Frequency of mitochondrial 12S rRNA gene A1555G and 961 insC mutations among children with sensorineural deafness in China

Objective： To investigate the frequency of mitochondrial 12S rRNA gene A1555G and 961 insC mutations among Chinese with sensorineural deafness. Methods： Blood samples from 78 sporadic cases with sensorineural deafness were obtained and DNA was extracted from the leukocytes, then the mitochondrial DNA target fragments were amplified by polymerase chain reaction（PCR）. The 1555G mutations were detected by BsmA 1 restriction endonuclease digestion, every fragment was analyzed by sequencing; All the 961 insC mutation were detected by direct sequencing. Results： The percent age of A1555G mutation and mt961C insertion were 6.4% and 2.6% in the hearing-impaired Chinese subjects respectively. Conclusion： A1555G and 961insC mutations in mitochondrial DNA 12S rRNA gene regions may play a role in the pathogenesis of hearing loss in the sporadic cases.

基于线粒体12S和16S rRNA基因部分序列的角蟾亚科部分属种的系统发育关系

测定了角蟾亚科 2属 8种 (亚种 )和外群 3种的线粒体 12S和 16SrRNA基因部分DNA序列 ,比对后序列长共 94 9bp ,其中变异位点数 32 0 ,简约位点数 2 0 6。邻接法和最大简约法分析的系统关系树一致表明内群为一单系群 ,其中腺角蟾首先与其他物种分开 ;沙坪角蟾与宽头短腿蟾聚为一支 ;余下的 5种 (亚种 )角蟾组成一支 ,其中小角蟾短肢亚种的广西种群和香港种群聚为一亚支 ,另一亚支包括峨眉角蟾、小角蟾指名亚种、尾凸角蟾和重庆武隆的角蟾种 ,后两种角蟾进化关系最近。本结果支持短肢角蟾为有效种 ,同时提示腺角蟾、沙坪角蟾与宽头短腿蟾可能隶属 3个不同的亚属或属。

Identification of sika deer and red deer using partial cytochrome b and 12s ribosomal RNA genes

A study was conducted on the identifications of the degraded samples of sika deer （Cervus nippon） and red deer （Cervus elaphus） by phylogenetic and nucleotide distance analysis of partial Cytb and 12s rRNA genes sequences. 402 bp Cytb genes were achieved by PCR-sequencing using DNA extracted from 8 case samples, and contrasted with 27 sequences of Cytb gene downloaded from GenBank database. The values of three nucleotide distance between three suspected samples and sika deer were identical （0.026±0.006）, which was smaller than the smallest nucleotide distance between eastern red deer and sika deer （0.036）. Furthermore, phylogenetic analysis of sika deer and red deer indicated that the evidences located within the same cluster as sika deer. The evidences were sika deer materials. As the same way, other three suspected samples were derived from red deer. The results were further confirmed by phylogenetic and nucleotide distance analysis of 387 bp 12s rRNA gene. The method was powerful and less time-consuming and helpful to reduce the related cases with wildlife.

Phylogenetic Relationships among 12 Species of Tetrigidae (Orthoptera:Tetrigoidea) Based on Partial Sequences of 12S and 16S Ribosomal RNA

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.

Species authentication of commercial beef jerky based on PCR-RFLP analysis of the mitochondrial 12S rRNA gene

In this study, we determined species-specific variations by analyzing the mitochondrial 12S rRNA gene sequence variation （-440 bp） in 17 newly obtained sequences and 90 published cattle, yak, buffalo, goat, and pig sequences, which represent 62 breeds and 17 geo- graphic regions. Based on the defined species-specific variations, two endonucleases, Alu I and Bfa I, were selected for species authentication using raw meat/tissue samples and the PCR-RFLP method. Goat and pig were identified using the Alu I enzyme, while cattle, yak, and buffalo were identified by digestion with Bfa I. Our approach had relatively high detection sensitivity of cattle DNA in mixed cattle and yak products, with the lowest detectable threshold equaling 20% of cattle DNA in a mixed cattle/yak sample. This method was successfully used to type commercial beef jerky products, which were produced by different companies utilizing various processing technologies. Our results show that several yak jerky products might be implicated in commercial fraud by using cattle meat instead of yak meat.

中国林蛙的分子系统关系

测定了 6种林蛙和用作外群的 2种侧褶蛙和 1种陆蛙的线粒体 12SrRNA基因序列 393bp。序列两两对位比较表明内外群间的位点替换率是 7 3%到 2 3 1% ,内群中物种间则为 0 0 %到 9 2 %。依据上述DNA序列 ,用距离法和最大简约法的系统发育分析表明 :①研究的 6种林蛙聚为一支 ,构成单系群 ,并有高的BPs值(90 %以上 )支持 ;② 6种林蛙可以分成 2个姐妹群 ,即中国林蛙、黑龙江林蛙和桓仁林蛙为一组 (BPs >94% ) ,峨眉林蛙、昭觉林蛙和镇海林蛙为一组 (BPs >5 0 % ) ;③昭觉林蛙与镇海林蛙有较近的亲缘关系 ;④中国林蛙的榆中种群与牡丹江种群间的遗传分化似乎达到了种级分化水平。

六种灵猫科动物的分子系统关系研究

对六种灵猫科物种线粒体12 S rRNA基因及其中四种的Cytb基因部分序列进行了测定,并从Gen-Bank获得斑林狸(Prionodon pardicolor)、熊狸(Arctictis binturong)的Cytb基因同源序列。两基因整合序列比对后长755 bp,12 S rRNA基因序列中有70个变异位点,31个简约信息位点,在Cytb基因序列中,共有120个位点呈现变异,60个简约信息位点,Cytb基因的碱基变异百分比高于12 S rRNA基因的碱基变异百分比。使用邻接法(NJ)、最大似然法(ML)重建的分子系统树显示:斑林狸从灵猫亚科中分离出来,支持灵猫亚科的多系起源,而且斑林狸可能是中国起源最早且最特化的灵猫科动物。另外,同属于灵猫亚科的大灵猫(Viverra zibe-tha)、小灵猫(Viverricula indica)聚为一支,同属于棕榈狸亚科的果子狸(Viverricula indica)、熊狸聚为姐妹群,这些与传统形态学分类观点一致。

Advances in cochlear implantation for hereditary deafness caused by common mutations in deafness genes

The pathogenic factors of deafness are complex;more than 50%of cases are caused by genetic factors.Between 75%and 80%of cases of hereditary hearing impairment are autosomal recessive,15%to 25%are autosomal dominant,and 1%to 2%are mitochondrial or X-linked.Cochlea implantation is the main method for treating severe and extremely severe bilateral sensorineural deafness and it is widely used in clinical treatment.As clinical cases of cochlea implantation accumulate,differences in the efficacy of implantation in individuals are emerging and attracting attention.In addition to residual hearing level,implantation age,and other factors,gene mutation is an important factor influencing postoperative rehabilitation in patients.With continuous progress in genetic testing technology for deafness,genetic diagnosis has become an important tool in preoperative evaluation and postoperative effect prediction in patients undergoing cochlear implantation.This article reviews the current status and future development of cochlear implantation in the treatment of hereditary deafness resulting from mutations in common deafness-causing genes.