Genetic diversity and phylogenetic relationships of the Manchurian zokor <Emphasis Type="Italic">Myospalax psilurus</Emphasis> (Rodentia,Muridae) according to RAPD-PCR analysis

The population structuring and low genetic diversity of the Manchurian zokor Myospalax psilurus Milne-Edwards, 1874, an East Asian endemic included in the Red List of Russia, were demonstrated. Two separate geographical groups differing in the level of their genetic diversity were found on the territory of the Primorskii krai. The subpopulation located closest to the main area of this species was determined as ancestral. A subspecies differentiation of the Primorskii krai and Transbaikal M. psilurus populations was shown, as was the monophyletic origin of M. psilurus and its high divergence from M. aspalax. The animals from northern localities are recommended for reintroduction in nature under species recovery programs in Primorskii krai.     

Features of the Biology of the False Zokor (<Emphasis Type="Italic">Myospalax aspalax</Emphasis>, Rodentia,Spalacidae) from Eastern Transbaikalia

The features, population characteristics of reproduction, nutrition, and lifestyle of an extremely poorly studied narrow-range species of underground rodents—the false zokor (Myospalax aspalax)—have been described on the basis of original field materials. The data were obtained within the Russian part of the species range in Zabaikal’skii krai. The false zokor is characterized by a pronounced sexual dimorphism in body size (males are larger) and a predominance of females in the population. Mating takes place in April; at other times of the year, zokors lead a solitary lifestyle. The size of the brood is small: 3.7 embryos per breeding female. Their preferred food is bulbs and rhizomes of Allium, Thermopsis, Phragmites, and Leymus. In Eastern Transbaikalia, they are active in winter.     

Two new species of Heligmoptera Nadtochiy, 1977 (Nematoda: Trichostrongylina: Heligmosomoidea) from myospalacine rodents in China (Gansu), with a redefinition of the genus

Two species, Heligmoptera giraudouxi n. sp. and H. querei n. sp., are described. These are co-parasites of the small intestine of Myospalax fontanierii in China (Gansu). H. giraudouxi is closely related to the only existing species of the genus, H. myospalaxi (Nadtochiy, 1970), a parasite of Myospalax psilurus in the Primor'e Region of Russia. It is distinguished by the pattern of the left lateral lobe. H. querei differs from the two other species by possessing a long dorsal ray and from H. giraudouxi by the length of the left ala. From a phylogenetic point of view, these three species may form a small clade, adapted to Myospalax spp., derived from related forms in Insectivora, this capture resulting in the appearance of monodelphy.     

Genetic differentiation and spatiotemporal history of diploidy and tetraploidy of Clintonia udensis

Polyploidy is an important factor shaping the geographic range of a species. Clintonia udensis (Clintonia) is a primary perennial herb widely distributed in China with two karyotypic characteristics—diploid and tetraploid and thereby used to understand the ploidy and distribution. This study unraveled the patterns of genetic variation and spatiotemporal history among the cytotypes of C. udensis using simple sequence repeat or microsatellites. The results showed that the diploids and tetraploids showed the medium level of genetic differentiation; tetraploid was slightly lower than diploid in genetic diversity; recurrent polyploidization seems to have opened new possibilities for the local genotype; the spatiotemporal history of C. udensis allows tracing the interplay of polyploidy evolution; isolated and different ecological surroundings could act as evolutionary capacitors, preserve distinct karyological, and genetic diversity. The approaches of integrating genetic differentiation and spatiotemporal history of diploidy and tetraploidy of Clintonia udens would possibly provide a powerful way to understand the ploidy and plant distribution and undertaken in similar studies in other plant species simultaneously contained the diploid and tetraploid.     

