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醫學遺傳學的研究方法范文1
【關鍵詞】生物多樣性;細胞學標記;DNA分子標記
【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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醫學遺傳學的研究方法范文2
1、新型網絡教育技術對醫學遺傳學教育改革的積極作用。
新型網絡教育技術是指運用現代教育理論和新型網絡教育技術,通過教育中教學過程和教育資源的設計、開發、利用來實現教學教育的改革與創新。新型網絡教育技術主要通過一下幾個方面發揮其積極作用。①培養拓展學生的研究精神與創新意識,增強學生主動性。學生通過新型網絡教育技術,改變了以往教師作為教育中心、教學活動主題的傳統模式,增強其主體地位和主體意識,為學生提供更為現實的思考環境。②為教學資源的存在形式提供了全新的載體。教學資源與教學成果作為信息的表現形式之一,尤其在先進信息爆炸時代,其巨大的數據體現亟須全新的載體,用以支持其產生、傳播、運用,儲存等。③拓展了資源共享平臺,新型網絡教育技術所依托的互聯網背后是一個巨大的資源庫,掌握最新的信息、資源是學習和研究的關鍵。網絡所提供的是一個完全透明的資源平臺,超越實踐空間的限制,信息共享從封閉走向開放,世界各地的學習者通過網絡共享資源,各取所需。
2、新型網絡教育技術的具體表現。
網絡教育技術的體現主要通過對過程和資源的運用和設計,因此在針對醫學遺傳學的教學中運用新型網絡教育技術的側重點主要有以下幾個方面:①提高醫學遺傳學教師的新型網絡教育技術技能。②提高醫學遺傳學專業學生的新媒體運用能力。③加強網絡教育技術的外部硬件條件,改善教育環境。
二、案例討論法在促進醫學遺傳學教學目的的實現中的作用和表現形式
1、案例討論法在促進醫學遺傳學教學中的積極作用。
案例討論法是指通過傳授臨床實踐中的真實遺傳病例及相關典型實驗操作過程來啟發學生對問題進行討論并提出解決方案的教學方法。它在教學中的積極作用主要體現在以下幾個方面:①主觀方面提高學生學習興趣,激發學習熱情。案例分析法本身需要學生通過主動了解病例,在了解過程中基于自身知識結構的欠缺勢必對病例本身產生疑問,疑問的解決方式有課堂講授及課后查找、閱讀、理解、討論等;②客觀上提高學生分析問題解決問題的能力。案例式教學不同于演繹法,更多的是啟發學生通過具體案例來結合理論,這種反向式的學習方法,更利于學生記憶、遷移、運用,并且能夠促進學生思考案例與理論之間的聯系點,刺激學生形成自我解決問題的思維模式。這對培養實踐性人才有著積極的促進作用;③增強互動性,提高課堂教學質量。案例分析法的學習過程通過兩個方面體現互動性,首先是學生與學生的互動,這種互動性主要是通過相互爭辯、討論、交流得以體現。互動性還通過學生與老師的互動得以體現。老師通過關鍵點的引導,刺激學生思考,從而達到教學設計的目的。
2、案例討論法在促進醫學遺傳學教學中的表現。
