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Abstract The rapid naturalization of Bombus terrestris across the Nemuro Peninsula has led to a decline in two closely related native Japanese species, namely Bombus hypocrita sapporensis and Bombus cryptarum florilegus, both belonging to the common subgenus Bombus. Although it is widely believed that cross-mating of native and non-native species is influenced by the common male sex pheromone in this region, no study has been conducted to substantiate this claim. Thus, we investigated the cross-activities of male sex pheromones between native and non-native bumblebees, as well as the frequencies of cross-mating, using chemical and DNA assays. Our gas chromatography–electroantennographic detector analyses and behavioral tests revealed the presence of sex pheromonal cross-activities between B. terrestris and the two Japanese bumblebees species. Furthermore, DNA analyses revealed the occurrence of cross-mating between native and non-native species in the Nemuro Peninsula. Overall, these results indicate the immediate need for conservation measures to safeguard Japanese bumblebee populations in the Nemuro Peninsula.

The Japanese endemic catfish Silurus lithophilus is distributed only in Lake Biwa, Lake Yogo, and their river drainages. There are four species of the genus Silurus in Japan, of which S. lithophilus has a limited distribution. This catfish needs to be collected for DNA data owing to the lack of information related to its conservation. Here, the complete mitochondrial genome of the S. lithophilus from Lake Biwa in Japan was analyzed using next-generation sequencing. The mitochondrial genome of S. lithophilus was identified as a 16,524 bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, along with one A + T-rich control region. The AT content was 55.89%. The heavy (H)-strand was predicted to have 12 PCGs and 15 tRNA, and 2 rRNA genes, whereas the light (L)-strand was predicted to contain one PCG and seven tRNA genes. The start codons ATG and GTG were found in 13 PCGs. The stop codons TAA, TAG, and AGA were observed in all PCGs, except CytB. All tRNA genes formed typical cloverleaf secondary structures. The molecular phylogenetic relationship, inferred using 13 PCGs (based on the maximum likelihood), was consistent with that reported in previous studies, which predicted a sister relationship between S. lithophilus and S. asotus. The results also clearly indicated that S. lithophilus is a valid species.

The east Asian catfish Silurus asotus is a common species living in fresh water in Japan. The complete mitochondrial genome of the S. asotus from Lake Biwa in Japan was analyzed using next-generation sequencing. The mitochondrial genome of S. asotus was identified as a 16,515 bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes, along with one A + T-rich control region. The AT content was 56.1%. Start codons ATG and GTG were found in 13 PCGs. Stop codons TAA, TAG, and AGA were observed in 13 PCGs. The heavy (H)-strand was predicted to have 12 PCGs and 14 tRNA and two rRNA genes, while the light (L)-strand was predicted to contain one PCGs and eight tRNA genes. The molecular phylogenetic analysis showed that S. asotus from Lake Biwa is genetically similar to S. asotus from China.

Some populations of the East Asian minnow Pungtungia herzi Herzenstein, 1892, which are naturally distributed in western Japan, have declined and are considered endangered. However, P. herzi has become a domestic invasive species in eastern Japan. Thus, knowledge of genetic features and phylogenetic relationships of P. herzi is important for conservation of this species and understanding its impact on ecosystems. We analyzed the complete mitochondrial genome using next generation sequencing of the East Asian minnow P. herzi from Yodo River, Osaka Prefecture, Japan. The mitochondrial genome of P. herzi consists of a circular molecule of 16,599 bp that includes 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one control region. The heavy (H)-strand was predicted to have 12 PCGs, 14 tRNA, and two rRNA genes, while the light (L)-strand was predicted to contain one PCGs and eight tRNA genes. The average AT content was 57.68%. The genes ATP8 and ATP6, ATP6 and COIII, ND4L and ND4, and ND5 and ND6 shared seven, one, seven, and four nucleotides, respectively. The initiation codons ATG and GTG were found in 12 and one genes, respectively. The termination codons TAA, TAG, incomplete TA–, and single T–– were observed in nine, one, one, and two genes, respectively. All the tRNA genes possessed a cloverleaf secondary structure. The phylogenetic relationships inferred using 13 PCGs (based on the maximum likelihood) were consistent with previous studies that predicted interrelationships of Cypriniformes.

