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1.
Invest Ophthalmol Vis Sci ; 65(3): 28, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38506850

ABSTRACT

Purpose: To characterize the natural history of normal-tension glaucoma (NTG) in Chinese patients. Methods: The prospective observational cohort study included patients with untreated NTG with a minimum follow-up of 2 years. Functional progression was defined by visual field (VF) deterioration, while structural progression was characterized by thinning of the retinal nerve fiber layer (RNFL) or ganglion cell inner plexiform layer (GCIPL). Results: Among 84 participants (mean age, 60.5 years; mean deviation, -5.01 decibels [dB]) with newly diagnosed NTG followed for an average of 69.7 months, 63.1% progressed during the observation period. Specifically, 29.8% progressed by VF, and 48.8% progressed by either RNFL or GCIPL. In Cox proportional hazards analysis, disc hemorrhage (hazard ratio [HR], 2.82; 95% confidence interval [CI], 1.48-5.35), female gender (HR, 1.98; 95% CI, 1.08-3.62), and mean IOP during the follow-up period (HR, 1.14 per mm Hg; 95% CI, 1.00-1.31) were significant predictors of glaucomatous progression. Additionally, longer axial length (AL; HR, 0.57 per millimeter; 95% CI, 0.35-0.94) was protective against VF progression faster than -0.50 dB/y, and higher minimum diastolic blood pressure (DBP; HR, 0.96 per mm Hg; 95% CI, 0.92-1.00) was protective against structural progression. Conclusions: Nearly two-thirds of untreated Chinese patients with NTG progressed over an average follow-up of 70 months by VF, RNFL, or GCIPL. Disc hemorrhage, female gender, higher mean IOP, shorter AL, and lower minimum DBP were significant predictors for disease progression.


Subject(s)
Glaucoma , Low Tension Glaucoma , Female , Humans , Middle Aged , China/epidemiology , Hemorrhage , Low Tension Glaucoma/diagnosis , Prospective Studies , Risk Factors , Male , Aged
2.
Acta Ophthalmol ; 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38259141

ABSTRACT

PURPOSE: To explore the association between progressive peripapillary capillary vessel density (pcVD) reduction and the progression of visual field (VF) impairment in individuals with normal tension glaucoma (NTG). DESIGN: Prospective cohort study. METHODS: The study enrolled 110 participants with one eye each, totalling 110 NTG eyes. VF defects were evaluated using standard automated perimetry mean deviation (MD), while pcVD measurements were obtained using optical coherence tomography angiography throughout the follow-up period. Estimates of VF progression were determined by event-based and trend-based analyses. Fast VF progression was defined as an MD slope steeper than -0.5 dB/year, while the slow progression or stable VF was defined as an MD slope better or equal to -0.25 dB/year. Linear mixed-effects models were employed to analyse the rates of change in pcVD reduction and VF MD decline over time. Additionally, univariable and multivariable linear models were used to examine the relationship between pcVD changes and VF loss rates in NTG. RESULTS: Slow VF progression or stable VF was observed in 45% of subjects, while 25% had moderate progression and 30% showed fast progression. Patients with VF progression exhibited faster rate of pcVD reduction in peripapillary global region (-0.73 ± 0.40%/year vs. -0.56 ± 0.35%/year, p = 0.022). Moreover, this rate positively correlated with VF MD decline in NTG (estimate 0.278, 95% CI 0.122-0.433, p = 0.001). CONCLUSION: In individuals with NTG, faster VF progression was linked to a quicker reduction in pcVD, suggesting a positive correlation between pcVD decline and VF deterioration.

