Transposable element libraries from 101 fish

Repetitive DNA make up a considerable fraction of most eukaryotic genomes.
In fish, transposable element (TE) activity has coincided with rapid
species diversification. Here, we annotated the repetitive content in 100
genome assemblies, covering the major branches of the diverse lineage of
teleost fish. We investigated if TE content correlates with family level
net diversification rates and found support for a weak negative
correlation. Further, we found that TE proportion correlate to genome
size, but not to the proportion of short tandem repeats (STRs), which
implies independent evolutionary paths. Marine and freshwater fish have
large differences in STR content. The most extreme propagation was found
in the genomes of codfish species and Atlantic herring. Such a high
density of STRs is likely to increase the mutational load, which we
propose could be counterbalanced by high fecundity as seen in codfishes
and herring.