The Japanese endemic catfish Silurus biwaensis is distributed only in Lake Biwa and Yodo river drainages. There are four species of the genus Silurus in Japan, of which S. biwaensis has a most limited distribution. This catfish needs to be collected for DNA data owing to the lack of information related to its phylogenetic relationship. Here, the complete mitochondrial genome of the S. biwaensis from Lake Biwa in Japan was analyzed using next-generation sequencing. The mitochondrial genome of S. biwaensis was identified as a 16,531 bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, along with one A + T-rich control region. The AT content was 55.83%. The heavy (H)-strand was predicted to have 12 PCGs, 14 tRNA, and 2 rRNA genes, whereas the light (L)-strand was predicted to contain one PCG and eight tRNA genes. The start codons ATG, ATC, and GTG were found in 13 PCGs. The stop codons TAA, TAG, and AGA were observed in all PCGs, except CytB and COX3. All tRNA genes formed typical cloverleaf secondary structures. The molecular phylogenetic relationships estimated using 13 PCGs (maximum-likelihood method) indicated that S. biwaensis is genetically distinct from the sympatric species S. asotus and S. lithophilus. This result clearly indicated that S. biwaensis is a valid species.

The dwarf honeybees Apis florea and Apis andreniformis inhabit the bush and forests of continental Asia and north Africa and some islands of Sundaland and the Philippines. We analysed, for the first time, the complete mitochondrial genomes of two dwarf honeybee species from Thailand using next-generation sequencing. Each mitochondrial genome was a circular and approximately 17 kbp molecule that included 13 protein-coding genes (PCGs), 22 tRNA genes, and two ribosomal RNA genes, along with one A + T-rich control region, besides three tRNA-Ser (AGN) repeats. The AT content values of the mitochondrial genomes of A. florea and A. andreniformis were 86.28% and 85.73%, respectively. The 1150 mutation sites in 13 PCGs differing between A. florea and A. andreniformis in Thailand were evenly distributed throughout their mitochondrial genomes. The phylogenetic relationship, inferred using 13 PCGs, was consistent with that reported in previous studies, which predicted a sister relationship between A. florea and A. andreniformis.

In this study, we analyzed the complete mitochondrial genome of the Mnais pruinosa Selys, 1853 from Saga Prefecture, Japan. The mitochondrial genome of M. pruinosa was identified as a circular molecule of 15,494 bp, and was found to be similar to that of other damselfly species. It was predicted to contain 13 protein-coding (PCG), 22 tRNA, and two rRNA genes, as well as one A + T-rich control region. The genes ATP8 and ATP6 shared seven nucleotides, ATP6 and COIII shared one nucleotide, ND4 and ND4L shared seven nucleotides, and ND6 and Cytb shared one nucleotide. The initiation codon ATG was found in eight genes, ATC in four, and ATT in one; the termination codons TAA, TAG, incomplete TA, and single T were observed in seven, one, two, and three genes, respectively. All the tRNA genes possessed a cloverleaf secondary structure, except for tRNA-His that lacks the TΨC loop. The average AT content of mitochondrial genome was 66.18%.

The paper wasp Polistes riparius is distributed in cold regions of northern East Asia to Russia. P. riparius are characterized by having longer cells than those of the closely related P. chinensis, which has a similar life history, as an adaptation to cold regions. The phylogenetic relationships of paper wasps have recently been studied; however, the genetic diversity and population structure of P. riparius has not been determined. The present study is the first to analyze the complete mitochondrial genome using next generation sequencing of P. riparius collected from Sapporo, Hokkaido Prefecture, Japan. The genome consisted of a closed loop that was 16,383 bp-long and included 13 protein coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one AT-rich control region. The average AT content was 84.54%. The heavy (H)-strand was predicted to have 12 PCGs and 14 tRNA genes, while the light (L)-strand was predicted to contain one PCGs, eight tRNA genes, and two rRNA genes. All PCGs started with ATG. Stop codons were of two types: TAA for 11 genes (ND1, ND2, ND3, ND4L, ND5, ND6, COXI, COXII, COXIII, COB, ATP6 and ATP8) and TAG for two genes (ND3 and ND4). The molecular phylogenetic relationship based on the maximum likelihood method using 13 PCGs was consistent with some previous studies in which a closely relationship between P. riparius and P. jokahamae.

