新型超声快速处理活检标本保存不同年限对DNA质量的影响

背景:新型超声组织处理技术越来越多地被用来进行分子生物学分析,研究新型超声处理不同存储年限组织DNA的质量,对进一步分子检测的标本质控具有重要意义。目的:探讨新型超声处理活检标本存储不同年限对DNA质量的影响,以期为分子检测探索最佳的标本存储时间。方法:收集40例乳腺穿刺小活检组织,采用超声技术制作石蜡标本,按照存储年限分为4组:<1年组、1-3年组、>3-5年组及>5年组,每组10例,对石蜡标本进行切片,每张切片厚3μm,切片10-15张,提取DNA后通过Nanophotometer N60超微量分光光度计和Qubit 4.0荧光计检测DNA的质量浓度,记录A_(260)/A_(280)比值判定DNA的纯度,利用全自动毛细管电泳核酸分析仪(Qsep 100)检测DNA片段完整性,以评估DNA片段的质量。结果与结论:4组样本A_(260)/A_(280)均值在1.8-2.0之间,达到纯度要求,无明显差异。4组样本的DNA质量浓度(Qubit浓度)均值分别为30.39,14.33,2.52,1.95 ng/μL;DNA的平均N/Q比值分别为6.48,14.18,24.56,29.86;DNA质量数均值分别为5.64,1.76,1.24,0.80;大片段占比均值分别为56.08%,17.72%,12.68%,7.90%。PCR检测内控基因Ct均值分别为15.32,17.09,18.39,21.24。与<1年组相比,其余3组DNA浓度显著降低,N/Q比值显著增加,DNA质量数和大片段占比均值显著降低,Ct值升高,差异有显著性意义(P<0.05)。实验结果表明,对于新型超声处理活检标本,应优先选择存储<1年的样本进行日常分子检测,储存3年内的样本可满足二代测序等检测要求,5年内样本仅可尝试进行PCR等检测,存储超过5年的样本不建议进行后续分子检测。

基于中医证候与精液质量相关参数构建精子DNA碎片预测模型与验证

背景:中医证候与精液质量相关参数相结合,共同预测精子DNA碎片指数(DNA fragmentation index,DFI)异常增高的发生并绘制列线图,能显著提高临床的实操性与应用效能,为临床全面评估精液质量,采取积极干预措施以改善临床结局及制定个体化医疗方案提供依据。目的:探讨基于中医证候与精液质量相关参数构建精子DNA碎片的预测模型与验证。方法:回顾性分析2019年7月至2021年7月在广西壮族自治区南溪山医院中医男科接受中医证候诊断及精子DNA碎片率检查的不育患者共420例,据《人类精液检查与处理实验室手册》(第6版),将其中137例精子DFI>30%患者纳入精子DFI异常增高组,将283例精子DFI≤30%作为对照组;首先采用单因素分析筛选精子DFI异常增高的影响因素,然后采用套索算法(LASSO)校正因子共线性问题并筛选出最佳匹配因子后,将其纳入多因素向前逐步Logistic回归找出其独立影响因素并绘制列线图,最后采用受试者工作曲线、校准曲线、临床决策曲线、临床影响曲线对该预测模型进行区分度与准确度及临床应用效能验证。结果与结论:①单因素分析结果显示,年龄、体质量指数、前向运动率、精子总活率、精子浓度、精子形态学、肾阳虚衰证、湿热下注证、肾精不足证为引发精子DFI异常增高的影响因子(P<0.05);②通过LASSO回归进一步筛选出的最佳匹配因素为年龄、体质量指数、精子总活率、精子浓度、精子形态学、肾阳虚衰证、湿热下注证、肾精不足证(P<0.05);③多因素向前逐步Logistic回归结果显示年龄、体质量指数、精子浓度、精子总活率、湿热下注证、肾阳虚衰证共6项为引发精子DFI异常增高的独立影响因素;④受试者工作曲线显示,模型组曲线下面积为0.760(0.713,0.806),验证组曲线下面积为0.745(0.714,0.776),说明该预测模型具有较好的区分度;⑤校准曲线平均绝对误差0.040,Hosmer-Lemeshow检验P>0.05,表明该模型预测发生精子DFI异常增高的概率与实际发生精子DFI异常增高的概率无显著统计学差异,证实该模型具有较好的准确度;⑥临床决策曲线与临床影响曲线显示,模型组与验证组分别在阈概率值为0.08-0.84与0.09-0.78时具有临床最大净获益,且在该阈概率范围内具有较好的临床应用效能;⑦结果表明,年龄、体质量指数、精子浓度、精子总活率、湿热下注证、肾阳虚衰证为引发精子DFI异常增高的独立影响因素,通过其构建的临床预测模型列线图具有较好的临床预测价值与临床应用效能,可为临床全面评估精液质量、预后与干预及个体化医疗服务提供依据。

