7848 alignments with Gblocks of cetaceans

Cetaceans (whales, dolphins, and porpoises) have undergone a radical
transformation from the typical terrestrial mammalian body plan to a
streamlined one while exhibited dramatic inter-specific size
ranges. However, the molecular
mechanisms underlying the diversifying evolution of
cetacean body size are largely unknown. Here, by using genome and
phenotypic data from 22 cetaceans,
we seek to investigate the genome-wide
gene-phenotype correlation and to explore the genetic
basis under the high diversity of body size in cetaceans. Results
of the functional enrichment showed that body size-related genes
in cetaceans were enriched in pathways associated with immunity, cell
growth, and metabolism, suggesting their potential roles in the
diversifying evolution of body size in cetaceans. A series
of genes was also found coevolution with body size that are
mainly involved in immune surveillance, tumor suppression function, and
development of ‘cheater’ tumors. This in turn suggests that the
genes play a role in tumor control and thus resolve
Peto’s paradox, a finding that the expansion in body size and thereby cell
number does not correlate with increases in cancer incidence in larger
whales. The present study could provide novel insights into the
evolution of great body size variation in cetaceans.