The role of gene DCDC2 in German dyslexics

Dyslexia is a complex reading and writing disorder with a strong genetic component. In a German case-control cohort, we studied the influence of the suspected dyslexia-associated gene DCDC2. For the first time in a German cohort, we describe association of a 2445 basepair deletion, first identified in an American study. Evidence of association for three DCDC2 single nucleotide polymorphisms (rs807724, rs793862, rs807701), previously identified in German or American cohorts, was replicated. A haplotype of these polymorphisms showed evidence for association as well. Thus, our data further corroborate association of DCDC2 with dyslexia. Analysis of functional subgroups suggests association of investigated DCDC2 variants mainly with nondysphonetic, nonsevere, but probably dyseidetic (surface) dyslexia. Based on the presumed function of DCDC2, our findings point to a role of impaired neuronal migration in the etiology of the disease. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Lipoprotein (a): a Unique Independent Risk Factor for Coronary Artery Disease

The current epidemic affecting Indians is coronary artery disease (CAD), and is currently one of the most common causes of mortality and morbidity in developed and developing countries. The higher rate of CAD in Indians, as compared to people of other ethnic origin, may indicate a possible genetic susceptibility. Hence, Lp(a), an independent genetic risk marker for atherosclerosis and cardiovascular disease assumes great importance. Lp(a), an atherogenic lipoprotein, contains a cholesterol rich LDL particle, one molecule of apolipoprotein B-100 and a unique protein, apolipoprotein (a) which distinguishes it from LDL. Apo(a) is highly polymorphic and an inverse relationship between Lp(a) concentration and apo(a) isoform size has been observed. This is genetically controlled suggesting a functional diversity among the apo(a) isoforms. The LPA gene codes for apo(a) whose genetic heterogeneity is due to variations in its number of kringles. The exact pathogenic mechanism of Lp(a) is still not completely elucidated, but the structural homology of Lp(a) with LDL and plasmin is possibly responsible for its acting as a link between atherosclerosis and thrombosis. Upper limits of normal Lp(a) levels have not been defined for the Indian population. A cut off limit of 20 mg/dL has been suggested while for the Caucasian population it is 30 mg/dL. Though a variety of assays are available for its measurement, standardization of the analytical method is highly complicated as a majority of the methods are affected by the heterogeneity in apo(a) size. No therapeutic drug selectively targets Lp(a) but recently, new modifiers of apo(a) synthesis are being considered.     

Identification of Students’ Content Mastery and Cognitive and Affective Percepts of a Bioinformatics Miniunit: A Case Study With Recommendations for Teacher Education

Bioinformatics, merging biological data with computer science, is increasingly incorporated into school curricula at all levels. This case study of 10 secondary school students highlights student individual differences (especially the way they processed information and integrated procedural and analytical thought) and summarizes a variety of critical situations that teachers may encounter when teaching bioinformatics. Students who integrated factual information with procedural and analytical skills were closest to content mastery; while students who had fundamental deficiencies in factual recall or were less adept in integrating higher order knowledge with specific facts and procedural skills had difficulty mobilizing critical analytical skills needed to master the bioinformatics tasks. Broader implications are presented for teacher education, curriculum design, and research.     

Powerful knowledge and quality talk: maximising learning of genetics during collaborative group work

This commentary brings additional theoretical perspectives to bear on data and findings presented by Anniken Furberg and Hans Christian Arnseth in their paper on students’ meaning making in genetics in collaborative learning activities. The theoretical perspectives converge on the importance of maximizing students’ learning in genetics. The perspectives include the notion of powerful knowledge which raises the issue of whether the curriculum being delivered is a means by which students can acquire powerful knowledge that will provide them with more reliable explanations and new ways of thinking about the world. The role of the teacher in fostering social interactions that result in conceptually focused discussions within small group work also is considered. Finally, the issue of whether students can be taught how to improve the quality of their talk within small groups is explored.

果蝇GAL4/UAS系统在本科遗传学实验中的应用

GAL4蛋白是酵母中的一类转录因子,它能够与特定的上游激活序列结合,并驱动UAS下游基因的表达。将酵母中的GAL4和UAS元件分别引入到果蝇中,含有UAS-目的基因的转基因果蝇品系,无法在亲本中表达,只有与驱动者GAL4品系杂交后的子一代中,目的基因才会表达。在本科遗传学实验中,引入eyelessGAL4和UAS-Ras转基因果蝇品系杂交实验,通过观察F1代复眼中原癌基因ras表达后的表型,使学生了解如何通过GAL4-UAS系统在模式动物黑腹果蝇中实现靶基因的时空表达,认识GAL4-UAS系统在研究果蝇遗传发育中的重要性和优越性,理解分子调控、靶基因表达与个体的遗传和发育每个环节都是可以操作和控制的现代遗传学实验理念。     

经典研究案例分析在大学遗传学教学中的应用

反映遗传学家原创性工作的一系列经典研究案例构成了遗传学发展史的主线,是遗传学进步的原动力,也是一批优秀的遗传学教学素材,具有潜在的教育和教学功能.实践证明,将经典研究案例应用于遗传学教学能使学生顺利地掌握遗传学的核心知识、提高学生的遗传分析能力和科学素养.在具体的教学过程中须重视在展现研究案例的同时强化教学大纲中相关的知识点,使科研案例真正为教学服务.     