Differentiation of large-scaled redfin <Emphasis Type="Italic">Tribolodon hakonensis</Emphasis> (Pisces,Cyprinidae) in the Russian part of the range as inferred from the data of karyological analysis and PCR-RFLP analysis of mitochondrial DNA

Considerable differences in karyotypes of Tribolodon hakonensis from Primorye and the rivers of the Sea of Okhotsk drainage were demonstrated. These differences raise doubts that these fishes belong to one species and point to the necessity of more precise definition of the species status of the southern form of T. hakonensis. The karyological evidence is consistent with the data of mtDNA PCR-RFLP analysis on genetic independence of the southern and the northern forms of T. hakonensis. In the northern form of T. hakonensis, variation of the chromosomal arm number was revealed. Specifically, the number of chromosomes was constant (2n = 50), whereas the number of chromosomal arms (NF) constituted 88, 92, and 94, which suggests genetic heterogeneity of the northern form. PCR-RFLP analysis of mtDNA showed that haplotypes of northern T. hakonensis split into two groups with 100% support. Based on comparative phylogenetic and karyological analyses of the Tribolodon species, independent divergence of the southern and the northern forms of T. hakonensis was suggested.     

鼢鼠亚科 Mysopalacinae动物系统学研究现状与展望

现生鼢鼠是分布于东亚的一类典型地下啮齿动物,中国西部是其多个种的模式产地和主要分布区域。该类动物分布广、数量多,经济和生态意义重要,有关其控制和管理问题长期存有困扰。有效的物种管理离不开分类及生态学知识,但学界对该类群的分类地位与系统发育关系等至今仍有争议。随着分子系统学等现代科学技术的发展,其系统发育和分类地位等产生了许多新的研究结果。本文对近年来鼢鼠现存种系统学方面取得的研究进展进行了梳理,综述了鼢鼠亚科动物各系统分类的观点及其主要依据,分析了一些存在的问题,并就如何进一步分类研究等提出了建议,旨在促进鼢鼠亚科动物系统分类学研究的发展,为该类群物种资源合理利用与管理等提供基础资料。     

Is the Profile of Fatty Acids,Tocopherols, and Amino Acids Suitable to Differentiate Pinus armandii Suspicious to Be Responsible for the Pine Nut Syndrome from Other Pinus Species?

Pinus armandii is suspicious to be responsible for the Pine Nut Syndrome, a long lasting bitter and metallic taste after the consumption of pine nuts. To find chemical characteristic features for the differentiation of P. armandii from other Pinus species, 41 seed samples of the genus Pinus from 22 plant species were investigated regarding the content and the composition of fatty acids, tocopherols, and amino acids. The predominant fatty acids in the seed oils were linoleic acid (35.2 – 58.2 g/100 g), oleic acid (14.6 – 48.5 g/100 g), and pinolenic acid (0.2 – 22.4 g/100 g), while the vitamin‐E‐active compounds were dominated by γ‐tocopherol. The amino acid composition was mainly characterized by arginine and glutamic acid with amounts between 0.9 and 8.9 g/100 g as well as 2.1 g/100 g and 8.3 g/100 mg. On the basis of this investigation, a Principle Component Analysis has been used to identify the most important components for the differentiation of P. armandii from other Pinus species. Using the data for glutamic acid, 20:2Δ^5,11, 18:3Δ^5,9,12, 18:1Δ⁹, and oil content, a classification of the 41 samples into four different groups by cluster analysis was possible, but the characteristic features of P. armandii were too close to some other members of the genus Pinus, making a clear differentiation of this species difficult. Nevertheless, the investigation showed the similarities of different members of the genus Pinus with regard to fatty acids, vitamin‐E‐active compounds, and amino acids.     

The impact of plateau zokor<Emphasis Type="Italic">Myospalax fontanierii</Emphasis> burrows on alpine meadow vegetation on the Qinghai-Xizang (Tibetan) plateau

The impact of burrows constructed by plateau zokorsMyospalax fontanierii (Milne-Edwards, 1867) on alpine meadow vegetation on the Qinghai-Xizang (Tibetan) plateau was investigated. Plant samples taken from quadrats directly over active zokor burrows, back-filled burrows, adjacent burrow controls, and random sites from a field, in which no burrows or mounds occurred were compared. The biomass of plants (below- and above-ground) directly over shallow active burrows was significantly lower than on control plots. This reduction in biomass was not significantly different than that between deep active burrows and control plots. There were no significant differences between above- and below-ground plant biomass on areas perpendicular to active burrows when compared to random sites. Back-filling soil in burrows could promote the growth of above-ground monocotyledonous plants. However, the burrowing activities of zokors had a negative effect on biomass of dicotyledonous plants.     

Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus smithii (Hymenoptera: Formicidae)

The general prevalence of sexual reproduction over asexual reproduction among organisms testifies to the evolutionary benefits of recombination, such as accelerated adaptation to changing environments and elimination of deleterious mutations. Documented instances of asexual reproduction in groups otherwise dominated by sexual reproduction challenge evolutionary biologists to understand the special circumstances that might confer an advantage to asexual reproductive strategies. Here we report one such instance of asexual reproduction in the ants. We present evidence for obligate thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring from unfertilized eggs, workers are sterile, and males appear to be completely absent. Obligate thelytoky is implicated by reproductive physiology of queens, lack of males, absence of mating behavior, and natural history observations. An obligate thelytoky hypothesis is further supported by the absence of evidence indicating sexual reproduction or genetic recombination across the species'' extensive distribution range (Mexico-Argentina). Potential conflicting evidence for sexual reproduction in this species derives from three Mycocepurus males reported in the literature, previously regarded as possible males of M. smithii. However, we show here that these specimens represent males of the congeneric species M. obsoletus, and not males of M. smithii. Mycocepurus smithii is unique among ants and among eusocial Hymenoptera, in that males seem to be completely absent and only queens (and not workers) produce diploid offspring via thelytoky. Because colonies consisting only of females can be propagated consecutively in the laboratory, M. smithii could be an adequate study organism a) to test hypotheses of the population-genetic advantages and disadvantages of asexual reproduction in a social organism and b) inform kin conflict theory.For a Portuguese translation of the abstract, please see Abstract S1.     

Pliocene white pine (Pinus subgenus Strobus) needles from western Yunnan,southwestern China

Abstract

The fossil records of Pinus L. are abundant since the Late Cretaceous, especially for the subgenus Pinus L. (the hard pines). However, those of the subgenus Strobus (D. Don) Lemmon (the white or soft pines) are not well documented. In this study, we describe a new species of white pines, Pinus plioarmandii sp. nov., from the Pliocene of western Yunnan, southwestern China. This species mostly resembles extant P. armandii Franch. in gross morphology and cuticular structure of needles. Molecular dating showed that the Asian white pines split into two lineages around the Late Miocene, and the Pinus armandii clade diverged at the Early Pliocene. The present fossil occurrence indicates that Pinus armandii might originate in southwest China and probably in the western Yunnan. The glacial events during the Pleistocene might be the major factors for the retreat of the white pines from western Yunnan, and the rapid uplift of the Yunnan Plateau and deep incision of the river valleys since the Pliocene had posed a significant geographic barrier for their reconnection in the subsequent warm climate condition.     

Intestinal Methanobrevibacter smithii but not total bacteria is related to diet‐induced weight gain in rats

It is increasingly understood that gastrointestinal (GI) methanogens, including Methanobrevibacter smithii, influence host metabolism.

Objective:

Therefore, we compared M. smithii colonization and weight gain in a rat model under different dietary conditions.

Design and Methods:

Sprague‐Dawley rats were inoculated with M. smithii or vehicle (N = 10/group), fed normal chow until day 112 postinoculation, high‐fat chow until day 182, then normal chow until day 253. Thereafter, five rats from each group were fed high‐fat and normal chow until euthanasia.

Results:

Both groups exhibited M. smithii colonization, which increased following inoculation only for the first 9 days. Change to high‐fat chow correlated with significant increases in weight (P < 0.00001) and stool M. smithii (P < 0.01) in all rats, with stool M. smithi decreasing on return to normal chow. Rats switched back to high‐fat on day 253 further increased weight (P < 0.001) and stool M. smithii (P = 0.039). Euthanasia revealed all animals had higher M. smithii, but not total bacteria, in the small intestine than in the colon. Rats switched back to high‐fat chow had higher M. smithii levels in the duodenum, ileum, and cecum than those fed normal chow; total bacteria did not differ in any bowel segment. Rats which gained more weight had more bowel segments colonized, and the lowest weight recorded was in a rat on high‐fat chow which had minimal M. smithii colonization.

Conclusions:

We conclude that M. smithii colonization occurs in the small bowel as well as in the colon, and that the level and extent of M. smithii colonization is predictive of degree of weight gain in this animal model.     