醫學遺傳學教學過程中基于其本省的學科特點,需要從幾個方面側重進行案例討論式教學,這幾個部分通過案例教學在一定程度是是否能夠成功教授本們課程的關鍵。這幾個部分分別是:①遺傳病傳播方式的案例分析,學生需要針對具體的病例自主的繪制系譜圖并討論圖表內容,并通過討論歸納傳播規律,在討論規律之后分析計算再發風險,并學會查詢資料了解例如如何提前判斷遺傳病等相關知識,提高各方面相關知識;②醫學遺傳學的技術方法傳授,對于新的研究技術和方法,直白的講授方法本身就與實踐操作有著天壤之別,但實踐操作并不適用于所有的教學環境,因此,通過具體的病例進行講授,便能夠克服晦澀的理論概念,促進學生自主探索治療該病例的技術方法,從而最終與所要講授的醫學遺傳學方法“不期而遇”來實現教學目的。③遺傳規律的講授,對于遺傳規律的講授也是堅持感性認識到理性認識再到討論分析,并對問題進行解釋,最終理解所授知識。
三、全新教育模式的設想與構造
以上是對新型網絡教育技術和案例討論法這兩種不同教育工具在醫學遺傳學教學終的作用以及表現的概括。本文的設想是結合兩種工具,設計出醫學遺傳學教學的一個整體構造。下面擬從兩個方面入手進行闡述:
1、資源分享平臺設計及運用。
依托醫學遺傳學自身新型發展特性,建立靜態與動態醫學遺傳學理論知識平臺。網絡平臺設計需要專業軟件工程設計,軟件設計形式包括教育網站,網站內資源平臺。①靜態醫學遺傳學理論知識平臺:其內容包含專業課理論知識核心展示及思考題、專業圖表制作方法索引及練習平臺、主要經典案例索引資源庫;②動態醫學遺傳學理論知識平臺:其內容主要為交流討論組、網絡模擬實驗室、實驗成果展示分享平臺。
2、課堂平臺設計及運用。
醫學遺傳學的研究方法范文3
關鍵詞:遺傳病主線;高職學校;醫學遺傳學;課程建設
醫學遺傳學是介于醫學與遺傳學之間的一門邊緣性學科,也是高職護理專業教學的重點和難點課程,學生學習起來普遍感到難度偏高。為了提高高職醫學遺傳學課程的建設質量,近年來,湖南環境生物職業技術學院構建了以遺傳病為主線的課程建設策略,從教學內容、教學方法、考核模式方面進行了優化,現將具體的教學措施總結如下。
一、資料與方法
(一)一般資料
將湖南環境生物職業技術學院2016級護理專業學生納入到本組研究中,均為女生,共計128人,分為觀察組與對照組,每組64人。對于觀察組學生,以遺傳病為主線進行教學改革,對照組采用常規的護理教學模式,兩組采用同樣的教材,由同一老師授課,學生基礎成績、課時等一般資料上,無顯著差異(P>0.05),不會對教學質量產生影響。
(二)教學方法
對照組學生,采用常用的理論+實踐的授課模式。對于觀察組,以遺傳病為主線對教學內容進行改革。
1.成立研究小組
成立《醫學遺傳學》研究小組,制作出玻片標本,以小組為單位開展染色體核型分析,鍛煉學生的動手能力。組織學生針對醫學遺傳問題進行社會調查,指導學生搜集自己家鄉的遺傳病調查資料,編制論文集,并將相關知識力所能及的傳遞給親人、朋友等。并普及《醫學遺傳學》的相關知識,在校內開展義診活動與知識競賽活動,結合教學目標來改革教學評估方式。
2.重構教學內容
在教學活動中,將遺傳病作為教學大綱,從遺傳病原理、分子基礎、遺傳病細胞、遺傳病臨床表現、傳遞方式、疾病診斷、治療和預防進行教學。并結合《醫學遺傳學》的內容來制作多媒體課件,課件滿足高職《醫學遺傳學基礎》教材規劃,介紹學科的發展動態,將抽象的知識形象化、具體化,幫助學生更好地理解、記憶。課件中有大量的遺傳病資料圖片,調動了學生學習的積極在與主動性。同時,設置網絡虛擬課堂,建立微信群,為學生提供關于遺傳病理論、實驗教學、教學課件、遺傳病視頻的相關知識,內容包括習題、教學視頻、參考資料、課件和教學大綱等,學生可以隨時下載、復習。此外,以遺傳病為主線,編寫實驗教學大綱,優化實驗教學內容,構建遺傳咨詢門診,成立診斷見習基地,在成績評價上,不僅關注學生的理論成績,也增加了實驗與社會實踐內容,提高考核的全面性。
