Environmental Genetics Lecture 1 PDF

Genetics for environmental studies ENV 212 Dr. Hadil Alahdal 2024 Lecturers Info  Loading… Exploring the Interplay Between Genes and the Environment It focuses on traits involved in interactions between and within...

Genetics for environmental studies ENV 212 Dr. Hadil Alahdal 2024 Lecturers Info  Loading… Exploring the Interplay Between Genes and the Environment It focuses on traits involved in interactions between and within species, and between an o Genetics for Reference book: Environmental "Principles of Conservation Genetics" by Richard Frankham, Jonathan D. Ballou, and David A. Bri Studies? 1- https://www.amazon.sa/-/en/Introduction-Conservation-Genetics-Richard-Frankham/dp/0 21&linkCode=df0&hvadid=703865593197&hvpos=&hvnetw=g&hvrand=136871430724138 525627258930&psc=1&mcid=00b16a0bb0c93cf6950ad7983cb82afb&gad_source=1 2- file:///C:/Users/al_ma/Downloads/AnIntroductiontoGeneticAnalysis.pdf What is the relation between Genetics and the Environment?  What we are going to cover Introduction to Genetics and Environmental Science Population Genetics Loading… Genetic Adaptation and Evolution Genomics and Environmental Health Epigenetics and Environmental Influences Genetic Diversity and Conservation Biology Genetically Modified Organisms (GMOs) and Environmental Impact Molecular Ecology Human Genetics and Environmental Interactions  Week 4: Debate activity (5 marks) Week 6: Midterm (15 marks) Theory 70 Marks Week 7-8: Collage Activity (5 marks) Week 8-9: Assignment (5 marks) Week 15: Final Exam (40 marks) NO BONUS!! Continuous lab assessments Practical 30 Marks Lab reports final exam Total 100 Marks Chapter 1:Introduction to Genetics and Environmental Science KEY QUESTIONS (Genetics ) What is the hereditary material? What is the chemical and physical structure of DNA? How is DNA copied in the formation of new cells and in the gametes that will give rise to the offspring of an individual? What are the functional units of DNA that carry information about development and physiology? What molecules are the main determinants of the basic structural and physiological properties of an organism? What are the steps in translating the information in DNA into protein? What determines the differences between species in their physiology and structure? What are the causes of variation between individuals within species? Objectives: * Understand the basic principles of genetics * Explore the history of genetics *Learn about the different types of genes and mutations * Learn about Genes, the environment, and the organism Genetic variation in the color of corn kernels. Each kernel represents a separate individual with a distinct genetic makeup. The photograph symbolizes the history of humanity’s interest in heredity. Humans were breeding corn thousands of years before the advent of the modern discipline of genetics. Extending this heritage, corn today is one of the main research organisms in classical and molecular genetics Genes as determinants of the inherent properties of species Genes are the units of heredity that determine the inherent properties of a species. Genetics concerns with genes, their effects on all living organisms, and patterns of inheritance of traits. What makes a species what it is? We know that cats always have kittens and people always have babies. This commonsense observation naturally leads to questions about the determination of the properties of a species. The determination must be hereditary because every generation of cats inherits the ability to have kittens. What causes variation within a species? We can distinguish one another and our pet cat from other cats. Such differences within a species require explanation. History of Nucleic Acid Discovery Who is this scientist? Loading… Gregor Mendel “Father of Genetics” What is he known for? Mendel ’s Laws of Inheritance, 1865 Discovering Nucleic Acid Structure 1950 – Edwin Chargaff find Cytosine complements Guanine and Adenine complements Thymine. 1952-1953 James D. Watson and Francis H. C. Crick deduced the double helical structure of DNA.  Central Genetics Molecular Dogma of Biology Molecular Biology Genotype = DN A mRN A Phenotype = Protei n Three fundamental properties are required of genes and DNA 1. Replication. Hereditary molecules must be capable of being copied at two key stages of the life cycle. (development and regeneration). 2. Generation of form. The working structures that make up an organism can be a form or substance, and DNA has the essential “information” needed to create form. (transcription and translation). 3. Mutation. A gene that has changed from one allelic form into another has undergone mutation—an event that happens rarely but regularly. Mutation is not only a basis for variation within a species but also, over the long term, the raw material for evolution.  How are genes working? Let's first discuss Nucleotides Each nucleotide consists of three components: 1. Nitrogenous bases 2. Phosphoric acid 3. Sugar  Nitrogenous Bases They are divided in two groups: 1. Purine (two rings) 2. Pyrimidine (one ring) In DNA ( A, G, C, T) In RNA ( A, G, C, U) All bases attach to the sugar on the 1st carbon. Is this nucleotide from DNA or RNA? DN A Why?  DNA Double Helix DNA is double helix with its sugar-phosphate backbones on the outside and its bases on the inside.  