Cytogenetics Lesson 2 - PDF

CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Lesson 2: Application & Importance of Cytogenetics Types: a. Abnormal Chromosome 1. D...

CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Lesson 2: Application & Importance of Cytogenetics Types: a. Abnormal Chromosome 1. DNA PROFILING Number (aneuploidy) - Comparing of DNA sequences Monosomy - one copy (DNA fingering) missing one - Purpose: establish or rule out chromosomes identity, relationship, ancestry Trisomy - three copy of a - Forensic Science: collecting of chromosome physical evidence b. Abnormal Chromosome 2. CONNECTS PAST TO PRESENT Structure - Determining family relationship Ex: Turner Syndrome: - Establishing geographic Missing X Chromosome, origins of specific population the gender of that - DNA testing can provide views person is female but her into past epidemics of sexual characteristics infectious diseases by are affected. detecting genes of the pathogens. 4. CANCER CYTOGENETICS - Ex.: Analysis of DNA in the - Chromosomal alterations & mummy of Egyptian King rearrangement that occur in Tutankhamun. Revealed DNA various type of cancers from microorganism that - Ex.: Philadelphia chromosome causes Malaria. in Chronic Myeloid Leukemia Specie: Plasmodium (CML) This happens due to an 3. CHROMOSOMAL ABNORMALITIES alteration of chromosome 9 & - Numerical changes 22; called TRANSLOCATION. (Aneuploidy) & structural - Acquired Cancer: due to abnormalities lifestyle, environmental factors - Help diagnose genetic and diet disorders: down syndrome, - Cancer: Abnormal turner syndrome, etc. Chromosomes - Prenatal Diagnosis: helps in detecting abnormalities in 5. CONSERVATION GENETICS developing fetuses - Way to rebuild population that (karyotyping & FISH) are headed toward species - Assisted Reproductive extinction Technologies (ARTS): various - Ex.: Northern White Rhinoceros medical procedures used of Africa primarily to address infertility Checking their chromosomes such as IVF ~> ensuring the for abnormalities. They did a genetic health of embryos cryopreservation. (chromosomal content) before implantation. CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. 6. GENETIC MODIFICATION APPLICATIONS IN METAGENOMICS: - Altering a gene/genome in a Bioremediation (studying microbial way that doesn’t occur in eliminating pollutants, Nature ~> genetically modified ex.: in oil spill, a certain bacteria with organism (GMOs) genes will be used so that it will eat - Arise from: recombinant DNA the oil) technology & genome editing Climate Change - Ex.: Green Mice: contain gene Agriculture (soil: microbial encoding a jellyfish green community) fluorescent protein Human Microbiome (organism Used to trace location of gene inhabiting organism) E.coli was put a gene of a Infectious Diseases (identifying human; due to diabetes & causative agents E.coli produced insulin - Ex.: Bacteria bearing human genes: provided many drugs (insulin & clothing factors) 7. PRECISION MEDICINE - Molecular mechanism underlying chromosomal abnormalities, gene expression & genomic stability. - Cure of some diseases - Pharmacogenetics: consults DNA information to select drugs that are most likely effective & less side effects. 8. EXOME SEQUENCING - Determines the order of the DNA bases of all part of the genome that encode protein - Can help diagnose rare genetic diseases/disorders by identifying mutations in the coding of genes. Metagenomics - study of genetic material recovered from environmental sample (soil, water, air, garbage) & host associated samples (human gut, skin, oral cavity) - This doesn’t need to be cultured CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. 2.1 Cell Introduction: 2.2 Cell Components: Cell 4 Basic Types of Tissue: - Basic unit of life that carries 1. Epithelial Tissue out necessary function to - Tight cell layers form linings maintain life. that protect, secrete, absorb - Function: reproduction, growth, and excrete response to stimuli and energy 2. Connective Tissue use. - Variety of cell type and - All multicellular organism like surrounding materials protect, animals, fungi, and plants have support, bind to cells, and fill cell, even celled-organism such spaces throughout the body; as PARAMECIUM & AMOEBA cartilage, bone, blood & fat. - Composed of Molecules 3. Muscle Tissue - Requires vitamins and minerals - Cells contract, providing in small amounts movement 4. Nervous Tissue More Wider View of Function of Cell: - Neurons transmit information 1. Chemical Reaction/Metabolism as electrochemical impulses a. Anabolism - simple molecule to that coordinate movement and large molecule, the input of also sense and respond to energy (ATP) environmental stimuli b. Catabolism - large molecule to simple molecule, gives off Cytology- study of cell; it’s structure energy (ATP) Molecules our Body Synthesize: Macromolecule - needed in large TYPES OF CELL: amounts; carbohydrates, protein, ❖ Somatic Cell lipids, nucleic acid - Also called as body cells