-Alus (i.e., AluMICB, AluTF, AluHJ, AluHG, and AluHF) in Zhuang and Yugu ethnic populations at first. Then, combined with HLA genotyping data, we studied associations between HLA-Alus and HLA-A alleles in Zhuang, Yugu, Bulang, Dai, and Hani ethnic populations. Our results showed that (1) the frequencies of five HLA-Alus were 1.5%~35.8% and 9.2%~34.8% in Zhuang and Yugu, respectively; and (2) the results of association between HLA-A alleles and HLA-Alu showed strong association between AluHG insertion and HLA-A 02 subtypes in all populations, association between AluHJ insertion and HLA-A 2402 in all populations, and association between AluHJ insertion and HLA-A 1101, -A 2407 in Bulang. The present study suggested that the distribution of HLA-Alus as well as the associations between HLA-Alus and HLA class I alleles are variable in different ethnic populations. HLA Alus alone or together with the HLA class I alleles are informative genetic markers for the identification of HLA class I allele and variation of haplotype lineages in different populations.

Pax-6 is an evolutionarily conserved transcription factor regulating brain and eye development. Four Pax-6 isoforms have been reported previously. Although the longer Pax-6 isoforms (p46 and p48) bear two DNA-binding domains, the paired domain (PD) and the homeodomain (HD), the shorter Pax-6 isoform p32 contains only the HD for DNA binding. Although a third domain, the proline-, serine- and threonine-enriched activation (PST) domain, in the C termini of all Pax-6 isoforms mediates their transcriptional modulation via phosphorylation, how p32 Pax-6 could regulate target genes remains to be elucidated. In the present study, we show that sumoylation at K91 is required for p32 Pax-6 to bind to a HD-specific site and regulate expression of target genes. First, in vitro-synthesized p32 Pax-6 alone cannot bind the P3 sequence, which contains the HD recognition site, unless it is preincubated with nuclear extracts precleared by anti–Pax-6 but not by anti-small ubiquitin-related modifier 1 (anti-SUMO1) antibody. Second, in vitro-synthesized p32 Pax-6 can be sumoylated by SUMO1, and the sumoylated p32 Pax-6 then can bind to the P3 sequence. Third, Pax-6 and SUMO1 are colocalized in the embryonic optic and lens vesicles and can be coimmunoprecipitated. Finally, SUMO1-conjugated p32 Pax-6 exists in both the nucleus and cytoplasm, and sumoylation significantly enhances the DNA-binding ability of p32 Pax-6 and positively regulates gene expression. Together, our results demonstrate that sumoylation activates p32 Pax-6 in both DNA-binding and transcriptional activities. In addition, our studies demonstrate that p32 and p46 Pax-6 possess differential DNA-binding and regulatory activities.

To investigate the effect of hypoxia environment induced by altitude on hypoxia inducible factor 1α (HIF1A) gene.Nine single nucleotide polymorphism (SNP) loci of the HIF1A gene from three Tibetan groups (Tibet, Qinghai Province and Yunnan Province) were genotyped using PCR-restriction fragment length polymorphism (PCR-RFLP) method.For non-synonymous mutation SNP site, there was no significant difference among the three Tibetan groups, except for SNP rs11549465 between Tibet Tibetan and Yunnan Tibetan, as well as between Qinghai Tibetan and Yunnan Tibetan. Frequencies of genotypes and alleles in rs4899056, rs1957757, rs10873142 and rs3783752 had significant differences between Tibet Tibetan and Yunnan Tibetan, and between Qinghai Tibetan and Yunnan Tibetan (all P0.05). We also observed that the difference was negatively correlated with the altitude.The results suggested that the HIF1A gene might be under hypoxic selection induced by high altitude in the three groups.

