BIOL10003 Lecture Notes - Lecture 34: Genomic Imprinting, Nondisjunction, Gametogenesis
Document Summary
Nail patella (not a serious disease) is linked to blood type (chromosome 9) Hard to test for nail patella but easy to test for blood type, so can determine from a pedigree. Look at association between blood group alleles (ia, ib, io) and nail patella alleles (n, n) Use a marker a gene locus with a recognisable phenotype, e. g. coloured/colourless, or could be molecular e. g. restriction enzyme cutting site, vntr/str/snp. Imprinting an epigenetic event the maternity/paternity of an inherited chromosome determines the phenotype. Wiped in primordial germ cells but re-established according to the sex of the parent e. g. prader willy (paternal chromosome) vs angelman syndrome (maternal chromosome) Both are a deletion of a region on chromosome 15 (15q11-q13); a result of monoallelic expression. Or uniparental disomy (both chromosomes came from the same parent nondisjunction) Isodisomy a single chromosome from one parent is duplicated (non-disjunction at meiosis ii)