Macromolecule - need in small - Have two copies of the genome amounts; vitamins & minerals and are said to be DIPLOID (2 chromosomes) If these two weren’t able to break ❖ Germ Cell down, there would be an Inborn error - Are sperm and egg cells / sex of metabolism & lack of enzyme. cells - Have one copy of the genome 2. Mitosis and are HAPLOID (one set of - 1 parent cell (46 chromosomes) chromosome) also gives off the same number - Meeting of the sperm & egg of chromosomes to its restores the diploid state. daughter cells ❖ Stem Cell - Diploid cell that divide to give 3. Reproduction rise to differentiated cells, in a - Production of new individual process called SELF-RENEWAL - Enable a body to develop, grow Bacteria & repair damage. - Most abundant organism on earth - Single celled CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Prokaryotic Cell Nucleus - Do not have a nucleus - Structure: Porous, double membrane sac containing DNA Eukaryotic Cell - Function: Separates DNA within - Different from prokaryotic cell cell as it has ORGANELLES: that - Most prominent organelles of perform specific functions. most cell - Contains DNA with many Major Macromolecules: proteins to form chromosomes, - That make up cells and use as some proteins form fibers that fuels: fill out the nucleus, its 1. Carbohydrates (sugar and SPHERICAL SHAPE. starches) - provides energy and - RNA is abundant too, enzymes contribute to the cell structure. and other types of proteins are 2. Lipids (fats & oils) - form the required to synthesize RNA and basis of hormones, form DNA membranes, provide insulation and store energy. Nucleoplasm 3. Protein (DNA & RNA) - enable - Fluid in the nucleus blood clot, has antibodies to fight infection. Nuclear Envelope 4. Nucleic Acid - (DNA & RNA) - - Layer that surrounds the study of genetics that translate nucleus information to generations into specific proteins that give Nuclear Pores cells its characteristics. - Rings of several types of proteins around an opening, 2.3.ORGANELLES like lined portholes in a ship’s - Enable a cell to retain as well side wherein biochemical as to use its genetic instruction exit/enter. to secrete substance, dismantle debris, and acquire Nuclear Lamina energy. - Fibrous material that is the inner face of the nuclear membrane. This layer is not just an inert covering, but turns off the expression of genes that contact from within it. - Provides mechanical support and holds the nuclear pores. Nucleolus (little nucleus) - Area that is darkened when seen in a microscope - Where Ribosomes are produced. CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Ribosomes - Structure: 2 associated Rough ER globular subunits of RNA & - Near the nucleus, flattened protein and studded with ribosomes - Function: scaffold & catalyst - Protein synthesis starts on for protein synthesis Rough ER, where mRNA attaches to ribosomes, linking Plasma Membrane (outer boundary) amino acids to form proteins - Is cytoplasm, also called the for cell exit or membrane entry. cell membrane. Smooth ER - Include stored proteins, - It’s a second formed when the carbohydrates and lipids; rough ER winds out the plasma pigment molecules and various membrane, the ribosomes small chemicals. (also called become fewer and the tubules CYTOSOL when other parts are widen. removed.) - Lipids are made and added to the proteins arriving from the THREE CELLULAR FUNCTION Rough ER, then are transported 1. Secretion until the Smooth ER narrows 2. Digestion inside the Cell and ends. 3. Energy Production Vesicles - Structure: Membrane bound 2.4 SECRETION: THE EUKARYOTIC sac PRODUCTION LINE - Function: Temporarily stores or Secretion transports substances - release of substance from a - Are exported without a vesicle cell. because a vesicle is itself made - begins when the body sends of lipid. biochemicals to a cell. Golgi Apparatus Messenger RNA (mRNA) - Structure: Stacks of membrane - Information in certain enzymes enclosed sacs that are transcribed into mRNA - Function: site where sugars are which then exit the nucleus. made and linked into starches Transfer RNA (tRNA) or joined to lipids or proteins; - Direct the manufacture of proteins finish folding, proteins. These include secretion stored. nutritive proteins called - The secretory production line, Caseins; antibodies that wherein the vesicle takes its protect against infection and contents which looks like a enzymes. stack of pancakes. Endoplasmic Reticulum (ER) - The Processing Center, a - Structure: Membrane network; column of 4-6 interconnected Rough ER has ribosomes flat, membrane enclosed sacs. Smooth ER does not have Lactocytes (milk cell) - Function: Site of protein - Epithelial (lining) cells from synthesis and folding; lipid tubules which secrete synthesis components of milk. - Acts as QUALITY CONTROL CENTER OF THE CELL CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Exosome Adrenoleukodystrophy - The type of transport of - Absence of peroxisomal molecules between cells