A 14 bp insertion/deletion polymorphism (+14 bp/-14 bp) in exon 8 of HLA-G gene has been investigated extensively because this polymorphism was associated with HLA-G mRNA stability and could influence HLA-G mRNA expression. In the present study, we genotyped 14 bp insertion/deletion polymorphisms in the HLA-G gene in Dai and Han populations in Yunnan Province. The frequencies of +14 bp in Dai and Han were 31.97% and 40.87%, respectively. The frequency of +14 bp/+14 bp in Dai was lower (8.20%) than that of Han (17.31%). Nevertheless, the frequency of +14 bp/-14 bp was similar in both populations (47.54% in Dai and 47.11% in Han). When compared with other populations, the frequency of 14 bp insertion/deletion of Han was similar to others, whereas the Dai showed significant difference from others and presented it's specific characteristic. We assumed that the distribution characteristic of 14 bp insertion/deletion in Dai might be the results of random genetic drift, but the role of natural selection cannot be excluded.

The effects of dynamic ultra high-pressure microfluidization on the structure of waxy rice starch solutions (6%) were analyzed using SEM, UV-Vis spectra, polarized light microscopy, and X-ray diffraction spectra. The results showed that: SEM graphs demonstrated that the crystal structure of waxy rice starch under different pressure treatment was destroyed with different degrees and impacted into flake up to 160 MPa; from the ultraviolet-visible spectrum we know the reduction in the blue iodine value and the decrease in the amylopectin content, which illustrated that the structure of waxy rice starch was fractured; polarized microscopic images showed that the polarization crosses of starch molecules became misty with the pressure increasing, and most of starch molecules lost polarization cross when the pressure reached 160 MPa; X-ray diffraction spectra indicated that relative crystallinity began to decline at 120 MPa with pressure treatment, and the decreased amplitude was slightly lower.

Immortalized cell lines of spinocerebellar ataxia type 2 (SCA2) with Parkinson disease symptoms were established in order to provide experimental material for future study.The immortalized cell lines were constructed by using Epstein Barr virus and cyclosporine A. Microsatellite markers were detected to see whether there is any change between the cell lines and the original blood samples, and the genetic stability of the cell lines were evaluated.Twenty-five immortalized cell lines were established successfully from the family and the microsatellite markers were unchanged.The karyotypes of the immortal cell lines were normal and the cell lines were genetically stable.

The pathogenesis of schistosomiasis is mainly caused by egg-induced granuloma formation and subsequent fibrosis. If Schistosoma japonicum infections could be detected in the early stage, especially before the egg deposition in the host tissues, the development of severe pathologic lesions might be prevented efficiently. The present study identified and characterized S. japonicum Sjp40, a potential antigen candidate for the early diagnosis of schistosomiasis. From the S. japonicum cercariae cDNA library, a clone encoding Sjp40 was identified by screening with the pooled rabbit sera collected on day 21 postinfection. Then, the recombinant Sjp40 protein (rSjp40) and monoclonal antibodies (McAbs) anti-rSjp40 were developed. The expression profiles of Sjp40 at 3 stages of S. japonicum, including egg, cercariae, and adult, were also determined at both mRNA and protein level, which displayed that the expression pattern of Sjp40 varied at different stages. Quantification of circulatory anti-Sjp40 IgG in the infected mice sera by time-resolved fluoroimmunoassay showed a statistically significant increase on days 21, 28, 35, and 42 postinfection compared with the mice sera prior to infection and the control mice. It was further confirmed by Western blot that all 8 clones of anti-rSjp40 McAbs could react specifically with the native antigen in S. japonicum cercariae, and rSjp40 could be recognized by the pooled infected mouse sera on days 21, 28, 35, and 42 postinfection as well as the pooled patient sera with acute schistosomiasis japonica. These findings indicated that Sjp40 and its antibodies are detectable from the host at a relatively early phase (day 21 postinfection with S. japonicum) and suggested that Sjp40 is a potential antigen candidate for the early diagnosis of schistosomiasis.

