Lec 1

• Genetics is the fraction of biology that studies heredity
• Genetics is the center of all biology because gene activity underlies all biological processes
• Genetics


  The study of biological properties that are transmitted from parents to offspring, including genes, the molecular nature of these genes, how these genes are transmitted from generation to generation, and the study of how these genes are expressed and how their activity is regulated
• An understanding of gene structure, activity and regulation helps to understand how these genes control all biological processes (from cell structure to reproduction)
• Veterinary Genetics


  The study of the heredity of characters (health and production related) associated with animal species, both livestock and other animal species
• Animal Breeding


  The application of principles of genetics in the breeding and selection of animals for the purposes of production of food, fiber and other products, recreation and other economic activities
• Classic Genetics


  The scientific research done in Genetics previous to the Central Dogma of genetics proposed by Beadle and Tatum in 1941, which encompassed mainly transmission genetics
• Modern Genetics


  The scientific research done in Genetics after 1941, which is mainly Molecular genetics
• Subdisciplines of Genetics


  • Transmission Genetics
  • Molecular Genetics
  • Quantitative Genetics
  • Population Genetics
• Transmission Genetics


  The study of how genes are transmitted from generation to generation and how they recombine
• Molecular Genetics


  The study of the molecular structure and function of genes, including analyzing the sequence of the nitrogen bases in a gene and how it may change its expression
• Quantitative Genetics


  The study of the heredity of a trait in a large group of individuals, where the individual trait is codified by many genes simultaneously
• Population Genetics


  The study of the heredity of one or a few genes in a large group of individuals (population)
• Tools used in Genetic Research

  • Classic techniques of breeding such as crosses, backcrosses and testcrossing
  • Microscopic techniques, such as SEM, TEM, and others
  • Molecular techniques such as DNA sequencing, PCR, cloning, etc.
  • Use of genetic model organisms
  • Construction of Genetic maps
  • Genetic Databases
• Genetic research has progressed very well since the term genetics was introduced in the early 20th century, advancing from traditional selective breeding of plants and animals to the modern genetics of DNA sequencing, genetic manipulation and genome editing
• The 12th Malaysia International Genetics Congress (MiGC12) highlighted genome editing specifically focusing on the CRISPR system, as well as genetic topics for plants, human, animal and microbes
• DNA (deoxyribonucleic acid)


  The genetic material in all prokaryotes, eukaryotes and some viruses, consisting of two strands (chains) of nucleotides
• Nucleotide


  A unit of DNA consisting of a phosphate group, a pentose (5C sugar) and a nitrogen base (A, G, C, T)
• Gene


  A specific sequence of nucleotides that codes for a protein
• Genome


  The full sequence of the DNA or all the genes
• Chromosome


  The structure in the cell that carries the genetic material (DNA)
• Chromosome


  • Chromatid - one of the two identical parts of the chromosome
  • Centromere - the point where the two chromatids touch, and where the spindle fibers attach and a kinetochore is formed
  • Short arm
  • Long arm
• Centromere


  A constricted region of a chromosome that separates it into a short arm (p) and a long arm (q)
• Gene


  A segment of the chromosome that codes for a protein, carrying biological information
• Exons


  The DNA bases that are transcribed into mRNA and eventually code for amino acids in the proteins (Coding DNA)
• Introns


  The DNA bases found between exons, which are not transcribed (Interrupting DNA)
• Genetic Marker


  Any alteration in a sequence of nucleic acids or other genetic trait that can be readily detected and used to identify individuals, populations, or species or to identify genes involved in inherited disease
• A gene can be defined as a region of DNA that controls a hereditary characteristic
• Gene


  A locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions and/or other functional sequence regions
• Gene


  • May not produce a single gene product
  • May produce many gene products of proteins and enzymes
• Introns


  DNA bases, which are found between exons, but are not transcribed (Interrupting DNA)
• Genes which contain introns are known as interrupted genes
• Genetic Marker


  Regions of DNA (genes) or some segments of DNA with no known coding function but whose pattern of inheritance can be determined
• Genetic Markers


  • Restriction fragment length polymorphism (RFLP), simple sequence length polymorphisms (SSLPs), single nucleotide polymorphism (SNPs), Insertions/deletions (indels)
• Gene


  A region of DNA that controls a hereditary characteristic
• Gene


  Corresponds to a sequence used in the production of a specific protein/proteins or RNA
• Gene


  Carries biological information in a form that must be copied and transmitted from each cell to all its progeny
• Gene


  Includes the entire functional unit: coding DNA sequences (exons), non-coding regulatory DNA sequences (introns)
• Gene Expression: Transcription


  1. Transcription = DNA → RNA (making copies)

  2. Translation = RNA → protein (what it means)
• Transcription: DNA serves as the template for the synthesis of RNA much as it does for its own replication