Evolutionary consequences of autopolyploidy

Abstract

Summary Autopolyploidy is more common in plants than traditionally assumed, but has received little attention compared with allopolyploidy. Hence, the advantages and disadvantages of genome doubling per se compared with genome doubling coupled with hybridizations in allopolyploids remain unclear. Autopolyploids are characterized by genomic redundancy and polysomic inheritance, increasing effective population size. To shed light on the evolutionary consequences of autopolyploidy, we review a broad range of studies focusing on both synthetic and natural autopolyploids encompassing levels of biological organization from genes to evolutionary lineages. The limited evidence currently available suggests that autopolyploids neither experience strong genome restructuring nor wide reorganization of gene expression during the first generations following genome doubling, but that these processes may become more important in the longer term. Biogeographic and ecological surveys point to an association between the formation of autopolyploid lineages and environmental change. We thus hypothesize that polysomic inheritance may provide a short‐term evolutionary advantage for autopolyploids compared to diploid relatives when environmental change enforces range shifts. In addition, autopolyploids should possess increased genome flexibility, allowing them to adapt and persist across heterogeneous landscapes in the long run.

Evolutionary history of two divergent Dmrt1 genes reveals two rounds of polyploidy origins in gibel carp

“…Recent genome-wide studies have confirmed that the problem of genetic incompatibility raised by polyploidy may be resolved by the accumulation of diverse mutational changes to form a stable chimerical and diploidized genome (Buggs et al, 2011;Chen and Ni, 2006;Louis et al, 2012;Tate et al, 2009). And, a lot of biogeographic and ecological investigations have revealed the close association between polyploidy occurrence and environmental change (Parisod et al, 2010;Wu et al, 2010). Perhaps, it is the early polyploidy and the subsequent diploidization as major evolutionary force that promote the common tetraploid ancestor to evolve into a number of extant diverse species or strains of genus Cyprinus and genus Carassius in Asia and Europe, and make them to become highly ecological tolerant and wide adaptive fishes (Gui and Zhou, 2010).…”

High male incidence and evolutionary implications of triploid form in northeast Asia Carassius auratus complex

“…Significantly, these rare unisexual animals are largely associated with polyploidy origin (Neaves and Baumann, 2011;Otto et al, 2007). In plants, polyploidy has been confirmed to be ubiquitous (Jiao et al, 2011), and polyploidy roles in increasing allelic diversity, altering genomic complexity, introducing novel traits, driving ecological transfiguration, and especially facilitating plant invasions have been suggested extensively (Doyle et al, 2008;Parisod et al, 2010;te Beest et al, 2012). Owing to the rarity of polyploid forms, the evolutionary consequence of polyploidy per se and the evolutionary potential of unisexual reproduction maintenance remain unknown in vertebrates.…”

Production of Autopolyploid Lowland Switchgrass Lines Through In Vitro Chromosome Doubling

“…However, the molecular mechanisms that contribute to the novel phenotypes of autopolyploidy plants remain largely unexplored [48][49][50][51]. Interestingly, one report has described the loss of selfincompatibility after polyploidation events [52].…”

“…This indicates that these lines have similar genetic contents but may differ in the dosage of each gene at certain loci. The autooctoploid switchgrass lines could be used as a model to illustrate the consequences of polyploidy on the genome and gene expression levels in switchgrass [51]. In this case, the pairs of tetraploid and autooctoploid lines derived from the same SE callus lines, with similar or close genetic backgrounds, could be used to identify genes that are differently regulated by chromosome doubling through expression profiling [54][55][56].…”