AUTHOR=Komata Shinya , Lin Chung-Ping , Fujiwara Haruhiko 

TITLE=doublesex Controls Both Hindwing and Abdominal Mimicry Traits in the Female-Limited Batesian Mimicry of Papilio memnon

JOURNAL=Frontiers in Insect Science

VOLUME=2

YEAR=2022

URL=https://www.frontiersin.org/journals/insect-science/articles/10.3389/finsc.2022.929518

DOI=10.3389/finsc.2022.929518

ISSN=2673-8600

ABSTRACT=<p><italic>Papilio</italic> butterflies are known to possess female-limited Batesian mimicry polymorphisms. In <italic>Papilio memnon</italic>, females have mimetic and non-mimetic forms, whereas males are monomorphic and non-mimetic. Mimetic females are characterized by color patterns and tails in the hindwing and yellow abdomens. Recently, an analysis of whole-genome sequences has shown that an approximately 160 kb region of chromosome 25 is responsible for mimicry and has high diversity between mimetic (<italic>A</italic>) and non-mimetic (<italic>a</italic>) alleles (highly diversified region: HDR). The HDR includes three genes, <italic>UXT</italic>, <italic>doublesex</italic> (<italic>dsx</italic>), and <italic>Nach-like</italic>, but the functions of these genes are unknown. Here, we investigated the function of <italic>dsx</italic>, a gene involved in sexual differentiation, which is expected to be functionally important for hindwing and abdominal mimetic traits in <italic>P</italic>. <italic>memnon</italic>. Expression analysis by reverse transcription quantitative PCR (RT-qPCR) and RNA sequencing showed that mimetic <italic>dsx</italic> (<italic>dsx-A</italic>) was highly expressed in the hindwings in the early pupal stage. In the abdomen, both <italic>dsx-A</italic> and <italic>dsx-a</italic> were highly expressed during the early pupal stage. When <italic>dsx</italic> was knocked down using small interfering RNAs (siRNAs) designed in the common region of <italic>dsx-A</italic> and <italic>dsx-a</italic>, a male-like pattern appeared on the hindwings of mimetic and non-mimetic females. Similarly, when <italic>dsx</italic> was knocked down in the abdomen, the yellow scales characteristic of mimetic females changed to black. Furthermore, when <italic>dsx-a</italic> was specifically knocked down, the color pattern of the hindwings changed, as in the case of <italic>dsx</italic> knockdown in non-mimetic females but not mimetic females. These results suggest that <italic>dsx-a</italic> is involved in color pattern formation on the hindwings of non-mimetic females, whereas <italic>dsx-A</italic> is involved in hindwing and abdominal mimetic traits. <italic>dsx</italic> was involved in abdominal and hindwing mimetic traits, but <italic>dsx</italic> expression patterns in the hindwing and abdomen were different, suggesting that different regulatory mechanisms may exist. Our study is the first to show that the same gene (<italic>dsx</italic>) regulates both the hindwing and abdominal mimetic traits. This is the first functional analysis of abdominal mimicry in butterflies.</p>