AIM To investigate the relationship between the expression of p16 gene and the gastric carcinogenesis,depth of invasion and lymph node metastases, and to evaluate the deletion and mutation of exon 2 in p16 gene in gas...AIM To investigate the relationship between the expression of p16 gene and the gastric carcinogenesis,depth of invasion and lymph node metastases, and to evaluate the deletion and mutation of exon 2 in p16 gene in gastric carcinoma.METHODS The expression of P16 protein was examined by streptavidin-peroxidase conjugated method (S-P); the deletion and mutation of p16 gene were respectively examined by polymerase chain reaction (PCR) and polymerase chain reaction single-strand conformation polymorphism analysis (PCR-SSCP) in gastric carcinoma.RESULTS Expression of P16 protein was detected in 96.25% (77/80) of the normal gastric mucosa, in 92.00% (45/50) of the dysplastic gastric mucosa and in 47.54% (58/122) of the gastric carcinoma. The positive rate of P16 protein expression in gastric carcinoma was significantly lower than that in normal gastric mucosa and dysplastic gastric mucosa (P＜0.05). The positive rate of P16 protein expression in mucoid carcinoma 10.00% (1/ 10) was significantly lower than that in poorly differentiated carcinoma 51.22% ( 21/ 41 ),undifferentiated carcinoma 57.69% (15/26) and signet ring cell carcinoma 62.50% (10/ 16) (P＜0.05). The positive rate of p16 protein in 30 cases paired primary and lymph node metastatic gastric carcinoma: There was 46.67% (14/30) in primary gastric carcinoma, 16.67% (5/30) in lymph node metastatic gastric carcinoma. The positive rate of lymph node metastatic carcinoma was significantly lower than that of primary carcinoma (P＜0.05). There was of p16 gene mutation in exon 2, but 5 cases displayed deletion of p16 gene in exon 2 in the 25 primary gastric carcinomas.CONCLUSIONS The expression loss of P16 protein related to the gastric carcinogenesis, gastric carcinoma histopathological subtypes and lymph metastasis. The mutation of p16 gene in exon 2 may not be involved in gastric carcinogenesis. But the deletion of p16 gene in exon 2 may be involved in gastric carcinogenesis.展开更多
Rice is one of the most important crops as it supports over25%of total caloric intake for humans（Kusano et al.,2015）.The world population reached 7.3 billion in 2015 and is projected to reach 8.5 billion in 2030（Wo...Rice is one of the most important crops as it supports over25%of total caloric intake for humans（Kusano et al.,2015）.The world population reached 7.3 billion in 2015 and is projected to reach 8.5 billion in 2030（Word Population Prospects：2015 Revision）.展开更多
AIM:To investigate the hepatitis B virus (HBV) x gene (HBx) state in the tissues of HBV-related hepatocellular carcinoma (HCC) in Chinese patients and whether there were particular HBx mutations. METHODS: HBx gene was...AIM:To investigate the hepatitis B virus (HBV) x gene (HBx) state in the tissues of HBV-related hepatocellular carcinoma (HCC) in Chinese patients and whether there were particular HBx mutations. METHODS: HBx gene was amplified and direct sequencing was used in genomic DNA samples from 20 HCC and corresponding non-cancerous liver tissues from HBsAg-positive patients. HBV DNA integration and HBx deleted mutation were validated in 45 HCC patients at different stages by Southern blot analysis and polymerase chain reaction methods. RESULTS: The frequencies of HBx point mutations were significantly lower in HCC than their corresponding non- cancerous liver tissues (11/19 vs 18/19, P = 0.019). In contrast, deletions in HBx gene were significantly higher in HCC than their non-cancerous liver tissues (16/19 vs 4/19, P < 0.001). The deletion of HBx COOH-terminal was detected in 14 HCC tissues. A specific integration of HBx at 17p13 locus was also found in 8 of 16 HCC, and all of them also exhibited full-length HBx deletions. Integrated or integrated coexistence with replicated pattern was obtained in 45.5% (20/45) - 56.8% (25/45) tumors and 40.9% (18/45) - 52.3% (23/45) non-tumor tissues. CONCLUSION: HBx deletion, especially the COOH- terminal deletion of HBx is a frequent event in HBV-associated HCC tissues in China. HBV integration had also taken place in partial HCC tissues. This supporting the hypothesis that deletion and probably integrated forms of the HBx gene may be implicated in liver carcinogenesis.展开更多
