BIOL 2040 Lecture Notes - Lecture 8: Heteroplasmy, Somatic Cell, Transfer Rna
Document Summary
~200-300kb >> ~17kb ***way smaller than bacteria genome; horizontal gene transfer*** 22- trna ; 2rrna ; 13 other genes. Some of the most debilitating diseases come from mtdna mutations; control enzymes critical in atp production = can be catastrophic to organism. Since all mitochondria can actually be different, there is almost unlimited heterogeneity not all of the mitochondria that are present in a cell contain these mutations. 1/5000 people are carriers of some deleterious mutations in mtdna genome. Typical human somatic cell has (~500-1000; few hundred ) mitochondria, and only some carry the mutation! Some chloroplasts carry mutations such that they can"t produce chlorophyll. Kss kearn sayne syndrome: droopy eyes; extra-ocular muscles. Merrf (myoclonic epilepsy and ragged-red fibre disease) 1/400,000; varying degrees expressivity due to heteroplasmy; mutation disrupts the mitochondrial gene trna lys and disrupts oxidative phosphorylation. Lhon (leber"s hereditary optic neuropathy) sudden bilateral blindness; variable onset; average loss of vision at 27.