3.
Planta ; 257(6): 110, 2023 May 07.
Article in English | MEDLINE | ID: mdl-37149499

ABSTRACT

MAIN CONCLUSION: Based on phenotypic, physiological and proteomic analysis, the possible mechanism by which Ds-26-16 regulates salt tolerance in Arabidopsis seedlings was revealed. Functional and mechanistic characterization of salt tolerance genes isolated from natural resources is crucial for their application. In this study, we report the possible mechanism by which Ds-26-16, a gene from Dunaliella, and its point mutation gene EP-5, enhance salt tolerance in Arabidopsis seedlings. Both Ds-26-16 and EP-5 transgenic lines displayed higher seed germination rates, cotyledon-greening rates, soluble sugar contents, decreased relative conductivity and ROS accumulation when germinating under 150 mM NaCl conditions. Comparative proteomic analysis revealed that there were 470 or 391 differentially expressed proteins (DEPs) in Ds-26-16 or EP-5, respectively, compared with the control (3301) under salt stress. The GO and KEGG enrichment analyses showed the DEPs in Ds-26-16 vs. 3301 and EP-5 vs. 3301 were similar and mainly enriched in photosynthesis, regulation of gene expression, carbohydrate metabolism, redox homeostasis, hormonal signal and defense, and regulation of seed germination. Thirty-seven proteins were found to be stably expressed under salt stress due to the expression of Ds-26-16, and eleven of them contain the CCACGT motif which could be bound by the transcription factor in ABA signaling to repress gene transcription. Taken together, we propose that Ds-26-16, as a global regulator, improves salt-tolerance by coordinating stress-induced signal transduction and modulating multiple responses in Arabidopsis seedlings. These results provide valuable information for utilizing natural resources in crop improvement for breeding salt-tolerant crops.


Subject(s)
Arabidopsis , Chlorophyceae , Seedlings/genetics , Arabidopsis/metabolism , Salt Tolerance/genetics , Proteomics , Gene Expression Regulation, Plant , Plant Breeding , Stress, Physiological/genetics , Plants, Genetically Modified/genetics , Germination/genetics
4.
Br J Ophthalmol ; 2022 Dec 20.
Article in English | MEDLINE | ID: mdl-36575622

ABSTRACT

PURPOSE: To investigate whether quantitative optical coherence tomography angiography (OCTA) metrics of the superficial/deep macular retina are associated with the development of visual field (VF) loss in the fellow eyes of normal tension glaucoma (NTG) patients with unilateral VF loss. METHODS: A longitudinal study was conducted in which 61 eyes with normal VF (mean VF mean deviation -0.7±1.6 dB) from 61 NTG patients were included. All subjects underwent OCTA imaging, spectral-domain-OCT imaging and VF testing. OCTA metrics of superficial capillary plexus and deep capillary plexus (DCP) in the macular region were measured. Relationships between baseline OCTA metrics, demographics and ocular characteristics and the risk of VF glaucoma progression were analysed with a Cox proportional hazards model. RESULTS: During a mean follow-up of 38 months, 11 fellow eyes (18.0%) with normal VF at baseline were determined to have VF progression, while 21.3% of affected eyes had VF progression. After adjustment for potential confounding factors, decreased baseline DCP in the fellow eyes was significantly associated with future VF progression (HR 1.33, 95% CI 1.03 to 1.73, p=0.031). CONCLUSION: Decreased DCP was associated with a higher risk of developing VF damage in NTG patients with unilateral VF loss. Assessments of DCP may help improve the evaluation of the risk of functional deterioration in fellow eyes with an initially normal VF.

5.
Front Cell Dev Biol ; 9: 634220, 2021.
Article in English | MEDLINE | ID: mdl-34178978

ABSTRACT

PURPOSE: The aim of this study was to probe the global profile of the EYS-associated genotype-phenotype trait in the worldwide reported IRD cases and to build a model for predicting disease progression as a reference for clinical consultation. METHODS: This retrospective study of 420 well-documented IRD cases with mutations in the EYS gene included 39 patients from a genotype-phenotype study of inherited retinal dystrophy (IRD) conducted at the Beijing Institute of Ophthalmology and 381 cases retrieved from global reports. All patients underwent ophthalmic evaluation. Mutations were revealed using next-generation sequencing, followed by Sanger DNA sequencing and real-time quantitative PCR analysis. Multiple regression models and statistical analysis were used to assess the genotype and phenotype characteristics and traits in this large cohort. RESULTS: A total of 420 well-defined patients with 841 identified mutations in the EYS gene were successfully obtained. The most common pathogenic variant was a frameshift c.4957dupA (p.S1653Kfs∗2) in exon 26, with an allele frequency of 12.7% (107/841), followed by c.8805C > A (p.Y2935X) in exon 43, with an allele frequency of 5.9% (50/841). Two new hot spots were identified in the Chinese cohort, c.1750G > T (p.E584X) and c.7492G > C (p.A2498P). Several EYS mutation types were identified, with CNV being relatively common. The mean age of onset was 20.54 ± 11.33 (4-46) years. Clinical examinations revealed a typical progression of RPE atrophy from the peripheral area to the macula. CONCLUSION: This large global cohort of 420 IRD cases, with 262 distinct variants, identified genotype-phenotype correlations and mutation spectra with hotspots in the EYS gene.