Background Duchenne muscular dystrophy （DMD） and Becker muscular dystrophy （BMD） are X-linked recessive, allelic disorders. This study was conducted to look into the spectrum of DMD gene mutations in Hong Kong Chi...Background Duchenne muscular dystrophy （DMD） and Becker muscular dystrophy （BMD） are X-linked recessive, allelic disorders. This study was conducted to look into the spectrum of DMD gene mutations in Hong Kong Chinese patients with Duchenne or Becker muscular dystrophy （DMD/BMD）, and to study genotype-phenotype correlation.展开更多
Background:Epidermal growth factor receptor(EGFR) mutations,including a known exon 19 deletion(19 del) and exon 21 L858 R point mutation(L858R mutation),are strong predictors of the response to EGFR tyrosine kinase in...Background:Epidermal growth factor receptor(EGFR) mutations,including a known exon 19 deletion(19 del) and exon 21 L858 R point mutation(L858R mutation),are strong predictors of the response to EGFR tyrosine kinase inhibitor(EGFR-TKI) treatment in lung adenocarcinoma.However,whether patients carrying EGFR 19 del and L858 R mutations exhibit different responsiveness to EGFR-TKls and what are the potential mechanism for this difference remain controversial.This study aimed to investigate the clinical outcomes of EGFR-TKI treatment in patients with EGFR 19 del and L858 R mutations and explore the genetic heterogeneity of tumors with the two mutation subtypes.Methods:Of 1127 patients with advanced lung adenocarcinoma harboring EGFR 19 del or L858 R mutations,532 received EGFR-TKI treatment and were included in this study.EGFR 19 del and L858 R mutations were detected by using denaturing high-performance liquid chromatography(DHPLC).T790 M mutation,which is a common resistant mutation on exon 20 of EGFR,was detected by amplification refractory mutation system(ARMS).Next-generation sequencing(NGS) was used to explore the genetic heterogeneity of tumors with EGFR 19 del and L858 R mutations.Results:Of the 532 patients,319(60.0%) had EGFR 19 del,and 213(40.0%) had L858 R mutations.The patients with EGFR 19 del presented a significantly higher overall response rate(ORR) for EGFR-TKI treatment(55.2%vs.43.7%,P = 0.017) and had a longer progression-free survival(PFS) after first-line EGFR-TKI treatment(14.4 vs.11.4 months,P = 0.034) compared with those with L858 R mutations.However,no statistically significant difference in overall survival(OS) was observed between the two groups of patients.T790 M mutation status was analyzed in 88 patients before EGFR-TKI treatment and 134 after EGFR-TKI treatment,and there was no significant difference in the co-existence of T790 M mutation with EGFR 19 del and L858 R mutations before EGFR-TKI treatment(5.6%vs.8.8%,P = 0.554)or after treatment(24.4%vs.35.4%,P = 0.176).In addition,24 patie展开更多
The next-generation hybrid seed technology enables the successful production of sortable hybrid seeds from genic male sterile(GMS)lines and maintainers;however,it requires multiple laborious and complicated steps.Here...The next-generation hybrid seed technology enables the successful production of sortable hybrid seeds from genic male sterile(GMS)lines and maintainers;however,it requires multiple laborious and complicated steps.Here,we designed a simple next-generation hybrid seed production strategy that takes advantage of the CRISPR/Cas9 technology to create a Manipulated GMS Maintainer(MGM)system via a single transformation.Under this schema,the maize male fertility gene ZmMS26 was nullified by removal of its fifth exon using the CRISPR/Cas9 system on a vector,and a second vector carrying a functional ZmMS26 cDNA was co-transformed to restore fertility.The second vector also contains a male gametophyte inactivation gene(ZmAA1)encoding maizeα-amylase driven by the pollen-specific promoter PG47 and an endosperm fluorescent marker(DsRED)driven by the barley endosperm aleurone-specific promoter Ltp2.The derived single-copy hemizygous MGM lines bore a mutated MS26 gene,leading to complete male sterility but normal vegetative growth and grain yield.The MGM system could prevent genetic transmission of the MGM elements via male gametophytes,providing an efficient method for sorting maintainer seeds labeled by DsRED.This strategy can be extended to any GMS gene and to hybrid crops other than maize.展开更多
