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医学遗传学的研究方法范文1
【关键词】生物多样性;细胞学标记;DNA分子标记
【Abstract】According to the Chinese Biodiversity Conservation Strategy and Action Planning (2010-2030), the continuous loss of genetic resources becomes one of three thorny issues threatening biodiversity conservation in China, which highlights the significance of genetic diversity monitoring plan in the future. After both Standard for the Assessment of Regional Biodiversity (HJ623-2011) and Regulation for the Collection of Genetic Resources (HJ628-2011) come into force, identification and collection of genetic resources becomes essential in biodiversity assessment projects. This review summarizes the front application of both cytological marker and DNA molecular marker techniques to distinguish plant varieties, and consequently the feasibility of large-scale application of DNA marker technique on future biodiversity monitoring and assessment projects is discussed.
【Key words】Biodiversity; Cytological marker; DNA molecular marker
0 Introduction
As one of three layers of biodiversity, which includes ecosystem, species and genetics, genetic diversity is the diversity of genetic factors that determine the traits of organisms and their combinations, so that becomes the basis of species and ecosystem diversity [1]. It is inevitable for a species of poor genetic diversity to move towards the extinction in natural selection process [2].
After a series of environmental policy has been worked out by centre government of China, such as Chinese Biodiversity Conservation Strategy and Action Planning (2010-2030), Standard for the Assessment of Regional Biodiversity (HJ623-2011) and Regulation for the Collection of Genetic Resources (HJ628-2011), it is essential for environmental engineers to include genetic diversity in biodiversity monitoring and assessment projects, and collection and identification of genetic resources in the nature definitely becomes the first step of this work. In present, identification of plant varieties mainly relies on the biological traits of plants[3], which are susceptible to environmental conditions and time-consuming when those biological traits are artificially cultivated and observed in experiment land [4]. However, the development of DNA marker technology provides a quicker and more accurate solution for environmental engineers to distinguish different sub-populations of a plant species in the nature, particularly when identification of economic traits is not essential in biodiversity assessment work. This review summarizes both cytological marker and DNA molecular marker for the differentiation of plant cultivars in recent years.
1 Cytological Marker
Due to its high stability and reproducibility, karyotype becomes one of the unique chromosome information to distinguish different species, populations of the same species and to identify the hybrids. Karyotype parameters, mainly including the absolute length and relative length of chromosome, arm ratio, centromere index, chromosome ploidy and asymmetry index, are frequently analyzed by botanists to study the variation in chromosome number and structure between species, the origin of species and the genetic evolution[4].
1.1 Traditional squash technique
Zhang etc [5] analyzed karyotype of three Fritillari thunbergii cultivars based on traditional squash technique. The karyotype formula of F. thunbergii (Xiaye, Kuanye, Duozi) varied among three varieties, indicating the feasibility of genetic identification of Fritillari thunbergii cultivars. The karyotype of all the varieties were classified into 3B type, and heterozygosity of homologous chromosome were found in both F. thunbergii(Xiaye) and F. thunbergii(Duozi).
The karyotype of three diploid oat species was studied by Liu etc [6] with application of traditional squash technique. Both karyotype formula and asymmetry index of Avena strigosa, Avena hispanica, Avena brevis were calculated for comparison, revealing more advanced evolution in karyotype for A.strigosa, followed by A.a brevis and A.hispanica. Three diploid oat species were effectively distinguished by a combination of both karyotype formula and asymmetry index.
The traditional slice-making method with micrograph technology was adopted by Dai etc[7] to study the cytology basis for cultivar identification of Secale cereale subsp.segetale. Three populations of Secale cereale subsp.segetale(89R4, 89R14, 89R60) and one variety Secale cereale L.(H36) were selected to conduct karyotype analysis. Karyorype formulae, asymmetry index and asymmetrical karyotype coefficient were provided and compared among these varieties in this research, which showed rich diversity in chromosome morphology.
Traditional squashing method was adopted by Liu etc[8] to analyze the karyotype of 7 R.hybrida cultivars and 5 R.rugosa cultivars. According to the results, all the R.hybrida cultivars were tetraloid (2n=4x=28), except that R.hybrida ‘Elmshorn’ was triploid (2n=3x=21), while all the 5 R.rugosa cultivars were diploid (2n=2x=14). A number of karyotype parameters, including karyotype formula, chromosome relative length, ratio of the longest chromosome to the shortest one in length, arm ratio, asymmetry index and centromere index, were interpreted as biomarkers for identification of varieties and correspondingly the genetic distance was analyzed, revealing that distinct differences in both karyotype and ploidy levels existed between R.hybrida and R.rugosa cultivars and R.rugosa cultivars appeared to be more advanced in karyotype evolution.
21 cultivars’ karyotype of ornamental Ginkgo was studied by Gao etc [9] with smear method. The karyotype of all cultivars was reported to be identical, and the relative length of chromosome varied from 4.31% to 15.34% for the female cultivars, as well as 4.37% to 17.12% for the male. For approximately 83.33% of all the varieties in this research, the arm ratio of chromosome was above 2:1, which belonged to asymmetric 3B type. Cluster analysis was conducted on the basis of karyotype calculation, showing that the mean arm ratio or length ratio of ornamental Ginkgo cultivars was significantly different from original Ginkgo Biloba, and consequently the originality, evolution and classification of these cultivars were discussed.