6.
Mol Vis ; 27: 706-717, 2021.
Article in English | MEDLINE | ID: mdl-35002215

ABSTRACT

Purpose: High myopia (HM) is one of the leading causes of irreversible vision loss in the world. Many myopia loci have been uncovered with linkage analysis, genome-wide association studies, and sequencing analysis. Numerous pathogenic genes within these loci have been detected in a portion of HM cases. In the present study, we aimed to investigate the genetic basis of 103 patients with nonsyndromic HM, focusing on the reported causal genes. Methods: A total of 103 affected individuals with nonsyndromic HM were recruited, including 101 patients with unrelated sporadic HM and a mother and son pair. All participants underwent comprehensive ophthalmic examinations, and genomic DNA samples were extracted from the peripheral blood. Whole exome sequencing was performed on the mother and son pair as well as on the unaffected father. Sanger sequencing was used to identify mutations in the remaining 101 patients. Bioinformatics analysis was subsequently applied to verify the mutations. Results: An extremely rare mutation in AGRN (c.2627A>T, p.K876M) was identified in the mother and son pair but not in the unaffected father. Another two mutations in AGRN (c.4787C>T, p.P1596L/c.5056G>A, p.G1686S) were identified in two unrelated patients. A total of eight heterozygous variants potentially affecting the protein function were detected in eight of the remaining 99 patients, including c.1350delC, p.V451Cfs*76 and c.1023_1024insA, p.P342Tfs*41 in SLC39A5; c.244_246delAAG, p.K82del in SCO2; c.545A>G, p.Y182C in P4HA2; c.415C>T, p.P139S in BSG; c.3266A>G, p.Y1089C in ZNF644; and c.2252C>T, p.S751L and c.1708C>T, p.R570C in CPSF1. Multiple bioinformatics analyses were conducted, and a comparison to a group with geographically matched controls was performed, which supported the potential pathogenicity of these variants. Conclusions: We provide further evidence for the potential role of AGRN in HM inheritance and enlarged the current genetic spectrum of nonsyndromic HM by comprehensively screening the reported causal genes.


Subject(s)
Genetic Predisposition to Disease , Myopia , China , DNA Mutational Analysis , Genome-Wide Association Study , Humans , Mutation , Myopia/genetics , Pedigree
7.
Br J Ophthalmol ; 105(5): 694-703, 2021 05.
Article in English | MEDLINE | ID: mdl-32675063

ABSTRACT

AIMS: To reveal the Usher syndrome type IIA (USH2A) gene variant profile in a large cohort of Chinese patients with non-syndromic retinitis pigmentosa (RP) or Usher syndrome type II (USH2) and to explore the genotype-phenotype correlation. METHODS: Targeted exome capture plus next-generation sequencing confirmed that 284 patients from 260 unrelated Chinese families carried USH2A disease-associated variants. Both personal medical history and family histories were reviewed. Ocular examinations were performed and audiograms were recorded if hearing loss was suspected. The genotype-phenotype correlation was evaluated by statistical analyses. RESULTS: A total of 230 variants in the USH2A gene were identified, of which 90 (39.13%) were novel. The most common variants in the RP and USH2 probands were p.Cys934Trp and p.Tyr2854_2894del, respectively, and 26.42% and 63.64% of the alleles in the RP and USH2 groups were truncating, respectively. Patients harbouring biallelic truncating variants had a younger age at the initial clinical visit and symptom onset than patients with missense variants; furthermore, the patients with USH2 had a younger age at the initial clinical visit and nyctalopia onset compared with the patients with RP (p<0.001). For the patients with USH2, the age of nyctalopia onset was positively correlated with that of hearing loss (p<0.05, r=0.219). In addition, three pseudo-dominant pedigrees were identified carrying biallelic USH2A variants. CONCLUSIONS: This study enrolled the largest cohort of Chinese patients with USH2A and identified the most prevalent USH2A variants in USH2 and RP. We found that the patients with USH2 had more truncating variants and experienced an earlier decline in visual function. The findings enhance the current knowledge of USH2A heterogeneity and provide valuable information for future therapies.


