Fig. 7: A schematic model depicting how inversions underwent relaxed genetic constraints and balanced birth and death of TPS genes in Curcuma species.
From: Inversions encounter relaxed genetic constraints and balance birth and death of TPS genes in Curcuma
Inversions acted as a counteracting evolutionary force of gene tandem duplication to keep a balance between gene birth and death of TPS genes, and genomic characteristics associated with inversions indicated relaxed genetic constraints. Recombination within inversions between haplotypes was suppressed, resulting in inefficient removal of TEs and deleterious mutations. Higher levels of TE content, deleterious mutations, PICs, and base substitutions were observed within inversions. Genes within inversions were barely expressed, and inversion-internal genes on different haplotypes lost different domains, implying that these genes were pseudogenes and the two haplotypes evolved independently. And fewer selected SNPs were detected within inversions. Red and blue arrows indicated an increase and decrease within inversions relative to the genome-wide background, respectively.