In total 6 varieties of Hippophae Rhamnoides L. were selected by Li etc[10] to analyze karyotype characteristics of chromosomes, including 4 strains from Russia and 2 strains from China. Karyotype formula, asymmetry index, centromere index and ratio of the longest chromosome to the shortest one in length were compared and contrasted between these varieties, providing the basis for the identification and evolutionary analysis of Hippophae Rhamnoides L. varieties. According to the asymmetry index, six of these cultivars were classified into middle centromere or sub-middle centromere, with karyotype types as 2A or 2B.
40 typical and stable varieties of Chinese large-flowered chrysanthemum were chosen to carry out cytological karyotype analysis for investigation of genetic differences[11]. 1-4 satellite chromosome(s) were reported in approximately 35% of the cultivars, with increasing possibility of satellite chromosome when chromosome number increased. The karyotypes of these varieties were summarized as 2A, 2B and 2C, and types 2A and 2C were more likely to appear in the cultivars with higher ploidy. The interrelationship of karyotype parameters including long-/short-arm ratio, asymmetry coefficient of karyotypes, karyotype asymmetry index and relative length of chromosomes were discussed in this research, indicating great values of karyotype parameters for cultivar identification, classification and genetic evolution analysis for chrysanthemums species. The relationship of karyotype parameters towards phenotypic characters was also examined, revealing that the variation of long-/short-arm ratio and asymmetry coefficient of karyotypes led to highest relevance to most phenotypic characters.
Wild Rosa species, which are broadly found in the Xinjiang Uygur autonomous region of China, possess many important unknown economic traits. Yu etc[12] collected karyological data from 13 samples of seven wild Rosa taxa (R. berberifolia, two botanical varieties of R. spinosissima, R. platyacantha, R. beggeriana, R. acicularis, and R. laxa), which were easily distinguished by karyotype parameters of chromosome ploidy, asymmetry index, centromere index, and distribution of relative lengths. The karyological data provided comprehensive cytogenetic resource to analyze the taxonomy, evolution and speciation in the genus Rosa as well as to identify suitable cultivars for breeding programs.
1.2 Fluorescence in situ hybridization (FISH) technique
Fluorescence binding technology with fluorescent dyes, which are capable of revealing AT or GC DNA sequences on chromosomes, can distinguish different types of heterochromatin on the chromosomes. For example, DAPI (4',6-diamino-2-pheny- lindole dihydrochloride) results in the appearance of AT rich region on chromosomes, whereas CMA (Chromomycin A3) can reveal the GC rich region [13]. Fluorescence in situ hybridization (FISH) technique provides the accurate mapping information of rDNA probes on the chromosome, which becomes the more effective markers to distinguish chromosomes of plants [14]. She etc [15] analyzed the mitotic metaphase chromosomes of Arachis hypogaea L. species by using a combination of DAPI+ banding technology and double fluorescence in situ hybridization (FISH) technique with both 5S and 45S rDNA probes. On the basis of the chromosome measurements, DAPI+ bands and rDNA FISH signals, the chromosomes of Arachis hypogaea L. were accurately paired and arranged, leading to a molecular cytogenetic karyotype in detail.
However, DAPI banding patterns varies between different plant species. Xu etc[16] compared DAPI fluorescent banding patterns among different plant species, indicating that fluorescent bands were obviously observed in maize and peanut species, followed by sesame and loofah whose DAPI bands were relatively weaker. However, no clear DAPI bands could be identified in soybean chromosomes.
2 DNA Molecular Marker
DNA molecular marker technologies for plant variety identification mainly include RFLP, RAPD,ISSR,AFLP,SNP and SSR. However, the ranking of these molecular marker techniques based on comprehensive effectiveness is AFLP>SSR>RAPD>RFLP, which has been internationally recognized in the 92th ASHS conference[17]. This review summarizes the recent development of both SSR and AFLP marker technology for variety differentiation.
2.1 SSR marker
EST-SSR molecular marker technique was conducted by Zhao etc [18] to identify 12 Chinese cabbage cultivars. Based on expressed sequence tags(ESTs)of Chinese cabbage in GenBank, 30 pairs of screened SSR primers were designed and synthesized, resulting in 21 pairs of EST-SSR primers which were effectively amplified, but only 10 pairs of EST-SSR primers were highly polymorphic. According to the identification results and the mapping difference, 10 pairs of primers with high polymorphism were designed as 2 sets of multiplex EST-SSR markers to distinguish these 12 Chinese cabbage varieties, with satisfactory polymorphic rate of 88.9% and 97.0% respectively, as well as high polymorphism information content of 0.910%.
Lai etc[19] selected 26 inbred lines and 54 test varieties for the examination of distinctness, uniformity and stability (DUS) of these varieties by adopting SSR markers. 49 pairs of SSR primers were screened from 952 pairs in total, based on the criteria of richness of polymorphism information content (PIC), the clearness of PCR bands and convenience of different allele identification. 49 pairs of SSR primers led to 57 loci with 311 alleles identified in total. The average number of alleles per locus was 5.5, ranging from 2 to 13, with a mean PIC of 0.53. Cluster analysis showed that all test varieties were clearly distinguished by 49 markers when the genetic similarity coefficient was set as 0.93.
In order to provide robust reference for the identification of barley varieties and avoid counterfeit and inferior varieties, Wang etc [20] selected 29 barley standard varieties and genetic diversity was analyzed by DUS testing. 28 pairs of highly polymorphic SSR primers were chosen, leading to 125 alleles measured in total. Each pair of polymorphic primers detected an average of 4.46 alleles, with polymorphism information content (PIC) varying from 0.81 to 0.25 and an average PIC of 0.62 among 28 pairs.
