首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Somatostatins play a crucial role in the regulation of growth and development in vertebrates, especially muscle growth. We assessed the association of somatostatin gene polymorphisms with growth traits by PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) and DNA sequencing methods in 694 individuals from six Chinese cattle breeds. A novel single nucleotide polymorphism, G126A, was detected, and significant associations were found with body length, body height, hip width, heart girth, and hucklebone width index. Polymorphism of the somatostatin gene was found to be highly associated with growth traits in the Qinchuan breed at various ages. Gene frequency analysis showed significant differences among the breeds. Individuals with genotype AA had significantly lower body height, body length, hip width, and hucklebone width values compared to AG at 1.5 years old, and had significantly lower hip width, body length and hucklebone width compared to AG at 2 years old. At 2.5 years old, populations with genotype AA had significantly lower body length, hip width and hucklebone width than AG individuals, with the exception of the Luxi breed, in which two genotypes were found. The Luxi and Ximentaer crossbreed had the lowest frequency of the G allele, while the highest G allele frequencies were found in the Luxi breed.  相似文献   

2.
We analyzed 20 exons, with their intron-exon boundaries, of the bovine Flt-1 gene, using a strategy combining PCR amplification and single-strand conformational polymorphism analysis (PCR-SSCP), followed by nucleotide sequence analysis, in 675 cattle. We then looked for associations between polymorphisms and growth traits. Twelve novel SNPs (ss#184956516, ss#184956517, ss#184956518, ss#184956519, ss#251343993, ss#251343994, ss#251343995, ss#251343996, ss#251343997, ss#251343998, ss#251343999, and ss#251344000) were detected in the bovine Flt-1 gene in all three breeds. We observed no significant associations between these polymorphisms and birth weight, body weight and average daily gain during different growth periods (6, 12, 18, and 24 months old) (P > 0.05), or in body height, body length, heart girth, or height at the hip in Nanyang cattle breeds.  相似文献   

3.
黄颡鱼MSTN基因多态性及其与生长性状的相关性分析   总被引:2,自引:0,他引:2  
Zhu YY  Liang HW  Li Z  Luo XZ  Li L  Zhang ZW  Zou GW 《遗传》2012,34(1):72-78
肌肉生长抑制素基因(Myostatin,MSTN)属于转化生长因子β家族,其主要功能是负向调控肌肉的生长发育。采用PCR-SSCP技术对黄颡鱼MSTN基因进行单核苷酸多态性检测和分型,并与其生长性状进行关联分析。结果表明,在第一内含子部分检测到1个缺失位点和2个突变位点(T1003del、G1022A和T1063G),基因型分别为:AA、AB、CC、CD和DD;在第三外显子部分检测到1个突变位点(T132C),基因型分别为:EE和EF。关联性分析表明,AA基因型个体的全长、体长、体高、体厚、头长和体重显著大于CD和DD基因型(P<0.05),AA基因型雌性个体的全长、体长、体高、体厚、头长、尾柄高、尾柄厚和体重也显著大于DD基因型(P<0.05)。由此推断,AA基因型是影响雌性黄颡鱼生长性状的有利基因型,DD基因型是影响雌性黄颡鱼生长性状的不利基因型,可以尝试利用这两个位点对雌性黄颡鱼进行标记辅助选育。  相似文献   

4.
The insulin-induced gene 1 (Insig-1) is a regulator of lipid metabolism and plays an important role in the sterol-mediated regulation of SREBP, SCAP and HMG-CoA reductase. We used PCR-RFLP and DNA sequencing to detect polymorphisms of the Insig-1 gene in 215 individuals of the Qinchuan cattle breed. Four SNPs [4366(A>G), 4534(T>C), 5001(T>C), and 5235(G>A)] were indentified. The association of the genetic viariation with growth and carcass traits (body length, withers height, hip width, slaughter weight, and carcass weight) was analyzed. The individuals with better performance had the GG genotype at locus A4366G, and CC genotypes at locus T4534C and locus T5001C. These could be used for beef cattle breeding improvement in China. Additionally, linkage disequilibrium analysis reflected that all mutations were in low linkage disequilibrium with each other. We concluded that polymorphisms in the Insig-1 gene are associated with growth and carcass traits and could be used for marker-assisted selection and management in beef cattle breeding programs.  相似文献   