3.建立遺傳咨詢門診
遺傳咨詢即根據咨詢對象的遺傳病發生情況、診斷、防治問題進行商談與討論,讓患者對自己家族的遺傳病有系統地了解,選擇合理的方式。在歐美發達國家中,遺傳咨詢門診已經非常普遍,是遺傳病治療的重要內容,負責為患者提供生殖保健、優生優育、遺傳病防治知識的宣傳。建立遺傳咨詢門診,學生可以感受醫生、患者的雙重身份,從而知道怎樣有的放矢地學習知識,鍛煉自己的綜合能力。
4.舉行社會實踐活動
在節假期,組織學生上社區、街道、特殊學校、社會福利院等,舉辦義診活動,宣傳優生優育的相關知識。在寒暑假,為學生發放調查表,為學生介紹調查方法、調查內容與注意事項,讓學生利用假期來進行調查,寫出報告匯編。通過調查,有的學生拍攝了珍貴的照片,最后由教師負責匯總。在一個個的實例中,學生感受到了消除傳統封建陋俗、保護環境的重要意義,增強了學生的責任意識。
(三)觀察內容
對比兩組學生的理論與實踐考核成績,滿分均為100分,60分及格。
(四)統計學方法
本次實驗數據采用SPSS12.0軟件進行統計學分析。其中,計量資料采用均數±標準差(±s)來表示,組間對比采用t檢驗,計數資料對比采用χ2檢驗,以P<0.05為差異有統計學意義。
二、結果
結果顯示,無論是理論考核成績還是實踐考核成績上,觀察組成績都優于對照組,上述數據組間比較差異顯著(p<0.05),差異有統計學意義。具體數據詳見表1。
表1兩組學生理論與實踐考核成績對比示意表
組別例數理論考核成績實踐考核成績
觀察組6486.4±7.688.4±6.1
對照組6473.9±8.275.9±7.8
三、討論
醫學遺傳學是高職護理教學的一門重要內容,涉及的內容復雜,包括醫學遺傳學、細胞生物學、分子生物學等多個知識,內容復雜、抽象度高,對學生的創新能力、自主學習能力、科研能力都有更高的要求。傳統教學模式方法陳舊、學生學習興趣不高,主動性與積極性均受到了影響,不符合新時期高職院校的育人需求。為了提高教學質量,需要創新教學模式,提高學生的綜合能力。
遺傳學課程既包括基礎知識,也包括與遺傳病防治相關的內容。為了解決傳統教學模式的問題,我院以遺傳病為主線,改革了傳統的教學模式,重構了教學內容,包括成立研究小組、重構教學內容、建立遺傳咨詢門診、舉行社會實踐活動四個方面,不僅包括理論教學內容,也對實驗、實踐教學活動進行了改革。以“遺傳病”為主線引導學生學習相關的理論知識,再將其付諸于自己的實踐中,利用節假日、寒暑假的時間,走出課堂,深入社會,進行調研,這種“理論+實踐”的教學模式,對于學生理論能力、實踐能力的培養十分有益。本組研究結果顯示,無論是理論考核成績,還是實踐考核成績上,觀察組成績都優于對照組,上述數據組間比較差異顯著(p<0.05),差異有統計學意義。
以遺傳病為主線的高職醫學遺傳學課程教學模式,有效調動了學生學習的積極性與主動性,將臨床實踐與理論真正結合起來,借助于各類新型教學模式,創新教學內容,完善教學體系,對于應用型、創新型人才的培養非常有益。
作者:趙忠桂
參考文獻:
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[2]張咸寧,俞萍,祁鳴,等.醫學遺傳學課程建設淺析[J].中國高等醫學教育,2007(1).
