640Lecture0505

640Lecture0505 - types of genetic variation Morphological...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
types of genetic variation Morphological variation Protein variation Nucleic acid variation ultimately DNA measurement of protein variation how do we measure protein variability? Quantify changes in structural similarity. immunological methods enzyme activity differences indirect comparison of shape/charge (electrophoresis) direct comparison of amino acid similarity (sequence) immunological methods to detect variation IDENTIFICATION OF GENETIC LOCI BASED ON USE OF AN ANTIBODY TO DETECT VARIATION IN A TARGET MOLECULE DEFINITIONS ANTIGEN molecule which causes a response by the immune system ANTIBODY molecule of the immune system which recognizes the antigen where/how is the antibody raised? – in human: natural antisera as response to “environmental” antigens – in laboratory animals: manufactured antisera as response to purified (“artificial”) antigen types of immunological variation BLOOD GROUPS(***) other cell surface markers variation within the system of immunological response Variation in immunoglobulin genes Variation in MHC loci Major hostocompatability complex differentiation in protein genes used as antigens (use of antibodies against these proteins to assess immunological “distance” between species) differentiation of blood by type classified according to immunological (antigenic) properties, which are determined by specific substances on the surface of red blood cells determined by genetically controlled, polymorphic, antigenic components of the RBC membrane. The allelic products of a particular genetic locus producing this antigenic component (directly or indirectly) are classified as a blood group system. Blood Groups
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
discovery of blood groups Hedrick , 1975
Background image of page 2
Blood Groups System of antigen (blood cell surface protein) and antibody (agglutinin) Antigen = glycoprotein on cell surface (usually membrane bound) –each glycoprotein is characterized by the presence of a specific complex carbohydrate > 80? different described blood groups 20 clearly recognized polymorphic groups examples: ABO, MNSs, Lutheran, Kell, Xg Many others are not "polymorphic“ – “Private” or “public” antigens Mostly RBC cell surface antigen; Some also act as WBC antigens Blood Groups Problem: Detection of a blood group depends greatly on presence of variation in the population Most highly polymorphic forms discovered first (because of transfusion incompatibility) –Antibody = immunoglobulin obtained from individuals who have transfusion reaction Blood Groups For Population Genetics: historically important because they were the only useful markers for 1900-1965 allowed comparison of different human populations A.E. Mourant - The distribution of the human blood groups, and other polymorphisms (1976) Blood Groups AGGLUTINATION NO AGGLUTINATION BLOOD TYPING REACTIONS AGGLUTINATION Blood Groups Detection depends greatly on presence of variation in
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 25

640Lecture0505 - types of genetic variation Morphological...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online