Cell number regulator genes in provide candidate genes for the control of fruit size in sweet and sour cherry.

Striking increases in fruit size distinguish cultivated descendants from small-fruited wild progenitors for fleshy fruited species such as (tomato) and spp. (peach, cherry, plum, and apricot). The first fruit weight gene identified as a result of domestication and selection was the tomato gene. Members of the gene family in corn () have been named (Cell Number Regulator) and two of them exert their effect on organ size by modulating cell number. Due to the critical roles of genes in regulating cell number and organ size, this family provides an excellent source of candidates for fruit size genes in other domesticated species, such as those found in the genus. A total of 23 family members were identified in the peach genome, spanning the eight chromosomes. Two of these were located within confidence intervals of major quantitative trait loci (QTL) previously discovered on linkage groups 2 and 6 in sweet cherry (), named and , respectively. An analysis of haplotype, sequence, segregation and association with fruit size strongly supports a role of in the sweet cherry linkage group 2 fruit size QTL, and this QTL is also likely present in sour cherry (). The finding that the increase in fleshy fruit size in both tomato and cherry associated with domestication may be due to changes in members of a common ancestral gene family supports the notion that similar phenotypic changes exhibited by independently domesticated taxa may have a common genetic basis.