Publications by Year: 2021

2021
Chen Y-J, Kim SI, Wan X. Mitochondrial genomes of the Dorcus velutinus complex (Coleoptera: Lucanidae) with the large intergenic spacer showing unique short sequence repeats and their implications for systematics. Journal of Asia-Pacific Entomology. 2021;24 :493-501. DOIAbstract
Mitochondrial genomes of the three lucanid species in the Dorcus velutinus complex – Dorcus velutinus Thomson, D. ursulus Arrow and D. tenuihirsutus Kim and Kim – were assembled and analyzed through next generation sequencing. The mitogenome sequences were used to infer phylogenetic relationships among Dorcus species. Our analyses revealed that the newly sequenced mitogenomes are comparable in their size, content, and gene arrangement to other lucanid mitogenomes reported to date. However, we confirmed the presence of a large intergenic spacer (IGS) between trnS(UCN) and ND1 genes, whose length varied from 170 bp (in D. tenuihirsutus) to 193 bp (in D. ursulus and D. velutinus). Within this IGS region, a short sequence fragment (TACTAAATT) was found uniquely across the three species of Dorcus velutinus complex. Our phylogenetic analyses show that the D. velutinus complex constitutes a distinct clade with a significant divergence from other species of the genus Dorcus sensu stricto. Furthermore, we reaffirm the validity of D. tenuihirsutus – a species originally described from Korea – as a distinct species, though the taxonomic status of D. ursulus remains to be studied further. Finally, we find the presence and location of large IGSs to be useful for studying evolutionary history and species delimitation in stag beetles.
Yu Y-S, Jin S, Cho N, Lim J, Kim C-H, Lee S-G, Kim SI, Park J-S, Kim K, Park C, et al. Genome Size Estimation of Callipogon relictus Semenov (Coleoptera: Cerambycidae), an Endangered Species and a Korea Natural Monument. Insects. 2021;12 (2). DOI (full text)Abstract
We estimated the genome size of a relict longhorn beetle, Callipogon relictus Semenov (Cerambycidae: Prioninae)—the Korean natural monument no. 218 and a Class I endangered species—using a combination of flow cytometry and k-mer analysis. The two independent methods enabled accurate estimation of the genome size in Cerambycidae for the first time. The genome size of C. relictus was 1.8 ± 0.2 Gb, representing one of the largest cerambycid genomes studied to date. An accurate estimation of genome size of a critically endangered longhorned beetle is a major milestone in our understanding and characterization of the C. relictus genome. Ultimately, the findings provide useful insight into insect genomics and genome size evolution, particularly among beetles.
Chamorro ML, de Medeiros BAS, Farrell BD. First phylogenetic analysis of Dryophthorinae (Coleoptera, Curculionidae) based on structural alignment of ribosomal DNA reveals Cenozoic diversification. Ecology and Evolution. 2021;11 (5). DOI (full text)Abstract
Abstract Dryophthorinae is an economically important, ecologically distinct, and ubiquitous monophyletic group of pantropical weevils with more than 1,200 species in 153 genera. This study provides the first comprehensive phylogeny of the group with the aim to provide insights into the process and timing of diversification of phytophagous insects, inform classification and facilitate predictions. The taxon sampling is the most extensive to date and includes representatives of all five dryophthorine tribes and all but one subtribe. The phylogeny is based on secondary structural alignment of 18S and 28S rRNA totaling 3,764 nucleotides analyzed under Bayesian and maximum likelihood inference. We used a fossil-calibrated relaxed clock model with two approaches, node-dating and fossilized birth-death models, to estimate divergence times for the subfamily. All tribes except the species-rich Rhynchophorini were found to be monophyletic, but higher support is required to ascertain the paraphyly of Rhynchophorini with more confidence. Nephius is closely related to Dryophthorini and Stromboscerini, and there is strong evidence for paraphyly of Sphenophorina. We find a large gap between the divergence of Dryophthorinae from their sister group Platypodinae in the Jurassic-Cretaceous boundary and the diversification of extant species in the Cenozoic, highlighting the role of coevolution with angiosperms in this group.