The human ear is a delicate sensory apparatus of hearing for normal communication, and its proper functioning is highly dependent on mitochondrial oxidative phosphorylation. The first mitochondrial point mutation for ...The human ear is a delicate sensory apparatus of hearing for normal communication, and its proper functioning is highly dependent on mitochondrial oxidative phosphorylation. The first mitochondrial point mutation for nonsyndromic and aminoglycoside-induced hearing loss was identified in 1993. Since then a number of inherited mitochondrial mutations have been implicated in hearing loss. Most of the molecular defects responsible for mitochondrial disorder-associated hearing loss are mutations in the 12S rRNA gene and tRNA genes. In this review, after a short description of normal hearing mechanisms and mitochondrial genetics, we outline the recent advances that have been made in the identification of deafness-associated mitochondrial mutations, and discuss how mitochondrial dysfunction contributes to hearing loss.展开更多
AIM: To detect the variations of mitochondrial 12S rRNA in patients with gastric carcinoma, and to study their significance and the relationship between these variations and the genesis of gastric carcinoma.METHODS: P...AIM: To detect the variations of mitochondrial 12S rRNA in patients with gastric carcinoma, and to study their significance and the relationship between these variations and the genesis of gastric carcinoma.METHODS: PCR amplified mitochondrial 12S rRNA of 44 samples including 22 from gastric carcinoma tissues and 22 from adjacent normal tissues, was detected by direct DNA sequencing. Then laser capture microdissection technique (LCM) was used to separate the cancerous cells and dysplasia cells with specific mutations. Denaturing high performance liquid chromatography (DHPLC) plus allele-specific PCR (ASPCR), nest-PCR and polyacrylamide gel electrophoresis (PAGE)were used to further evaluate this mutant property and quantitative difference of mutant type between cancerous and dysplasia cells. Finally, RNAdraw biosoft was used to analyze the RNA secondary structure of mutant-type 12S rRNA.RESULTS: Compared with Mitomap database, some new variations were found, among which np652 G insertion and np716 T-G transversion were found only in cancerous tissues.There was a statistic difference in the frequency of 12S rRNA variation between intestinal type (12/17, 70.59%) and diffusive type (5/17, 29.41%) of gastric carcinoma (P＜0.05).DHPLC analysis showed that 12S rRNA np652 G insertion and np716 T-G transversion were heteroplasmic mutations.The frequency of 12S rRNA variation in cancerous cells was higher than that in dysplasia cells (P＜0.01). 12S rRNA np652 G insertion showed obviously negative effects on the stability of 12S rRNA secondary structure, while others such as T-G transversion did not.CONCLUSION: The mutations of mitochondrial 12S rRNA may be associated with the occurrence of intestinal-type gastric carcinoma. Most variations exist both in gastric carcinomas and in normal tissues, and they might not be the characteristics of tumors. However, np652 G insertion and np716 T-G transversion may possess some molecular significance in gastric carcinogenesis. During the process from normality to dysplasia, then to carcinoma, 12S rRNA tends to convert from homoplasmy (wild type) to heteroplasmy,then to homoplasmy (mutant type, np717 T-G).展开更多
