Balance Hypothesis: From Classical Genetics to Modern Qenomics

摘要

The concept of genetic balance traces back to the early days of genetics. Additions or subtractions of single chromosomes to the karyotype (aneuploidy) produced greater impacts on the phenotype than whole-genome changes (ploidy). Studies on changes ingene expression in aneuploid and ploidy series revealed a parallel relationship leading to the concept that regulatory genes exhibited a stoichiometric balance, which if upset, would modulate target gene expression. The responsible regulatory genes forthese types of effects primarily have been found to be members of signal transduction pathways or transcription factors of various types. Recent studies of retention of selected duplicate genes following diploidization of ancient polyplodization events have found that signal transduction and transcription factors have been preferentially maintained in a dosage-sensitive relationship. In this essay, we review the historical progression of ideas about genetic balance and discuss some challenges in this field for the future.