The various levels of ploidy relate to the number of chromosome to a basal chromosome complement (n). A mammalian gamete is usually considered haploid (n), most mammalian cells are diploid (2n) with one copy of each chromosome from each parent.
In the
Xenopus family of frogs there are a number of instances of species with 4,8 and 12 times the basal complement of chromosomes:- Tetraploid (4n),Octoploid (8n) and dodecaploid (12n).
Xenopus tropicalis for example is diploid while
Xenopus laevis is tetraploid, both are common laboratory animal especially in developmental biology.
Tropicalis was previously named
Silurana tropicalis.
The referenced paper used mitochondrial DNA to construct a phylogeny of the various species of
Xenopus and tried to determine the number and extent of polyploidy events amongst the species. They estimate that polyplodisation has occurred at least 6 times amongst the species of
Xenopus, since the lineages began to diverge.
TTFN,
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