Comparative genomic and phylogenetic analysis of the complete mitochondrial genome of Cricula trifenestrata (Helfer) among lepidopteran insects

Abstract

Cricula trifenestrata Helfer (commonly known as Amphutukoni muga/Cricula silkworm), a wild sericigenous insect produces golden yellow silk similar to Antheraea assamensis (muga silkworm), with significant potential as a natural fiber and biomaterial. Cricula is considered as a pest as it competes for food with muga, which produces the prized golden silk. This study focuses on decoding the mitochondrial genome of C. trifenestrata using next-generation sequencing technology and includes comparative analysis with Bombycoids and other lepidopteran insects. We found that the Cricula mitogenome spans 15,425 bp and exhibits typical gene content and arrangement consistent with other Saturniids and lepidopterans. All protein-coding genes were found to undergo purifying selection, with the highest and lowest conservation observed in the cox1 and atp8 gene respectively, indicating their potential role in future evolutionary events. We identified two types of mismatches: 23 “G-U” and 6 “U-U” pairs, similar to those found in Actias selene among the Saturniids. Additionally, our study uncovered the presence of two 33 bp repeat units and a ‘TTAGA’ motif in the control region, in contrast to the typical ‘ATAGA’ motif, suggesting functional similarity with evolving sequences. Furthermore, phylogenetic analysis supports the close relationship of Cricula with other species within the Saturniidae family.