Giant water bugs (genus Kirkaldyia and Lethocerus) are well known species from aquatic habitats throughout the world’s subtropical and tropical areas. Only one species of the Kirkaldyia deyrolli is distributed in Japan. K. deyrolli has been designated as second category rare species according Law for Conservation of Endangered Species of Wild Fauna and Flora in Japan, in 2019. We analyzed, for the first time, the complete mitochondrial genomes of the giant water bug K. deyrolli from Japan using next-generation sequencing. The mitochondrial genome was a circular and 15,579 bp molecule that included 13 protein-coding genes (PCGs), 22 tRNA genes, and two ribosomal RNA genes, along with one AT-rich control region. The AT content value was 69.55%. The heavy strand was predicted to have nine PCGs and 15 tRNA genes, whereas the light strand was predicted to contain four PCGs, seven tRNA genes, and two rRNA genes. Start codons were variable for all PCGs: four ATA, three ATC, four ATG, two ATT genes as the start codon. Stop codons were of two types: TAA for 12 genes and TAG for one gene. Incomplete stop codon T was identified. The molecular phylogenetic relationship, inferred using 13 PCGs, was consistent with that reported in previous studies, which predicted a sister relationship to the genus Lethocerus.

Varroa destructor is a parasite mite of the eastern honey bee Apis cerana, which is native to Asia. The European honey bee Apis mellifera was imported to Asia from Europe and the USA for apiculture in the 19th century. In a short period of time, V. destructor parasitized the artificially introduced honey bees. Varroa destructor was estimated to have spread around the world with A. mellifera when it was exported from Asia to locations worldwide about 50 years ago. The mitochondrial DNA of the parasitic honey bee mite V. destructor was analyzed using next-generation sequencing. The complete mitochondrial genome of V. destructor was identified as a 16,476-bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one AT-rich control region. The heavy strand was predicted to have nine PCGs and 13 tRNA genes, whereas the light strand was predicted to contain four PCGs, nine tRNA genes, and two rRNA genes. All PCGs began with ATA as the start codon, except COIII and CytB, which had ATG as the start codon. Stop codons were of two types: TAA for eight genes and TAG for five genes. Molecular phylogenetic analysis revealed that V. destructor from Japan was genetically distant from that of France. A high base substitution rate of 2.82% was also confirmed between the complete mitochondrial DNA sequences of V. destructor from Japan and the USA, suggesting that one Varroa mite strain found in the USA is not from Japan.

We analyzed the complete mitochondrial genome of the invasive Asian hornet Vespa velutina from Kyushu Island, Japan. The mitochondrial genome of V. velutina was identified as a circular molecule of 16,388 bp. We predicted that the genome contains 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, along with one A + T-rich control region. The average AT content is 81.68%. Molecular phylogenetic analysis using the 13 mitochondrial PCGs from 11 closely related taxa of Vespidae indicated that the V. velutina invading the Japanese Islands of Kyushu and Tsushima have a common origin.

The complete is mitochondrial genome of the Japanese bumblebee Bombus hypocrita sapporensis from Hokkaido Island, Japan is analysed using next generation sequencing. The mitochondrial genome of B. h. sapporensis was observed to be a circular molecule of 15,835 bp. The average AT content in the B. h. sapporensis mitochondrial genome was 85.53%. It was predicted to contain 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes, along with one A + T-rich control region. The PCGs had ATA, ATG, or ATT as the initiation codon and were terminated by the typical stop codon TAA, except for Cytb. All the tRNA genes typically formed a cloverleaf secondary structure, except for trnE, trnF, and trnS1. The molecular phylogenetic analysis indicated that the B. h. sapporensis from Hokkaido Island population was most similar to that of the geographically isolated B. h. sapporensis from Rebun Island.

In Japan, two closely-related damselflies, Mnais costalis Selys, 1869 (Odonata: Calopterygidae) and M. pruinosa Selys-Longchamps (Odonata: Calopterygidae), 1853, coexist, and they exhibit geographic variations in wing color, body size, and habitat preference. In this study, we analyzed the complete mitochondrial genome of M. costalis from Saga Prefecture, Japan (sympatric populations that exhibit wing color polymorphism), and compared the genome with M. costalis that exhibit monomorphic orange wing color. The mitochondrial genome of M. costalis from Saga Prefecture was identified as a circular molecule of 15,488 bp, similar to that found in other M. costalis populations. It was predicted to contain 13 protein-coding (PCG), 22 tRNA, and two rRNA genes, along with one A + T-rich control region. Among the PCGs, ATP8 and ATP6, ATP6 and COIII, ND4 and ND4L, and ND6 and Cytb shared seven, one, seven, and one nucleotides, respectively. The initiation codon ATG was found in eight genes, ATC in four, and ATT in one, while the termination codons TAA, TAG, TA, and T were observed in seven, one, two, and three genes, respectively. All the tRNA genes possessed a cloverleaf secondary structure, except for tRNA-His that lacks the TΨC loop. The average AT content of mitochondrial genome was 66.06%. From a phylogenetic analysis, the loss of wing color polymorphism in monomorphic sympatric populations is likely to occur with the coexistence of two Mnais species.

