C-value estimates for 31 species of ladybird beetles (Coleoptera: Coccinellidae)

Abstract

This study provides C-value (haploid nuclear DNA content) estimates for 31 species of ladybird beetles (representing 6 subfamilies and 8 tribes), the first such data for the family Coccinellidae. Despite their unparalleled diversity, the Coleoptera have been very poorly studied in terms of genome size variation, such that even this relatively modest sample of species makes the Coccinellidae the third best studied family of beetles, behind the Tenebrionidae and Chrysomelidae. The present study provides a comparison of patterns of genome size variation with these two relatively well-studied families. No correlation was found between genome size and body size in the ladybirds, in contrast to some other invertebrate groups but in keeping with findings for other beetle families. However, there is some indication that developmental time and/or feeding ecology is related to genome size in this group. Some phylogenetic patterns and possible associations with subgenomic features are also discussed.

Genome Size in North American Fireflies: Substantial Variation Likely Driven by Neutral Processes

“…This is not unusual for beetles- while a positive correlation between body size and genome size has been noted across a diversity of animal taxa, including other insects (reviewed in Gregory 2001), previous studies within beetles have documented either a negative or no correlation (e.g. Tenebrionidae: Juan and Petitpierre 1991; Palmer et al 2003; Coccinellidae: Gregory et al 2003; Chrysomelidae: Petitpierre and Juan 1994). Our negative finding, incorporating phylogenetic correction, suggests this previous beetle work is robust to assumptions about relatedness of species.…”

“…Genome size also correlates with developmental rate and complexity in many taxa (e.g. Drosophila : Gregory and Johnston 2008; mosquitos: Ferrari and Rai 1989; ladybird beetles: Gregory et al 2003), although such correlations are not always present (Juan and Petitpierre 1991; Gregory et al 2003). In addition, if mutational bias is strong, then it will be a major determinant of genome size evolution (Petrov 2002).…”

A guided tour of large genome size in animals: what we know and where we are heading

“…This relationship is expected in species with a determinate growth pattern (i.e., when body size increases are mostly a result of cell size increases rather than increases in cell numbers). However, no correlation between genome size and body size was previously found in oligochaete annelids (Gregory and Hebert 2002), or beetles (Juan and Petitpierre 1991;Gregory et al 2003). Mammals show a positive relationship between body size and genome size at the species and genus levels but not at higher levels (Gregory 2005b).…”

Genome size increase in the phytophagous ladybird beetle Henosepilachna vigintioctomaculata species complex (Coleoptera: Coccinellidae)

“…Although genome sizes of 31 species within 5 subfamilies of ladybird beetle were previously reported (Gregory et al . ), no data have been obtained for the genus Henosepilachna .…”

“…Gregory et al . () reported the genome size of another phytophagous species, Cynegetis impunctata , belonging to a different tribe Cynegetinini of the same subfamily Epilachninae, as 0.5 Gb (i.e. 0.511 pg).…”