Evolutionary profile of the family Calliphoridae, with notes on the origin of myiasis

Mohamed G Nasser; Eslam M Hosni; Mohamed A Kenawy; Sulaiman A Alharbi; Hesham S Almoallim; Magda H Rady; Bouthaina A Merdan; Adrian C Pont; Sara A Al-Ashaal

doi:10.1016/j.sjbs.2021.01.032

Evolutionary profile of the family Calliphoridae, with notes on the origin of myiasis

Saudi J Biol Sci. 2021 Apr;28(4):2056-2066. doi: 10.1016/j.sjbs.2021.01.032. Epub 2021 Jan 28.

Authors

Mohamed G Nasser¹, Eslam M Hosni¹, Mohamed A Kenawy¹, Sulaiman A Alharbi², Hesham S Almoallim³, Magda H Rady¹, Bouthaina A Merdan¹, Adrian C Pont⁴, Sara A Al-Ashaal¹

Affiliations

¹ Department of Entomology, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt.
² Department of Botany & Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
³ Department of Oral & Maxillofacial Surgery, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.
⁴ Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK.

Abstract

The family Calliphoridae is a group of heterogenous calyptrate flies with a worldwide distribution including species of ecological, veterinary, medical, and forensic importance. Notorious for their parasitic habits, the larvae of many blowflies are characterised - like some other dipteran larvae - by their ability to develop in animal flesh. When parasitism affects a living host, it is termed "myiasis". This has led the Calliphoridae to be considered as a pivotal family in its relationship with a man. Nevertheless, even after more than 50 years of research, the phylogenetic relationships among calliphorid subfamilies together with the evolutionary origin of myiasis remain unclear. In order to elucidate these problems, we constructed three phylogenetic trees by using nucleotide sequence data from cytochrome oxidase subunit one (COI), representing a mitochondrial conservative gene, and nuclear 28S subunit of ribosomal RNA gene (28S rRNA) in order to interpret the evolutionary profile of myiasis in the family Calliphoridae. The sequenced data represented species associated with ectoparasitic life-styles, either saprophagy or facultative and obligate parasitism. A total number of 50 accessions were collected for 28S rRNA, 56 for COI, and 38 for combined sequences phylogeny. Molecular Evolutionary Genetics Analysis (MEGA) software was used to align 2197 nucleotide positions of 28S rRNA and 1500 nucleotide positions of COI with a gap opening penalties and gap extension penalties equalling 20 and 0.1 respectively. The results reveal the non-monophyly of the family Calliphoridae despite the stable monophyletic status of the Chrysomyinae, Luciliinae, and Auchmeromyiinae. Also, our findings recommend ranking the Toxotarsinae as a separate family. Furthermore, comparative analysis of the phylogenetic trees shows that the habit of obligatory myiasis originated independently more than five times. This strengthens our hypothesis that the origin of eating fresh meat is a case of convergent evolution that has taken place after speciation events millions of years ago. Finally, estimating the divergence dates between lineages from molecular sequences provides a better chance of understanding their evolutionary biology.

Keywords: Blowflies; Conservative genes; Data science; Evolution; Phylogeny.