MBG+L1+Genetic+analysis+-+Genes%2C+Chromosomes+and+Inheritance

Molecular Biology and Genetics Overview

  • Course Name: Molecular Biology and Genetics 4LMS0007

  • Instructors:

    • Cristina Barrero-Sicilia (c.barrero-sicilia@herts.ac.uk)

    • Alena Pance (a.pance@herts.ac.uk)

    • Maria Dimitriadi (m.dimitriadi@herts.ac.uk)

  • Reference: Trends in Genetic (2022): 39 (10)

  • Artistic repr esentation: Enhancer-mediated transcription in 3D nuclear space

Course Structure

  • Credits: A 15-credit module

  • Topics Covered:

    • Genetic inheritance principles: meiosis, primordial germ cells, gametes

    • Linkage and basic human genetic epidemiology

    • Mutation, genetic variations, and diseases

    • Introduction to gene regulation

    • Molecular methods for studying DNA and inheritance

    • Applications in research, diagnosis, and treatment

  • Format:

    • Lectures: 2 hours every Monday

    • Workshops: 2 hours every other week, discussion on practical application

    • Practical sessions in genomics and bioinformatics (computer lab)

Timetable and Resources

  • Lecture Availability:

    • PowerPoint slides available weekly

  • Workshop Attendance: Highly recommended; sessions not recorded

  • Recommended Textbook:

    • Meneely et al. (2017) Genetics Genes, Genomes and Evolution, OUP

  • Further Reading: Detailed guidance provided during lectures

Assignments and Assessments

  • Assessment Policy: No alternative work or catch-up allowed

  • Compensation for Missed Assessments:

    • Dependent on successful EC application

    • Deferred work due by assessment deadline

  • Assignment Details:

    • MBG1: Practical exercise - online quiz (Week 29); formative assessment

    • MGB2: Online progress test (Week 37); accounts for 50% of module

      • 25 multiple choice questions & 2 short answer questions

      • On campus exam; duration of 2 hours

Genetics: Basic Concepts

  • Historical Perspective:

    • Overview of inheritance concepts and the gene

    • Importance of scientific inquiry and evolution of ideas

    • Significance of mutants in genetics and their role in evolution

  • Learning Outcomes:

    • Grasp the basis of inheritance and apply genetic knowledge

    • Familiarity with Mendel’s analyses of traits inheritance

Trait Selection and Domestication

  • First Domesticated Crop: Figs cultivated in Jordan around 11,400 years ago

  • Notable Historical Figures:

    • Thomas Fairchild: Crossed Dianthus flowers (1716)

    • John Garton: Established cross-pollination techniques for plant varieties by 1980s

Animal Domestication

  • Animals domesticated around 11,000 years ago

  • Notable Figure: Robert Blackwell (18th century) began selective breeding for traits

Mendelian Inheritance

  • Established by Gregor Mendel (1865):

    • Proposed discrete traits inherited as distinct factors

    • Employed simple traits analysis, focusing on one pair of traits at a time

    • Understood probability and sample sizing in experiments

  • Experiments with Peas:

    • Example: Green versus yellow peas; yellow is dominant, green is recessive

    • Resulting ratios confirmed Mendel's hypotheses

Punnett Square and Data Significance

  • Punnett Square: Tool for displaying all possible allele combinations from gametes

  • Data Analysis in Inheritance:

    • Demonstrated ratios across various traits in Mendelian studies

    • Empirical evidence supporting dominant and recessive traits in plants

Significant Genetic Contributors

  • Carl Correns: Restated Mendel's work in 1900

  • Erich Tschermak and William Spillman: Independently verified Mendelian theory through new crop varieties

  • Hugo de Vries: Proposed traits as particles known as pangenes and introduced mutation theory

The Chromosome Theory

  • Theodor Boveri: Discovered chromosomes; emphasized their order for development

  • Walter Sutton: Proposed chromosomes as heredity's physical entities (1902, 1903)

Thomas H. Morgan's Contributions

  • Link between Chromosomes and Inheritance: Basic pattern established through experiments with Drosophila

  • Gene Mutation Evidence: Discovered linkage of traits (e.g., eye color) to specific chromosomes

Griffith's Transforming Principle

  • Experiments: Used Streptococcus pneumoniae to identify genetic material through transformation

  • Avery and Colleagues: Purified DNA, demonstrating it as the "transforming principle"

DNA Structure and Composition

  • Basic Structure: DNA consists of nucleotides, each with a phosphate group, sugar, and nitrogenous base

  • Pyrimidines and Purines: Two main classifications of nitrogenous bases in DNA

Understanding Genomes

  • Definitions:

    • Genome: All genetic info in DNA within haploid chromosomes

    • Genes: Small segments coding for various RNA types

  • Advanced Techniques: Modern genetics utilizes molecular techniques for reverse and forward genetics analysis

Genetic Terminology

  • Diploid Organisms: Have two alleles; homozygous (identical) or heterozygous (different)

  • Phenotypes: Dominant traits (common) vs. recessive traits (rare)

Human Genetic Diseases

  • Dominant and Recessive Patterns: Examples include Achondroplasia (dominant) and Cystic fibrosis (recessive)

  • Sickle-Cell Anemia: Illustrative of genetic phenotype consequences

Cli nical Insights into Albinism

  • Gene Variants: Multiple genes associated with different types of albinism, each with distinct phenotypic presentations

  • Mutant Analysis: Critical for understanding inheritance and gene function

The Test Cross Method

  • Definition: Used to determine unknown genotype via crosses with homozygous recessives

  • Genetic Variants: Essential for studying inheritance in genetics

Summary of Key Figures and Ideas

  • Notable Researchers: Drawing important connections between phenotype and genotypes over history

  • Curiosity and Scientific Evolution: Emphasized the importance of understanding genetic variants and research in genetics.