The specificity and stability of 123 representative rice varieties were analyzed by Tian ect[21] based on SSR fingerprinting profiles, and the value of SSR core markers chosen in this study was examined. 24 pairs of primers detected 138 alleles in total, with 12 loci detected in single cultivar and 21 loci successfully distinguishing japonica and indica rice varieties. On the basis of genetic similarity coefficient set as 0.96 for the classification, all tested varieties showed their unique specificity by cluster analysis, which indicated that 24 pairs of SSR core primers was able to effectively identify 123 varieties of rice.
2.2 AFLP marker
Six pairs of AFLP primers with rich polymorphism were screened by Li etc[22] to conduct fingerprinting analysis on two Chinese cabbage samples (label 587 and 586) as well as a standard sample. Euclidean distances coefficient of each sample was estimated, indicating that distinct difference was found between the sample 587 and standard sample, with the polymorphism band rate of 31.7%. Consequently variety 587 was identified as a different variety from the standard sample. In comparison, variety 586 showed consistent PCR bands with the standard sample, which was consequently identified as the same variety as the standard sample. This research demonstrated that AFLP was capable of providing reliable differentiation technology for plant cultivars.
In total 14 samples of eight varieties and six wild populations of Toxicodendron vernicifluum from Shaanxi were chosen by Wei etc [23] for the development of variety identification technique. Both morphological and AFLP molecular markers were examined with 26 morphological character indexes and 8 AFLP primers (EcoRⅠ+3/MseⅠ+3). Multivariate statistic analysis was conducted on morphological markers, resulting in 3 principle component index (PCI). The fist PCI included the ratio of petal and anther, length to width of the fifth lobular, the length and diameter of filament; the second PCI covered the length of compound leaf and petiole of compound leaf, the numbers of leaflet, the fifth lobular, and the top lobular; and the third PCI were the top lobular and the vertex angle of the fifth lobular, which respectively contributed to 30.383%, 19.321% and 13.777% of variance in morphology of 14 varieties. Further more, molecular markers of 8 AFLP primers (EcoRⅠ+3/MseⅠ+3) also completely distinguish 14 cultivars, in consistence with morphological markers.
Wen etc[24] tried to distinguish 26 jujube cultivars and 1 sour jujube by adopting fluorescent-labeled AFLP markers. 8 AFLP primer pairs were chosen, leading to 886 AFLP markers identified in total. Among these AFLP markers, 112 markers were identified as unique bands for specific varieties, whereas 60 markers were deletion bands for specific varieties, leading to effective identification of jujube cultivars.
Song etc[25] chosen 90 cultivars of Chinese cabbages from 7 different production areas, and developed fingerprinting technique based on AFLP markers for the identification. In total 20 pairs of AFLP primers were designed to examine the genetic polymorphism of these cultivars, and AFLP primers varied broadly in terms of differentiation capacity of Chinese cabbage varieties. The number of polymorphic bands that were detected by AFLP primers differed from 9 to 32. A combination of primers (E-ACA/M-CTG) resulted in 71 amplified bands, including 32 polymorphic bands, which effectively distinguished all of the 90 varieties. In comparison, the genetic polymorphism between individuals of the same variety was also examined by AFLP marker technique. Two hybrid cultivars (Beijingxin 2 and Jingxiawang) of Chinese cabbage were selected and 10 individuals were chosen from each cultivar. The AFLP bands showed consistence between individuals of the same variety, except that one of Beijingxin 2 differed from the others.
2.3 Capillary electrophoresis with fluorescence detection
Compared with polyacrylamide gel electrophoresis and silver staining technique, capillary electrophoresis with fluorescence detection method is more automated and programmed. The system software of capillary electrophoresis with fluorescence detection is able to calibrate the differences between capillary electrophoresis, and reduce the artificial and systematic errors, which consequently improves the stability and repeatability of variety identification tests [26]. Feng etc[3] screened 58 SSR primers to identify 14 Poplar varieties by application of capillary electrophoresis with fluorescence detection, which included 4 varieties of Populus deltoids, 5 varieties of Populus nigra (including 3 transgenic varieties) and 4 hybrid varieties. The results showed that the 4 varieties of P. deltoids, 5 varieties of P. nigra, and 4 hybrid varieties were effectively identified by 4 primers, 5 primers, and 4 primers respectively, with significant difference observed at the SSR loci between P. deltoides and P. nigra. Different SSR genotypes were also identified between the transgenic and non-transgenic varieties.
3 Conclusion and Implication for Biodiversity Monitoring and Assessment
In comparison to the DNA molecular marker, cytological marker techniques result in less polymorphism for the sub-populations’ differentiation of a plant species, but obviously reduce the cost of this work, once biodiversity monitoring and assessment projects are implemented at large scale. Consequently, cytological marker would be more suitable as the main solution for environmental engineers to conduct genetic resource collection work, based on which DNA molecular marker would become a complementary solution. Capillary electrophoresis with fluorescence detection method certainly leads to higher accuracy and stability for identification tests. Nevertheless, the relatively cheaper facilities required by polyacrylamide gel electrophoresis and silver staining technique would be more acceptable in practice, which has been adopted by recent National Standards including Protocol of Purity Identification for Soybean Variety using-SSR Molecular Markers (NY/T 1788-2009), as well as Genuineness and Purity Verification of Potato Seed Tuber - SSR Molecular Marker (GB/T 28660-2012).