FTA-环介导等温扩增技术直接提取变异链球菌DNA的效果评价

背景:变异链球菌是龋病的重要病原菌,及时检测变异链球菌水平对龋病的早发现、早治疗有重要意义。目的:建立并评价FTA-环介导等温扩增(loop-mediated isothermal amplification,LAMP)技术直接提取变异链球菌DNA的应用效果。方法:①制备含有ATCC标准菌株变异链球菌的菌悬液,接种于脑心浸出液培养基,充分混匀后按10倍梯度稀释成7种浓度(4.2×10^(7),4.2×10^(6),4.2×10^(5),4.2×10^(4),4.2×10^(3),4.2×10^(2),4.2×10 CFU/mL),每个稀释级做2个平行对照,并增加无菌水作为空白对照;②分别采用FTA卡、常规煮沸法、试剂盒提取及裂解液提取4种方法直接提取菌株DNA,通过LAMP技术进行扩增,并进行特异性试验,比较4种提取方法的差异。结果与结论:①4种方法提取的DNA均满足LAMP扩增的要求;②特异性试验结果显示,只有变异链球菌才可特异扩增出靶基因;③裂解液提取法最低检测限为4.2×10^(3) CFU/mL,FTA卡提取法最低检测限为4.2×10^(4) CFU/mL,试剂盒提取法和常规煮沸法最低检测限分别为4.2×10^(6) CFU/mL和4.2×10^(7) CFU/mL;④4种提取方法其他方面的比较显示,试剂盒提取法的实验成本、步骤数和时间都是最高;其他3种方法步骤数一致,其中FTA卡所需仪器设备最少,常规煮沸法单次成本最低,裂解液提取法所需时间最少;FTA卡和裂解液提取法仅需少量菌即可提取成功,后者在时间方面优于FTA卡,但相较于FTA卡其单次成本高,所需设备多;⑤结果说明,该研究建立的FTA-LAMP技术具有操作简便、特异性强、灵敏度高、结果可视化等优势,有望为高效提取检测变异链球菌提供新途径。