The complete mitochondrial genome of the three-keeled pond turtle Mauremys reevesii from Japan was analyzed using next-generation sequencing. The mitochondrial genome of M. reevesii was observed to be a circular molecule of 15,528 bp containing 13 protein-coding genes, 22 tRNA genes, and two rRNA genes, along with one A + T-rich control region. The average AT was found to be 61.11%. One extra base was present at the 174th position in the ND3 gene. Molecular phylogenetic analysis revealed that M. reevesii from Japan was few genetically distant from the geographically isolated M. reevesii from South Korea. This turtle might have been exported to Japan from the Korean Peninsula after the Middle Ages.

We analyzed the complete mitochondrial genome of the small hive beetle Aethina tumida, a major honeybee pest that was accidentally transported to the Hawaii Islands, USA. The mitochondrial genome of A. tumida was identified as a 15,198 bp circular molecule containing 13 protein-coding genes, 22 tRNA genes, and two rRNA genes, along with one A + T-rich control region. The average AT content was found to be 76.2%. The heavy strand was predicted to have nine protein-coding and 14 tRNA genes; while the light strand was predicted to contain four protein-coding, eight tRNA, and two rRNA genes. Among the 13 PCGs, the initiation codon ATT was found in five, ATA in three, ATG in four, and TTG in one gene. Six PCGs used TAA as the stop codon, whereas three PCGs used TAG as the stop codon. Incomplete stop codon TA (COIII, ND5, and ND4) and T (COII) were identified. We found that the genetic distance between A. tumida from Hawaii and the beetles’ natural home South Africa, was small, indicating that the Hawaii population may have originated for the South Africa region.

The complete mitochondrial genome of the Japanese pond turtle Mauremys japonica from Japan was analyzed using next-generation sequencing. The mitochondrial genome of M. japonica was identified as a 16,443 bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, along with 1 A + T-rich control region; the average AT content was 62.82%. One extra base was present at the 174th position in the ND3 gene. The phylogenetic analyses of the complete mitochondrial DNA genes strongly supported the result obtained from the phylogenetic analysis of partial DNA sequences, grouping the monophyletic species within the genus Mauremys.

We analyzed the complete mitochondrial genome of the dusky brown-gray–colored honeybee Apis mellifera, collected from North Island, New Zealand. We determined that the mitochondrial genome was a 16,336 bp and predicted 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes. The start codon ATA was found in two genes, ATG in four genes, ATT in six genes, and ATC in one gene, whereas the termination codon TAA was observed in all PCGs. The non-coding regions of tRNA-Leu and COII were consistent with the C haplotype of A. mellifera carnica. Phylogenetic analysis suggests a close relationship with the European A. mellifera.

The complete mitochondrial genome of the yellow coloured honeybee Apis mellifera from North Island, New Zealand was analyzed using next-generation sequencing. The mitochondrial genome was a 16,349bp circular molecule and was predicted to contain 13 protein-coding genes (PCGs), 22 tRNA genes and two rRNA genes. The initiation codon ATA was found in two genes, ATG in four genes, ATT in six genes, and ATC in one gene, while the termination codon TAA was observed in all the PCGs. Phylogenetic analysis using the sequence of 23 closely related taxa suggested a sister relationship with the Italian strain A. mellifera ligustica.

We analyzed the complete mitochondrial genome of the ‘Buckfast bee’, Apis mellifera, collected from North Ireland, UK. It consisted of a circular molecule of 16,353 bp. The genome contained 13 protein-coding, 22 tRNA, and 2 rRNA genes, along with one A + T-rich control region. The average AT content was 84.9%. The genes ATP8 and ATP6 shared 19 nucleotides. A phylogenetic analysis, suggested that the matriline ‘Buckfast bee’ has remained most closely related to the A. mellifera ligustica race from which it originated in 1917, despite being cross-bred with many other A. mellifera races over the past 100 years.

