Reconstructing the ancestral karyotypes of S. rosmarinus, S.
miltiorrhiza and S. splendens
AEK (ancestral eudicot karyotype) was reconstructed from a
grape–cacao–peach comparison , and obtained seven protochromosomes
with 6,284 ordered protogenes. AEK genome was used for karyotype
projections of S. rosmarinus , S. miltiorrhiza and S.
splendens . To obtain the karyotype changes of species, we inferred the
possible chromosomal evolution process through the comparison of
homologous regions between species and AEK genome, and represented seven
protochromosomes with different colors.
Karyotype projections indicated the large amount of chromosomal
rearrangements occurred in S. rosmarinus , S. miltiorrhizaand S. splendens . Chromosomes rearrangements occurred along with
WGD-2 in S. rosmarinus . The MRCA (most recent common ancestor) ofS. miltiorrhiza and S. splendens could be considered as
the ancestor of S. rosmarinus. Collinear homologous regions were
identified by blastp in S. miltiorrhiza and S. splendens ,
based on karyotype projections results, protochromosomes were inferred
in MRCA of S. miltiorrhiza and S. splendens . And then
chromosomal rearrangements along with WGD-2 were inferred based on
karyotype projectory in S. rosmarinus and collinear comparison
between S. rosmarinus and S. miltiorrhiza . Finally, we
inferred protochromosomes of the MRCA of S. rosmarinus, S.
miltiorrhiza and S. splendens , and represented the process of
chromosomes karyotype evolution in S. rosmarinus, S. miltiorrhizaand S. splendens .