基于活产建立体外受精-胚胎移植精子DNA碎片指数的参考阈值及子代短期安全性

背景:精子DNA碎片指数与受精、胚胎发育潜能、胚胎植入、流产及子代安全性等存在显著的相关性。然而,其临床参考值受多种因素的影响,导致临床意义极其有限,该研究以活产为结局,通过倾向评分匹配校正其他混杂因素后,构建精子DNA碎片指数与活产的最佳临床截断值,并对其进行内外部验证,具有较好的预测价值及临床应用效能。目的:探讨基于活产建立体外受精-胚胎移植精子DNA碎片指数的参考阈值及子代短期安全性。方法:选取2019年5月至2021年5月于常州市妇幼保健院接受体外受精-胚胎移植患者1921例,以倾向匹配容差0.02为标准,1∶1进行倾向评分匹配,结果活产组与非活产组各成功匹配540例,以此建立模型组;通过选取同时期广西壮族自治区南溪山医院接受体外受精-胚胎移植患者135例作为外部验证组;采用受试者工作曲线探求精子DNA碎片指数对活产的临床最佳截断值,分别采用限制性立方样条曲线、标准曲线、临床决策曲线、临床影响曲线及内外部验证等方法,对该截断值的准确性及临床应用效能进行评估。结果与结论:(1)非活产组精子DNA碎片指数显著高于活产组且与活产存在显著的负相关性(r=-0.444,P<0.001);(2)受试者工作曲线结果显示,DNA碎片指数对活产的最佳截断值为24.33%,曲线下面积为0.775(0.746,0.804),特异度为72.60%,敏感度为78.90%,准确度为75.70%;(3)限制性立方样条曲线拟合Logistic回归结果显示,当精子DNA碎片指数大于24.57%时,临床非活产的风险呈趋势性增涨;(4)Logistic回归概率分析结果显示,精子DNA碎片指数为活产的危险因素[OR(95%CI)=0.916(0.904,0.928),P<0.001],且当精子DNA碎片指数大于27.78%时,临床活产发生的概率将小于50%,随着精子DNA碎片指数每增高1个单位,活产的概率下降8.4%;(5)内外部对该临床截断值的验证均显示,该截点具有一定的临床预测价值及准确性;(6)临床决策曲线与临床影响曲线显示,以该临床截断值建立的预测模型在阈概率为0.22-0.73时具有临床最大净获益值,且在该阈概率范围内损失与获益的比值始终小于1,证实该预测模型具有较好的临床应用效能;(7)精子DNA碎片指数与子代短期安全性分析结果显示,精子DNA碎片指数与出生儿早产、体质量、畸形、性别差异无显著性;(8)结果表明,精子DNA碎片指数对体外受精-胚胎移植活产的最佳临床截断值为24.33%,以此建立的临床预测模型具有较好的区分度、准确度与临床应用效能,精子DNA碎片指数对子代短期安全性影响并不显著,但仍需大样本及长期的追踪评估。

Peripheral mitochondrial DNA as a neuroinflammatory biomarker for major depressive disorder

In the pathogenesis of major depressive disorder, chronic stress-related neuroinflammation hinders favorable prognosis and antidepressant response. Mitochondrial DNA may be an inflammatory trigger, after its release from stress-induced dysfunctional central nervous system mitochondria into peripheral circulation. This evidence supports the potential use of peripheral mitochondrial DNA as a neuroinflammatory biomarker for the diagnosis and treatment of major depressive disorder. Herein, we critically review the neuroinflammation theory in major depressive disorder, providing compelling evidence that mitochondrial DNA release acts as a critical biological substrate, and that it constitutes the neuroinflammatory disease pathway. After its release, mitochondrial DNA can be carried in the exosomes and transported to extracellular spaces in the central nervous system and peripheral circulation. Detectable exosomes render encaged mitochondrial DNA relatively stable. This mitochondrial DNA in peripheral circulation can thus be directly detected in clinical practice. These characteristics illustrate the potential for mitochondrial DNA to serve as an innovative clinical biomarker and molecular treatment target for major depressive disorder. This review also highlights the future potential value of clinical applications combining mitochondrial DNA with a panel of other biomarkers, to improve diagnostic precision in major depressive disorder.

Microdissection of Haynaldia villosa Telosome 6VS and Cloning of Species-specific DNA Sequences

The material T240_6 derived from SC 2 young embryo of the combination CA9211/RW15 (6D/6V alien substitution) was telosomic substitution line of 6VS identified by GISH (genomic in situ hybridization) analysis. The 6VS was microdissected with a needle and transferred into a 0.5 mL Ep tube. In the 'single tube', all the subsequence steps were conducted. After two round of LA (Linker adaptor)_PCR amplification, the size of PCR bands ranged from 100 to 3 000 bp, with predominate bands 600-1 500 bp. The products were confirmed by Southern blotting analysis using Haynaldia villosa (L.) Schur. genomic DNA labeled with 32 P as probe. The PCR products were purified and ligated into clone vector-pGEM_T easy vector. Then, the plasmids were transformed into competence E. coli JM109 with cool CaCl 2. It was estimated that there were more than 17 000 white clones in the library. The size of insert fragments distributed from 100-1 500 bp, with average of 600 bp. Using H. villosa genomic DNA as probe, dot blotting results showed that 37% clones displayed strong and medium positive signals, and 63% clones had faint or no signals. It is demonstrated that there were about 37% repeat sequence clones and 67% single/unique sequence clones in the library. Eight H. villosa_specific clones were screened from the library, and two clones pHVMK22 and pHVMK134 were used for RFLP analysis and sequencing. Both of them were H. villosa specific clones. The pHVMK22 was a unique sequence clone, and the pHVMK134 was a repeat sequence clone. When the pHVMK22 was used as a probe for Southern hybridization, all the powdery mildew resistance materials showed a special band of 2 kb, while all the susceptible ones not. The pHVMK22 may be applied to detect the existence of Pm21.