Collection and storage of sampling location information as well as photos of plant morphological characters are usually necessary for the genetic resource collection work as indicated by Regulation for the Collection of Genetic Resources (HJ628-2011), and GIS technology provides a supportive tool for the collection and storage of both location information and field sampling photos [27] in this process.
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医学遗传学的研究方法范文2
1、新型网络教育技术对医学遗传学教育改革的积极作用。
新型网络教育技术是指运用现代教育理论和新型网络教育技术,通过教育中教学过程和教育资源的设计、开发、利用来实现教学教育的改革与创新。新型网络教育技术主要通过一下几个方面发挥其积极作用。①培养拓展学生的研究精神与创新意识,增强学生主动性。学生通过新型网络教育技术,改变了以往教师作为教育中心、教学活动主题的传统模式,增强其主体地位和主体意识,为学生提供更为现实的思考环境。②为教学资源的存在形式提供了全新的载体。教学资源与教学成果作为信息的表现形式之一,尤其在先进信息爆炸时代,其巨大的数据体现亟须全新的载体,用以支持其产生、传播、运用,储存等。③拓展了资源共享平台,新型网络教育技术所依托的互联网背后是一个巨大的资源库,掌握最新的信息、资源是学习和研究的关键。网络所提供的是一个完全透明的资源平台,超越实践空间的限制,信息共享从封闭走向开放,世界各地的学习者通过网络共享资源,各取所需。
2、新型网络教育技术的具体表现。
网络教育技术的体现主要通过对过程和资源的运用和设计,因此在针对医学遗传学的教学中运用新型网络教育技术的侧重点主要有以下几个方面:①提高医学遗传学教师的新型网络教育技术技能。②提高医学遗传学专业学生的新媒体运用能力。③加强网络教育技术的外部硬件条件,改善教育环境。
二、案例讨论法在促进医学遗传学教学目的的实现中的作用和表现形式
1、案例讨论法在促进医学遗传学教学中的积极作用。
案例讨论法是指通过传授临床实践中的真实遗传病例及相关典型实验操作过程来启发学生对问题进行讨论并提出解决方案的教学方法。它在教学中的积极作用主要体现在以下几个方面:①主观方面提高学生学习兴趣,激发学习热情。案例分析法本身需要学生通过主动了解病例,在了解过程中基于自身知识结构的欠缺势必对病例本身产生疑问,疑问的解决方式有课堂讲授及课后查找、阅读、理解、讨论等;②客观上提高学生分析问题解决问题的能力。案例式教学不同于演绎法,更多的是启发学生通过具体案例来结合理论,这种反向式的学习方法,更利于学生记忆、迁移、运用,并且能够促进学生思考案例与理论之间的联系点,刺激学生形成自我解决问题的思维模式。这对培养实践性人才有着积极的促进作用;③增强互动性,提高课堂教学质量。案例分析法的学习过程通过两个方面体现互动性,首先是学生与学生的互动,这种互动性主要是通过相互争辩、讨论、交流得以体现。互动性还通过学生与老师的互动得以体现。老师通过关键点的引导,刺激学生思考,从而达到教学设计的目的。
2、案例讨论法在促进医学遗传学教学中的表现。
医学遗传学教学过程中基于其本省的学科特点,需要从几个方面侧重进行案例讨论式教学,这几个部分通过案例教学在一定程度是是否能够成功教授本们课程的关键。这几个部分分别是:①遗传病传播方式的案例分析,学生需要针对具体的病例自主的绘制系谱图并讨论图表内容,并通过讨论归纳传播规律,在讨论规律之后分析计算再发风险,并学会查询资料了解例如如何提前判断遗传病等相关知识,提高各方面相关知识;②医学遗传学的技术方法传授,对于新的研究技术和方法,直白的讲授方法本身就与实践操作有着天壤之别,但实践操作并不适用于所有的教学环境,因此,通过具体的病例进行讲授,便能够克服晦涩的理论概念,促进学生自主探索治疗该病例的技术方法,从而最终与所要讲授的医学遗传学方法“不期而遇”来实现教学目的。③遗传规律的讲授,对于遗传规律的讲授也是坚持感性认识到理性认识再到讨论分析,并对问题进行解释,最终理解所授知识。
三、全新教育模式的设想与构造
以上是对新型网络教育技术和案例讨论法这两种不同教育工具在医学遗传学教学终的作用以及表现的概括。本文的设想是结合两种工具,设计出医学遗传学教学的一个整体构造。下面拟从两个方面入手进行阐述:
1、资源分享平台设计及运用。
依托医学遗传学自身新型发展特性,建立静态与动态医学遗传学理论知识平台。网络平台设计需要专业软件工程设计,软件设计形式包括教育网站,网站内资源平台。①静态医学遗传学理论知识平台:其内容包含专业课理论知识核心展示及思考题、专业图表制作方法索引及练习平台、主要经典案例索引资源库;②动态医学遗传学理论知识平台:其内容主要为交流讨论组、网络模拟实验室、实验成果展示分享平台。
2、课堂平台设计及运用。
医学遗传学的研究方法范文3
关键词:遗传病主线;高职学校;医学遗传学;课程建设
