29 research outputs found

    On the Terrestrial Earthworm Fauna of Yamagata Prefecture, northeastern Japan

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    We conducted to collect earthworms in order to clarify the earthworm fauna of Yamagata Prefecture. We could collect 16 species belonging to two families including two undescribed species from six localities. To our knowledge, it is first time to record Pheretima aokii, P. megascolidioides, P. micronaria and Aporrectodea caliginosa from Yamagata Prefecture. Therefore, except for two species which could not identified as known species, 18 valid species of earthworms exist in Yamagata Prefecture including our result. Keywords : earthworm fauna, Megascolecidae, Lumbricidae, Oligochaeta, Yamagata Prefectur

    Analysis of Genetic Variation and Phylogeny of the Predatory Bug, Pilophorus typicus, in Japan using Mitochondrial Gene Sequences

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    Pilophorus typicus (Distant) (Heteroptera: Miridae) is a predatory bug occurring in East, Southeast, and South Asia. Because the active stages of P. typicus prey on various agricultural pest insects and mites, this species is a candidate insect as an indigenous natural enemy for use in biological control programs. However, the mass releasing of introduced natural enemies into agricultural fields may incur the risk of affecting the genetic integrity of species through hybridization with a local population. To clarify the genetic characteristics of the Japanese populations of P. typicus two portions of the mitochondrial DNA, the cytochrome oxidase subunit I (COI) (534 bp) and the cytochrome B (cytB) (217 bp) genes, were sequenced for 64 individuals collected from 55 localities in a wide range of Japan. Totals of 18 and 10 haplotypes were identified for the COI and cytB sequences, respectively (25 haplotypes over regions). Phylogenetic analysis using the maximum likelihood method revealed the existence of two genetically distinct groups in P. typicus in Japan. These groups were distributed in different geographic ranges: one occurred mainly from the Pacific coastal areas of the Kii Peninsula, the Shikoku Island, and the Ryukyu Islands; whereas the other occurred from the northern Kyushu district to the Kanto and Hokuriku districts of mainland Japan. However, both haplotypes were found in a single locality of the southern coast of the Shikoku Island. COI phylogeny incorporating other Pilophorus species revealed that these groups were only recently differentiated. Therefore, use of a certain population of P. typicus across its distribution range should be done with caution because genetic hybridization may occur

    渓流沿い植物タニガワコンギク(キク科) の形態学的および解剖学的比較

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    渓流沿い植物であるタニガワコンギク(Aster microcephalus var. ripensis)( キク科) とその近縁の陸生種ノコンギク(A. microcephalus var. ovatus)を用いて形態学的および解剖学的比較を行った。形態学的解析の結果,タニガワコンギクはノコンギクよりも葉が細く,葉形指数は5.1 ± 1.9(タニガワコンギク)と2.3 ± 0.4(ノコンギク)であった。解剖学的解析の結果,タニガワコンギクの狭葉化は細胞の数と大きさの両方が減少していたことに起因していた。さらに,ノコンギクに対してタニガワコンギクは,孔辺細胞も小さく,単位面積あたりの気孔密度も有意に高かった。タニガワコンギクの葉形指数を各河川間で比較した結果,高知県の物部川水系は他の河川よりも有意に低い値となった。したがって,物部川水系では増水頻度などの選択圧が他の河川よりも低い可能性が示唆された

