Hisashi Okuyama
Kyoto Sangyo University
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Publication
Featured researches published by Hisashi Okuyama.
Mitochondrial DNA Part B | 2018
Ikumi Nakagawa; Mito Maeda; Mao Chikano; Hisashi Okuyama; Robert Murray; Jun-ichi Takahashi
Abstract 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.
Mitochondrial DNA Part B | 2017
Hisashi Okuyama; Salim Tingek; Jun-ichi Takahashi
Abstract 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.
Mitochondrial DNA Part B | 2017
Ryoichi Takahashi; Hisashi Okuyama; Takuya Kiyoshi; Jun-ichi Takahashi
Abstract 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%.
Mitochondrial DNA Part B | 2017
Takeshi Wakamiya; Salim Tingek; Hisashi Okuyama; Takuya Kiyoshi; Jun-ichi Takahashi
Abstract 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.
Conservation Genetics Resources | 2018
Yuri Shinmura; Hisashi Okuyama; Takuya Kiyoshi; Chung Ping Lin; Tatsuhiko Kadowaki; Jun-ichi Takahashi
The Asian cavity-nesting honeybee, Apis cerana is widely distributed across Asia and nearby islands, showing interesting patterns of genetic differences caused by repeated isolation and re-unification of populations owing to repeated changes in sea levels. In the present study, we analyzed the complete mitochondrial genome of A. cerana from Taiwan and eastern China for the first time. The mitochondrial genomes of these honeybee populations were circular 15,251- and 15,332-bp molecules, respectively, and included 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one AT-rich control region. The average AT content in mitochondrial genome of Taiwanese and Chinese honeybees was 83.50 and 83.54%, respectively. The heavy strand encoded nine PCGs and 14 tRNA genes and the light strand encoded four PCGs, eight tRNA genes, and two rRNA genes. The ATP6 and ATP8 genes shared 19 nucleotides. Eight PCGs of the A. cerana mitochondrial genome started with ATT, ATP6, COIII, and Cytb genes with ATG, ATP8 gene with ATC, and ND4 gene with ATA. All tRNA genes formed typical cloverleaf secondary structures, except for tRNA-Ser (AGN). The phylogenetic analysis inferred from the 13 mitochondrial PCGs, based on maximum likelihood, indicated that the Taiwanese and eastern Chinese populations of A. cerana are closely related taxa. The 272 sites that differed between A. cerana from Taiwan and eastern China were evenly distributed throughout the mitochondrial genome. We found that the genetic distance between the two population was 0.025, indicating that they are genetically different enough to be considered different subspecies or local populations.
Mitochondrial DNA Part B | 2017
Hisashi Okuyama; Stephen J. Martin; Jun-ichi Takahashi
Abstract 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%.
Mitochondrial DNA Part B | 2017
Jun-ichi Takahashi; Salim Tingek; Hisashi Okuyama
Abstract 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.
Mitochondrial DNA Part B | 2018
Hisashi Okuyama; John Hill; Stephen J. Martin; Jun-ichi Takahashi
Abstract 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.
Mitochondrial DNA Part B | 2018
Ryoichi Takahashi; Hisashi Okuyama; Yûsuke N. Minoshima; Jun-ichi Takahashi
Abstract 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.
Mitochondrial DNA Part B | 2018
Jun-ichi Takahashi; Sureerat Deowanish; Hisashi Okuyama
Abstract 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.