医学遗传学是介于医学与遗传学之间的一门边缘性学科,也是高职护理专业教学的重点和难点课程,学生学习起来普遍感到难度偏高。为了提高高职医学遗传学课程的建设质量,近年来,湖南环境生物职业技术学院构建了以遗传病为主线的课程建设策略,从教学内容、教学方法、考核模式方面进行了优化,现将具体的教学措施总结如下。
一、资料与方法
(一)一般资料
将湖南环境生物职业技术学院2016级护理专业学生纳入到本组研究中,均为女生,共計128人,分为观察组与对照组,每组64人。对于观察组学生,以遗传病为主线进行教学改革,对照组采用常规的护理教学模式,两组采用同样的教材,由同一老师授课,学生基础成绩、课时等一般资料上,无显著差异(P>0.05),不会对教学质量产生影响。
(二)教学方法
对照组学生,采用常用的理论+实践的授课模式。对于观察组,以遗传病为主线对教学内容进行改革。
1.成立研究小组
成立《医学遗传学》研究小组,制作出玻片标本,以小组为单位开展染色体核型分析,锻炼学生的动手能力。组织学生针对医学遗传问题进行社会调查,指导学生搜集自己家乡的遗传病调查资料,编制论文集,并将相关知识力所能及的传递给亲人、朋友等。并普及《医学遗传学》的相关知识,在校内开展义诊活动与知识竞赛活动,结合教学目标来改革教学评估方式。
2.重构教学内容
在教学活动中,将遗传病作为教学大纲,从遗传病原理、分子基础、遗传病细胞、遗传病临床表现、传递方式、疾病诊断、治疗和预防进行教学。并结合《医学遗传学》的内容来制作多媒体课件,课件满足高职《医学遗传学基础》教材规划,介绍学科的发展动态,将抽象的知识形象化、具体化,帮助学生更好地理解、记忆。课件中有大量的遗传病资料图片,调动了学生学习的积极在与主动性。同时,设置网络虚拟课堂,建立微信群,为学生提供关于遗传病理论、实验教学、教学课件、遗传病视频的相关知识,内容包括习题、教学视频、参考资料、课件和教学大纲等,学生可以随时下载、复习。此外,以遗传病为主线,编写实验教学大纲,优化实验教学内容,构建遗传咨询门诊,成立诊断见习基地,在成绩评价上,不仅关注学生的理论成绩,也增加了实验与社会实践内容,提高考核的全面性。
3.建立遗传咨询门诊
遗传咨询即根据咨询对象的遗传病发生情况、诊断、防治问题进行商谈与讨论,让患者对自己家族的遗传病有系统地了解,选择合理的方式。在欧美发达国家中,遗传咨询门诊已经非常普遍,是遗传病治疗的重要内容,负责为患者提供生殖保健、优生优育、遗传病防治知识的宣传。建立遗传咨询门诊,学生可以感受医生、患者的双重身份,从而知道怎样有的放矢地学习知识,锻炼自己的综合能力。
4.举行社会实践活动
在节假期,组织学生上社区、街道、特殊学校、社会福利院等,举办义诊活动,宣传优生优育的相关知识。在寒暑假,为学生发放调查表,为学生介绍调查方法、调查内容与注意事项,让学生利用假期来进行调查,写出报告汇编。通过调查,有的学生拍摄了珍贵的照片,最后由教师负责汇总。在一个个的实例中,学生感受到了消除传统封建陋俗、保护环境的重要意义,增强了学生的责任意识。
(三)观察内容
对比两组学生的理论与实践考核成绩,满分均为100分,60分及格。
(四)统计学方法
本次实验数据采用SPSS12.0软件进行统计学分析。其中,计量资料采用均数±标准差(±s)来表示,组间对比采用t检验,计数资料对比采用χ2检验,以P<0.05为差异有统计学意义。
二、结果
结果显示,无论是理论考核成绩还是实践考核成绩上,观察组成绩都优于对照组,上述数据组间比较差异显著(p<0.05),差异有统计学意义。具体数据详见表1。
表1两组学生理论与实践考核成绩对比示意表
组别例数理论考核成绩实践考核成绩
观察组6486.4±7.688.4±6.1
对照组6473.9±8.275.9±7.8
三、讨论
医学遗传学是高职护理教学的一门重要内容,涉及的内容复杂,包括医学遗传学、细胞生物学、分子生物学等多个知识,内容复杂、抽象度高,对学生的创新能力、自主学习能力、科研能力都有更高的要求。传统教学模式方法陈旧、学生学习兴趣不高,主动性与积极性均受到了影响,不符合新时期高职院校的育人需求。为了提高教学质量,需要创新教学模式,提高学生的综合能力。
遗传学课程既包括基础知识,也包括与遗传病防治相关的内容。为了解决传统教学模式的问题,我院以遗传病为主线,改革了传统的教学模式,重构了教学内容,包括成立研究小组、重构教学内容、建立遗传咨询门诊、举行社会实践活动四个方面,不仅包括理论教学内容,也对实验、实践教学活动进行了改革。以“遗传病”为主线引导学生学习相关的理论知识,再将其付诸于自己的实践中,利用节假日、寒暑假的时间,走出课堂,深入社会,进行调研,这种“理论+实践”的教学模式,对于学生理论能力、实践能力的培养十分有益。本组研究结果显示,无论是理论考核成绩,还是实践考核成绩上,观察组成绩都优于对照组,上述数据组间比较差异显著(p<0.05),差异有统计学意义。
以遗传病为主线的高职医学遗传学课程教学模式,有效调动了学生学习的积极性与主动性,将临床实践与理论真正结合起来,借助于各类新型教学模式,创新教学内容,完善教学体系,对于应用型、创新型人才的培养非常有益。
作者:赵忠桂
参考文献:
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医学遗传学的研究方法范文4
