BIOLOGY 1M03 Lecture Notes - Lecture 16: Crispr, Sickle-Cell Disease, Tachycardia

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1M03
• Professor: Lovaye Kajiura

Document Summary

Hemoglobin: oxygen-carrying hemoglobin (hb) contains 2 kinds of polypeptides. Hb is a tetramer (2 similar pairs of polypeptide chains called globin chains, 4 chains in total, 2 of each type) . Alpha-globin and beta-globin: coded by families of genes (have shared nucleotide or protein sequences) on different chromosomes. Humans express different versions of alpha and beta genes as they develop from embryo fetus adult. These genes evolved from duplication and mutation of an ancestral globin gene. C(cid:396)ossi(cid:374)g ove(cid:396) of the h(cid:271) ge(cid:374)e has lead to u(cid:374)e(cid:395)ual (cid:272)(cid:396)ossi(cid:374)g fo(cid:396)(cid:373)i(cid:374)g a fa(cid:373)ily of b ge(cid:374)es (cid:894)b" [b(cid:1005)], b/b" [b(cid:1006)], b [b(cid:1007)](cid:895) Beta-globin gene went under sequence divergence (accumulated mutations over time) Regulation through transcription facts: klf1 & bcl11a. Fetal form mostly used until about 6 weeks before birth. Adult form used from about birth onwards (dominant after 6 week after birth) Fetal gamma-hb has a higher affinity for oxygen (fetus can get more oxygen from mother)