1 INTRODUCTION
Sarcophaga peregrina (Robineau-Desvoidy, 1830) (Diptera:
Sarcophagidae), commonly known as flesh fly, which is closely associated
with human life in ecological habits. The species is widely spread from
tropical to subtropical areas of the Palaearctic, Oriental, and Oceanian
regions (Xue et al. 2011). Moreover, it is also a large-sized
flesh fly with significant body surface features, including the brightly
red-tipped eyes, gray and black longitudinal stripes on the thorax, and
a checkerboard-like pattern on the abdomen (Majumder et al. 2012)
(Additional file 1: Figures S1).
The common carrion-feeding flies mainly include Sarcophagidae,
Calliphoridae and Muscidae family, which play a crucial role in forensic
investigations associated with decomposed corpses (Byrd& Castner 2010).
Compared with the other necrophagous flies, flesh flies are
characterized by the reproductive pattern of ovoviviparity (or
ovolarviparity), depositing eggs which immediately hatch into larvae
onto carrion (Goff et al. 1989; Majumder et al. 2014). The
reproductive cycle of S. peregrina comprises three definite
stages, including larva, pupa and adult. The mode of reproduction
appears to be the result of adaptive evolution, making them more
competitive compared to other species. Given that this reproduction
reduces the stage of larval development (the time when eggs hatch to
first larvae), the species can be used very accurately to estimate the
postmortem interval (PMI) of decomposed corpses, and it is therefore an
important necrophagous flesh fly in the field of forensic entomology
(Byrd& Castner 2010). For instance, S. peregrina is one of the
most common species of insect succession patterns on cadavers as well as
at many death scenes colonizing on a corpse (Guo et al. 2014;
Siti Aisyah et al. 2015; Sukontason et al. 2010; Wanget al. 2017a), which would provide valuable data for forensic
investigations, especially floating corpse cases and indoor death-scene
(Tomberlin et al. 2011). Recent studies on the species have
mainly focused on the effect of drugs and heavy metals (eg. cadmium) on
growth and development of larvae (Goff et al. 1989; Wu et
al. 2013), molecular identification (Wells& Stevens 2008), larval
morphology (Sukontason et al. 2010), cuticular hydrocarbon
composition in pupal exuviae for taxonomic differentiation (Gongyinet al. 2007), as well as the developmental data collection at
constant temperatures (Wang et al. 2017b).
S. peregrina has also profound implications for human hygiene and
the livestock economy. It is an important sanitary insect pest and one
of the vector fly species of intestinal infectious diseases and
parasitic diseases in human and livestock, and as an ectoparasite
causing myiasis (parasitic infestation) in human and other mammals (Leeet al. 2011). They can cause myiasis in the hospital environment
which is also called nosocomial myiasis (Miura et al. 2005). As
such, the species is considered as an indicator of wound care neglect,
either by the nurses or oneself (Nazni et al. 2011).
Additionally, in off-shore islands, the larvae of this species are also
the key pest of meat industries, which take nutrient from uncovered meat
and contaminate food material, ultimately leading to economic losses in
the livestock industries (Majumder et al. 2012).
Although S. peregrina possesses ecological, medical and forensic
importance, there are few genomic resources for the family Sarcophagidae
(Agrawal et al. 2010; Martinson et al. 2019), which
seriously hinder the investigation of the specific mechanisms of
biological phenomena from the perspective of genomics, transcriptomics
and epigenetics. Fortunately, with the emergence of next-generation
sequencing technology, genomics and transcriptomic have been recently
developed for dipteran flies (Anstead et al. 2015; dos Santoset al. 2014; Kim et al. 2018; Scott et al. 2014),
which serve as a reference for molecular studies of related species. But
due to the defect of short Illumina reads, the combination of SMRT
(Single Molecule Real-Time) sequencing and
chromosome conformation capture
(Hi-C) can anchor the scaffolds into chromosomal levels (Belton et
al. 2012; Roberts et al. 2013), which ensure the availability of
high-quality reference genome assembly. Here we reported a
chromosome-level de novo genome assembly of S. peregrinaand perform comparative analysis with other published dipteran insects
in order to enrich our understanding of adaptive evolution in S.
peregrina .