To obtain the transgenic tomato plant expressed multiepitope antigenic gene of Toxoplasma gondii (Tg-MAG).Tg-MAG under the control of E35S promoter, E35S-E81.1 chimeric promoter and E8 2.2 promoter in the plant expression vectors was transferred into the tomato cotyledons and hypocotyls via Agrobacterium-mediated T-DNA transformation. The candidate buds were obtained and elongated by kanamycin resistant screening. After further rooting selection, the selected tomato lines were trained and transplanted to soil and grown in a greenhouse till blossoming and bearing fruit. The transgenic tomato plants were identified using PCR, RT-PCR and Western blotting.Tg-MAG was introduced into the transgenic plant genomic DNA and transcribed correctly at expected size 360 bp identified by PCR and RT-PCR. Western blotting results indicated that the recombinant Tg-MAG from 8 transgenic lines, expressed in tomato fruits at expected size 11900, 2 of them showed strong reaction band with HRP labeled McAb K7H3 against the major surface antigen 1( SAG1) of T. gondii tachyzoites.Tg-MAG transgenic tomato lines were obtained. Tg-MAG recombinant protein with good immune activity was expressed successfully in transgenic tomato fruits.

This study was aimed to explore the effect of nerve growth factor (NGF) on erythropoiesis and to elucidate the underlying mechanism. Using flow cytometry, colony forming assay, blood cell counter, fluorescent real-time quantitation PCR, and enzyme-linked immunosorbent assay (ELISA), the changes in the bone marrow cells (BMCs) proliferation cycle, CFU-E and BFU-E counts, the peripheral blood erythroid related parameters, kidney EPO, BMC GM-CSF, spleen EPO receptor (EPOR) mRNA expression, and serum EPO, GM-CSF, and IL-1 concentrations were all determined after NGF was injected intramuscularly into the thigh of mice, meanwhile the change of BFU-E and CFU-E counts and its relationship with EPO, IL-3 were investigated. The results indicated that the cell proportion in S+G2/M phase, the CFU-E and BFU-E counts of BMCs and the spleen EPOR mRNA expression in injection of NGF (7.5 microg/kg) for 7 days were significantly higher than that in injection of physiological saline for 13-19 days; red blood cell, hemoglobin, and reticulocyte counts increased as well. In vitro, NGF stimulated a dose-dependent increase of CFU-E colonies formation in the semisolid culture system with or without exogenous EPO; the colony counts in the system with NGF alone were significantly higher than that in the system with exogenous EPO alone. The BFU-E counts in the system with exogenous NGF and IL-3 were significantly higher than that in the system with exogenous EPO and IL-3. It is concluded that the NGF promotes the responsibility of hematopoietic cells to EPO and activates the same signal transduction pathway as EPO in hematopoietic cells, and then accelerates the BMCs into mitosis, the HSCs differentiating into erythroid cells, and CFU-E and BFU-E formation.

To explore the effect of nerve growth factor (NGF) on hematopoiesis of granulocyte-macrophage and to elucidate the underlying mechanism.Using flow cytometry, colony forming assay, blood cell count, fluorescent real-time quantitation PCR, and enzyme-linked immunosorbent assay (ELISA), changes in the bone marrow cells (BMCs) proliferation cycle, CFU-GM counts, the peripheral white blood cell (WBC)counts, BMC GM-CSF mRNA quantities, and serum GM-CSF, IL-3 concentrations were observed after NGF was injected intramuscularly into the thigh of normal and combined 60Co gamma ray irradiated and cyclophosphamide peritoneal cavity injected(combined radiation and chemistry injury mice, 60Co-Cy injury) mice. The effect of NGF on CFU-GM formation in vitro cooperation with exogenous GM-CSF or alone was also observed.An injection of NGF [7.5 microg/(kg x d) or 10 microg/(kg x d)] lasted 7 days, the S+G2/M proportions and the CFU-GM counts of BMCs rose greater than injection of physiological saline (PS) in normal and 60Co-Cy injury mice; the serum GM-CSF,IL-3 concentration in 60Co-Cy injury mice rose obviously. In vitro, NGF stimulated a dose-dependent increase of CFU-GM colonies formation in the semisolid culture system with exogenous rmGM-CSF.NGF cooperates with hematopoietic stimulating factors in culture system to promote the CFU-GM colonies in normal and 60Co-Cy injury mice in vitro. NGF accelerates the BMCs into mitosis, the hematopoietic stem cells differentiation into granulocyte-macrophage hematopoietic cells, the CFU-GM formation and promotes the white blood cells count in normal and 60Co-Cy injury mice in vivo, also NGF stimulates the secreting of GM-CSF and IL-3 in 60Co-Cy injury mice,this may be one of the reasons why NGF stimulate the granulocyte-macrophage hematopoiesis repair after combined radiation and chemistry injury.