Genetic Polymorphism of Eighteen Lycium barbarum Resources Based on nrDNA ITS Sequence

[Objective] The study aimed to investigate the genetic polymorphism of eighteen Lycium barbarum resources via nrDNA ITS sequencing. [Method] The genomic DNAs from Lycium barbarum leaves were isolated by modified CTAB method for PCR amplification on the nrDNA ITS region using specifically synthesized primers; the amplified fragments were cloned and sequenced, then the sequencing results were clustered. [Result] nrDNA ITS sequences of the tested eighteen Lycium barbarum were firstly obtained in the present study. For all eighteen tested materials, the variation range of whole ITS region was 559-634 bp, with an average of 612 bp; alignment analyses showed that the whole length of internal transcribed spacer (ITS1+ITS2) was 480 bp, within which there are 194 variation sites (accounting for 40.4%) and 286 conserved sites (accounting for 59.6%). The cluster results showed that the eighteen tested materials could be grouped into three classes. [Conclusion] Analysis of nrDNA ITS sequence may avail to identify the Lycium barbarum germplasm resources.

Isolation of Zizania latifolia Species-specific DNA Sequences and Their Utility in Identification of Z. latifolia DNA Introgressed into Rice

根据两个植物抗病基因N和RPS2中核酸结合位点 (NBS)和富亮氨酸重复区 (LRR)中的保守序列设计了一对特异引物 ,用PCR从具有水稻 (OryzasativaL .)改良所需要的许多优良性状的水稻近缘野生种菰 (Zizanialatifolia(Griseb .)Turcz.exStapf)的基因组DNA中扩增同源片段。PCR产物经克隆后 ,分别以菰和水稻的基因组DNA为探针 ,通过点杂交对所得克隆进行了分析。点杂交结果表明 ,在所分析的 6 0个克隆中有 2个克隆是菰专化的序列 ,即它们与水稻无杂交信号。基因组DNA的Southern杂交进一步证实了这 2个克隆的专化性。为了验证一些可能的“水稻_菰”渐渗杂交系是否确实含有源自供体菰的DNA ,以这 2个克隆为探针 ,与经EcoRⅠ酶切的 5个可能的渐渗杂交系进行了Southern杂交。结果表明 ,这 2个克隆均能检测出其中的一个系含有其同源序列。这一结果为曾经报道的经一种非常规有性杂交方法将菰DNA导入水稻提供了确凿的证据。

Characterization of Two Groups of Low_copy and Specific DNA Sequences Isolated from Chromosome 7B of Common Wheat

Recent work revealed that, in the genomes of polyploid wheat, there exists a class of low_copy and chromosome_specific sequences that are labile upon polyploid formation. This class of sequences was proposed to play a critical role in the stabilization and establishment of nascent plant polyploids as new species. To further study this issue, five wheat chromosome 7B_specific sequences, isolated from common wheat (Triticum aestivum L.) by chromosome microdissection, were characterized. The sequences were studied by genomic Southern hybridizations on a collection of polyploid wheats and their diploid progenitors. Four sequences hybridized to all polyploid species, but at the diploid level to only species closely related to the B_genome of polyploid wheat. This indicates that these sequences originated with the divergence of the diploid species, and was then vertically transmitted to polyploids. One sequence hybridized to all species at both the diploid and polyploid levels, suggesting its elimination after the polyploid wheat formation. The hybridization of this sequence to two synthetic polyploid wheats indicated that sequence elimination is a rapid event and probably related to methylation status of the sequence. Based on the above results, we suggest that selective changes of low_copy sequences occur rapidly after polyploid formation, which may contribute to the differentiation of chromosomes in newly formed allopolyploid wheats.

