Fig. 1

Size of the Aedes albopictus genome and physical map. a Cytofluorimetric-based estimates of the genome size of Ae. albopictus strains, including Foshan and Rimini from which genome assemblies were derived based on short-read Illumina sequencing [3, 4] and Ae. albopictus wild-collected samples from the native home range (Malaysia, Singapore, Thailand), an old-colonized region (La Reunion), and newly invaded areas (the USA, Mexico, Italy). The Ae. albopictus genome size is estimated to be in the range of 1095–1299 Mb, comparable or slightly larger than that of Ae. aegypti (1066–1309 Mb) [5]. b Physical genome map of Ae. albopictus based on 50 DNA probes hybridized in situ to mitotic chromosomes. Chromosomes and chromosome arms are indicated by numbers 1, 2, and 3 and letters p and q, respectively. Chromosome divisions and subdivisions are shown on the left sides of the idiograms. Scaffolds are indicated by arrows or lines. Arrows indicate orientations of the scaffolds. SC stands for scaffold; rDNA stands for ribosomal locus. c Examples of fluorescence in situ hybridization. Chromosomal locations of transcripts XM_019675405 and XM_020077126 from scaffolds 4 and 48, respectively; rDNA, polyphenol oxidase (PPO) gene clusters, and the largest viral integration in the genome (Canu-Flavi19) are demonstrated. Transcripts are indicated on a figure by the last four digits of their accession numbers. d Schematic illustration of chromosomal locations of PPO cluster triplication in the new assembly of Ae. albopictus (GCF_006496715.1). Comparative genomics analysis of the synteny in the AaegL5 genome reveals an array of 6 genes localized in a region of 123.44 kb at chromosome 2 (2:199,230,485-199,353,929) and was locally duplicated twice in Ae. albopictus, resulting in 18 PPO genes. PPO gene cluster array of chromosome 2 of Ae. aegypti includes AAEL015116 (PPO1), AAEL015113 (PPO2), AAEL013492 (PPO5), AAEL013493 (PPO7), AAEL013501 (PPO4), and AAEL013496 (PP08)