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醫學遺傳學的研究方法范文4
醫學遺傳學知識更新快, 理論教科書內容經典, 但不能緊跟形勢, 隨著科技的不斷發展, 各種新思路、新技術和新手段不斷涌現, 如果依舊照本宣科, 就無法將最新的前沿內容教授給學生, 使理論與實際脫離。因此, 在醫學遺傳學教學中, 我們根據精準醫療的發展, 及時加入了相應前沿內容, 使學生能在第一時間接觸和了解精準醫療發展動態。如在染色體與染色體疾病一章中, 在講21三體綜合征檢測方法的時候, 除傳統的B超、羊水穿刺檢測染色體之外, 還給學生介紹這幾年發展迅速的外周血基因檢測方法, 該檢測無創傷, 不會引起流產風險, 準確率高。在講分子病與酶蛋白病一章時, 告訴學生:對于地中海貧血、苯丙酮尿癥等分子病也能通過基因測序的手段進行提前診斷。這些都是精準醫療最為基本的實踐運用。此外在緒論部分增加二代測序、外顯子測序、RNA-seq等知識, 通過優化教學內容, 為遺傳咨詢提供了更為先進的思路和技術, 使學生對精準醫療的具體內容有更深入的認識[5]。
2 改進教學方法, 加深對精準醫療的理解
為更好地開展精準醫療教學, 我們采用案例式教學方法, 引導學生樹立精準醫療理念。通過典型案例, 將臨床內容融入課堂教學, 讓學生帶著興趣學習, 提高參與課堂教學的主動性。例如在腫瘤遺傳學教學中, 我們提出案例:安吉麗娜朱莉有乳腺癌家族史, 她通過基因技術檢測出BRCA1基因缺陷, 意味著她分別擁有87%患乳腺癌和50%患卵巢癌的概率, 根據醫生的分析和建議, 她接受了乳腺切除術。在課堂上引入精準醫療案例, 使學生全面了解精準醫療理念、流程和技術, 再進一步與理論知識結合、拓展, 結合上述案例提出問題:為什么安吉麗娜朱莉要接受切除手術?然后導出:BRCA1基因是抑癌基因, 如果該基因突變會導致抑癌功能丟失, 乳腺癌、卵巢癌發病率就會明顯升高。引出抑癌基因、原癌基因等概念, 幫助學生系統回顧遺傳學、細胞生物學、分子生物學等多學科知識, 并綜合運用于特定疾病的分析中, 啟發學生認識精準醫療能夠通過基因測序技術預測可能的疾病, 從而采取相應的預防措施。在藥物遺傳學章節教學中, 我們提出個性化用藥案例:William Elder Jr在8歲時候被診斷患有囊性纖維化疾病, 經基因測序發現是G551D突變導致, 由于使用了Kalydeco (該藥物僅對G551D突變患者有效) , 他的病情得到有效控制。通過這個案例引導學生認識到在疾病確診后用藥的靶向性問題, 明確通過基因測序技術可以指導患者在合適的時間選擇最佳劑量及最有效的藥物, 產生最佳的治療效果。
在教學中, 教師采用案例教學法, 以典型案例為基礎, 引導學生運用理論分析臨床問題, 將臨床問題和基礎知識結合起來, 結合課本掌握發病機制及遺傳病的檢測原理和方法等, 激發學生學習興趣, 加深對精準醫療的理解, 促進學生進行深入思考。
3 改進考核方法, 提高學生創新能力
評價方式主要分為總結性評價和形成性評價。近些年來, 形成性評價被廣泛關注, 形成性評價是指通過診斷教育方案、教育過程與活動中存在的問題, 結合學習者在學習過程中反映出來的情感、態度、方法等, 對教師教學過程及學習者學習過程和結果進行評價。形成性評價更關注學生的綜合素質和創新能力。對醫學遺傳學我們采取了形成性評價, 重點對學生學習過程進行考核, 比如教師安排有挑戰性的任務, 學生分組討論, 小組成員課后查閱資料, 課上展示, 培養學生的創新能力、團隊合作能力。