To construct the haplogroup and perform an analysis of mitochondrial whole-genome sequence in Tibetan and Han Chinese. Variations of nucleotide of mitochondrial DNA (mtDNA) were identified and compared between the Tibetan and Han population.The mtDNA whole sequences of 40 Tibetan and 50 Han individuals were sequenced by an Applied Biosystems 3730 DNA automatic sequencer. The sequences were assembled using software phredPhrap16.0, and all assembled sequences were manually verified according to the criterion of rCRS (revised Cambridge Reference Sequence). The haplogroups of mtDNA were constructed using phylogenetic analysis according to the criteria of MITOMAP by Network method. The data were elucidated by integrated methods.Authors' results showed that all the pooled 90 subjects belonged to the Macrohaplogroup M and N, and were classified into 13 haplogroups. No differences were observed among the haplogroups of the two populations except for M9 haplogroup. A total of 21 variants were detected by comparing the mtDNA whole sequences between Tibetan and Han population; of those, 5 variants have not been reported before. In addition, we constructed the haplotypes of 5 variants harboring the D-loop region, and founded prominent difference in both supertype 1 and supertype 2 between Tibetan and Han population.The phylogenetic analysis indicates that the Tibetan and Han ethnic groups shared close maternal relationship in origin. The biological implication of the significant variants is worth elucidating; whether they are the results of adaptive selection or neutral selection or pathological variations need to be further studied.

To optimize the process of tomato genetic transformation, screening and seed selection using multiepitope antigenic gene (MAG) and truncated major surface antigen 1 (tSAG1) of Toxoplasma gondii as the target insert genes.Tomato high-frequency regeneration system was optimized with different choices of media and explants. The genetic transformation procedure was optimized using different tomato cultivars, explants, culture temperatures, media and acetosyringone (AS) supplements. Three concentrations of kanamycin were utilized for resistant selection of the transgenic candidate roots. The selected lines were trained, transplanted to soil and grown in a greenhouse till maturity. Sterile seeding using kanamycin-incorporated medium was conducted for screening transgenic tomato generations.Cotyledons were better than hypocotyls as the regeneration explants. The regeneration rate of cotyledons reached 98% (59/60) using the optimized regeneration medium ZB3. The culture medium and temperature were the key factors for tomato transgenic shoot induction. The number of transgenic buds increased significantly at the appropriate temperature condition (23-/+1 degrees celsius;), and AS of 100 micromol/L in the medium before inoculation also significantly raised transformation rate. The budding rate of Zhongshu No.5 cotyledons was 35% (28/81) using the medium ZB2 under (23-/+1) degrees celsius;. Kanamycin at 80 mg/L was optimal for transgenic plantlet rooting selection with the rooting rate of 48% (31/65). 117 transgenic lines were obtained. Non-transgenic tomato plant growth, especially the root and elongation, was inhibited obviously with kanamycin at 100 mg/L or above, and the roots became purple and lacked lateral roots. The transgenic tomato seeds could be selected effectively with kanamycin at 150 mg/L.