A new species of <Emphasis Type="Italic">Euflemingites</Emphasis> spath (Ammonoidea) from the Lower Triassic of Southern Primorye

A new species, Euflemingites artyomensis sp. nov., is described from the Olenekian of the vicinity of the town of Artyom (Southern Primorye). Geographical differentiation of the genus Euflemingites is discussed.     

Evolutionary and dispersal history of Eurasian house mice Mus musculus clarified by more extensive geographic sampling of mitochondrial DNA

We examined the sequence variation of mitochondrial DNA control region and cytochrome b gene of the house mouse (Mus musculus sensu lato) drawn from ca. 200 localities, with 286 new samples drawn primarily from previously unsampled portions of their Eurasian distribution and with the objective of further clarifying evolutionary episodes of this species before and after the onset of human-mediated long-distance dispersals. Phylogenetic analysis of the expanded data detected five equally distinct clades, with geographic ranges of northern Eurasia (musculus, MUS), India and Southeast Asia (castaneus, CAS), Nepal (unspecified, NEP), western Europe (domesticus, DOM) and Yemen (gentilulus). Our results confirm previous suggestions of Southwestern Asia as the likely place of origin of M. musculus and the region of Iran, Afghanistan, Pakistan, and northern India, specifically as the ancestral homeland of CAS. The divergence of the subspecies lineages and of internal sublineage differentiation within CAS were estimated to be 0.37–0.47 and 0.14–0.23 million years ago (mya), respectively, assuming a split of M. musculus and Mus spretus at 1.7 mya. Of the four CAS sublineages detected, only one extends to eastern parts of India, Southeast Asia, Indonesia, Philippines, South China, Northeast China, Primorye, Sakhalin and Japan, implying a dramatic range expansion of CAS out of its homeland during an evolutionary short time, perhaps associated with the spread of agricultural practices. Multiple and non-coincident eastward dispersal events of MUS sublineages to distant geographic areas, such as northern China, Russia and Korea, are inferred, with the possibility of several different routes.     

Cryptic speciation in the narrow‐headed vole Lasiopodomys (Stenocranius) gregalis (Rodentia: Cricetidae)

Recent study on Lasiopodomys (Stenocranius) gregalis has revealed four clear mitochondrial lineages with differences exceeding the species level. The most divergent is the clade from south‐eastern Transbaikalia. Multilocus (six nuclear genes), morphological (dental characters of m1 and M3) and behavioural (breeding experiments) analyses were conducted to test the hypothesis that L. gregalis is a complex of two cryptic species. All of the applied methods distinguish the independent status of voles from south‐eastern Transbaikalia. This clade occupies a portion of the distribution range of the currently valid subspecies L. g. raddei including its terra typica. According to the results of cyt b analysis, the lectotype of L. g. raddei belongs to the Transbaikal clade. We re‐establish the species status for the taxon Lasiopodomys raddei including populations from south‐eastern Transbaikalia, as a cryptic species of the narrow‐headed vole complex.     

Cytogenetics of the European plethodontid salamanders of the genus Hydromantes (Amphibia,Urodela)

A karyological analysis was carried out on different European species of the genus Hydromantes (Plethodontidae). All the species examined share the same chromosome number (2n=28) and, with the exception represented by pair XIV, morphologically similar karyotypes. While the karyotypes display a similar distribution — mainly centromeric and pericentric — of C-heterochromatin, quantitative variations in pericentric heterochromatin are observed among species. In the continental species Hydromantes italicus and ambrosii as well as in the eastern Sardinian species imperialis, flavus and specie nova, pair XIV consists of heteromorphic sex chromosomes of the XX/XY type. It is proposed that the differentiation of the Y might have taken place through the occurrence of a structural rearrangement, such as a pericentric inversion, starting from a hypothetical, homomorphic pair XIV. A sex-related heteromorphism is not found in the western Sardinian species H. genei. A further karyological differentiation among these species concerns the position of the nucleolus organizing region (NOR), which is located on chromosome XII (H. italicus and ambrosii) or on chromosome X, close to the centromere (H. genei, H. imperialis and H. specie nova), or in an intercalary position (H. flavus). The location and the number of the 5 S DNA sites have been conserved during species divergence. On the basis of these karyological data, as well as of results obtained through a preliminary restriction enzyme analysis of the ribosomal and genomic DNAs, the phyletic relationships among the European Hydromantes species are discussed.     