Discriminant Classification Model of DNA Sequence

[Objective] The research aimed to construct the discriminant classification model of DNA sequence by combining with the biology knowledge and the mathematical method.[Method] According to the polarity nature of side chain radical in the amino acid,the classification information of amino acid which represented the sequence characteristic from the content and array situation of base was extracted from the different sequences that the amino acid content was different.The four-dimension vector was used to represent.Mahalanobis distance and Fisher discriminant methods were used to classify the given sequence.[Result] In the model,the back substitution rates of sample obtained by two kinds of classification methods were both 100%,and the consistent rate of classification was 90%.[Conclusion] In the model,the calculation method was simple,and the accuracy of classification result was higher.It was superior to the discriminant classification model which was only based on the base content.

Genetic Diversity of Indocalamus Determined by Chloroplast DNA Sequence

[Objective]The aim was to research the relationship and genetic diversity of Indocalamus.[Method]Using 13 samples of Indocalamus and 3 samples of Sasa as materials,the intergenic regions of trnL-trnF gene in chloroplast were amplified by PCR,and sequence analysis and phylogenetic trees construction were carried out.[Result]Using the universal primer,the intergenic regions of trnL-trnF were amplified,the lengths of the segments varied from 1 008 bp to 1 103 bp,of which 940 bp was compared.The dendrogram of trnL-trnF sequences showed that Indocalamus and Sasa were clustered together and they were homologous by 99%.All the samples were divided into five groups,the first group included 12 samples such as Indosalamus pedalis,I.pumilus,I.victorialis,I.longiauritus,I.tessellatus,Sasa sinica,Sasa pygmaea,I.barbatus,I.guangdongensis,I.herklotsii,I.Hirtivaginatus and S.fortunei.I.decorus,I.lacunosus,I.Latifolius and I.Migoi were respectively divided into four groups.[Conclusion]The high homology of all samples showed the low evolution speed and little information sites which suggested that the phylogeny of Indocalamus could not be well resolved by the intergenic region of trnL-trnF.

ITS1 SEQUENCES OF NUCLEAR RIBOSOMAL DNA IN WILD RICES AND CULTIVATED RICES OF CHINA AND THEIR PHYLOGENETIC IMPLICATIONS

The first internal transcribed spacer(ITS1) of nuclear ribosomal DNA of three wild rice species and two subspecies of cultivated rice, which are distributed in China, was amplified using PCR technique and sequenced with automated fluorescent sequencing. The sequences of ITS1 ranged from 193 bp to 218 bp in size and G/C content varied from 69.3% to 72.7%. In pairwise comparisons among the five taxa, sequence site divergence ranged from 1.5% to 10.6%. Phylogenetic analysis of ITS1 sequences using Wagner parsimony generated a single well resolved tree, which revealed that Oryza rufipogon was much more closely related to cultivated rice species than to the other two wild species. Oryza granulata was less closely related to either cultivated rice species or the other two wild species, and might be a unique and isolated taxon in the genus Oryza. The phylogenetic relationships of the three wild rice species and two cultivated rice subspecies inferred from ITS1 sequences is highly concordant with those based on the molecular evidence from isozyme, chloroplast DNA (cpDNA), mitochondrial DNA(mtDNA) and nuclear DNA (nDNA) of the genus Oryza .