核苷酸替代和indels(插入、缺失统称)发生是进化的重要动力。以茄科植物为研究对象,探讨茄属中番茄和马铃薯、烟草属中绒毛状烟草和普通烟草分化时叶绿体基因组indels和核苷酸替代的发生方式,以及这两种突变对基因组造成的影响。结果显...核苷酸替代和indels(插入、缺失统称)发生是进化的重要动力。以茄科植物为研究对象,探讨茄属中番茄和马铃薯、烟草属中绒毛状烟草和普通烟草分化时叶绿体基因组indels和核苷酸替代的发生方式,以及这两种突变对基因组造成的影响。结果显示:indels和核苷酸替代的发生都不是随意的。indels发生在A+T丰富的区域,1 bp indels占据总数的30%以上,大部分indels都为低于10bp的较短片段。核苷酸替代表现出Ts(转换)/Tv(颠换)偏差,但T→G,A→C颠换频率却明显增加。Ts/Tv比值出现种属特异性,番茄和马铃薯比较时替代的Ts/Tv比值低于绒毛状烟草和普通烟草比较时Ts/Tv比值。不同物种替代的(A+T)/(G+C)比值有一定差异,从而影响基因组的(G+C)%,此比值的差异与形成物种的生长习性有一定的关系。展开更多
Primary intestinal lymphangiectasia(PIL)is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy.Patients with PIL develop hypoalbuminemia,hypocalcemia,lympho...Primary intestinal lymphangiectasia(PIL)is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy.Patients with PIL develop hypoalbuminemia,hypocalcemia,lymphopenia and hypogammaglobulinemia,and present with bilateral lower limb edema,fatigue,abdominal pain and diarrhea.Endoscopy reveals diffusely elongated,circumferential and polypoid mucosae covered with whitish enlarged villi,all of which indicate intestinal lymphangiectasia.Diagnosis is conf irmed by characteristic tissue pathology,which includes dilated intestinal lymphatics with diffusely swollen mucosa and enlarged villi.The prevalence of PIL has increased since the introduction of capsule endoscopy.The etiology and prevalence of PIL remain unknown.Some studies have reported that several genes and regulatory molecules for lymphangiogenesis are related to PIL.We report the case of a patient with PIL involving the entire small bowel that was confirmed by capsule endoscopy and double-balloon enteroscopy-guided tissue pathology who carried a deletion on chromosome 4q25.The relationship between this deletion on chromosome 4 and PIL remains to be investigated.展开更多
High-molecular-weight glutenin subunits（HMW-GSs） play a critical role in determining the viscoelastic properties of wheat dough. The HMW-GSs are encoded by Glu-A1, Glu-B1, and Glu-D1 loci on the long arms of chromos...High-molecular-weight glutenin subunits（HMW-GSs） play a critical role in determining the viscoelastic properties of wheat dough. The HMW-GSs are encoded by Glu-A1, Glu-B1, and Glu-D1 loci on the long arms of chromosomes 1A, 1B, and 1D, respectively. In the present study, four near-isogenic lines with different HMW-GS deletions and compositions at the Glu-A1 and Glu-D1 loci in Yangmai 18 background were used for quality analysis. Deletion in Glu-D1 showed much weaker gluten quality and dough strength than null Glu-A1 genotype and wild genotype（WT）, based on the measurements of sodium dodecyl sulfate（SDS）-sedimentation, lactic acid solvent retention capacity（SRC）, gluten index, development time, stability time, and alveograph P and L values. The deletion of Glu-D1 did not significantly affect grain hardness, grain protein content, water SRC, sodium carbonate SRC, and sucrose SRC. Double null genotype in Glu-A1 and Glu-D1 and single null genotype in Glu-D1 showed significantly higher cookie diameter, crispness, and lower cookie height compared with single null genotype in Glu-A1 and WT. These indicate that the null Glu-D1 genotype is useful for improvement of biscuit quality, and use of this germplasm would be a viable strategy to develop new wheat varieties for biscuit processing.展开更多
Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC)....Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.展开更多
基金the grant from the Teaching Committee of HunanProvince,No.97B095the"8th 5-year Plan"of Health Department of Hunan Province,No.9301