5.
运用PCR-SSCP技术研究100尾牙鲆(Paralichthys olivaceus)MyoD基因的单核苷酸多态性(Single nucleotide polymorphisms, SNPs), 并将筛选到的突变位点与牙鲆生长性状进行相关性分析。结果表明, 在外显子1和内含子1上存在3个SNPs, 在外显子1 (MyoD2)基因座发现3种基因型AA、AB和BB, G863A突变, 属于同义突变。在内含子MyoD4基因座检测到DD、FF、CD、CE、DE和DF型个体。利用最小二乘法研究MyoD基因多态性位点对牙鲆生长性状的影响。结果表明, 外显子1的SNPs对生长性状无显著影响(P0.05)。内含子1的SNPs对牙鲆的生长性状影响均显著(P0.05)。研究结果为SNPs位点与牙鲆生长性能关联分析奠定了基础。    相似文献   

6.
山羊MyoD基因家族多态性及与体尺性状的相关性   总被引:2,自引:0,他引:2  
张海军  陈宏  房兴堂  张润锋  鲍斌  高雪原  邵汝英 《遗传》2007,29(9):1077-1082
用PCR-SSCP技术研究了波尔山羊和徐淮山羊2个群体共147个个体MyoD基因家族中3个基因座位的单核苷酸多态性(single nucleotide polymorphism, SNP)。结果表明, 在徐淮白山羊群体中, myf-5基因座发现有3种基因型AA、AB和BB, 波尔山羊均为AA型。在myf-6基因座和myoD 5′侧翼区基因座, 两个山羊群体均检测到了AA和AB型个体。对山羊myf-5、myf-6基因座, myoD 5′侧翼区基因座不同基因型与两品种山羊体尺性状相关分析表明, myf-5基因座对管围和管围指数的效应差异显著(P<0.05)。myf-6基因座对徐淮白山羊体尺性状的效应均不显著(P>0.05), 而对波尔山羊的体高和管围指数效应差异显著(P<0.05)。两个山羊品种myoD 5′侧翼区不同基因型个体的体尺性状差异均不显著。  相似文献   

7.
Leptin基因的PCR-SSCP与牛体重、体尺指标的相关性   总被引:5,自引:0,他引:5  
利用PCR—SSCP技术研究了南阳牛、秦川牛、郏县红牛、西镇牛、鲁西牛和荷斯坦奶牛6个牛品种539个个体leptin基因的遗传多态性。结果表明,PCR扩增产物大小为330bp,PCR—SSCP分析表现出多态。南阳牛、秦川牛、郏县红牛、西镇牛、鲁西牛和荷斯坦奶牛的A等位基因频率分别为0.558,0.492,0.571,0.658,0.591,0.615;B等位基因频率分别为0.442,0.508,0.429,0.342,0.409,0.385。不同基因型与体重、体尺等生长性状指标相关性分析的结果表明:南阳牛群体内除12月龄的体高和日增重、18月龄的坐骨端宽和日增重外,BB型个体的六月龄、十二月龄、十八月龄、二十四月龄体斜长、胸围、体重、坐骨端宽、体高和日增重均显著的大于AB和AA型个体(P〈0.05);秦川牛群体内BB基因型个体十字部高上显著高于群体AA、AB型个体(P〈0.05),即BB〉AA、AB,可作为秦川牛体尺指标(十字部高)候选基因之一,但在体重、胸围、体长指标上均无显著差异(P〉0.05),所以不宜作为体重、胸围、体长指标候选基因;郏县红牛群体内AB与BB基因型个体在十字部高和坐骨端宽上显著高于群体AA型个体(P〈0.05),而群体内不同基因型在体重和体尺指标(体高、体斜长、胸围)上无显著差异(P〉0.05)。序列分析表明,leptin基因多态是第66位发生G→T、第67位发生A→C及299位发生新的单核苷酸突变C→T所造成。  相似文献   