Mitochondrial 12S and 16S ribosomal RNA genes sequences were sequenced using dye-labeled terminator on an ABI 377 automated sequencer in 11 individuals and 1 species' sequences were gained from GenBank,representin...Mitochondrial 12S and 16S ribosomal RNA genes sequences were sequenced using dye-labeled terminator on an ABI 377 automated sequencer in 11 individuals and 1 species' sequences were gained from GenBank,representing 6 genera of family Tetrigidae.The collated sequences were aligned using Clustal X version 1.81 and then,the sequence variability and heredity distances based on Kimura 2-parameter model were calculated using Mega 2.1.In obtained sequences (736 bp),the average A+T content is 73.9%,ranging from 71.2% to 77.5%;the overall G+C content is 26.1%,ranging from 22.5% to 28.8%.Based on alignment of the combined sequences,185 parsimony-informative sites were revealed in 755 available base pairs.Phylogenetic trees were reconstructed using NJ,MP and ML methods with Cylindraustralia kochii as outgroup.The results indicated that the monophyletic nature of Tetrix is questioned and suggest that T.tubercarina may be given tribal rank.Our results also show that Coptltettix huanjiangensis and C.gongshanensis are the same species,i.e.Coptltettix gongshanensis Zheng,and C.huanjiangensis is the synonyms of C.gongshanensis.展开更多
我国水母暴发主要发生在黄渤海和东海海域,在南海海域较为少见。文章对2019年5月海南海口、文昌和广东茂名等南海北部多处海域的水母暴发原因种进行了形态学观察和分子鉴定。形态学观察结果显示,海口与文昌附近海域的暴发水母为同一种水...我国水母暴发主要发生在黄渤海和东海海域,在南海海域较为少见。文章对2019年5月海南海口、文昌和广东茂名等南海北部多处海域的水母暴发原因种进行了形态学观察和分子鉴定。形态学观察结果显示,海口与文昌附近海域的暴发水母为同一种水母,其伞部为半球形,生殖下穴呈梨形突起,口腕布满丝状物并在末端有1条鞭状附属物,与鞭腕水母(Acromitus flagellatus)形态相似;而茂名附近海域暴发水母区别于海口和文昌,该水母伞部呈较平的半球形,生殖下穴乳状突起,口腕无丝状物,与端棍水母(Catostylus townsendi)形态相似。基于线粒体核糖体大亚基基因(16S r RNA)序列比对,海口和文昌附近海域暴发水母与东太平洋鞭腕水母相似性为97.5%和97.7%,茂名附近海域暴发水母与马六甲海峡端棍水母相似性为93.5%。基于线粒体COI基因和16S r RNA基因构建的系统发育树结果表明,海口和文昌附近海域水母为同一种水母,与鞭腕水母聚在一支,而茂名附近海域水母与端棍水母亲缘关系近。结合形态学观察和分子系统数据认为,海口和文昌附近海域暴发水母为鞭腕水母(Acromitus flagellatus),茂名附近海域暴发水母为端棍水母(Catostylus sp.)。展开更多
基金We acknowledge the support by a grant award from Jiangsu Natural Science Foundation,Grant No.BK2006247grant awards from Jiangsu Health Administration,Grant No.WK0623 and K200502.
文摘The human ear is a delicate sensory apparatus of hearing for normal communication, and its proper functioning is highly dependent on mitochondrial oxidative phosphorylation. The first mitochondrial point mutation for nonsyndromic and aminoglycoside-induced hearing loss was identified in 1993. Since then a number of inherited mitochondrial mutations have been implicated in hearing loss. Most of the molecular defects responsible for mitochondrial disorder-associated hearing loss are mutations in the 12S rRNA gene and tRNA genes. In this review, after a short description of normal hearing mechanisms and mitochondrial genetics, we outline the recent advances that have been made in the identification of deafness-associated mitochondrial mutations, and discuss how mitochondrial dysfunction contributes to hearing loss.