基于SRAP标记的紫溪山华山松种子园无性系遗传多样性分析

为明确云南楚雄市紫溪山华山松种子园内不同种源无性系间的遗传背景,该研究收集了园内6个种源的60个华山松无性系单株针叶,采用改良CTAB法提取其总DNA,并利用SRAP分子标记对其进行遗传多样性分析。结果表明:(1)从100对引物组合中共筛选出15对具有多态性的SRAP引物,经SRAP-PCR扩增后,共获得出194个位点,多态位点百分率(PPB)为85.05%,Nei's基因多样性指数(H)为0.233 7,Shannon's信息指数(I)为0.341 9,种源间的遗传分化系数(GST)为0.355 5。(2)华山松6个种源遗传多样性较高,且遗传变异主要存在于华山松种源内,种源地会泽(HZ)与巍山(WS)种源的遗传距离最近(D=0.050 1),会泽(HZ)与宜良(YL)种源的遗传距离最远(D=0.361 8)。(3)聚类分析显示将6个华山松种源一共聚为3类:会泽(HZ)和巍山(WS)种源聚为一类;楚雄(CX)、南华(NH)和宜良(YL)种源聚为一类;腾冲(TC)种源单独为一类。综合上述结果显示,紫溪山华山松种子园内无性系间的遗传分化处于较高水平,为华山松杂交育种时亲本的选配及种质资源的评价提供了分子水平的理论依据。     

秦岭森林鼠类对华山松种子捕食及其扩散的影响

森林鼠类的种子贮藏行为对植物的扩散和自然更新有着非常重要的影响。通过塑料片标记法,2008和2009年的9月—11月分别在秦岭南坡的佛坪国家级自然保护区内调查了森林鼠类对华山松(Pinus armandii)种子的捕食和扩散,结果显示:森林鼠类对华山松种子有着非常大的捕食压力。在2008年,几乎所有的种子(96.4%)在第3天后就被全部取食,而在2009年,也有将近一半的种子(49.6%)在第3天后被取食。但与此同时,鼠类对华山松种子的扩散也起着非常重要的作用。尤其在2009年,第3天时鼠类最高分散贮藏了17.75%的种子,而且直到第19天后仍然有12.25%被贮藏的种子存活下来。华山松种子在两个年份间的扩散历程有很大差异。在2008年,几乎所有的种子都被鼠类取食,贮藏量非常小;而在2009年,种子被贮藏的比例显著的增加。这个结果可能与种子大小年现象有着十分紧密的联系。2008年是华山松种子的小年,产量非常低。鼠类为了满足其日常的能量需求,只能大量的取食有限的种子,而减少其贮藏量。而2009年是华山松种子的大年,产量非常高。鼠类在满足其日常能量需求的同时,还有大量剩余的种子供其贮藏。     

<Emphasis Type="Italic">Melilotus officinalis</Emphasis> (yellow sweetclover) causes large changes in community and ecosystem processes in both the presence and absence of a cover crop

Non-native species are hypothesized to decrease native species establishment and cover crops are hypothesized to decrease non-native species abundance. Although many studies have compared invaded to non-invaded habitats, relatively few studies have experimentally added non-native species to directly examine their effects. In a greenhouse mesocosm experiment, we tested the effects of non-native forbs (Melilotus officinalis, Verbascum thapsus, and Lespedeza cuneata), a proposed C₃ grass cover crop (Pascopyrum smithii), and a commonly seeded non-native C₃ grass (Bromus inermis) on the establishment of target native C₄ prairie grass species. All treatments contained the same seed density of target C₄ species and were begun on bare soil collected from the field. The legume M. officinalis strongly decreased the abundance of all other species, species diversity, and light and soil moisture levels. Surprisingly, M. officinalis took up relatively large amounts of labeled nitrogen (¹⁵N) from the soil early in its development, but M. officinalis fixed nitrogen, thus increasing nitrogen in biomass nearly fivefold by the end of the study. We found few effects of either C₃ grass species on non-native forbs or C₄ target species, but seeded P. smithii did increase species diversity. Non-native plants therefore impeded native C₄ grass establishment through long-lasting effects of target species seedbank depletion (death of most target seedlings) and altered nutrient availability. The effects of M. officinalis were not reduced by the presence of a cover crop.