Exploring Middle School Students’ Understanding of Three Conceptual Models in Genetics

Genetics is the cornerstone of modern biology and a critical aspect of scientific literacy. Research has shown, however, that many high school graduates lack fundamental understandings in genetics necessary to make informed decisions about issues and emerging technologies in this domain, such as genetic screening, genetically modified foods, etc. Genetic literacy entails understanding three interrelated models: a genetic model that describes patterns of genetic inheritance, a meiotic model that describes the process by which genes are segregated into sex cells, and a molecular model that describes the mechanisms that link genotypes to phenotypes within an individual. Currently, much of genetics instruction, especially in terms of the molecular model, occurs at the high school level, and we know little about the ways in which middle school students can reason about these models. Furthermore, we do not know the extent to which carefully designed instruction can help younger students develop coherent and interrelated understandings in genetics. In this paper, we discuss a research study aimed at elucidating middle school students’ abilities to reason about the three genetic models. As part of our research, we designed an eight-week inquiry unit that was implemented in a combined sixth- to eighth-grade science classroom. We describe our instructional design and report results based on an analysis of written assessments, clinical interviews, and artifacts of the unit. Our findings suggest that middle school students are able to successfully reason about all three genetic models.     

Lack of association of the ACE genotype with the muscle strength response to resistance training

Abstract

Introduction: Previous studies have attempted to link the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene with the variability in muscle strength responses to resistance training (RT); however, the literature is inconclusive. The purpose of the present study was to investigate the association between the ACE I/D genotype and muscle strength response to a RT program in young men.

Methods: 124 men (22±2.6 years; 174.8±6.5cm; 71.5±13.8 kg) without resistance training experience were tested before and after 11 weeks of five whole-body RT exercises (bench press, seated row, knee extension, knee flexion and sit ups). The bench press 1RM test was used to assess upper-body muscle strength and the isokinetic knee extensor peak torque (PT) was used as a measure of lower-body strength.

Results: At baseline, there were no differences among ACE genotype for 1RM load (54±11.7 kg for II, 58.5±8.9 kg for ID and 52.3±12.2 kg for DD) or knee extensor peak torque (PT) (220.1±36.8 N·m for II, 209.4 ±44.4 N·m for ID and 199.7±32.4 N·m for DD). Moreover, ACE genotype was not associated with lower-body (7.1±10.5%, 15.7±10.4% and 14.1±22.7% for II, ID and DD, respectively) or upper-body strength gains (16.2±8.9%, 14.5±11.3% and 21.9±17.1% for II, ID and DD, respectively) in response to RT.

Conclusion: The ACE I/D genotype was not associated with the muscle strength responses to RT.     

Genetic and environmental bases of reading and spelling: A unified genetic dual route model

We develop and test a dual-route model of genetic effects on reading aloud and spelling, based on irregular and non-word reading and spelling performance assessed in 1382 monozygotic and dizygotic twins. As in earlier research, most of the variance in reading was due to genetic effects. However, there were three more specific conclusions: the first was that most of the genetic effect is common to both regular and irregular reading. In addition to this common variance evidence was found for distinct genes influencing the acquisition of a lexicon of stored words, and additional genetic effects influencing the acquisition of grapheme–phoneme correspondence rules. The third conclusion, from a combined model of reading and spelling, is that reading and spelling have a common genetic basis. Models that did not distinguish lexical and non-lexical performance fit significantly worse than dual route genetic models. An implication of the research is that models of reading, whether connectionist or dual-route, must allow for the genetic independence of neurological processes underlying the decoding of non-words and irregular words.     

基于雨课堂的医学遗传学混合式教学模式的应用研究

在“互联网+”背景下,开展混合式教学是教育创新改革的迫切需要。“医学遗传学”课程教学中引入新型智慧教学工具“雨课堂”,通过课前资料推送、课中实时互动、课后测试反馈、学习过程全程评价等方法开展混合式教学,提高了学生学习的主动性和积极性,提升了课堂教学质量。