To study the genetic stability of an immortalized cell line transformed by Epstein-Barr virus (EBV) after long subculture process.In the present study, the genetic stability including chromosome diploidy, karyotypes and microsatellite DNA were evaluated with chromosome banding techniques and microsatellite DNA detection. The telomerase activity of the immortalized cell line was detected by using the telomerase assay kit.From passage 1 to 30, there were no change of the diploidy, karyotypes of chromosome and microsatellite DNA, and the telomerase activity is negative.This study indicates that the immortalized cell line remains stable genetically within limited passages.

To analyze the epidemiology of methicillin resistant Staphylococcus aureus (MRSA) in molecular level in burn centre of Shanghai Ruijin hospital.The vicissitude of Staphylococcus aureus in the burn centre from 2003 to 2005 was analyzed with software WHONET5. Multiprimer random amplified polymorphic DNA(RAPD) was used to analyze the homology of 17 MRSA strains.RAPD analysis (primer ERIC2 and RAPD7) showed that all 17 MRSA strains were identical (Burn-A type).MRSA with same RAPD type is prevalent in our burn centre for many years, so emphasis should be laid on the anti-infection therapy and its cross infection control. Staphylococcus aureus

To investigate the polymorphism of DYS287 among 28 ethnic populations in 9 provinces of China.YAP element was detected by Touchdown PCR amplification and 2% agarose gel electrophoresis.YAP+ frequencies in these ethnic populations were as follows: Zang 36.7%, Tu 23.8%, Yi 18.4%, Pumi 11.3%, Tajik 7.4%, Bai 6.7%, Jino 5.1%, Shandong Han 4%, Mulao 2.7%, and Maonan 1.3%. The rest ethnic populations in our study, including Gansu Han, Yunnan Han, Zhuangzu, Daizu, Lizu, Nuzu, Lisu, Naxi, Lahu, Dulong, Hani, Shezu, Weiwuer, Sala, Kerkizi, Dongxiang, Vazu, and Korea didn't carry YAP + element.Zangzu, Tuzu, Yizu, Pumi, Jino, and Baizu, which belong to Sino-Tibetan language family, carry a high YAP + frequency. Sala, Tuzu, and Tajik, regarded as Central Asia by origin in history and linguistics, also have a high YAP + frequency. Mulao and Maonan, which origin from "Baiyue" ancient ethnic groups, also have a considerable YAP + frequency.

To investigate the polymorphism of nine Y-short tandem repeat loci in 117 male individuals from four minority populations of China, and to obtain the polymorphism information in these populations.Nine loci in all samples were amplified by PCR. Products were electrophoresed on ABI PRISM 377 DNA sequencer. The electrophoresis result was analyzed by Genotyper 2.0 software. Allele frequencies, diversities and genetic distance were calculated.Forty-three alleles and 32 haplotypes were found in Manchu population, 43 alleles and 33 haplotypes in Uygur population, 31 alleles and 15 haplotypes in Kirgiz population and 34 alleles and 23 haplotypes in Zhuang population. The closest genetic distance is 0.02530 between Manchu and Uygur, the highest genetic distance is 0.34590 between Kirgiz and Zhuang.High haplotype diversities were found in four populations. The study of genetic diversity among different populations is useful in research of their origins, migrations and their relationships.

