Female (top) and male half-smooth tongue solesSL CHEN
Species: Half-smooth tongue sole (Cynoglossus semilaevis)
Genome size: 477 million base pairs
In flatfish like the half-smooth tongue sole (Cynoglossus semilaevis), males have two Z chromosomes, while females have a Z and a W. Researchers have sequenced the genomes of both a male and a female tongue sole. The assemblies were published in Nature Genetics this week (February 2).
An international team sequenced one male (ZZ) and one female (ZW) tongue sole separately, annotating 21,516 protein-coding genes. The researchers identified sequences specific to the W chromosome by subtracting the male genome assembly from the female one. They found that transposable elements represented less than 6 percent of the tongue sole genome—much less than other vertebrates. They also compared gene expression before and after metamorphosis, identifying ...