文摘AIM To investigate the relationship between the expression of p16 gene and the gastric carcinogenesis,depth of invasion and lymph node metastases, and to evaluate the deletion and mutation of exon 2 in p16 gene in gastric carcinoma.METHODS The expression of P16 protein was examined by streptavidin-peroxidase conjugated method (S-P); the deletion and mutation of p16 gene were respectively examined by polymerase chain reaction (PCR) and polymerase chain reaction single-strand conformation polymorphism analysis (PCR-SSCP) in gastric carcinoma.RESULTS Expression of P16 protein was detected in 96.25% (77/80) of the normal gastric mucosa, in 92.00% (45/50) of the dysplastic gastric mucosa and in 47.54% (58/122) of the gastric carcinoma. The positive rate of P16 protein expression in gastric carcinoma was significantly lower than that in normal gastric mucosa and dysplastic gastric mucosa (P＜0.05). The positive rate of P16 protein expression in mucoid carcinoma 10.00% (1/ 10) was significantly lower than that in poorly differentiated carcinoma 51.22% ( 21/ 41 ),undifferentiated carcinoma 57.69% (15/26) and signet ring cell carcinoma 62.50% (10/ 16) (P＜0.05). The positive rate of p16 protein in 30 cases paired primary and lymph node metastatic gastric carcinoma: There was 46.67% (14/30) in primary gastric carcinoma, 16.67% (5/30) in lymph node metastatic gastric carcinoma. The positive rate of lymph node metastatic carcinoma was significantly lower than that of primary carcinoma (P＜0.05). There was of p16 gene mutation in exon 2, but 5 cases displayed deletion of p16 gene in exon 2 in the 25 primary gastric carcinomas.CONCLUSIONS The expression loss of P16 protein related to the gastric carcinogenesis, gastric carcinoma histopathological subtypes and lymph metastasis. The mutation of p16 gene in exon 2 may not be involved in gastric carcinogenesis. But the deletion of p16 gene in exon 2 may be involved in gastric carcinogenesis.
基金supported by the grants from National Natural Science Foundation of China (Nos. 31230051, 31470397 and 31110103915)China Innovative Research Team, Ministry of Education, 111 Project (B14016)+2 种基金Project on Breeding from Agriculture Commission of Shanghai (2014-1/3 and 2015e20)Key Project on Basic Research from Science and Technology Commission of Shanghai (Nos. 14JC1403900 and 14391917100)National Transgenic Major Program Grants (No. 2016ZX08009-003-007)
文摘Rice is one of the most important crops as it supports over25%of total caloric intake for humans（Kusano et al.,2015）.The world population reached 7.3 billion in 2015 and is projected to reach 8.5 billion in 2030（Word Population Prospects：2015 Revision）.
基金The National Natural Science Foundation of China, No. 30070344 and 30070839MZ and NIH grants CA104025 and CA111427 to MAF
文摘AIM:To investigate the hepatitis B virus (HBV) x gene (HBx) state in the tissues of HBV-related hepatocellular carcinoma (HCC) in Chinese patients and whether there were particular HBx mutations. METHODS: HBx gene was amplified and direct sequencing was used in genomic DNA samples from 20 HCC and corresponding non-cancerous liver tissues from HBsAg-positive patients. HBV DNA integration and HBx deleted mutation were validated in 45 HCC patients at different stages by Southern blot analysis and polymerase chain reaction methods. RESULTS: The frequencies of HBx point mutations were significantly lower in HCC than their corresponding non- cancerous liver tissues (11/19 vs 18/19, P = 0.019). In contrast, deletions in HBx gene were significantly higher in HCC than their non-cancerous liver tissues (16/19 vs 4/19, P < 0.001). The deletion of HBx COOH-terminal was detected in 14 HCC tissues. A specific integration of HBx at 17p13 locus was also found in 8 of 16 HCC, and all of them also exhibited full-length HBx deletions. Integrated or integrated coexistence with replicated pattern was obtained in 45.5% (20/45) - 56.8% (25/45) tumors and 40.9% (18/45) - 52.3% (23/45) non-tumor tissues. CONCLUSION: HBx deletion, especially the COOH- terminal deletion of HBx is a frequent event in HBV-associated HCC tissues in China. HBV integration had also taken place in partial HCC tissues. This supporting the hypothesis that deletion and probably integrated forms of the HBx gene may be implicated in liver carcinogenesis.