    在来種ネズミモチと移入種トウネズミモチ(モクセイ科) の保全遺伝学的研究

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    Genetic introgression from introduced, non-native species into native populations is a growing challenge for biological conservation, and one that raises unique practical and ethical issues. Ligustrum lucidum is native to China, and cultivated or used in gardens in various areas in Japan. Recently, some studies reported that this species escaped from cultivated areas and was sympatric with L. japonicum. This indicates that L. japonicum faces the ecological and genetic risk of hybridization and introgression with non-native L. lucidum. Therefore, we examined whether hybridization between L. japonicum and the non-native L. lucidum has occurred in a coexisting population using phenological and molecular analyses. The phenological results indicate that there is very little overlap in the flowering times of the two species. Moreover, molecular analyses using PCR-RFLP of chloroplast and nuclear DNA sequences could not detect any hybridization or introgression of L. lucidum and L. japonicum in the population.移入種から在来種への遺伝子移入は生物学的保全のための懸念課題であり,実用的かつ倫理的な問題を提起している。中国原産のトウネズミモチ(Ligustrum lucidum)は日本の広い地域で園芸として栽植されているが逸出により分布を拡大しており,在来種のネズミモチ(L. japonicum)と同所的に生育していることが近年報告されている。このため,ネズミモチはトウネズミモチとの雑種形成や浸透交雑の生態学的リスクにさらされていると考えられる。そこで本研究では,在来種のネズミモチと移入種のトウネズミモチの間での雑種形成による遺伝的攪乱の有無を明らかにすることを目的として,開花期調査および分子遺伝学的調査を行った。開花期の調査結果より,両種の開花期がずれていることが明らかとなった。PCR-RFLP解析の結果,ネズミモチとトウネズミモチの間に交雑個体および浸透交雑個体を検出することはできなかったため,両種間での交雑は起こっていないと考えられる

    Association of variations in HLA class II and other loci with susceptibility to EGFR-mutated lung adenocarcinoma

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    Lung adenocarcinoma driven by somatic EGFR mutations is more prevalent in East Asians (30-50%) than in European/Americans (10-20%). Here we investigate genetic factors underlying the risk of this disease by conducting a genome-wide association study, followed by two validation studies, in 3,173 Japanese patients with EGFR mutation-positive lung adenocarcinoma and 15,158 controls. Four loci, 5p15.33 (TERT), 6p21.3 (BTNL2), 3q28 (TP63) and 17q24.2 (BPTF), previously shown to be strongly associated with overall lung adenocarcinoma risk in East Asians, were re-discovered as loci associated with a higher susceptibility to EGFR mutation-positive lung adenocarcinoma. In addition, two additional loci, HLA class II at 6p21.32 (rs2179920; P =5.1 × 10(-17), per-allele OR=1.36) and 6p21.1 (FOXP4) (rs2495239; P=3.9 × 10(-9), per-allele OR=1.19) were newly identified as loci associated with EGFR mutation-positive lung adenocarcinoma. This study indicates that multiple genetic factors underlie the risk of lung adenocarcinomas with EGFR mutations

    Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

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    Publisher Copyright: © 2021, The Author(s).Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.Peer reviewe

    Earthworm species and density in semi-natural grasslands on rice paddy levees in Japanese satoyama

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    Earthworms contribute to the sustainability of food webs in the semi-natural grasslands of levees at paddy margins, which are typical components of satoyama, the traditional agricultural landscapes of Japan. Thus far, few studies have focused on earthworm fauna of paddy levees in satoyama. In this study, we investigated earthworm fauna and regional and monthly changes in earthworm density. We found at least 11 species of earthworms living within levees on Sado Island, central Japan. Two endogeic species, Amynthas corticis (Megascolecidae) and Eisenia japonica (Lumbricidae), were dominant in terms of number of adult individuals; these two species appeared in all study regions. We also estimated an average of ~57.4 individuals/m2 for all stages of earthworms in levees, suggesting that rice paddy levees have relatively-high earthworm density. However, such tendencies differed depending on the region. In addition, monthly changes in density were observed in the topsoil of the levees. Our results imply that differences in earthworm assemblages amongst regions and months may influence the availability of food resources for various animals inhabiting satoyama

    The complete mitochondrial genome sequences of Japanese earthworms Metaphire hilgendorfi and Amynthas yunoshimensis (Clitellata: Megascolecidae)

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    Many studies have reported the complete mitochondrial genome sequences of Chinese Megascolecidae earthworms, however, there have been no reports on sequences originating from Japanese Megascolecidae earthworms. In this study, we determined complete mitochondrial genome sequences of two Japanese earthworms belonging to the Pheretima complex within the Megascolecidae family. Metaphire hilgendorfi is one of the most common earthworms in Japan and Amynthas yunoshimensis was found to be morphologically similar to M. hilgendorfi. The complete mitochondrial genomes of M. hilgendorfi (15,186 bp; LC573968) and A. yunoshimensis (15,109 bp; LC573969) contained typical 13 protein coding genes, 22 tRNA genes, and 2 rRNA genes. The phylogenetic analysis revealed that these two species were sister species. Therefore, our findings will further contribute to phylogenetic and genetic diversity analyses of Megascolecidae earthworms
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