Molecular phylogenetic relationship of Stigmaeopsis spider mites (Acari : Tetranychidae) collected from Yamagata Prefecture

We investigated the phylogenetic relationships of Stigmaeopsis spider mites (Acari: Tetranychidae) using sequence variation in the cytochrome oxidase subunit I (COI) region of mitochondria DNA. We sequenced a total of 32 samples including four samples of S. takahashii and ten of S. longus from Yamagata Prefecture. Phylogenetic analyses based on the neighbor-joining and the Bayesian method revealed that Stigmaeopsis consists of five monophyletic groups corresponding to each species. Among them, the monophyletic group of S. longus was further divided into two subgroups; one is the northern group composed of the samples from the Hokkaido and Tohoku districts, and the other is the southern group of the samples from the Tohoku, Hokuriku, Shikoku, and Kyushu districts. This suggests that the current distribution of this species has employed two routes of expansion. It is interesting that the samples of S. longus from Yamagata Prefecture were divided into the two groups. This implies that S. longus had multi-expanded patterns of distribution in this prefectur

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

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

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

Simultaneous bilateral testicular tumors: a case report

We report a case of bilateral simultaneously-occurring testicular tumors. A 43-year-old man was admitted to our clinic with a complaint of right inguinal pain in May 1992. Under the diagnosis of bilateral testicular neoplasms, bilateral high orchiectomy was performed. Histological examination revealed typical seminoma of bilateral testes. The patient was diagnosed with stage IIIO seminoma, and he was treated with combination chemotherapy (PVB). No evidence of disease has been seen after chemotherapy