医学遗传学知识更新快, 理论教科书内容经典, 但不能紧跟形势, 随着科技的不断发展, 各种新思路、新技术和新手段不断涌现, 如果依旧照本宣科, 就无法将最新的前沿内容教授给学生, 使理论与实际脱离。因此, 在医学遗传学教学中, 我们根据精准医疗的发展, 及时加入了相应前沿内容, 使学生能在第一时间接触和了解精准医疗发展动态。如在染色体与染色体疾病一章中, 在讲21三体综合征检测方法的时候, 除传统的B超、羊水穿刺检测染色体之外, 还给学生介绍这几年发展迅速的外周血基因检测方法, 该检测无创伤, 不会引起流产风险, 准确率高。在讲分子病与酶蛋白病一章时, 告诉学生:对于地中海贫血、苯丙酮尿症等分子病也能通过基因测序的手段进行提前诊断。这些都是精准医疗最为基本的实践运用。此外在绪论部分增加二代测序、外显子测序、RNA-seq等知识, 通过优化教学内容, 为遗传咨询提供了更为先进的思路和技术, 使学生对精准医疗的具体内容有更深入的认识[5]。
2 改进教学方法, 加深对精准医疗的理解
为更好地开展精准医疗教学, 我们采用案例式教学方法, 引导学生树立精准医疗理念。通过典型案例, 将临床内容融入课堂教学, 让学生带着兴趣学习, 提高参与课堂教学的主动性。例如在肿瘤遗传学教学中, 我们提出案例:安吉丽娜朱莉有乳腺癌家族史, 她通过基因技术检测出BRCA1基因缺陷, 意味着她分别拥有87%患乳腺癌和50%患卵巢癌的概率, 根据医生的分析和建议, 她接受了乳腺切除术。在课堂上引入精准医疗案例, 使学生全面了解精准医疗理念、流程和技术, 再进一步与理论知识结合、拓展, 结合上述案例提出问题:为什么安吉丽娜朱莉要接受切除手术?然后导出:BRCA1基因是抑癌基因, 如果该基因突变会导致抑癌功能丢失, 乳腺癌、卵巢癌发病率就会明显升高。引出抑癌基因、原癌基因等概念, 帮助学生系统回顾遗传学、细胞生物学、分子生物学等多学科知识, 并综合运用于特定疾病的分析中, 启发学生认识精准医疗能够通过基因测序技术预测可能的疾病, 从而采取相应的预防措施。在药物遗传学章节教学中, 我们提出个性化用药案例:William Elder Jr在8岁时候被诊断患有囊性纤维化疾病, 经基因测序发现是G551D突变导致, 由于使用了Kalydeco (该药物仅对G551D突变患者有效) , 他的病情得到有效控制。通过这个案例引导学生认识到在疾病确诊后用药的靶向性问题, 明确通过基因测序技术可以指导患者在合适的时间选择最佳剂量及最有效的药物, 产生最佳的治疗效果。
在教学中, 教师采用案例教学法, 以典型案例为基础, 引导学生运用理论分析临床问题, 将临床问题和基础知识结合起来, 结合课本掌握发病机制及遗传病的检测原理和方法等, 激发学生学习兴趣, 加深对精准医疗的理解, 促进学生进行深入思考。
3 改进考核方法, 提高学生创新能力
评价方式主要分为总结性评价和形成性评价。近些年来, 形成性评价被广泛关注, 形成性评价是指通过诊断教育方案、教育过程与活动中存在的问题, 结合学习者在学习过程中反映出来的情感、态度、方法等, 对教师教学过程及学习者学习过程和结果进行评价。形成性评价更关注学生的综合素质和创新能力。对医学遗传学我们采取了形成性评价, 重点对学生学习过程进行考核, 比如教师安排有挑战性的任务, 学生分组讨论, 小组成员课后查阅资料, 课上展示, 培养学生的创新能力、团队合作能力。
精准医疗的发展是遗传学、生物学和生物信息学的交叉综合应用, 在临床工作中, 面对众多复杂的医疗环节, 很难依靠个人对遗传病进行明确诊断。精准医疗的实现要求遗传学咨询师与生物信息人员、临床医生、基因检测公司以及患者之间能够进行良好的沟通, 并能对各学科资料进行有效分析和整合, 最终实现精准医疗的目标。因此在平时的训练中, 应注重培养学生组织协调能力和创新能力。
4 积极开展第二课堂, 培养学生遗传学数据检索技能
通过开展第二课堂, 培养学生医学遗传学数据检索技能。在对遗传病的研究中, OMIM数据库被誉为医学遗传学界的圣经, OMIM包括所有已知的遗传病、遗传决定的性状及其基因, 除了简略描述各种疾病的临床特征、诊断、鉴别诊断、治疗与预防外, 还提供已知有关致病基因的连锁关系、染色体定位、组成结构和功能、动物模型等资料, 并附有经缜密筛选的相关参考文献。OMIM制订的各种遗传病、性状、基因的编号, 为全世界所公认。开展第二课堂, 教学生掌握如何通过OMIM数据库检索某一疾病的遗传学信息, 包括基本描述、临床特征、基因定位、遗传方式、分子遗传学、动物模型知识等。
当前基因组学技术快速发展, 二代测序、生物信息学等新技术不断发展, 都在不断推动医学遗传学的发展, 促进医学遗传学采用新的教学思路和新的思维。精准医疗是现代医学发展的方向之一, 具有重要的战略意义。未来医学发展将进入3P医学时代预测 (Predictive) 、预防 (Preventive) 和实现个体化 (Personalized) , 作为医学遗传学教育工作者, 要针对未来生物医学基础和临床科学的发展, 整合基因组生物学新的学科前沿, 将新的概念和技术融入临床医学教学, 通过在教学中逐步培养学生创新思维, 强化学生精准医疗意识, 促进高素质复合型医学人才的培养。但是, 实现精准医疗在医学遗传学教学中的渗透, 对教师也提出了较高的挑战, 要求教师深刻理解精准医疗的内涵和规律, 掌握多学科知识, 才能设计好教学方法并运用于教学实践。在今后的教学中, 我们将继续加强学习和思考, 努力发掘适应精准医疗背景下的医学生创新思维培养方式, 进一步提升教学水平, 提高复合型医学人才的培养质量。
参考文献
[1]汤必奎, 胡明洁, 黄银久, 等.精准医疗思维在医学遗传学教学中的实践探索[J].齐齐哈尔医学院学报, 2017, 38 (1) :91-92.
