Statistical Genetics Research Of Plant Polyploidy

Polyploidy occurs extensively during plant evolution and plays an important role in plant differentiation and development.Polyploidy can be divided into autoploidy and alloploidy.It has been shown that the subgenomic gene loss from polyploidy varies greatly among plants,and this variation may be related to the type of polyploidization event.Two statistical measures,the expression polyploidy index and the methylation polyploidy index,were developed to measure the differences in expression and methylation among the subgenomes generated by polyploidy.Combined with the existing gene loss polyploidy index,the subgenomes generated by polyploidy were analyzed for gene loss,gene expression and gene methylation,and the differences in gene composition,expression dominance and epigenetics among the subgenomes generated by polyploidy were explored using 14 representative plants as the study subjects.The analysis showed that the expression polyploidy index and methylation polyploidy index were numerically smaller and more concentrated compared to the polyploidy index for gene loss,which was more dispersed between 0 and 1 and seemed to be more suitable for polyploidy type inference.The other two are more susceptible to individual gene mutations,and plants with smaller polyploidy index for gene loss also have smaller gene expression polyploidy indices and methylation polyploidy indices,reflecting a certain correlation.A practical use of the two statistics of the expression polyploidy index and the methylation polyploidy index in maize found mild difference in both biological features between the two subgenomes produced by an ancient maize-lineage specific tetraploidization.An interesting and consistent finding is that one set maize subgenome preferentially preserved more genes,mildly dominated at the expression level,and were subjected to more DNA methylation.Together with the previously proposed polyploidy index,these statistics provide new means to study subgenomic divergence for polyploides and possible polyploidy types,contributing to the understanding polyploid biology,evolutionary past and functional innovation of land plants.Figure 15;Table 14;Reference 76...