uses enzyme vesicles that bud from one cell - Early symptoms: low blood to merge with and empty their sugar, skin darkening, contents into other cells. weakness, visual loss, altered - 30-100 nanometers in diameter behavior and cognition, - Carry proteins, lipids, and RNA irregular heartbeat. and remove debris, transport MITOCHONDRIA immune system molecules, and - Extracts energy (ATP) provide a vast communication - Provide energy by breaking the network among cells. chemical bonds that hold together the nutrient 2.5 INTRACELLULAR DIGESTION - molecules in food. LYSOSOMES & PEROXISOMES - A liver cell has 1,700 mitochondria while muscle cell Lysosomes (bodies that cut) has 10,000 mitochondria - Structure: Sac containing Cristae digestive enzymes - Outer membrane similar to - Function: Degrades debris, those in ER and Golgi recycles cell content Apparatus and and inner - Handles the garbage membrane creates fold - Trash center - These folds hold enzyme that - Membrane-bounded sacs that catalyzes the biochemical contain enzymes that reactions that release energy dismantle bacterial remnants, from nutrient molecules worn out organelles and other Adenosine Triphosphate (ATP) materials like excess - Freed energy is captured and cholesterol stored in the bonds that hold - Contains 43 types of digestive together a molecule enzyme, which must be Fatigue maintained. - Major symptom of diseases Autophagy (eating self) that affect mitochondria. - Where cells disposed its trash Endosome 2.6 BIOLOGICAL MEMBRANE: MEMBRANE - Type of vesicle that forms the STRUCTURE plasma membrane ferries extra Biological Membrane low density lipoprotein (LDL) - Has distinctive structure cholesterol to lysosomes. - Double layer of molecules Peroxisomes called PHOSPHOLIPIDS; a fat - Structure: Sac containing molecule with attached enzyme PHOSPHATE GROUPS; (PO4) is - Function: Breaks down and a phosphorus atom bonded to detoxifies various molecules four oxygen atoms - Abundant in liver & kidney cells - Phospholipids is depicted as a which handle toxins. head with two parallel tails CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Motor Molecules - Power the movement of organelles along these rails as they convert chemical energy into mechanical energy. 2.7 CYTOSKELETON, THREE MAJOR TYPES OF ELEMENTS - The phosphate end of a - Distinguished by protein, type, phospholipid is attracted to diameter and how they aggregate water; HYDROPHILIC (water into larger structures. loving) and the other end, which consists of two chains of 1. Microtubules fatty acids, moves away from - Long, hollow microtubules water and therefore is provide many cellular HYDROPHOBIC (water fearing) movements - Composed of pairs (dimers) of 2.6 THE PLASMA MEMBRANE ENABLES protein called tubulin. CELL TO CELL COMMUNICATION: 2. Microfilaments Signal Transduction - Long, thin rod composed of - Cellular communication many molecules of the protein involves molecules in the actin. plasma membrane detecting - Provide many other functions and transmitting signals while in the cell through proteins other molecules orchestrate that interact with actin responses. - When absence/abnormality, Cellular Adhesion genetic diseases result. - The plasma membrane helps 3. Intermediate Filaments cells attach to other cells. - Proteins composed of different These are important in forming cell types dividing cytoskeleton tissue components Faulty Signal Transduction or - Consists of paired proteins Cellular Adhesion entwined to form nested coiled - Can harm health as it cause rods cancer - Abundant in NERVE and SKIN - Cancer cells have abnormal CELLS cellular adhesion which enables them to invade healthy tissue. 2.8 CELL DIVISION AND DEATH The Cytoskeleton They interplay between Mitosis, - Meshwork of protein rods and Cytokinesis, which divide the DNA and the tubules that serves as the cell’s rest of the cell, APOPTOSIS is a form of cell architecture, positioning death. organelles and providing a 3D shape - The proteins are broken down Adult Human Body: 30 trillion cells and built up as the cell performs activities. CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. Apoptosis apportions one set of - Greek: leaves falling from a tree chromosomes along with - Programmed cell death as part organelles into each two of normal development resulting cells called the - Synchronized with Mitosis: daughter cells. mitosis produce new skin, a - Maintains set of 23 scraped knee, peels aways chromosome pairs sunburnt skin cells that might - Another form of cell division: become cancerous Meiosis - produces sperm or Necrosis eggs which have half the - Form of cell death associated amount of genetic material with inflammation & damage that somatic cells do Cancer - Profound derangement of the INTERPHASE balance between cell division & - Cell continues basic function of life cell death while also replicating its DNA and - Mitosis occurs frequently some organelles - Apoptosis occurs infrequently - DIVIDED into two gaps: G1 & G2 