精準醫療的發展是遺傳學、生物學和生物信息學的交叉綜合應用, 在臨床工作中, 面對眾多復雜的醫療環節, 很難依靠個人對遺傳病進行明確診斷。精準醫療的實現要求遺傳學咨詢師與生物信息人員、臨床醫生、基因檢測公司以及患者之間能夠進行良好的溝通, 并能對各學科資料進行有效分析和整合, 最終實現精準醫療的目標。因此在平時的訓練中, 應注重培養學生組織協調能力和創新能力。
4 積極開展第二課堂, 培養學生遺傳學數據檢索技能
通過開展第二課堂, 培養學生醫學遺傳學數據檢索技能。在對遺傳病的研究中, OMIM數據庫被譽為醫學遺傳學界的圣經, OMIM包括所有已知的遺傳病、遺傳決定的性狀及其基因, 除了簡略描述各種疾病的臨床特征、診斷、鑒別診斷、治療與預防外, 還提供已知有關致病基因的連鎖關系、染色體定位、組成結構和功能、動物模型等資料, 并附有經縝密篩選的相關參考文獻。OMIM制訂的各種遺傳病、性狀、基因的編號, 為全世界所公認。開展第二課堂, 教學生掌握如何通過OMIM數據庫檢索某一疾病的遺傳學信息, 包括基本描述、臨床特征、基因定位、遺傳方式、分子遺傳學、動物模型知識等。
當前基因組學技術快速發展, 二代測序、生物信息學等新技術不斷發展, 都在不斷推動醫學遺傳學的發展, 促進醫學遺傳學采用新的教學思路和新的思維。精準醫療是現代醫學發展的方向之一, 具有重要的戰略意義。未來醫學發展將進入3P醫學時代預測 (Predictive) 、預防 (Preventive) 和實現個體化 (Personalized) , 作為醫學遺傳學教育工作者, 要針對未來生物醫學基礎和臨床科學的發展, 整合基因組生物學新的學科前沿, 將新的概念和技術融入臨床醫學教學, 通過在教學中逐步培養學生創新思維, 強化學生精準醫療意識, 促進高素質復合型醫學人才的培養。但是, 實現精準醫療在醫學遺傳學教學中的滲透, 對教師也提出了較高的挑戰, 要求教師深刻理解精準醫療的內涵和規律, 掌握多學科知識, 才能設計好教學方法并運用于教學實踐。在今后的教學中, 我們將繼續加強學習和思考, 努力發掘適應精準醫療背景下的醫學生創新思維培養方式, 進一步提升教學水平, 提高復合型醫學人才的培養質量。
參考文獻
[1]湯必奎, 胡明潔, 黃銀久, 等.精準醫療思維在醫學遺傳學教學中的實踐探索[J].齊齊哈爾醫學院學報, 2017, 38 (1) :91-92.
[2]湯必奎, 胡明潔, 張靜, 等.基于互聯網思維的醫學遺傳學教學改革探索[J].基礎醫學教育, 2016, 18 (5) :400-401.
[3]Vinay Prasad.Perspective:The precision oncology illusion[J].Nature, 2016 (37) :63.
醫學遺傳學的研究方法范文5
關鍵詞:醫學遺傳學;實驗教學;改革;探索
醫學遺傳學是醫學和遺傳學結合的學科,是高等醫學教育的必修課程和專業基礎課程。該學科涉及數千種疾病的基礎理論和臨床實踐,已成為現代醫學中十分活躍的學科。醫學遺傳學理論教學學時數較少,我國目前沒有專門的臨床遺傳學學科,對于各種遺傳病例,學生沒有實踐機會,實驗課就顯得尤為重要。在醫學遺傳學實驗教學中,我們采用多種方式,結合實驗內容的更新和實驗教學方法的改進,不僅完成了教學大綱規定的教學內容,還引導學生參加大學生科研訓練計劃,提高了學生的學習興趣,培養了其自主學習能力和創新能力,為他們將來的繼續深造和實踐工作奠定了良好的基礎。
