The researchers came up with 21 pairs of ancestral
eutherian chromosomes, they report today in the Proceedings of the National Academy of Sciences.
So team member Jaebum Kim, now at Konkuk University in Seoul, and colleagues wrote a sophisticated computer program that was able to reconstruct the original
eutherian chromosomes based on what parts of the chromosomes are together today in those 19 species.
Not exact matches
To figure out how
chromosomes of placental mammals have changed over time, researchers need to know what those early
eutherians started with.
Rat
chromosomes, too, are very different than the early
eutherian's, but for a different reason: Their
chromosomes swapped pieces between
chromosomes rather than within a given
chromosome.