Typically, it is assumed that the maternal and paternal alleles for most genes are equally expressed. Known exceptions include canonical imprinted genes, random X-chromosome inactivation, olfactory receptors and clustered protocadherins. Here, I will discuss our recent work showing that allele-specific expression is frequent in the genome and involves subtypes of epigenetic allelic effects that differ in terms of heritability, clonality and stability over time. An emerging area involves understanding allelic effects in a cell-type and developmental stage-specific manner and determining how these effects influence the impact of genetic variants and mutations on cell functions. A deeper understanding of epigenetics at the allele and cellular level could help clarify the mechanisms underlying phenotypic variance. I will discuss evidence that organisms benefit from diploidy and polyploidy and diversity in allelic expression because it enables increased capacity to adapt to an unpredictable environment. I will show how polyploidy is selected for during cataclysmic events and allows species to escape extinction. Finally, I will show data from a new unpublished study of novel differential allelic expression effects in the human body and introduce methods that could be used to measure tumor evolvability in a new and improved way.
Results/Conclusions
Allele-specific expression is frequent in the human body, polymorphic in populations and cell-type specific. This work deepens our understanding of the genetic and epigenetic basis of phenotypes and has implications for understanding cancer evolution and designing new Extinction Therapy treatment regimes.