[2]汤必奎, 胡明洁, 张静, 等.基于互联网思维的医学遗传学教学改革探索[J].基础医学教育, 2016, 18 (5) :400-401.
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医学遗传学的研究方法范文5
关键词:医学遗传学;实验教学;改革;探索
医学遗传学是医学和遗传学结合的学科,是高等医学教育的必修课程和专业基础课程。该学科涉及数千种疾病的基础理论和临床实践,已成为现代医学中十分活跃的学科。医学遗传学理论教学学时数较少,我国目前没有专门的临床遗传学学科,对于各种遗传病例,学生没有实践机会,实验课就显得尤为重要。在医学遗传学实验教学中,我们采用多种方式,结合实验内容的更新和实验教学方法的改进,不仅完成了教学大纲规定的教学内容,还引导学生参加大学生科研训练计划,提高了学生的学习兴趣,培养了其自主学习能力和创新能力,为他们将来的继续深造和实践工作奠定了良好的基础。
一、实验教学内容的改革
实验课是教学中的重要环节,是理论联系实际,培养学生分析问题、解决问题能力的重要途径。医学遗传学教学内容以基因病、染色体病为主,对于单基因遗传病可以进行基因诊断,但我校实验室不具备基因诊断的实验条件,因此实验教学的重点放在染色体的观察上。首先,安排正常人类染色体的核型分析,让学生对遗传物质有直观的认识,通过对染色体带型、核型的识别,对理论课讲授的染色体相关内容进行验证,同时也为后续实验奠定基础。了解了正常染色体,再在显微镜下观察染色体病患者的染色体标本,学生能够在显微镜下找到细胞分裂相,观察病人的染色体发生了怎样的畸变,理论和实践结合,对染色体病的诊断加深了认识。实验教学也要结合不同专业对教学内容合理安排。对临床专业的学生,重点引导其结合实验理解染色体病的发病机制;对于检验专业的学生,侧重点在细胞遗传学诊断染色体病,识别染色体的带型特征,进行染色体核型分析。除了完成教学大纲规定的实验内容,我们还计划开展开放式实验,在学生的课余时间开放实验室,引导学生设计实验内容,完成实验流程,进行多学科综合实验,培养学生的创新能力。
二、培养学生独立完成实验
实验教学锻炼学生的动手能力和独立能力,要求教师讲课不能超过20分钟,把时间留给学生完成实验,并对实验结果进行分析,找出失败的原因,思考如何改进。对于医学遗传学的重点内容单基因遗传病,学生对具体病例很有兴趣。教师可以把学生分成小组,让他们通过各种途径查找遗传病例;也可以让学生做家族遗传性状的调查,做出多媒体课件,在实验课上展示。这种实验内容的改革深受学生的欢迎,大家的学习兴趣和积极性明显提高。在这一过程中,大家学到了很多理论课上无法学到的内容,拓展了知识面,对单基因病有了更深刻的认识,同时还增强了制作多媒体课件、汇报表达以及团队合作能力。
三、结合实验内容引导学生参加科研训练
实验教学新增了人类皮纹分析,皮肤纹理是真皮向表皮突出,形成许多整齐的线,称为嵴纹。在突起的嵴纹之间形成凹陷的沟,这些凹凸的纹理构成了人体的指/趾纹和掌纹。皮纹在胚胎发育第13周开始出现,第19周左右形成,出生后终生不变,每个人都有其特定的皮纹。人体的皮纹既有个体的特异性,又有高度的稳定性。大量的研究表明,某些遗传病患者的皮纹发生变异,可作为遗传病诊断的辅助指标。目前,皮纹学的知识和技术广泛应用于人类学、遗传学、法医学以及作为临床某些疾病的辅助诊断。学生对这一部分内容很感兴趣,通过实验课掌握了皮纹分析的内容和方法。我们还引导学生将实验内容与科研相结合,指导学生参与我校大学生科研训练计划,对新疆医科大学513名维吾尔族与汉族学生皮肤纹理进行分析,研究维吾尔族与汉族学生皮肤纹理的差异与特异性,最后汇总资料进行统计分析,最终。
综上所述,通过医学遗传学实验教学的改革和探索,不仅学生的独立完成实验能力和科研创新能力得到了培养和提高,教师在教学中经过学习、思考、探索,也更新了知识,改革了教学方法,培养出了更多优秀的医学人才。
参考文献:
[1]朱慰云,谢天炽,李佩琼,等.医学遗传学实验教学改革和实践探索[J].基础医学教育,2015,17(2).