Subject(s)
DNA/genetics , Extracellular Matrix Proteins/genetics , Mutation, Missense , Retinitis Pigmentosa/genetics , Adolescent , Adult , Aged , Child , Child, Preschool , China , DNA Mutational Analysis , Extracellular Matrix Proteins/metabolism , Female , Genetic Association Studies , Humans , Infant , Male , Middle Aged , Pedigree , Phenotype , Retinitis Pigmentosa/metabolism , Usher Syndromes/genetics , Usher Syndromes/metabolism , Young Adult
8.
Plant Mol Biol ; 104(4-5): 513-527, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32833149

ABSTRACT

KEY MESSAGE: Os4BGlu14, a monolignol ß-glucosidase, plays a negative role in seed longevity by affecting primary metabolism during seed development and aging. Seed longevity is a crucial trait in agriculture and in the conservation of germplasm resources. ß-Glucosidases (BGlus) are multifunctional enzymes that affect plant growth and their adaptation to the environment. The function of rice BGlus in seed longevity, however, remains unknown. We report here that Os4BGlu14, a rice ß-Glucosidase, negatively affected seed longevity during accelerated aging. Os4BGlu14 was highly expressed in rice embryos and induced by accelerated aging. Compared to the wild type, rice lines overexpressing Os4BGlu14 had significantly greater grain length, but smaller grain width and thickness. Overexpressing (OE) lines also showed lower starch but higher glucose contents. After accelerated aging treatment, OE lines displayed a significantly lower germination percentage than the wild type. Additionally, these lines had higher lignin accumulation before and after accelerated aging. Metabolome analysis detected 217 metabolites in untreated and aged rice seeds. Comparison of the differential metabolites between WT and OE5 revealed that ten key metabolites, four of which (e.g., uridine 5'-diphosphoglucose-glucose, UDPG) were increased, while the other six (e.g., γ-aminobutyric acid and methionine) were decreased, might be the crucial factors that lead to seed deterioration. Further analysis confirmed higher UDPG levels and more severe programmed cell death in OE lines than in the wild type. Furthermore, OE lines presented a lower germination rate after abscisic acid and paclobutrazol treatment during germination, compared to the wild type. Our study provides a basis for understanding the function of Os4BGlu14 in seed longevity in rice.


Subject(s)
Oryza/genetics , Oryza/metabolism , Plant Proteins/genetics , Seeds/physiology , beta-Glucosidase/genetics , Abscisic Acid/pharmacology , Cell Death , Gene Expression Regulation, Plant , Germination/drug effects , Lignin/genetics , Lignin/metabolism , Metabolome , Oxidative Stress/physiology , Plant Cells/physiology , Plant Proteins/metabolism , Plants, Genetically Modified , Seeds/metabolism , Uridine Diphosphate Glucose/metabolism , beta-Glucosidase/metabolism
9.
Invest Ophthalmol Vis Sci ; 61(3): 12, 2020 03 09.
Article in English | MEDLINE | ID: mdl-32176259

ABSTRACT

Purpose: The microRNA cluster miR-183C, which includes miR-183 and two other genes, is critical for multiple sensory systems. In mouse retina, removal of this cluster results in photoreceptor defects in polarization, phototransduction, and outer segment elongation. However, the individual roles of the three components of this cluster are not clearly known. We studied the separate role of mouse miR-183 in in vivo. Methods: miR-183 knockout mice were generated using the CRISPR/Cas9 genome-editing system. Electroretinography were carried out to investigate the changes of retinal structures and function. miR-183 was overexpressed by subretinal adeno-associated virus (AAV) injection in vivo. Rnf217, a target of miR-183 was overexpressed by cell transfection of the photoreceptor-derived cell line 661W in vitro. RNA sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to compare the gene expression changes in AAV-injected mice and transfected cells. Results: The miR-183 knockout mice showed progressively attenuated electroretinogram responses. Over- or under-expression of Rnf217, a direct target of miR-183, misregulated expression of cilia-related BBSome genes. Rnf217 overexpression also led to compromised electroretinography responses in WT mice, indicating that it may contribute to functional abnormalities in miR-183 knockout mice. Conclusions: miR-183 is essential for mouse retinal function mediated directly and indirectly through Rnf217 and cilia-related genes. Our findings provide valuable insights into the explanation and analysis of the regulatory role of the individual miR-183 in miR-183C.