文摘Background Duchenne muscular dystrophy （DMD） and Becker muscular dystrophy （BMD） are X-linked recessive, allelic disorders. This study was conducted to look into the spectrum of DMD gene mutations in Hong Kong Chinese patients with Duchenne or Becker muscular dystrophy （DMD/BMD）, and to study genotype-phenotype correlation.
基金supported by grants from the National Natural Sciences Foundation Key Program(No.81330062)Education Ministry Innovative Research Team Program(No.IRT13003)+1 种基金Peking University-Tsinghua University Joint Center for Life Sciences Clinical Investigator,National High Technology Research and Development Program 863(No.SS2015AA020403)Beijing Technology Project(No.Z141100000214013)
文摘Background:Epidermal growth factor receptor(EGFR) mutations,including a known exon 19 deletion(19 del) and exon 21 L858 R point mutation(L858R mutation),are strong predictors of the response to EGFR tyrosine kinase inhibitor(EGFR-TKI) treatment in lung adenocarcinoma.However,whether patients carrying EGFR 19 del and L858 R mutations exhibit different responsiveness to EGFR-TKls and what are the potential mechanism for this difference remain controversial.This study aimed to investigate the clinical outcomes of EGFR-TKI treatment in patients with EGFR 19 del and L858 R mutations and explore the genetic heterogeneity of tumors with the two mutation subtypes.Methods:Of 1127 patients with advanced lung adenocarcinoma harboring EGFR 19 del or L858 R mutations,532 received EGFR-TKI treatment and were included in this study.EGFR 19 del and L858 R mutations were detected by using denaturing high-performance liquid chromatography(DHPLC).T790 M mutation,which is a common resistant mutation on exon 20 of EGFR,was detected by amplification refractory mutation system(ARMS).Next-generation sequencing(NGS) was used to explore the genetic heterogeneity of tumors with EGFR 19 del and L858 R mutations.Results:Of the 532 patients,319(60.0%) had EGFR 19 del,and 213(40.0%) had L858 R mutations.The patients with EGFR 19 del presented a significantly higher overall response rate(ORR) for EGFR-TKI treatment(55.2%vs.43.7%,P = 0.017) and had a longer progression-free survival(PFS) after first-line EGFR-TKI treatment(14.4 vs.11.4 months,P = 0.034) compared with those with L858 R mutations.However,no statistically significant difference in overall survival(OS) was observed between the two groups of patients.T790 M mutation status was analyzed in 88 patients before EGFR-TKI treatment and 134 after EGFR-TKI treatment,and there was no significant difference in the co-existence of T790 M mutation with EGFR 19 del and L858 R mutations before EGFR-TKI treatment(5.6%vs.8.8%,P = 0.554)or after treatment(24.4%vs.35.4%,P = 0.176).In addition,24 patie
基金supported by grants from Beijing Municipal Science and Technology(Major Program D171100007717001)the National Major Project of Developing New GM Crops(2019ZX08010-003)+1 种基金the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences,the National Science Foundation of China(no.31771808&31361140364)the China National Modern Corn Industry Tech no logy System.
文摘The next-generation hybrid seed technology enables the successful production of sortable hybrid seeds from genic male sterile(GMS)lines and maintainers;however,it requires multiple laborious and complicated steps.Here,we designed a simple next-generation hybrid seed production strategy that takes advantage of the CRISPR/Cas9 technology to create a Manipulated GMS Maintainer(MGM)system via a single transformation.Under this schema,the maize male fertility gene ZmMS26 was nullified by removal of its fifth exon using the CRISPR/Cas9 system on a vector,and a second vector carrying a functional ZmMS26 cDNA was co-transformed to restore fertility.The second vector also contains a male gametophyte inactivation gene(ZmAA1)encoding maizeα-amylase driven by the pollen-specific promoter PG47 and an endosperm fluorescent marker(DsRED)driven by the barley endosperm aleurone-specific promoter Ltp2.The derived single-copy hemizygous MGM lines bore a mutated MS26 gene,leading to complete male sterility but normal vegetative growth and grain yield.The MGM system could prevent genetic transmission of the MGM elements via male gametophytes,providing an efficient method for sorting maintainer seeds labeled by DsRED.This strategy can be extended to any GMS gene and to hybrid crops other than maize.