8.
PCR–RFLP was applied to analyse polymorphisms within the MRF4 and heart fatty acid-binding protein (H-FABP) gene for correlation studies with growth traits in three-month-old Qinchuan (QQ), Qinchuan × Limousin (LQ) and Qinchuan × Red Angus (AQ) cattle. The results showed that 874 bp PCR products of MRF4 digested with XbaI and 2,075 bp PCR products of H-FABP digested with HaeIII were polymorphic in the three populations. Moreover, the frequencies of allele A at MRF4 locus and allele B at H-FABP locus in the QQ, AQ, and LQ populations were 0.8358/0.8888/0.8273 and 0.8358/0.7500/0.8195 respectively. Allele A at MRF4 locus and allele B at H-FABP locus were dominant in the three populations. No statistically significant differences in growth traits were observed among the genotypes of the all three populations at H-FABP locus. However, the association of MRF4 polymorphism with growth traits was then determined in all three populations. The body weight, withers height, heart girth and height at hip cross of individuals with genotype AA were higher than those with genotype AB or BB (P < 0.05). Therefore, we suggest that the MRF4 gene may function in the control or expression of growth traits, particularly body weight, withers height, heart girth and height at hip cross.  相似文献   

9.
Liver X receptor α (LXRα) has emerged as an important regulator of lipid and energy metabolism. In this study, to better understand the effects of LXRα gene on growth traits in cattle, the mRNA tissue expression patterns and the polymorphisms of some exons of LXRα were revealed. The expression profile of the bovine LXRα gene was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in 11 different Jiaxian cattle tissues and was found mainly expressed in spleen, liver, fat tissue, kidney, muscle, and lung. Meanwhile, it showed that four single nucleotide polymorphisms (SNPs), named g.1028 T>C, g.1514 T>C, g.2929G>A, and g.3493 T>C, were detected and 12 different haplotypes were constructed. Haplotype with CCGT was dominant with frequency of 40.8 %. There was a strong link between g.1028 T>C and g.1514 T>C (r 2?=?0.374). Association analysis of SNPs with growth- and body-related traits was carried out in 445 Chinese native cattle. The results displayed that the heterozygous genotypes of g.1028 T>C and g.1514 T>C showed a molecular heterosis on four performance traits related to body size: height at withers, body length, hipbone width, and hip width (P?<?0.05). The multiple effects of four sites showed that the height at withers, body length, hipbone width, and hip width of individuals of TC-TC-GG-TT combined genotypes were significantly higher than other genotypes (P?<?0.05). The effects of the four loci genotype combination on conformation traits were consistent with the effects of g.1028 T>C and g.1514 T>C loci. The SNPs of g.1028 T>C and g.1514 T>C of the bovine LXRα gene could be potential genetic markers for growth traits in cattle. These results suggest that LXRα gene is expressed in many tissues and may provide primary molecular information for further studies on body size traits in Chinese indigenous cattle.  相似文献   

10.
为了研究尼罗罗非鱼(Oreochromis niloticus)生长激素促分泌素基因(ghrelin)的多态性及其与生长的相关性, 研究以两个尼罗罗非鱼群体(快长群体和基础群体)的DNA样本各40份为模板, 通过PCR扩增和测序获得ghrelin基因序列。通过Dnasp v5和MEGA 5.0分析序列多态性、筛选有效SNP 位点; 采用Snapshot法对两个群体子代ghrelin基因中SNP位点进行基因分型, 然后分析SNP位点基因型与生长性状的相关性。结果表明, 快长群体ghrelin基因中的单核苷酸变异位点数(S)比基础群体要少, 而核苷酸多态性(Pi)和平均核苷酸差异数(K)要略高于基础群体。共筛得3个有效SNP 位点(S1、S2和S3), 均分布于第1个内含子中。遗传结构分析表明, 3个SNP 位点在两个群体的子代中均为低度多态性位点(PIC0.25), 但处于Hardy-Weinberg平衡(P0.05);快长群体子代中3个SNP 位点的观测杂合度、期望杂合度和多态信息含量等遗传多样性参数均小于基础群体子代的相应值, 3个SNP 位点的遗传多样性参数、基因型和基因频率在同一群体中高度一致, SNP 位点之间完全连锁。两个群体子代中3个SNP 位点处的优势基因型相同, 但快长群体子代中优势基因型频率要明显大于基础群体子代中相应基因型频率。对两个群体子代的生长性状与SNP基因型进行关联性分析的结果表明,尼罗罗非鱼个体的多项生长指标(体重、体长、体高、头长和尾柄高等)在不同基因型中存在显著差异(S1:GG AG, S2:TT AT, S3:AA AT)(P0.05)。D1双倍型(S1:GG, S2:TT, S3:AA)所对应的尼罗罗非鱼个体的多项生长指标(体重、体长、体高、头长和尾柄高等)显著高于D2双倍型(S1:AG, S2:AT, S3:AT)。以上结果表明, 尼罗罗非鱼ghrelin基因3个SNP 位点完全连锁, D1双倍型与快长性状密切相关, 可作为尼罗罗非鱼分子标记辅助育种的候选标记。  相似文献   

