The mitochondrial genome of Qinghuang_1, the first modern improved strain of Chinese oak silkworm,Antheraea pernyi (Lepidoptera: Saturniidae)

Abstract

Chinese oak silkworm, Antheraea pernyi Guérin-Méneville 1855 (Lepidoptera: Saturniidae), is a traditional edible insect in China and is considered the edible insect with the highest potential. Information on the mitochondrial genome (mitogenome) of the first modern improved strain of this silkworm, Qinghuang_1, is currently unavailable. Here, we determine the mitogenome of Qinghuang_1 by long PCR amplification followed by Illumina sequencing and then compare the resulting mitogenome with the five available mitogenomes of this species. The mitogenome of Qinghuang_1 is 15,573 bp in length and exhibits an identical gene organisation to known A. pernyi mitogenomes. The base A content of this mitogenome is higher than those of the other four strains but lower than that of the wild type. Sequence comparisons identified 200 single-nucleotide variants (1.28%) and 32 amino acid changes among the five inbred strains, indicating a considerable degree of nucleotide diversity in the mitogenomes of A. pernyi germplasm resources. The 3’ end of ND1 was identified as a hotspot in the A. pernyi mitogenome. Ka/Ks analysis indicated that all protein-coding genes evolved under negative selection except for ND5, which presented values larger than 1, suggesting that positive selection may act on this gene. The phylogenetic analyses confirmed the basal position of Qinghuang_1 among the inbred strains of A. pernyi. Our results indicated that the mitogenome is helpful for understanding the intraspecific phylogenetic relationships of A. pernyi and for its genetic improvement.

The complete mitochondrial genome of the wild silkmoth Antheraea yamamai from Heilongjiang, China (Lepidoptera: Saturniidae)

“…Among these 19 SNPs, four were present in rRNAs and one was in the intergenic spacer region ND2-tRNA trp ; the remaining 14 occurred in protein-coding genes, resulting in five amino acid changes. The number of SNVs between the two A. yamamai mitochondrial genomes were smaller than those between the cultivated and noncultivated A. pernyi mitochondrial genomes [264 SNVs (213 SNPs and 51 indels)] and between the two A. assamensis mitochondrial genomes [246 SNVs (158 SNPs and 88 indels)], but similar to those between strains of A. pernyi (Li et al 2021). These results indicated a low intraspecific variation between Chinese and Korean populations of A. yamamai, suggesting that they might be derived from a common population.…”

Edible insects: Challenges and prospects

“…The Qinghuang_1 strain was the first modern improved strain of Chinese oak silkworm improved in 1954 through a systematic selection method from a local population in Liaoning Province, China. Due to its high yield, stability, strong resistance and wide adaptability, it served as the dominant strain for 40 years, and provided a foundation for the industrial production and breeding of Chinese oak silkworm (Li et al, 2021). In silkworm (B. mori) strains had a significant effect on the content of carotenoids of the pupae (Chieco et al 2019).…”

Characterization of the complete mitochondrial genome of Antheraea pernyi strain Luhong

“…The total genomic DNA was extracted from a single individual. The long PCR amplification, sequence determination and genomic annotation were done as previously described for Qinghuang_1 (Li et al 2020 ). The mt genome was manually annotated by comparing with the published mt genomes of A. pernyi .…”