Podcast
Questions and Answers
What significant term was proposed to replace 'unit factors' in the early 1900s?
What significant term was proposed to replace 'unit factors' in the early 1900s?
Which breakthrough occurred in the 1950s that initiated the Molecular Biology Era?
Which breakthrough occurred in the 1950s that initiated the Molecular Biology Era?
In which decade was the term 'genetics' first used to describe the study of inheritance?
In which decade was the term 'genetics' first used to describe the study of inheritance?
What was one of the major advancements in genetic technology during the 1970s?
What was one of the major advancements in genetic technology during the 1970s?
Signup and view all the answers
What was confirmed in the 1940s regarding the genetic material?
What was confirmed in the 1940s regarding the genetic material?
Signup and view all the answers
What technological advancement in genetic research became widely available in the 2000s?
What technological advancement in genetic research became widely available in the 2000s?
Signup and view all the answers
Which of the following statements about chromosomes is true?
Which of the following statements about chromosomes is true?
Signup and view all the answers
What major milestone in whole genome sequencing (WGS) was achieved by 2018?
What major milestone in whole genome sequencing (WGS) was achieved by 2018?
Signup and view all the answers
Which of the following is NOT a role of genetic information encoded by DNA?
Which of the following is NOT a role of genetic information encoded by DNA?
Signup and view all the answers
What does the phrase 'induced pluripotent stem (iPS) cells' refer to in genetic research?
What does the phrase 'induced pluripotent stem (iPS) cells' refer to in genetic research?
Signup and view all the answers
Study Notes
Genetics - An Introduction
- The lecture was prepared by Professor Matthew Campbell, School of Genetics & Microbiology, TCD.
- It was delivered by Dr Laetitia Chauve.
- The textbook used is "Biology - A Global Approach" (11th edition, Pearson), by Campbell, Urry, Cain, Wasserman, Minorsky & Reece.
Key Concepts
- The lecture will cover:
- History of Genetics
- DNA, Genes, Chromosomes
- The Central Dogma of Biology
- Genomics
- Genetic diseases
History of Genetics
- 1860s: Mendel's research on inheritance of unit factors. Cytologists described chromosomes and their behavior during mitosis and meiosis.
- 1900s: Rediscovery of Mendel's work. "Gene" was proposed to replace unit factors. Genetics became its own discipline.
- 1905: William Bateson used the term "genetics" to describe the study of inheritance.
- 1940s: Confirmation that the genetic material is DNA, not protein.
- 1950s: Watson and Crick described the double-helical structure of DNA - marking the beginning of the Molecular Biology Era.
- 1960s: Cracking the triplet code and defining the pathway of information flow: "DNA makes RNA makes protein."
DNA Structure
- DNA molecules are composed of two long chains arranged in a double helix.
- Each chain consists of four chemical building blocks (nucleotides): Adenine, Guanine, Thymine, Cytosine.
- The human genome contains 3 billion bases (3 x 109 bp of DNA).
- This is equivalent to about a million pages of text.
Key Aspects of Genetics
- Humans have 10-100 trillion cells, each containing approximately 2 meters of DNA.
- DNA from every cell in the body, if stretched end-to-end, would reach to the moon and back over 800 times.
- The genome is tightly packed into chromosomes.
- Humans have 23 pairs of chromosomes.
Human Karyotype
- A karyotype is a visual representation of an organism's chromosomes.
- It shows the number and type of chromosomes present in a cell.
- Different methods are used to identify chromosomes. These include staining with dyes (G-banding), which creates different banding patterns.
- The sex chromosomes are noted as XX for females and XY for males.
The Central Dogma of Molecular Biology
- It summarizes the process of how genetic information flows from DNA to RNA to proteins.
- Only ~1% of the genome codes for proteins.
- Much of the genome makes RNA but does not code for protein (non-coding RNAs).
- The sequence provides the blueprint for making a protein.
Genetic Diseases (Mendelian Disorders)
-
Single-gene defects: Diseases due to mutations in a single gene.
- Autosomal dominant: 50% of offspring inherit the affected allele and develop the disease (e.g., Achondroplasia).
- Autosomal recessive: both parents need to carry the affected allele for offspring to have a chance of inheriting the affected gene (e.g., Cystic Fibrosis, Retinitis Pigmentosa).
- X-linked recessive: Affected gene is on the X chromosome which causes a higher incidence in males (e.g., Haemophilia).
Genomics:
- Genomics is the study of the entire set of genes in one or more species.
- To do this, it depends on:
- High-throughput technology
- Bioinformatics (computational tools)
- Interdisciplinary research teams
Genomics Applications
- Human genome sequence (2003; estimated $2-3 billion)
- Whole human genome sequencing cost less than $1000 by 2019
Gene-based medicines
- Knowledge of the genes causing genetic conditions enables the development of intervention methods.
- Dominant diseases: Often involve suppressing expression of the mutant gene.
- Recessive diseases: Involve supplying a normal copy of the gene to provide the normal protein.
Drug Development
- Using information from the human genome project, along with tools like viral vectors and animal models helps develop therapies for genetic disorders.
Inherited Retinal Disorders
- LCA (Leber Congenital Amaurosis) is a recessive genetic eye disorder, frequently causing visual loss early in life.
- The RPE65 gene is important for regenerating light-sensitive molecules in the retina.
Gene Therapy
- Examples such as Luxturna (RPE65 replacement) show the use of viral vectors carrying a healthy gene.
- This method provides the key therapeutic approach for many genetic disorders.
Advanced topics
- Pharmacogenomics: Personalised medicine approach tailoring treatments to a patient's genetic makeup, especially important with therapeutic proteins and drug metabolism.
- Examples of important genes encoding drug-metabolizing enzymes (DMEs) are described and their role discussed.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the foundational concepts of genetics, including the history, structure of DNA, and genetic diseases. This quiz is based on the textbook 'Biology - A Global Approach' and covers essential topics such as the Central Dogma and genomics.
