First extensive examination of genome size in phylum Brachiopoda (lamp shells) collected from Japan.

摘要

Genome size (C value) is a fundamental characteristic of every species and is very important for the progress of cytogenetic, genomic, and phylogenic studies. However, information on the C value of phylum Brachiopoda is scarce. In this study, we collected 8 brachiopod species from Japan, including 5 from class Articulata, and determined their C values by flow cytometry. The mean C values for these 8 species-namely, Lingula anatina, Lingula reevii, Discradisca stella, Terebratulina crossei, Laqueus rubellus, Laqueus blanfordi, Terebratalia coreanica, and Platidia japonica - were 0.41 pg, 0.41 pg, 0.46 pg, 0.33 pg, 0.44 pg, 0.42 pg, 0.37 pg, and 0.31 pg, respectively. Although the C values were examined across the various taxa within Brachiopoda, we detected very little variation (approximately 1.5-fold, from 0.31 pg in P. japonica to 0.46 pg in D. stella). This low C value variation suggests that the occurrences of evolutionary events such as changing the number of transposable elements and intron size, polyploidy, and DNA loss - all of which could cause a change in genome size - are fewer than in other taxa of the animal kingdom.