GENE 320 Lecture Notes - Lecture 9: Symbiogenesis, Gamete, Zygosity
Document Summary
Extranuclear inheritance inheritance of genetic information to offspring through cytoplasm not nucleus. Organelle heredity - dna contained in the mitochondria or chloroplasts determines certain phenotypic characteristics of the offspring. Infectious heredity - result from a symbiotic or parasitic association with a microorganism. 13 proteins required for aerobic cellular respiration disruption of mitochondrial. Disorder criteria: must exhibit maternal inheritance re ect de ciency in bioenergetic function of organelle must have mutation in one or more mitochondrial gene. Variation in genetic content of organelles zygotes receives large numbers of organelles through egg. Mutation in one or few will be diluted out by many mitochondria that lack mutation and function normally. Adult cells have variable mixture of normal and abnormal organelles. Threshold effect: the number of mutatnt mitochondria in cells determiens if the carriers are affected see on pedigree. For most deleterious mitochondrial mutations, there is a threshold effect.