The cavity-nesting honeybee Apis nuluensis inhabits only the highlands of Mount Kinabalu of Sabah, Borneo Island. The mitochondrial genome is a circular molecule of approximately 1.6 kb that includes 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one AT-rich control region. The average AT content was 84.5%. The start codons ATC, ATG, and ATT were found in one, three, and nine genes, respectively, whereas the stop codon TAA was observed in all genes. The phylogenetic relationship, inferred using 13 PCGs, was consistent with that reported in previous studies that predicted a sister taxon relationship between A. nuluensis and A. cerana.

The complete mitochondrial genome of the cavity-nesting honeybee Apis cerana from Sabah on Borneo Island was analyzed using next-generation sequencing. The mitochondrial genome of A. cerana was a circular molecule of 15,884 bp and was similar to that of the other cavity-nesting honeybee species. The average AT content in the A. cerana mitochondrial genome was 84.4%. It was predicted to contain 13 protein-coding, 22 tRNA, and two rRNA genes, along with one A + T-rich control region.

We analyzed the complete mitochondrial genome of the Asian tropical hornet Vespa affinis from Ishigaki Island, Japan. It consisted of a circular molecule with 19,109 bp, which is larger to other hornet species e.g. V. velutina. We predicted the genome contained 13 protein-coding, 22 tRNA, and two rRNA genes, along with one A + T-rich control region. The repetitive sequences were confirmed at multiple positions in the non-coding genes. The initiation codons ATA was found in one, ATG in seven, and ATT in five genes, while the termination codons TAA and TAG were observed 11 and two genes, respectively. The average AT content of the genome was 78.4%.

In short QT syndrome, inherited gain-of-function mutations in the human ether a-go-go-related gene (hERG) K+ channel have been associated with development of fatal arrhythmias. This implies that drugs that activate hERG as a side effect may likewise pose significant arrhythmia risk. hERG activators have been found to have diverse mechanisms of activation, which may reflect their distinct binding sites. Recently, the new hERG activator ICA-105574 was introduced, which disables inactivation of the hERG channel with very high potency. We explored characteristics of this new drug in several experimental models. Patch clamp experiments were used to verify activation of hERG channels by ICA-105574 in human embryonic kidney cells stably-expressing hERG channels. ICA-105574 significantly shortened QT and QTc intervals and monophasic action potential duration (MAP90) in Langendorff-perfused guinea-pig hearts. We also administered ICA-105574 to anesthetized dogs while recording ECG and drug plasma concentrations. ICA-105574 (10 mg/kg) significantly shortened QT and QTc intervals, with a free plasma concentration of approximately 1.7 μM at the point of maximal effect. Our data showed that unbound ICA-105574 caused QT shortening in dogs at concentrations comparable to the half maximal effective concentration (EC50, 0.42 μM) of hERG activation in the patch clamp studies. Keywords:: hERG activator, QT and QTc interval, KCNH2, IKr channel, pro-arrhythmia

In the present report, we describe the complete mitochondrial genome of the common bumblebee, Bombus hypocrita hypocrita, from the Otome Plateau, in Yamanashi Prefecture, Japan. The mitochondrial genome of B. h. hypocrita is a circular molecule of 15,795 bp. It contains 13 protein-coding, 22 tRNA and two rDNA genes. The protein-coding genes had ATA, ATG or ATT as the initiation codon and were terminated by the typical stop codon TAA, except for ND4 and Cytb. All the tRNA genes typically formed a cloverleaf secondary structure, except for trnE and trnS1.

In this study, we analyzed the complete mitochondrial genome of the cavity-nesting honeybee, A. koschevnikovi. The mitochondrial genome of A. koschevnikovi was observed to be a circular molecule of 15,278 bp and was similar to that of the other cavity-nesting honeybee species. The average AT content in the A. koschevnikovi mitochondrial genome was 84%. It was predicted to contain 13 protein-coding, 24 tRNA and two rRNA genes, along with one A + T-rich control region, besides three tRNA-Met repeats.

In this study, we analyzed the complete mitochondrial genome of the invasive Asian hornet Vespa velutina from Japan. The mitochondrial genome of V. velutina was identified as a circular molecule of 16,765 bp, similar to that in other hornet species. It was predicted to contain 13 protein-coding, 20 tRNA, and two rRNA genes, along with one A + T-rich control region. The initiation codons ATC was found in one, ATG in four, ATT in five, and ATA in three genes, while TAA was the termination codon in all these genes. The average AT content of 13 protein-coding was 82%.