一、實驗教學內容的改革
實驗課是教學中的重要環節,是理論聯系實際,培養學生分析問題、解決問題能力的重要途徑。醫學遺傳學教學內容以基因病、染色體病為主,對于單基因遺傳病可以進行基因診斷,但我校實驗室不具備基因診斷的實驗條件,因此實驗教學的重點放在染色體的觀察上。首先,安排正常人類染色體的核型分析,讓學生對遺傳物質有直觀的認識,通過對染色體帶型、核型的識別,對理論課講授的染色體相關內容進行驗證,同時也為后續實驗奠定基礎。了解了正常染色體,再在顯微鏡下觀察染色體病患者的染色體標本,學生能夠在顯微鏡下找到細胞分裂相,觀察病人的染色體發生了怎樣的畸變,理論和實踐結合,對染色體病的診斷加深了認識。實驗教學也要結合不同專業對教學內容合理安排。對臨床專業的學生,重點引導其結合實驗理解染色體病的發病機制;對于檢驗專業的學生,側重點在細胞遺傳學診斷染色體病,識別染色體的帶型特征,進行染色體核型分析。除了完成教學大綱規定的實驗內容,我們還計劃開展開放式實驗,在學生的課余時間開放實驗室,引導學生設計實驗內容,完成實驗流程,進行多學科綜合實驗,培養學生的創新能力。
二、培養學生獨立完成實驗
實驗教學鍛煉學生的動手能力和獨立能力,要求教師講課不能超過20分鐘,把時間留給學生完成實驗,并對實驗結果進行分析,找出失敗的原因,思考如何改進。對于醫學遺傳學的重點內容單基因遺傳病,學生對具體病例很有興趣。教師可以把學生分成小組,讓他們通過各種途徑查找遺傳病例;也可以讓學生做家族遺傳性狀的調查,做出多媒體課件,在實驗課上展示。這種實驗內容的改革深受學生的歡迎,大家的學習興趣和積極性明顯提高。在這一過程中,大家學到了很多理論課上無法學到的內容,拓展了知識面,對單基因病有了更深刻的認識,同時還增強了制作多媒體課件、匯報表達以及團隊合作能力。
三、結合實驗內容引導學生參加科研訓練
實驗教學新增了人類皮紋分析,皮膚紋理是真皮向表皮突出,形成許多整齊的線,稱為嵴紋。在突起的嵴紋之間形成凹陷的溝,這些凹凸的紋理構成了人體的指/趾紋和掌紋。皮紋在胚胎發育第13周開始出現,第19周左右形成,出生后終生不變,每個人都有其特定的皮紋。人體的皮紋既有個體的特異性,又有高度的穩定性。大量的研究表明,某些遺傳病患者的皮紋發生變異,可作為遺傳病診斷的輔助指標。目前,皮紋學的知識和技術廣泛應用于人類學、遺傳學、法醫學以及作為臨床某些疾病的輔助診斷。學生對這一部分內容很感興趣,通過實驗課掌握了皮紋分析的內容和方法。我們還引導學生將實驗內容與科研相結合,指導學生參與我校大學生科研訓練計劃,對新疆醫科大學513名維吾爾族與漢族學生皮膚紋理進行分析,研究維吾爾族與漢族學生皮膚紋理的差異與特異性,最后匯總資料進行統計分析,最終。
綜上所述,通過醫學遺傳學實驗教學的改革和探索,不僅學生的獨立完成實驗能力和科研創新能力得到了培養和提高,教師在教學中經過學習、思考、探索,也更新了知識,改革了教學方法,培養出了更多優秀的醫學人才。
參考文獻:
[1]朱慰云,謝天熾,李佩瓊,等.醫學遺傳學實驗教學改革和實踐探索[J].基礎醫學教育,2015,17(2).
[2]張銀,王芳,孫樹漢.八年制模擬遺傳咨詢教學中建構主義學習理論的應用[J].基礎醫學教育,2015,17(2).
[3]甄紅英,白云,杜曉娟.醫學細胞生物學教學的困惑和改革探索[J].中華醫學教育雜志,2014,34(3).