Phases and One Synthesis (S) Phase, 2.9 THE CELL CYCLE: a cell can exit the cycle at G1 to enter - Series of events that describe the a quiet phase called G0 sequence of activities as a cell prepares for and undergoes division. DURING GO - A quiet phase - Cell is alive and maintains its specialized characteristics but doesn't replicate its DNA to divide. From GO, a cell may also proceed to mitosis and divide or die. DURING G1 PHASE - Following Mitosis, the cell resumes synthesis of proteins, lipids and carbohydrates. These molecules combine to produce extra plasma membrane required to surround the two new cells that form from one original one. - A period that varies most in duration DURING S PHASE - The cell replicates its entire genome. This happens simultaneously from several starting points to get the enormous job done. Two Major Phases: - After DNA replication, each 1. INTERPHASE (not dividing) chromosome consists of 2 copies of 2. MITOSIS (dividing) the genome joined at an area called - Cell duplicates its the centromere. chromosomes, in cytokinesis; it CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. - Nucleolus is no longer visible 2. METAPHASE SPINDLE - Chromosomes attach to the - Proteins synthesize during this phase spindle at their centromeres forming a mitotic spindle, separating and align along the center of chromosomes. the cell, which is called EQUATOR CENTRIOLES - Chromosomes align - Microtubules form structures near 3. ANAPHASE the nucleus - plasma membrane indents at the center where the CENTROMERES chromosomes line up. - Oblong structures that are formed - A band of microfilaments forms when centriole microtubules join with on the inside face of the proteins and are oriented at right plasma membrane, angles to each other, organize other constricting the cell down the microtubules into the spindle. middle. - Centromeres and chromatid DURING G2 PHASE separates - Occurs after the DNA has been 4. TELOPHASE replicated, proteins synthesize, - Final stage of mitosis membranes assembled, and stored - Spindle falls apart, division of as empty vesicles beneath plasma the genetic material is membranes. complete. MITOSIS 2.10 CONTROL OF THE CELL CYCLE Chromatids 1. Cell Cycle Checkpoint - Long strands of chromosomal - Ensure that mitotic events material in replicated occur in the correct sequences chromosomes, if attached at a centromere, are called sister a. DNA DAMAGE CHECKPOINT: after S chromatids. phase - Space between sister - Checks if DNA is correctly chromatids are called Furrow made b. APOPTOSIS CHECKPOINT: after G2 phase - Checks if the cell is not damaged - If damage, automatic cell death or apoptosis c. SPINDLE ASSEMBLY CHECKPOINT: during metaphase 1. PROPHASE - If the chromosomes has been - First stage of mitosis attached to the spindle or it is - This coiling shortens and aligned thickens the chromosomes, easing their separation. 2. Cells Obey an Internal “Clock” - The spindle assembles, - Approximate times to divide centrioles appear, the nuclear envelope breaks down CYTOGENETICS PRELIM - BMLS 2E DAVAO DOCTORS COLLEGE INC. PREPARED by LANCE, KEZZIAH RAPHA D. - Mammalian Cells (cultured): properly. 40-60x division LDL - low density - Connective Cells from a Fetus: lipoprotein/bad 50 more times cholesterol - Connective Cells from Adults: only 14-29x Proteins: Causes urine to Maple Syrup Urine have a distinct Disease sweet smell 3. Telomeres resembling a maple - Chromosomes tips tells how syrup many cell division remains Cannot break down: - At each mitosis, telomeres Valine, Leucine and loses 50-200 endmost bases, Isoleucine shortening chromosomes Nucleic Acid: Deficiency in - Mitosis stop approx. 50 Lesch - Nyhan enzyme HGPRT divisions Syndrome (Hypoxanthine-guanine phosphoribosyltransfer ase) 4. External Factors Body could not a. Crowding - slow or halts mitosis recycle purines Contact Inhibition: if the (DNA building cell detects it has a blocks) instead of neighboring cell, it stops converting them into uric acid which dividing. crystallized in urine Cancer Cells loses Can cause kidney contact inhibition stones; Gouty creating tumors Arthritis b. Hormone & Growth Factor Vitamins: Slows body’s use of - Chemical signals that Biotinidase vitamin biotin (B7) control the cell from the Deficiency Can cause skin outside problems, - Cell division & repair; dermatitis, muscle scab weakness, blurry c. Proteins vision, hearing loss - Cyclins & Kinases: Minerals: Liver could no interact inside cell Wilson Disease longer control the activating the genes excess copper whose product carry out (found in laman mitosis. loob) that the digestive tract absorbed from food Can cause CNS 2.11 INBORN ERRORS IN METABOLISM: disorder, Kayser-Fleischer Carbohydrate: Lacks lactase which Ring Eye, Lactase Deficiency enables the Cardiomyopathy, digestive system to Hepatomegaly, breakdown lactose Renal tubular dysfunction, Lipids: Genetic defect in Arthritis Familial the body’s ability to Hypercholesterole metabolize mia cholesterol