基金Supported by the National Natural Science Foundation of China,No.30371607
文摘AIM: To detect the variations of mitochondrial 12S rRNA in patients with gastric carcinoma, and to study their significance and the relationship between these variations and the genesis of gastric carcinoma.METHODS: PCR amplified mitochondrial 12S rRNA of 44 samples including 22 from gastric carcinoma tissues and 22 from adjacent normal tissues, was detected by direct DNA sequencing. Then laser capture microdissection technique (LCM) was used to separate the cancerous cells and dysplasia cells with specific mutations. Denaturing high performance liquid chromatography (DHPLC) plus allele-specific PCR (ASPCR), nest-PCR and polyacrylamide gel electrophoresis (PAGE)were used to further evaluate this mutant property and quantitative difference of mutant type between cancerous and dysplasia cells. Finally, RNAdraw biosoft was used to analyze the RNA secondary structure of mutant-type 12S rRNA.RESULTS: Compared with Mitomap database, some new variations were found, among which np652 G insertion and np716 T-G transversion were found only in cancerous tissues.There was a statistic difference in the frequency of 12S rRNA variation between intestinal type (12/17, 70.59%) and diffusive type (5/17, 29.41%) of gastric carcinoma (P＜0.05).DHPLC analysis showed that 12S rRNA np652 G insertion and np716 T-G transversion were heteroplasmic mutations.The frequency of 12S rRNA variation in cancerous cells was higher than that in dysplasia cells (P＜0.01). 12S rRNA np652 G insertion showed obviously negative effects on the stability of 12S rRNA secondary structure, while others such as T-G transversion did not.CONCLUSION: The mutations of mitochondrial 12S rRNA may be associated with the occurrence of intestinal-type gastric carcinoma. Most variations exist both in gastric carcinomas and in normal tissues, and they might not be the characteristics of tumors. However, np652 G insertion and np716 T-G transversion may possess some molecular significance in gastric carcinogenesis. During the process from normality to dysplasia, then to carcinoma, 12S rRNA tends to convert from homoplasmy (wild type) to heteroplasmy,then to homoplasmy (mutant type, np717 T-G).
文摘Mitochondrial 12S and 16S ribosomal RNA genes sequences were sequenced using dye-labeled terminator on an ABI 377 automated sequencer in 11 individuals and 1 species' sequences were gained from GenBank,representing 6 genera of family Tetrigidae.The collated sequences were aligned using Clustal X version 1.81 and then,the sequence variability and heredity distances based on Kimura 2-parameter model were calculated using Mega 2.1.In obtained sequences (736 bp),the average A+T content is 73.9%,ranging from 71.2% to 77.5%;the overall G+C content is 26.1%,ranging from 22.5% to 28.8%.Based on alignment of the combined sequences,185 parsimony-informative sites were revealed in 755 available base pairs.Phylogenetic trees were reconstructed using NJ,MP and ML methods with Cylindraustralia kochii as outgroup.The results indicated that the monophyletic nature of Tetrix is questioned and suggest that T.tubercarina may be given tribal rank.Our results also show that Coptltettix huanjiangensis and C.gongshanensis are the same species,i.e.Coptltettix gongshanensis Zheng,and C.huanjiangensis is the synonyms of C.gongshanensis.
文摘我国水母暴发主要发生在黄渤海和东海海域,在南海海域较为少见。文章对2019年5月海南海口、文昌和广东茂名等南海北部多处海域的水母暴发原因种进行了形态学观察和分子鉴定。形态学观察结果显示,海口与文昌附近海域的暴发水母为同一种水母,其伞部为半球形,生殖下穴呈梨形突起,口腕布满丝状物并在末端有1条鞭状附属物,与鞭腕水母(Acromitus flagellatus)形态相似;而茂名附近海域暴发水母区别于海口和文昌,该水母伞部呈较平的半球形,生殖下穴乳状突起,口腕无丝状物,与端棍水母(Catostylus townsendi)形态相似。基于线粒体核糖体大亚基基因(16S r RNA)序列比对,海口和文昌附近海域暴发水母与东太平洋鞭腕水母相似性为97.5%和97.7%,茂名附近海域暴发水母与马六甲海峡端棍水母相似性为93.5%。基于线粒体COI基因和16S r RNA基因构建的系统发育树结果表明,海口和文昌附近海域水母为同一种水母,与鞭腕水母聚在一支,而茂名附近海域水母与端棍水母亲缘关系近。结合形态学观察和分子系统数据认为,海口和文昌附近海域暴发水母为鞭腕水母(Acromitus flagellatus),茂名附近海域暴发水母为端棍水母(Catostylus sp.)。