Subject(s)
Gene Deletion , MicroRNAs/genetics , Retina/physiopathology , Retinal Degeneration/genetics , Animals , Cells, Cultured , Cilia/metabolism , Disease Models, Animal , Electroretinography , Gene Editing/methods , Gene Expression Regulation/physiology , Genetic Vectors , Mice, Knockout , MicroRNAs/physiology , Photoreceptor Cells, Vertebrate/metabolism , Retinal Degeneration/physiopathology , Transfection/methods
10.
Invest Ophthalmol Vis Sci ; 60(12): 4052-4062, 2019 09 03.
Article in English | MEDLINE | ID: mdl-31560770

ABSTRACT

Purpose: High myopia (HM) is defined as a refractive error worse than -6.00 diopter (D). This study aims to update the phenotypic and genotypic landscape of nonsyndromic HM and to establish a biological link between the phenotypic traits and genetic deficiencies. Methods: A cross-sectional study involving 731 participants varying in refractive error, axial length (AL), age, myopic retinopathy, and visual impairment. The phenotypic traits were analyzed by four ophthalmologists while mutational screening was performed in eight autosomal causative genes. Finally, we assessed the clinical relevance of identified mutations under the guidance of the American College of Medical Genetics and Genomics. Results: The relationship between refractive error and AL varied in four different age groups ranging from 3- to 85-years old. In adult groups older than 21 years, 1-mm increase in AL conferred 10.84% higher risk of pathologic retinopathy (Category ≥2) as well as 7.35% higher risk of low vision (best-corrected visual acuities <0.3) with P values < 0.001. The prevalence rates of pathologic retinopathy and low vision both showed a nonlinear positive correlation with age. Forty-five patients were confirmed to harbor pathogenic mutations, including 20 novel mutations. These mutations enriched the mutational pool of nonsyndromic HM to 1.5 times its previous size and enabled a statistically significant analysis of the genotype-phenotype correlation. Finally, SLC39A5, CCDC111, BSG, and P4HA2 were more relevant to eye elongation, while ZNF644, SCO2, and LEPREL1 appeared more relevant to refracting media. Conclusions: Our findings shed light on how multiple HM-related phenotypes are associated with each other and their link with gene variants.


Subject(s)
Asian People/genetics , Axial Length, Eye/pathology , Myopia, Degenerative/genetics , Retinal Diseases/diagnosis , Vision, Low/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Aging/physiology , Child , Child, Preschool , China/epidemiology , Cross-Sectional Studies , DNA Mutational Analysis , Female , Genetic Association Studies , Genotype , Humans , Male , Middle Aged , Myopia, Degenerative/diagnosis , Phenotype , Young Adult
11.
Exp Eye Res ; 188: 107778, 2019 11.
Article in English | MEDLINE | ID: mdl-31472110

ABSTRACT

Myopia is one of the leading ocular disorders causing visual impairment worldwide, with the prevalence increasing rapidly. It's a significant global public health concern in 21st century. Myopia, particularly high myopia, often exhibits apparent familial aggregation, and multiple evidences have shown that genetic factors significantly contribute to its pathogenesis. Recent molecular technologies such as linkage analysis, candidate gene authentication, genome-wide association study (GWAS), and next-generation sequencing (NGS) have identified many myopia-associated loci and genetic mutations or variants. There exist ethnic variations in myopia occurrence as observed in populations of different genetic backgrounds, and different genetic components are found to be associated with the development of myopia-related phenotypes. A better understanding of the genetic basis triggering and controlling myopic changes may further help in myopia prevention. This review is to provide an updated overview of genetic findings in non-syndromic myopia.


Subject(s)
Myopia/genetics , Genetic Linkage , Genetic Predisposition to Disease , Genome-Wide Association Study , High-Throughput Nucleotide Sequencing , Humans , Mutation , Phenotype
12.
Nanoscale Res Lett ; 14(1): 182, 2019 May 29.
Article in English | MEDLINE | ID: mdl-31144059

ABSTRACT

This study proposes a novel direct-lit mini-chip-scale packaged light-emitting diode (mini-CSPLED) backlight unit (BLU) that used quantum dot (QD) film, diffusion plate, and two prism films to improve brightness uniformity. Three different luminous intensity units, 120° mini-CSPLED, 150° mini-CSPLED, and 180° mini-CSPLED with different emission angle structures were fabricated using a CSP process. In terms of component characteristics, although the 180° mini-CSPLED light output power is about loss 4% (at 10 mA) compared with 150° mini-CSPLED, it has a large emission angle that forms a planar light source that contributes to improving the BLU brightness uniformity and reduced quantity of LEDs at the same area. In terms of BLU analysis, the blue mini-CSPLEDs with different emission angles excite the different QD film thicknesses; the chromaticity coordinates conversion to the white light region. The BLU brightness increases as the QD film thickness increases from 60, 90, and 150 µm. This result can achieve a brightness uniformity of 86% in a 180° mini-CSPLED BLU + 150-µm-thick QD films as compared to the 120° mini-CSPLED BLU and 150° mini-CSPLED BLU.