11.
Body measurement traits are known to play numerous important roles in the assessment of productivity and economic value. They are influenced by several factors, among which genetic factors are predominant. The gene GDF?? is involved in skeletal morphogenesis and is associated with body measurement traits. It may be an important candidate gene for marker-assisted selection. We used the PCR-SSCP technology to examine a possible association of the single nucleotide polymorphism (SNP) (G142A) of the bovine GDF?? gene with body measurement traits in 417 animals belonging to six different Chinese cattle populations: Xue long (Xl), Luxi (Lx), Qinchuan (Qc), Jiaxian red (Jx), Xianang (Xn), and Nanyang (Ny). In the Jx population, least squares analysis revealed significant effects on hip width, chest depth and chest circumference. The animals with the GG genotype had higher mean values than those with the GA genotype for all three traits. We conclude that the SNP of the GDF?? gene could be a very useful genetic marker for body traits in Jx cattle reproduction and breeding.  相似文献   

12.
Body measurement and meat quality traits which play important roles in the assessment of productivity and economy in cattle were influenced by genes and environmental factors. Latest studies showed that LYR motif containing 1 (LYRM1) may be involved in influencing fatness deposition in animals. The objective of this study was to detect bovine LYRM1 gene polymorphism and analyze its association with body measurement and meat quality traits of cattle. Blood samples were taken from a total of 404 Qinchuan cattle aged from 18–24 months. Created restriction site-polymerase chain reaction-restriction fragment length polymorphism (CRS-PCR–RFLP) and DNA sequencing were used to find out LYRM1 single polymorphism nucleotide (SNPs). Sequence analysis of LYRM1 gene revealed two SNPs (g.165 C > A, g.193 A > G) in 3′ untranslated region (3′UTR) of exon 3. And g.165 C > A showed two genotypes namely AC and CC while g.193 A > G showed three genotypes: AA, AG and GG. Analysis results showed that there were significant associations between polymorphism of these two and body measurement and meat quality traits in Qinchuan cattle population. Based on the results obtained from this study, it is inferred that LYRM1 gene may have potential effects on body measurement and meat quality traits in Qinchuan cattle population and could be used for marker-assisted selection.  相似文献   

13.
The genotypes of growth hormone gene polymorphisms (GH-DdeI, GH-MspI, GH-HaeII, GH-ApaI, GH-CfoI) were determined in 78 pigs [Czech Large White sires (CLWsire line) x Polish Large White (PLW) sows, Polish Large White sires x Polish Large White sows], by the PCR-RFLP method. Preliminary studies found only GH DdeI polymorphism to be associated with performance traits. The associations of this polymorphism with growth and carcass traits were investigated. The linear model included the effects of candidate genes, genetic groups, sex and linear covariables of age at slaughter and body weight at weaning. The DdeI polymorphism of the GH gene showed associations with carcass length (P 相似文献   

14.
Growth hormone-releasing hormone receptor (GHRHR) plays a critical role in growth hormone (GH) synthesis, release and regulation of pituitary somatotroph expansion in vertebrates. The objective of this study was to investigate variations in goat GHRHR gene and their associations with growth traits in 668 dairy goats. The results showed four novel single nucleotide polymorphisms (SNPs): NC_007302:g.5203C>T, 7307C>G, 9583G>A and 9668A>C. In detail, the novel SNP C>T in the 5203rd nucleotide identified a missense mutation: CCC (Pro)>TCC (Phe) at position 116aa of the goat GHRHR (423aa). Besides, 9583G>A and 9668A>C polymorphism were in complete linkage disequilibrium. The genetic diversity analysis revealed that the Guanzhong dairy goat possessed intermediate genetic diversity in P3 and P7 loci, and the Xinong Sannen dairy goat belonged to poor genetic diversity in P4 locus. Significant associations between the genotypes of P3 locus and body length, body height and chest circumference was observed in Guanzhong goat (P < 0.05). However, in Xinong saanen population, significant statistical difference was only found in body height and body length (P < 0.05). In P4 and P7 loci, no significant associations were detected between any variant sites and body length, body height and chest circumference, as well as for the milk traits (P > 0.05). These results strongly suggested that the goat GHRHR gene is a candidate gene that influences growth traits in dairy goat.  相似文献   

