SOCR 330 Lecture Notes - Organelle, Chloroplast, Retinitis Pigmentosa
Document Summary
Inherited genetic disorder shows symptoms earlier and with increased severity in each succeeding generation. Caused by meiotic slippage increasing number of abnormal trinucleotide repeats each generation. Also known as extranuclear inheritance or maternal inheritance. Trait coded for by genes located in dna of mitochondria or chloroplast. Cytoplasmic organelles in most organisms have high levels of uniparental inheritance, usually maternal. Cytoplasm of ovum or ovule contains multiple mitochondria and/or chloroplasts with copies of maternal organelle dna. Inheritance of variegated leaves in four o"clock plants. Reciprocal crosses do not give same f1 phenotypes. Maternal but not paternal extranuclear genotype inherited by f1 offspring. Mixture of white and green chloroplasts white, green, and variegated f1. Increasing number of human diseases recognized as caused by maternally inherited mitochondrial defects. Maternal genotype influences offspring phenotype independently of inheritance of maternal genes. Some mothers (cows, horses, humans ) produce bigger babies because mother"s genotype creates favorable uterine environment.
