Methodological comparison of sequence-based genome size estimation in beetles (Coleoptera)

Revealing the myriad evolutionary causes behind this variation has proven to be a difficult and enduring challenge. Knowledge of genome size can be important to understand phenomena such as whole genome duplication and polyploidy, genome reduction driven by changes in selective pressure, or proliferation of non-coding DNA sequence. Traditional methods for determining genome size, such as Feulgen densitometry and flow cytometry, involve staining cells with a DNA-specific dye and comparing the results to stained cells from a standard reference of a known genome size. These methods are well-tested and generally reliable; however, these they rely on live, fixed, or frozen tissues with largely intact cells, effectively limiting study to organisms that can be raised in the lab or easily found in nature and transported live. This can be an insurmountable problem if the specimens are difficult to collect, endangered or extinct, or only known from museum collections. Fortunately, alternative approaches exist for estimating genome size using easily obtainable shallow genomic sequencing data. Despite the potential value of sequence-based genome size estimation methods, little empirical research to verify them has been conducted. In this study, we will perform several of these sequence-based genome size estimation techniques, focusing on clade of beetles, the suborder Adephaga, and directly compare their effectiveness to genome size estimates derived from flow cytometry.