129 samples of Han population in Yunnan province were detected by polymerase chain reaction and microtitre plate hybridization (PCR-MPH). The samples of DR*15 subgroup being detected by PCR-MPH were further analyzed by Single-Strand Conformation Polymorphism (SSCP). By first polymerase chain reaction and microtitre plate hybridization (PCR-MPH), all of the 129 samples were divided into the following subgroups, viz. DR*01,DR*03,DR*04,DR*0701,DR*08,DR*09012,DR*1001,DR*11,DR*12,DR*13,DR*14,DR*15, DR*1602 and DR*1604. The samples of DR*04, DR*08/12, DR*03/11/13/14 were further detected by second PCR-MPH and the ones of DR*15 by SSCP. 36 kinds of alleles on HLA-DRB1 were detected in these samples. Among them, DRB1*1501(0.1240),DRB1*09012(0.0969), DRB1*08032(0.0930),DRB1*1202(0.0891),DRB1*1201(0.0814), DRB1 *1401(0.0775),DRB1 *0701(0.0620),are the most frequent. The chi(2) test of HLA-DRB1 alleles was done between Yunnan Han and the other 9 Han populations. In detail, comparing with Yunnan Han on the chi(2) test, the chi(2) values of few alleles in the few Han populations was more than 10, they were Xian Han(DR8,chi(2)=13.9712), Shanghai Han(DR4,chi(2)=10.1632), Guangdong Han(DR9,chi(2)=12.6121)and Nanjing Han(DR4,chi(2)=10.5796). Comparing with 9 Han populations, the genetic distance between Yunnan Han and Liaoning Han was the nearest(0.0541),Guangdong Han was the farthest(0.1851). In the 9 Han populations, the genetic distance between Shanghai Han and Nanjing Han was the nearest(0.0122),and the one between Tianjin Han and Shanxi Han was also nearer(0.0219). Based on above analysis, the conclusion may be deduced that the resource of Yunnan Han may be close to Liaoning Han and it was not a typical southern Han population though Yunnan Han are resident in the South. Some gene flow may be exit between Yunnan Han and the local minorities and made Yunnan Han become a special population.

To study the genetic polymorphism of Y chromosome in different Chinese ethnic group populations.Genotypes of 17 biallelic markers located in the nonrecombining portion of the Y chromosome in 76 men from 3 Chinese ethnic group populations (Han in Shandong, Bai in Yunnan, and Tu in Qinghai) were examined with polymerase chain reaction (PCR) and allelic-specific PCR (ASPCR). Their haplotypes made of these 17 binary markers were constructed. The principle component (PC) analysis was conducted based on the haplotype frequency distribution among these 3 and other 15 published Chinese ethnic group populations.The diversities of M50, M110, M103, M88, M3, and M7 were not found in these 3 populations. The frequencies of YAP+ were 23.8%, 6.7%, and 4% respectively in Tu, Bai, and Shandong Han. Eleven haplotypes were found in 3 populations--7 haplotypes (H1, H3, H5, H6, H8, H9, and H11) in Shandong Han (Han.SD), 8 haplotypes (H1, H2, H3, H5, H6, H8, H11, and H16) in Tu, and 9 haplotypes (H1, H3, H4, H5, H6, H8, H9, H11, and H13) in Bai. The predominant haplotypes were H1, H3, H5, H6, H8, and H11. According to PC analysis, Bai was close to Northern Han; Shandong Han, Southern Han (Han.S), Bai and Yunnan Tibetan clustered together; and Tu was close to Yi, Hui and Manchurian.Shandong Han may have had genetic exchanges with southern populations in China. It has been confirmed that some gene components of Han had flowed into Bai's gene pool. Gene flowed from Central Asia had impacted Chinese western populations.

By using the mini-gene construct containing partial sequence of Bcl-X gene as model, we examined the function of TPA on Bcl-X pre-mRNA alternative splicing in vivo and vitro with RT-PCR and site-directed mutagesis assay. The results show that PKA signaling system can regulate Bcl-X pre-mRNA alternative splicing, the possible mechanism is that the responsible sequence affect the choice of the 5'-downstream or upstream splice site of Bcl-X pre-mRNA.

