Trans-Sensing Effects: The Ups and Downs of Being Together

Transvection Interactions between mutant alleles typically depend upon diffusible factors. However, transvection must depend upon pairing, because when either allele is present on a structurally rearranged chromosome (such as a Steven Henikoff* and Luca Comai† *Howard Hughes Medical Institute Fred Hutchinson Cancer Research Center 1100 Fairview Avenue North Seattle, Washington 98109-1024 †Department of Botany translocation), gene expression is reduced (Figure 1A). A remarkable feature of transvection is that the interacUniversity of Washington Seattle, Washington 98195 tion is disrupted in structural heterozygotes by break points that can be very distant from the affected locus, often anywhere between it and the centromere. Break