BIOL10003 Lecture Notes - Lecture 10: Sickle-Cell Disease, Missense Mutation, Anemia

• School: University of Melbourne
• Department: Biology
• Course: BIOL10003
• Professor: All

Document Summary

Mutant haemoglobin subunit missense mutation: base substitution, where one amino acid is exchanged for another. The polypeptide only differs by one amino acid from the wild-type protein. Recessive (must be homozygous to have the sickle cell phenotype) Hba (normal): dna code = gag ctc mrna code = gag (glutamic acid) Hbs (mutant): gtg cac gug (valine) causes sickle cell anaemia = deoxygenation of tissues. Therefore, hbs alleles become less common in non-malarial areas. But in malarial areas, hbs gives immunity to malaria so hbs becomes more common. The relevant characteristics are heritable therefore, individuals that survive produce more surviving offspring. Pesticide kills nn, making rn more common, eventually resulting in an rr population. Patients may be re-infected while a dose is decaying. Repeat regularly to keep dosage high (complete courses of drugs) Don"t delay until pest /disease returns (cid:894)repeat doses at short intervals(cid:895) Use chemicals with rapid decay (minimise selection time during decay) New mutations always have bad side effects.