Isolation of Rice EPSP Synthase cDNA and Its Sequence Analysis and Copy Number Determination

In order to isolate the total cDNA of rice (Oryza sativa L.) epsps gene, RT-PCR was carried out with template of rice first-strand cDNA and primers designed according to rice EPSP synthase genomic sequence obtained in previous study. A 1 585-bp cDNA fragment was amplified and cloned. The 1 585-bp cDNA contains an open reading frame (ORF) comprising of 1 533 nucleotides (nt) which encodes a 511 residue polypepetides, including 67 amino acids chloroplast transit peptide and 444 amino acids EPSP synthase mature peptide. A comparison between the EPSP synthase of different sources indicates that the mature peptide shows more than 51% identity except for the fungi EPSP synthase and the transit peptide shows considerably less sequence conservation. The copy number of rice epsps gene is estimated to be one copy per haploid rice genome using southern blot. RT-PCR indicated that rice epsps gene is expressed in rice leaves, endosperms and roots and has the highest expression level in leaves.

p21^(WAF1/CIP1) Gene DNA Sequence Change and Their Relationship with the Phenotype of Human Osteosarcoma

Objective: To investigate the p21WAF1 /CIP1gene DNA sequence change and their relationship with the phenotype of human osteosarcoma. Methods: p21WAF1 /CIP1gene DNA of 36 osteosarcoma spec- imens was examined by using polymerase chain reaction-single strand conformation polymorphism (PCR- SSCP) method. The PCR products were sequenced directly. Results: In p21WAF1 /CIP1 gene exon3 of 36 cases of human osteosarcoma, the change of C→T in the p21WAF1 /CIP1gene CDNA sequence of position 609th occurred in 17 cases with the incidence being 44.4%. In 10 normal blood samples, DNA sequence analysis showed the change of C→T in the p21WAF1 /CIP1gene CDNA sequence of position 609th occurred in 8 cases with the incidence being 80%. Conclusion: The novel location of p21WAF1 /CIP1gene polymorphism of osteosarcoma, but not mutation was de?ned, and this location might provide the meaningful reference for the further research of p21WAF1/CIP1 gene.p2lWAF1/CIP1基因DNA序列分析及其与骨肉瘤表型的关系

Classification and Identification of Marine Penicillium Species Based on ITS Sequences of rDNA

[ Objective ] The aim of this study is to identify 6 marine fungi species by analyzing ITS nucleotide sequence, which had been primarily identified as penicillium based on morphological characteristics. [ Method ] The ITS regions of these species were cloned by molecule biology method and phylogenetic analyzed using ClustalX1.83 software. [ Result] The ITS regions of these species were sequenced, and phylogenetic analysis between the yield sequences and the ITS sequences assessed in GenBank showed that the 6 strains all belonged to penicillium. [ Condusion] The present study suggests ITS sequence analysis could not be used as an only proof, but it is a very useful supplementary tool for the classification and identification of marine peniciUium combined with morphological characteristics.

Sequence Difference of Mitochondrial DNA Control Region and Genetic Differentiation of Cervinae in China

[Objective] The study aimed at analyzing Genetic Differentiation of Cervinae. [Method] The complete mitochondrial DNA control region of five species of Cervinae was determined by direct DNA sequencing. Homologous sequences of others Cervinae were gained from GenBank, and then analyzed through biology software. [Result] The lengths of their control region were 921-1 072 bp, the nucleotide content of T, A, C, and G was 32.1%, 30.2%, 22.7% and 15.0% separately. Genetic distance of each species ranged from 0.062-0.106, which belonged to level of inter-genus. The molecular phylogenetic tree indicated that red deer, skia deer and White-lipped Deer had close relationship, and they constituted one branch with sambar deer. Eld＇s deer and elk deer constituted the second branch, and hog deer constituted the third branch alone. [Conclusion] Hog deer and fallow deer should be incorporated in Cervus, divergence time is about 1.55-2.60 million years among Cervinae in China.

Sequence Analysis of ITS Region of rDNA of Alternaria Nees. from Some Areas of China

[Objective] The study aimed to identify Alternaria Nees from some areas of China at molecular level by analyzing the rDNA ITS sequence. [ Method ] The DNA sequences coding for the 5.8S rDNA and the flanking internal transcribed spacers （ ITS1 and ITS2） were amplified by PCR with universal primers ITS4 and ITS5 and subsequently sequenced for 34 Alternaria isolates from different areas of China. [Result] Sequences analysis showed that 5.8S rDNA was 159 bp and no variation in tested 34 isolates. There had variables sites in ITS. The isolates that had same sequences as A. tenuissima or A. alternata all put up eurytopicity to area and host. The variables sites of the isolates showed the diver- sity of Alternaria in the hosts of Oleaceae, Rosaceae and Solanaceae. At the same time that ITS could not clearly separated the isolates was indicated. The results indicated that the phylogenetic relationship were not closely related to the geographical origin and hosts of these isolates. [ Conclusion] The sequence analysis of ITS region could provide theory basis for the identification of Alternaria Nees..