15.
阿黑皮素原(Pro-opiomelanocortin, POMC)在动物采食和能量平衡调控中发挥重要作用, 文章对绵羊POMC基因外显子3进行扩增和测序, 筛选多态性位点, 并分析多态位点与湖羊和东弗里生×湖羊杂种羊生长性状的相关性。测序后发现湖羊POMC基因外显子3有2个单碱基突变(g.273 T/C和g.456 G/A), 根据273位点处发生的T/C突变, 建立PCR-RFLP分析方法, 并对162只湖羊和130只东湖杂种羊进行检测分析。结果发现, 在湖羊群体中检测到TT(0.469)、TC(0.438)和CC(0.093)3种基因型, 而在东湖杂种羊群体中仅检测到TT(0.754)和TC(0.246)两种基因型。POMC基因外显子3的273位点多态性与生长性状的相关性研究结果显示:湖羊群体中CC基因型个体的2月龄断奶重、4月龄尻高及TC基因型个体4月龄体长和管围均显著高于TT型个体(P<0.05); CC基因型个体的4月龄重、6月龄重极显著高于TT和TC基因型个体(P<0.01); CC基因型个体的4月龄体高和体长极显著高于TT型个体(P<0.01), 且显著高于TC基因型个体(P<0.05)。此外, CC型个体的管围极显著高于TT基因型个体(P<0.01)。东湖杂种羊群体中TC基因型个体的2月龄断奶重、4月龄重及4月龄体高、体长、胸深和管围都显著高于TT型个体(P<0.05), TC型个体的6月龄重极显著高于TT型个体(P<0.01)。研究结果表明, POMC基因外显子3与绵羊生长性状相关, C等位基因对体重及体尺性状的增加更有利。该结果为进一步探讨POMC基因作为绵羊生长性状的辅助选育标记奠定了基础。  相似文献   

16.
Milk composition and body measurement traits, influenced by genes and environmental factors, play important roles in value assessments of efficiency and productivity in dairy goats. Lactoferrin (LF), involved in the efficient expression of protein in milk, is also an anabolic factor in skeletal tissue and a potent osteoblast survival factor. Therefore, it is an important candidate gene for milk composition and body measurement trait selection in marker-assisted selection. We employed PCR-SSCP and DNA sequencing to screen the genetic variations of the LF gene in 549 Chinese dairy goats. A novel single-nucleotide polymorphism (SNP) (G198A in exon II) of the LF gene was detected. The frequencies of the AA genotype were 0.0285 and 0.0261 in GZ and SN populations, respectively. Both populations were found to have low levels of polymorphism and were in Hardy-Weinberg disequilibrium (P < 0.05). We found significant (P < 0.05) associations of the SNP marker with milk protein and acidity in the total population; animals with the AA genotype had higher mean values for milk protein than those with the GA genotype. Animals with genotype AA had higher mean values for withers height than those with genotype GG (P < 0.05). We concluded that this SNP of the LF gene has potential as a genetic marker for milk composition and body traits in dairy goat breeding.  相似文献   

17.
NOTCH1 is one of the four mammalian Notch receptors, which is involved in the Notch signaling pathway. Specifically, NOTCH1 promotes the proliferation of myogenic precursor cells, and the NICD domain of NOTCH1 can impair regeneration of skeletal muscles. However, similar research on the bovine NOTCH1 gene is lacking. In this study, we detected the polymorphisms of the bovine NOTCH1 gene in a total of 448 individuals from Chinese Qinchuan cattle with DNA pooling, forced PCR-RFLP, and DNA sequencing methods. Five novel SNPs were identified within the NICD domain, and eight haplotypes comprising combinations of these five SNPs were studied as well. The association analysis of SNPs’ effects with growth traits revealed that g.A48250G was significantly associated with body height, body weight, and height at hip cross, and that g.A49239C only showed significant associations with body height. This suggests that the NOTCH1 gene is a strong candidate gene that could be utilized as a promising marker in beef cattle breeding programs.  相似文献   