[2]张银,王芳,孙树汉.八年制模拟遗传咨询教学中建构主义学习理论的应用[J].基础医学教育,2015,17(2).
[3]甄红英,白云,杜晓娟.医学细胞生物学教学的困惑和改革探索[J].中华医学教育杂志,2014,34(3).
医学遗传学的研究方法范文6
例如从中央电视台的《学术报告厅》栏目录制了巴德年院士的报告《21世纪的医学与医学教育》,杨胜利院士的报告《现代生物技术》,从《走近科学》栏目录制了介绍脆骨病病例的《玻璃娃娃》,从《聚焦三农》栏目录制了介绍我国南部地区地中海贫血发生和防止状况的影片资料,从《科技之光》栏目转录了介绍武汉艾氏家族Huntington舞蹈病的《致命的舞蹈》,从《大师讲科学》栏目录制了杨雄里院士的报告《探索脑的奥秘》等,此外还有《饿死肿瘤》、《干细胞》、《基因工程》、《基因组计划》、《孟德尔》、药物不良反应引起的胎儿发育缺陷等。录制的视频材料剪辑后制作成一个个电子文件,带有科普性质的或与教学内容间接相关的材料,例如《21世纪的医学与医学教育》、《现代生物技术》、《基因组计划》等,根据教学阶段或与教学内容的关系,在教学初期阶段的课前或课间选择播放。这些教学辅助材料可使学生在轻松愉悦的状态下了解和学习到与课程相关的知识,了解学科发展的前沿,同时,潜移默化中激发了学生产生热爱科学的激情,甚至能起到营造良好的学习氛围和环境的作用。与教学内容直接相关的材料,例如《致命的舞蹈》、《玻璃娃娃》、《地中海贫血》等,恰当地插入到相应教学内容的多媒体教学课件中,大大增强了授课的直观性和生动性,可激发学生对教学内容的兴趣。强烈的视觉刺激会给学生留下深刻印象,此教学手段或策略的采用,对激发学生对课程的兴趣和学习积极性、提高教学效果起到了不可忽视的作用,这可看作医学教学的较高境界[2]。医学遗传学研究内容是人类遗传性疾病,其学科内容决定了自身不能脱离临床医学实践。我们通过与医院建立密切的工作联系,一方面为医院就医的患者提供遗传病的实验室诊断和遗传咨询服务,另一方面从患者或医院获取患者的临床资料,以充实教师的临床医学知识和教学内容。在实验教学中,采用了案例教学法[3],在实验教材中编入病例分析的内容,这些病例都是我们实际工作中接诊的典型病例。教学中要求学生根据教材中提供的患者临床资料和实验检测信息对疾病做出诊断,分析发病机制和再发风险,并给患者或其家属提出有价值的建议[4]。这一教学过程进一步激发了学生对医学遗传学课程的学习兴趣,培养了学生应用医学遗传学知识与技能解决实际问题的能力。教学与医学实践相结合体现了医学遗传学的应用性,教师的临床实践为教学提供临床资料、遗传学资料和图片资料,可激发学生学习兴趣,有助于学生对抽象理论的理解,符合培养学生掌握分析解决临床实际问题的医学遗传学知识与技能的教学目标。因此,教学与医学实践和科研实际相结合应作为医学遗传学教学总的指导思想,而不仅仅是课堂教学偶尔一用的教学方法。
精心设计教学方法,提高课堂教学效果
若要选择应用恰当的方法、手段和技巧,使课堂教学游刃有余,必须在备课环节下大工夫,分析教学内容,精心构思、设计每一章节的教学方法、方式与技巧。在我们的教学实践中运用并认为值得推荐的教学方法与技巧有:由浅入深逐步递进法、辨析相近或相关的概念、列表比较并列相关的内容、树形结构图展示层次性知识结构、充分利用图形、图像、图解、动画、视频等直观教学材料和问题教学法等[5]。在问题教学法中对问题的设计颇有讲究,通常就一个知识点设计一连串相关的问题,后一个问题以前一个问题为基础,是前一个问题的拓展或深入。针对具体教学内容精心设计出一连串相关的问题,对学生的学习能起到很好的引导作用,能激发学生的讨论热情和学习兴趣。通过精心设计和应用一系列方法、技巧,课堂教学效果大为提高。由于篇幅所限,有关教学方法和技巧另文详细介绍和讨论。在精选的教学内容中,包括基础知识、基本原理、基本概念等绝大部分内容是要讲授的,而主要靠记忆而不是理解的资料性内容、艰深的尖端技术和前沿成就留给学生自学。为了提高课堂教学效果,在开课之初就给学生强调预习的重要性,同时会把课程教学进度表和各章的教学基本要求给予学生,使学生的预习更有针对性。为了学生有较好的自学效果并及时复习巩固课堂讲授的内容,教师编写了配合教材的习题,要求学生与教学进度同步练习和及时复习。在课程结束后交给老师,平定后作为平时成绩计入课程总成绩。通过这些措施,对学生预习和复习起到了有效的督促作用。
教学策略实施的效果