13.
Yi Chuan ; 40(10): 916-923, 2018 Oct 20.
Article in Chinese | MEDLINE | ID: mdl-30369473

ABSTRACT

Chinese genetics educators have carried out a comprehensive and systematic exploration and reform since 1978. With the guidance and help of the Genetics Society of China, they have made significant strides in the fields of genetics teaching system, publication of genetics textbooks, content of genetics teaching, workshop on genetics teaching, experimental teaching, application of advanced techniques, etc. These efforts have made remarkable achievements and promoted the vitality of genetics. The comprehensive development of education and teaching has trained a large number of excellent genetic talents for the development of China's economy and society. Here, we sum up the overall achievements of the teaching reform and propose some suggestions on the future development of genetics teaching in China, hoping that the quality of genetics teaching in China will take a new step in the new era.


Subject(s)
Genetics/education , Teaching/history , China , Genetics/history , Genetics/standards , History, 20th Century , History, 21st Century , Humans , Teaching/education , Teaching/standards
14.
Opt Express ; 26(12): 15851-15866, 2018 Jun 11.
Article in English | MEDLINE | ID: mdl-30114840

ABSTRACT

Starch is an essential and widely distributed natural material, but its detailed conformation and thermal transition properties are not yet well understood. We present a rapid Mueller matrix imaging system to explore the structural characteristics of starch granules by using 16 measurements with different incoming and outgoing polarizations. Due to the minimum rotation of the optical elements and the self-calibration ability of this system, the full Mueller matrix images can be accurately obtained within ten-odd seconds. Both structural and molecular features of the starch granule were investigated in the static state and gelatinization process by means of multiple optical characteristics deduced from the Mueller matrix. The experimental results for the structural changes during the gelatinization were close to other nonlinear optical approaches; moreover, the crystallinity and optical rotation of the starch granule are also determined through the use of this approach.

15.
Yi Chuan ; 37(9): 873-84, 2015 09.
Article in English | MEDLINE | ID: mdl-26399527

ABSTRACT

Lactoferrin is an iron-binding glycoprotein with a molecular weight of about 80 kDa that belongs to the transferrin family. Due to its unique physical and chemical properties, lactoferrin has a variety of biological functions including antibacterial, antiviral, anticancer, immunomodulatory activities and regulation of iron absorption. High-yield production of recombinant lactoferrin with biological activity and its application in clinical treatment have been a hot topic for long time. With the development of genetic engineering techniques, various expression systems have been developed to produce recombinant lactoferrin. In this review, we summarize physicochemical characteristics, biological activities, clinical studies and current recombinant expression systems of lactoferrin, in order to provide references for its clinical application.


Subject(s)
Lactoferrin/chemistry , Lactoferrin/physiology , Recombinant Proteins/biosynthesis , Animals , Chemical Phenomena , Escherichia coli/genetics , Fungi/genetics , Genetic Engineering , Glycosylation , Humans , Plants, Genetically Modified/genetics
16.
Yi Chuan ; 35(2): 233-40, 2013 Feb.
Article in Chinese | MEDLINE | ID: mdl-23448937

ABSTRACT

Haematococcus pluvialis is a freshwater planktonic single-cell microalgae. It will accumulate high amount of carotenoids under unfavorable environmental conditions. As one of carotenoids, lycopene is an important intermediate in the carotenoid biosynthesis pathway. Lycopene ß-cyclase (LycB) is the key enzyme that catalyzes the circularization of lycopene to form ß-carotene. In this study, we constructed a p1301-BS-RNAi vector using lycB from Dunaliella salina as the interference sequence with kanamycin and atrazine resistance marker, and then transformed it into H. pluvialis by electroporation. Sixteen independent transgenic lines were obtained after resistance selection, genome PCR, and RT-PCR analyses. Seven well-grown lines were selected to determine the contents of carotenoids by HPLC analysis after inducing by high light. The lycopene content in these lines was increased by 99.4% while the ß-carotene content was decreased by 48.4%, indicating that the interference by heterogenous lycB could inhibit the conversion of lycopene into ß-carotene. The amount of increase in lycopene was only 5% of the amount of decrease in ß-carotene, indicating that 95% of the decreased ß-carotene was converted into other metabolites. Therefore, in order to largely increase the lycopene content in H. pluvialis, it is necessary to coordinatively regulate other metabolic pathways.