醫學遺傳學的研究方法范文6
例如從中央電視臺的《學術報告廳》欄目錄制了巴德年院士的報告《21世紀的醫學與醫學教育》,楊勝利院士的報告《現代生物技術》,從《走近科學》欄目錄制了介紹脆骨病病例的《玻璃娃娃》,從《聚焦三農》欄目錄制了介紹我國南部地區地中海貧血發生和防止狀況的影片資料,從《科技之光》欄目轉錄了介紹武漢艾氏家族Huntington舞蹈病的《致命的舞蹈》,從《大師講科學》欄目錄制了楊雄里院士的報告《探索腦的奧秘》等,此外還有《餓死腫瘤》、《干細胞》、《基因工程》、《基因組計劃》、《孟德爾》、藥物不良反應引起的胎兒發育缺陷等。錄制的視頻材料剪輯后制作成一個個電子文件,帶有科普性質的或與教學內容間接相關的材料,例如《21世紀的醫學與醫學教育》、《現代生物技術》、《基因組計劃》等,根據教學階段或與教學內容的關系,在教學初期階段的課前或課間選擇播放。這些教學輔助材料可使學生在輕松愉悅的狀態下了解和學習到與課程相關的知識,了解學科發展的前沿,同時,潛移默化中激發了學生產生熱愛科學的激情,甚至能起到營造良好的學習氛圍和環境的作用。與教學內容直接相關的材料,例如《致命的舞蹈》、《玻璃娃娃》、《地中海貧血》等,恰當地插入到相應教學內容的多媒體教學課件中,大大增強了授課的直觀性和生動性,可激發學生對教學內容的興趣。強烈的視覺刺激會給學生留下深刻印象,此教學手段或策略的采用,對激發學生對課程的興趣和學習積極性、提高教學效果起到了不可忽視的作用,這可看作醫學教學的較高境界[2]。醫學遺傳學研究內容是人類遺傳性疾病,其學科內容決定了自身不能脫離臨床醫學實踐。我們通過與醫院建立密切的工作聯系,一方面為醫院就醫的患者提供遺傳病的實驗室診斷和遺傳咨詢服務,另一方面從患者或醫院獲取患者的臨床資料,以充實教師的臨床醫學知識和教學內容。在實驗教學中,采用了案例教學法[3],在實驗教材中編入病例分析的內容,這些病例都是我們實際工作中接診的典型病例。教學中要求學生根據教材中提供的患者臨床資料和實驗檢測信息對疾病做出診斷,分析發病機制和再發風險,并給患者或其家屬提出有價值的建議[4]。這一教學過程進一步激發了學生對醫學遺傳學課程的學習興趣,培養了學生應用醫學遺傳學知識與技能解決實際問題的能力。教學與醫學實踐相結合體現了醫學遺傳學的應用性,教師的臨床實踐為教學提供臨床資料、遺傳學資料和圖片資料,可激發學生學習興趣,有助于學生對抽象理論的理解,符合培養學生掌握分析解決臨床實際問題的醫學遺傳學知識與技能的教學目標。因此,教學與醫學實踐和科研實際相結合應作為醫學遺傳學教學總的指導思想,而不僅僅是課堂教學偶爾一用的教學方法。
精心設計教學方法,提高課堂教學效果
若要選擇應用恰當的方法、手段和技巧,使課堂教學游刃有余,必須在備課環節下大工夫,分析教學內容,精心構思、設計每一章節的教學方法、方式與技巧。在我們的教學實踐中運用并認為值得推薦的教學方法與技巧有:由淺入深逐步遞進法、辨析相近或相關的概念、列表比較并列相關的內容、樹形結構圖展示層次性知識結構、充分利用圖形、圖像、圖解、動畫、視頻等直觀教學材料和問題教學法等[5]。在問題教學法中對問題的設計頗有講究,通常就一個知識點設計一連串相關的問題,后一個問題以前一個問題為基礎,是前一個問題的拓展或深入。針對具體教學內容精心設計出一連串相關的問題,對學生的學習能起到很好的引導作用,能激發學生的討論熱情和學習興趣。通過精心設計和應用一系列方法、技巧,課堂教學效果大為提高。由于篇幅所限,有關教學方法和技巧另文詳細介紹和討論。在精選的教學內容中,包括基礎知識、基本原理、基本概念等絕大部分內容是要講授的,而主要靠記憶而不是理解的資料性內容、艱深的尖端技術和前沿成就留給學生自學。為了提高課堂教學效果,在開課之初就給學生強調預習的重要性,同時會把課程教學進度表和各章的教學基本要求給予學生,使學生的預習更有針對性。為了學生有較好的自學效果并及時復習鞏固課堂講授的內容,教師編寫了配合教材的習題,要求學生與教學進度同步練習和及時復習。在課程結束后交給老師,平定后作為平時成績計入課程總成績。通過這些措施,對學生預習和復習起到了有效的督促作用。
教學策略實施的效果