Non-Mendelian genetics

1
Non-Mendelian genetics

• Gil McVean, Department of Statistics, Oxford

2
Genomic imprinting

• Parent-of-origin specific expression
• Mammals, plants, insects

3
Paramutation

• Inherited interactions between homologous alleles
• Weak alleles convert Strong alleles

4
Maternal effects

• Maternally derived products in embryos
• Leads to death of non-carrier offspring

5
Phenotypic buffering

• HSP90 chaperone can mask the deleterious
  effects of mutation
• Block HSP90 gt mutations exposed
• Select for mutations
• Exposed phenotype stable even with HSP90

Rutherford Lindquist (1998)
6
Mechanisms of epigenetics

• Methylation
• Chromatin remodelling
• Histone modification
• RNA interference/interactions

7
Epigenetics and evolution

• What selection pressures led to the origin of
  epigenetic systems?
• Are epigenetically inherited characters important
  in evolution?