Base Pairing Purines (two rings) pairs with Pyrimidines (one ring) A pairs with T , G pairs with C. Hydrogen bonds ??? 2 bonds between A and T, 3 bonds between C and G Then, How are the strands combined? How does DNA replicate? *Search how DNA is replicated and when. DNA DNA is composed of two nucleotide chains held together by complementary pairing of A with T and G with C. DNA is replicated by the unwinding of the two strands of the double helix and the building up of a new complementary strand on each of the separated strands of the original double helix. 2- Transcription and Translation How areroleproteins 1- The biological of most genes is produced? to carry information specifying the chemical composition of proteins or the regulatory signals that will govern their production by the cell. This information is encoded by the sequence of nucleotides. A typical gene contains the information for one specific protein. During transcription, one of the DNA strands of a gene acts as a template for the synthesis of a complementary RNA molecule. Overview of gene expression  Translation The process of producing a chain of amino acids based on the sequence of nucleotides in the mRNA is called translation. AUU CCG UAC GUA AAU UUG codon codon codon codon codon codon The information in genes is used by the cell in two steps of information transfer: DNA is transcribed into mRNA, which is then translated into the amino acid sequence of a polypeptide. The flow of information from DNA to RNA to protein is a central focus of modern biology 3- What is mutation? Give me three different types of mutations.  Acquire and Accumulate Mutations A third characteristic of genes is that they accumulate changes, or mutations. mutation is essential for variation in phenotypic traits in populations. Sickle Cell HIV Resistance No Effect Genetic Disease Lactose Tolerance Diseases and Tetrachromat Disorders  Sickle Cell Disease The sickle red blood cells cannot fit through tiny capillaries, so they clog and rupture them, starving parts of the body for blood and causing internal bleeding and pain. Furthermore, the sickle cells are so fragile that they burst, leaving the patient anemic. Sickle Cell Disease  Genes as determinants of the inherent properties of species * Genes are made up of DNA, which is a molecule that contains the instructions for building proteins. An organism’s basic complement of DNA is called its genome. Loading… The somatic cells of most plants and animals contain two copies of their genome (diploid). The cells of most fungi, algae, and bacteria contain just one copy of the genome (haploid). The genome itself is made up of one or more extremely long molecules of DNA that are organized into chromosomes. Genes are simply the regions of chromosomal DNA that are involved in the cell’s production of proteins. Genes and environment * Proteins are the building blocks of cells and tissues, and they play a role in all aspects of an organism's life, including its growth, development, and metabolism. * The environment can also influence the expression of genes, which means that the same gene can produce different phenotypes (observable characteristics) in different environments.  The mutational site in the DNA can be : 1- The most common type is nucleotide-pair substitution, which can lead to amino acid substitution or to premature stop codons. 2- Small deletions and duplications also are common. 3- Such mutations are called frameshift mutations. Even a single base deletion or insertion produces widespread damage at the protein level; because mRNA is read from one end “in frame” in groups of three, a loss or gain of one nucleotide pair shifts the reading frame, and all the amino acids translationally downstream will be incorrect. MESSAGE New alleles formed by mutation can result in no function, less function, more function, or new function at the protein level. Molecular basis of allelic variation If the DNA of the tyrosinase-encoding gene changes in such a way that one of these crucial amino acids is replaced by another amino acid or is lost, then there are several possible consequences. First, the enzyme might still be able to perform its functions but in a less efficient manner. Second, the enzyme might be incapable of any function and cause the disease. Third, more rarely, the altered protein may perform its function more efficiently and thus be the basis for future evolution by natural selection. Genetic Variation * Genetic variation is the diversity of genes within a population. * Genetic variation is important for evolution, as it allows populations to adapt to changes in their environment. * There are two main types of genetic variation: heritable variation and non-heritable variation. * Heritable variation is passed from parents to offspring. * Non-heritable variation is not passed from parents to offspring. Key Takeaways: Genetics is fundamental to understanding life, from individual organisms to entire ecosystems. The interplay between genetics and the environment is crucial for the adaptation and evolution of species. Conservation genetics provides valuable tools and insights for protecting biodiversity in the face of environmental challenges. References Frankham, Introduction to Conservation Genetics, Chapters 1 and 2 Introduction to genetics analysis Chapter 1 page 6-12 Molecular genetics, Weaver. chapter 1 history of molecular genetics