Cloning and Sequence Analysis of 16S rRNA and COI Gene in Mitochondrial DNA of Scortum barcoo

[Objective] The aim was to provide molecular biological basis for the researches on the genetic resources,genetic relationship among species and phyletic evolution of S.barcoo.[Method] PCR amplification and sequencing were used to study the 16S rRNA and COI gene fragments.[Result] As for 16S rRNA gene fragments,nucleotide sequences of 791 bp were obtained,and the A,T,G and C contents in this fragment were 31.6%,21.4%,20.4% and 26.7%respectively.As for the COI gene fragments,the size was 631 bp and the A,T,G And C contents were 27.7%,23.6%,29.8% and 18.9% respectively.Among these two gene fragments,the content of GC was lower than AT,and AT/GC of these two fragments was 1.13 and 1.05 respectively.[Conclusion] The genetic characteristics of gene fragments of 16S rRNA and COI of S.barcoo suggested that the variation in the same species was relatively low.The sequences of 16S rRNA gene in three samples the same,while the sequences of COI gene was also the same,indicating that these two gene of S.barcoo were conservative.

Sequence Analysis of Mitochondrial DNA D-loop Region in Xinjiang Goose

[Objective] The sequences of mitochondrial DNA D-loop region of Xinjiang Goose with three different colors of plumage were analyzed in order to study the genetic diversity of Xinjiang Goose, as well as the phylogeny and evolution. [Method] Ten geese were selected randomly from the core populations of grey-, mosaic- and white-plumaged Xinjiang Goose respectively with a total number of thirty as experi- mental materials, of which the blood samples were collected from the largest vein under the wing （brachial vein） for DNA extraction. Sequences of mitochondrial DNA D-loop regions were determined using DNA sequencing technology to analyze the polymorphism. In addition, the genetic distances among different populations were estimated through the comparison with the reference sequences. [Resull] The con- tents of A, G, C and T nucleotides in the D-loop region of Xinjiang Goose were 28.85%, 17.05%, 25.38% and 28.72%, respectively. The average haplotype diversity and nucleotide diversity of Xinjiang Goose were 0.583 and 0.056. Xinjiang Goose and Greylag Goose were clustered into the same group. [Conclusion] The results showed that Xinjiang Geese with three different colors of plumage all descend from Greylag Goose （Anser anser）.

Genetic structure of wintering Hooded Cranes (Grus monacha) based on mitochondrial DNA D-loop sequences

The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative effects on the structure of our wintering populations. For its effective protection, it is important to conduct an intensive study on the genetic structure of this population. A total of 221 faecal samples, nine feather samples and four muscle samples of Hooded Cranes from four wintering populations, i.e., from Caizi Lake and Shengjin Lake in Anhui, Poyang Lake in Jiangxi and Chongming Dongtan in Shanghai, were collected for this study. Full-length 1103–1104 bp mtDNA D-loop sequences from 72 samples were amplified using PCR. Based on our amplified D-loop sequences and the sequences of two individual birds obtained from GenBank (AB017625 and AB023813), we analyzed the genetic structure of these four wintering Hooded Crane populations. Twenty six variable sites were found among 72 target sequences in the four wintering populations and 23 haplotypes were defined. Genetic diversity analyses showed that the haplotype diversity of Hooded Cranes was 0.823 ± 0.042 with a nucleotide diversity of 0.00157 ± 0.00021. The FST values of the four populations show that there is no significant genetic differentiation among the populations of Hooded Cranes wintering in the middle and lower reaches of the Yangtze River. Tajima’s D and Fu’s tests suggest that the Hooded Crane populations may have experienced population expansion in their evolutionary history.