Based on the structural analysis to reveal the mechanism of ligand binding to beta-secretase and the specificity of each binding sub-site.Molecular dynamics was used to simulate on the ligand free beta-secretase and ligand bound beta-secretase. The trajectories were analyzed using the essential dynamics, and the significant conformational change was illustrated employing the DynDom program.The essential dynamics and DynDom analyses clearly showed that the beta-secretase experienced a large conformational change upon the substrate or inhibitor binding. The flap structure adopted a swing motion, gradually covering the active site to facilitate the ligand binding process. Residues Ser86 and Ile87 served as the hinge point. Inhibitor-enzyme interaction analysis revealed that residues at P2, P1, and P1' positions of the inhibitor were very important for the binding, and residues at P2' and P3' positions may be modified to improve the binding specificity. S3 subsite of the enzyme still had space to modify the inhibitors in increasing the binding affinity.The information presented here is valuable and could be used to identify small molecular inhibitors of beta-secretase.

Background and Purpose Atherothrombotic cerebral infarction [atherothrombotic stroke (ATS)] shares common risk factors and pathophysiological mechanisms with coronary artery disease (CAD), and both diseases appear to have common susceptibility loci. The muscle RAS oncogene homolog gene (MRAS) has been identified as a susceptibility locus for CAD and is implicated in atherosclerosis. The aim of this study was to elucidate whether the single-nucleotide polymorphisms (SNPs) and haplotypes of MRAS are associated with increased risk of ATS in a population of Han Chinese. Methods A case-controlled association study was conducted in which only patients with ATS (identified as a major subtype in the Korean modification of the Trial of Org 10172 in Acute Stroke Treatment classification) were enrolled. Subgroup analyses were carried out to determine whether the effect of the MRAS polymorphism was specific to age and gender among the subjects. Results In total, 194 ATS and 186 control subjects were included in the present study. Two tagging SNPs were identified in MRAS (rs40593 and rs3755751). A multivariate regression analysis revealed a positive association between rs40593 and ATS under dominant and additive models after adjustment for covariates. Subgroup analyses revealed that there were no gender differences with respect to allele or genotype frequencies between the groups. The AG genotype for rs40593 (p=0.028), the CT genotype for rs3755751 (p=0.036), and G-allele carriers (AG plus GG) for rs40593 (p=0.015) exhibited a significant protective effect among those aged ≥45 years. For the haplotype analysis, ATS subjects aged ≥45 years had a higher frequency of the ACAC haplotype (76.0%) than the controls (68.1%; p

PURPOSE. Telomerase is a specialized polymerase that catalyzes synthesis of telomeres in most eukaryotes. When introduced into somatic cells, it extends the proliferative lifespan and prevents replicative senescence. Whether it has similar functions in lens epithelial cells, especially in human lens epithelial cells (HLECs) remains to be determined. In this study, the human telomerase reverse transcriptase (hTERT) catalytic subunit was introduced into HLECs. A stable cell line expressing hTERT was established and the functions of hTERT were studied. METHODS. The telomeric repeat amplification protocol (TRAP) assay was used to analyze the telomerase activity. Western blot analysis was used to examine hTERT expression. Southern blot analysis was used to detect telomere length. HLECs isolated from intact lenses were cultured in DMEM and transfected with hTERT cDNA. The expression of the exogenous hTERT was examined with RT-PCR, Western blot analysis, and TRAP assay. The functions of hTERT were examined with various techniques. RESULTS. Among the human, bovine, and rabbit lenses examined, only the central epithelium from the 6-month rabbit lens displayed telomerase activity. In both transparent and cataractous human lenses, hTERT activity and expression were not detected. However, the template RNA was present in both types of human lenses. The telomeres in transparent lenses were approximately 1 kb longer than those in cataractous lenses. The primary cultures and later passages of HLECs also displayed no detectable telomerase activity. Introduction of hTERT cDNA into HLECs followed by G418 selection yielded a stable line of HLECs expressing hTERT. In this line, hTERT has supported normal growth after 48 population doublings (PDs) to date and also enhanced antiapoptotic activity against oxidative stress. CONCLUSIONS. Telomere lengths may be associated with cataractogenesis. hTERT introduced into HLECs prevents replicative senescence through telomere synthesis. Furthermore, hTERT displays functions beyond telomere synthesis in normal HLECs.