文摘核苷酸替代和indels(插入、缺失统称)发生是进化的重要动力。以茄科植物为研究对象,探讨茄属中番茄和马铃薯、烟草属中绒毛状烟草和普通烟草分化时叶绿体基因组indels和核苷酸替代的发生方式,以及这两种突变对基因组造成的影响。结果显示:indels和核苷酸替代的发生都不是随意的。indels发生在A+T丰富的区域,1 bp indels占据总数的30%以上,大部分indels都为低于10bp的较短片段。核苷酸替代表现出Ts(转换)/Tv(颠换)偏差,但T→G,A→C颠换频率却明显增加。Ts/Tv比值出现种属特异性,番茄和马铃薯比较时替代的Ts/Tv比值低于绒毛状烟草和普通烟草比较时Ts/Tv比值。不同物种替代的(A+T)/(G+C)比值有一定差异,从而影响基因组的(G+C)%,此比值的差异与形成物种的生长习性有一定的关系。
文摘Primary intestinal lymphangiectasia(PIL)is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy.Patients with PIL develop hypoalbuminemia,hypocalcemia,lymphopenia and hypogammaglobulinemia,and present with bilateral lower limb edema,fatigue,abdominal pain and diarrhea.Endoscopy reveals diffusely elongated,circumferential and polypoid mucosae covered with whitish enlarged villi,all of which indicate intestinal lymphangiectasia.Diagnosis is conf irmed by characteristic tissue pathology,which includes dilated intestinal lymphatics with diffusely swollen mucosa and enlarged villi.The prevalence of PIL has increased since the introduction of capsule endoscopy.The etiology and prevalence of PIL remain unknown.Some studies have reported that several genes and regulatory molecules for lymphangiogenesis are related to PIL.We report the case of a patient with PIL involving the entire small bowel that was confirmed by capsule endoscopy and double-balloon enteroscopy-guided tissue pathology who carried a deletion on chromosome 4q25.The relationship between this deletion on chromosome 4 and PIL remains to be investigated.
基金supported by the Independent Innovation Funding for Agricultural Science and Technology of Jiangsu Province, China (CX(13)5070)the Natural Science Foundation of Jiangsu Province, China (BK20160448)the earmarked fund for China Agriculture Research System (CARS-03)
文摘High-molecular-weight glutenin subunits（HMW-GSs） play a critical role in determining the viscoelastic properties of wheat dough. The HMW-GSs are encoded by Glu-A1, Glu-B1, and Glu-D1 loci on the long arms of chromosomes 1A, 1B, and 1D, respectively. In the present study, four near-isogenic lines with different HMW-GS deletions and compositions at the Glu-A1 and Glu-D1 loci in Yangmai 18 background were used for quality analysis. Deletion in Glu-D1 showed much weaker gluten quality and dough strength than null Glu-A1 genotype and wild genotype（WT）, based on the measurements of sodium dodecyl sulfate（SDS）-sedimentation, lactic acid solvent retention capacity（SRC）, gluten index, development time, stability time, and alveograph P and L values. The deletion of Glu-D1 did not significantly affect grain hardness, grain protein content, water SRC, sodium carbonate SRC, and sucrose SRC. Double null genotype in Glu-A1 and Glu-D1 and single null genotype in Glu-D1 showed significantly higher cookie diameter, crispness, and lower cookie height compared with single null genotype in Glu-A1 and WT. These indicate that the null Glu-D1 genotype is useful for improvement of biscuit quality, and use of this germplasm would be a viable strategy to develop new wheat varieties for biscuit processing.
基金Supported by the grant from the National Science Council(NSC 96-2320-B-030-004-MY3),Executive Yuan,Taiwan
文摘Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.