18.
Hsu YH  Niu T  Terwedow HA  Xu X  Feng Y  Li Z  Brain JD  Rosen CJ  Laird N  Xu X 《Human genetics》2006,118(5):568-577
In order to assess the contribution of polymorphisms in the RANKL (TNFSF11), RANK (TNFRSF11A) and OPG (TNFRSF11B) genes to variations in bone mineral density (BMD), a population-based cohort with 1,120 extreme low hip BMD cases or extreme high hip BMD controls was genotyped on five SNPs. We further explored the associations between these genetic variations and forearm BMDs by genotyping 266 offspring and 309 available parents from 160 nuclear families. A family-based association test was used. Significantly positive associations were found for A163G polymorphisms in the promoter regions of the OPG gene, a missense substitution in exon 7 (Ala192Val) of the RANK gene and rs9594782 SNP in the 5′ UTR of the RANKL gene with BMD in men only. Men with TC/CC genotypes of the rs9594782 SNP had a 2.1 times higher risk of extremely low hip BMD (P=0.004), and lower whole body BMD (P<0.001). Subjects with the TC genotype of the Ala192Val polymorphism had a 40% reduced risk of having extremely low hip BMD (P<0.01), and higher whole body BMD (P<0.01). Subjects with the GG genotype of the A163G polymorphism had a 70% reduced risk of having extremely low hip BMD (P<0.05), and higher whole body BMD (P<0.01). Significant gene–gene interactions were also observed among the OPG, RANK and RANKL genes. Our findings suggest that genetic variation in genes involved in the RANKL/RANK/OPG bone remodeling pathway are strongly associated with BMD at different skeletal sites in adult men, but not in women. Electronic Supplementary Material Supplementary material is available for this article at  相似文献   

19.
Growth traits are complex quantitative traits controlled by numerous candidate genes, and they can be well-evaluated using body measurement traits. As the members of the nicotinamide adenine dinucleotide-dependent family of histone deacetylases, class I sirtuin genes (including SIRT1, SIRT2 and SIRT3) play crucial roles in regulating lipid metabolism, cellular growth and metabolism, suggesting that they are potential candidate genes affecting body measurement traits in animals. Hence, the objective of this work aimed to detect novel insertions/deletions (indels) of SIRT1, SIRT2 and SIRT3 genes in 955 cattle belonging to five breeds, as well as to evaluate their effects on body measurement traits. Herein, the novel 12-bp indel of SIRT1 gene, the 7-bp indel of SIRT2 gene and the 26-bp indel of SIRT3 gene were firstly reported, respectively. The association analysis indicated that the indels within SIRT1 and SIRT2 genes were significantly associated with body measurement traits such as body weight, chest circumference, height at hip cross, hip width, body height, etc. (P?<?0.05 or P?<?0.01). Therefore, based on these findings, the two novel indel variants within bovine SIRT1 and SIRT2 genes could be considered as potential molecular markers for growth traits in cattle selection practices and breeding.  相似文献   

20.
A total of 129 Limousin calves were used to investigate how leptin gene polymorphisms affect growth traits, such as body weight, average daily gain, wither height, sacrum height and chest girth in beef cattle. Two single nucleotide polymorphisms (SNPs) were genotyped, including the Sau3AI polymorphism in intron 2 and the A59V polymorphism in exon 3. The genotype and allele frequencies for each SNP and the haplotype frequencies for both SNPs were estimated in the studied herd. Statistical analysis revealed that the A59V polymorphism significantly affected the body weight at 210 days of age (P ≤ 0.01) and the average daily gain between 3 and 210 days of age (P ≤ 0.05) with T as a desirable allele. No associations were observed between the Sau3AI polymorphism and the growth traits mentioned above. However, the average daily gain between 3 and 210 days of age was significantly higher in the CT/CT haplotype animals compared with the CC/CC and CC/CT individuals. These results indicated that selection for the A59V TT animals might contribute to an improved body weight in Limousin cattle. The article is published in the original.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号