Subject(s)
Carotenoids/biosynthesis , Chlorophyta/genetics , Chlorophyta/metabolism , Gene Silencing , Intramolecular Lyases/genetics , Intramolecular Lyases/metabolism , Carotenoids/metabolism , Gene Expression Regulation, Plant , Gene Order , Lycopene , Plants, Genetically Modified , RNA Interference
17.
Yi Chuan ; 28(11): 1435-9, 2006 Nov.
Article in Chinese | MEDLINE | ID: mdl-17098714

ABSTRACT

When SRAP (Sequence-Related Amplified Polymorphism) marker was used in constructing genetic map and analyzing QTL for high temperature resistance in cucumber (Cucumis sativus L.), it exhibited certain characteristics in detecting genomic polymorphism. When each forward primer was combined with different reverse primers, the number of primer combinations that produced polymorphism ranged from five to eight. When each reverse primer was in combination with different forward primers, the number of polymorphic primer combinations ranged from two to eleven. The reverse primers SA4 or EM6 produced identical polymorphic bands when combined with all the forward primers tested. These bands might be amplified by the reverse primers. The polymorphic bands amplified from OD3ME11 co-segregated in the F2 population. The utilization of these characteristics in our research was discussed.


Subject(s)
Cucumis sativus/genetics , Genome, Plant/genetics , Polymorphism, Genetic , Cucumis sativus/physiology , DNA Primers , Genetic Markers/genetics , Hot Temperature , Quantitative Trait Loci
18.
Yi Chuan ; 28(5): 551-6, 2006 May.
Article in Chinese | MEDLINE | ID: mdl-16735234

ABSTRACT

The zeta class of glutathione S-transferase (GSTZs), which is an important multifunctional enzyme, relates to the cell metabolism and contamination elimination. The GSTZ genes from Arabidopsis thaliana L. and Brassica napus L. cv. Shan 2B and Ken C1 were cloned into the multi-cloning site of the shuttle expression vector pYES2. After the recombinants were obtained, the recombinant plasmids were isolated and introduced into the defective mutant INCSc1 of Saccharomyces cerevisiae. Then the recombinant strains Y2At, Y2BnB and Y2BnC were obtained after cultured on SC-U selective plates. When induced in the medium containing galactose and maltose, the recombinant yeast expressed as active GSTZs showing the dichloroacetic acid dechlorinating activity, which existed in the yeast cell as a soluble state. The comparison of different carbon sources showed that sucrose and glucose significantly exhibited the expression of GSTZ gene; glycerol somewhat affected the growth of yeast but increased the specific activity of GSTZ by 17%; and galactose slightly affected the yeast growth with no affection to the activity of GSTZ. Zero to ninety-six hrs induction experiments showed that specific activity of GSTZ in recombinant yeast reached highest when induced for 36 hours. The specific activity of AtGSTZ, BnGSTZ-B and BnGSTZ-C was 5.3 U/mg, 4.3 U/mg and 0.3 U/mg, respectively. The values are lower than that expressed in the E. coli and wheat-sperm cell-free protein synthesis system. However, the relative activity of three sources was similar in E. coli and wheat cell free system. The Km value of GSTZ genes from different sources was 0.59 mmol/L and 0.79 mmol/L for AtGSTZ and BnGSTZ-B, respectively, suggesting the GSTZ enzyme from Abrabidopsis thaliana has higher affinity to DCA than that from Brassica napus.


Subject(s)
Arabidopsis/enzymology , Brassica napus/enzymology , Gene Expression , Glutathione Transferase/genetics , Plant Proteins/genetics , Saccharomyces cerevisiae/genetics , Cloning, Molecular , Glutathione Transferase/chemistry , Glutathione Transferase/metabolism , Kinetics , Plant Proteins/chemistry , Plant Proteins/metabolism , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/metabolism
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