中国科学院微生物研究所菌物标本馆馆藏菌寄生属Hypomyces标本的分类研究

对中国科学院微生物研究所菌物标本馆保存的菌寄生属标本进行了分类学方面的清理和订正,鉴定出9个种,其中大孢菌寄生H. marcrosporus、丝层菌寄生H. subiculosus和侧毛斑菌寄生H. tegillum为中国新记录种。     

Pollen morphology of the genus Cornukaempferia (Zingiberaceae) in Thailand

Cornukaempferia is a recently described genus of Zingiberaceae which only occurs in Thailand as a rare genus with limited geographical distribution. Only three species have been described so far, including a recently described new species, C. larsenii. These three species are morphologically very similar and additional data on other biological aspects are useful for the elucidation of their relationship. Pollen morphology of all three species of genus Cornukaempferia has been studied by light microscopy and scanning electron microscopy. The pollen grains are monad, spherical, inaperturate. The exine sculpture is echinate with psilate between the spines for C. aurantiflora and C. longipetiolata, or echinate with regulate between the spines for C. larsenii. This obser-vation helps support the taxonomic status of C. larsenii.     

Diversity,host associations,and phylogeography of temperate aurofusarin-producing Hypomyces/Cladobotryum including causal agents of cobweb disease of cultivated mushrooms

Temperate species of Hypomyces and Cladobotryum that produce the red pigment aurofusarin are common on agaricoid and polyporoid basidiomata of species from five orders of Agaricomycetes. Several cause cobweb disease of commercially cultivated mushrooms resulting in serious losses. We sequenced rpb1, rpb2, tef1, and FG1093 regions in 90 wild strains and 30 strains from mushroom farms, isolated from Europe, North America, Africa, Asia, Australia, and New Zealand. Multigene analyses support the distinctness of five species but reveal Hypomyces rosellus to be paraphyletic, comprising several cryptic lineages. Hypomyces rosellus s. str. is characterised by wide dispersal and gene flow across Eurasia but does not occur in North America. Instead, the lineages from the West and the East Coast appear distinct, having given rise to species inhabiting the Southern Hemisphere. Our results reveal wide misuse of the name H. rosellus, especially for cobweb isolates. The majority of these belong to Hypomyces odoratus, including a weakly supported group of fungicide-resistant strains from Europe and North America sharing identical sequence data. New collections are presented for Cladobotryum rubrobrunnescens and Cladobotryum tenue as well as Cladobotryum multiseptatum and Hypomyces dactylarioides, all previously known only from their type material. The former species pair occurs in Europe and the latter in Australia and New Zealand. Separate lineages appear to be maintained by geographic isolation in North America and temperate Australasia but by host specialisation in the species occurring sympatrically in Europe and Asia. Both specialist and generalist host use strategies have evolved in the group. Although teleomorphs are known in most of the species and unnamed lineages, analyses of the five-gene regions suggest the prevalence of clonal reproduction in H. odoratus. This can be the reason for its success in mushroom farms, also facilitating the spread of fungicide resistance. While tef1 and rpb2 can be recommended for species delimitation, low variation, not exceeding 1 % in the whole ingroup, impeaches the use of ITS as a barcoding gene region in this group of fungi.     

Phylogeny and zoogeography of three new species of the genus Hexabathynella (Crustacea, Malacostraca, Bathynellacea) from North America

Three new species of the genus Hexabathynella , H. otayana sp. n., H. hessleri sp. n. and H. muliebris sp. n., from North America are described. A comparison with previous studies results in the reevaluation of characters already known and the discovery of new constitutive characters. The distal spine of the mandibular spine row is regarded as a synapomorphy of the three new species and two previously known species, H. knoepffleri , H. minuta , which constitute a monophyletic group within the genus, the knoepffleri-group. The phylogenetic relationships between the five species are depicted with a cladogram. The setation on the uropodal exopod is shown to be not only a new unique character for the genus, but also a significant one in classifying its species. The presence of the ancestor species of the genus before the Triassic and dispersal during Mesozoic continental drift are assumed to explain the transatlantic occurrence of the knoepffleri-group and the distribution pattern of the other species.     

New species of Hypocreales (Fungi,Ascomycetes)

The new ascomycetes Hypomyces succineus, Podostroma eperuae, and Nectria phialotrichi are proposed. Hypomyces succineus occurs on basidiomata of Pholiota sp. in New York; its anamorph is described as the new species Cladobotryum succineum. Podostroma eperuae occurs on decaying pods of a species of Eperua found in French Guiana and Guyana. Its anamorph is unknown. Nectria phialotrichi occurs on perithecia of Nectria sp. and bark in Guyana; its anamorph is referred to the anamorph genus Onychophora.     

中国拟缺齿藓属Haplodontium Hampe(真藓科)的分类学研究

报道了中国新记录属--拟缺齿藓属（Haplodontium Hampe）分类学的研究进展。目前本属在中国分布有3种,其中包括1新种：臧氏拟缺齿藓（Haplodontium zangii X.R.Wang&J.C.Zhao）,2个新组合：喜马拉雅拟缺齿藓[H.himalayanum（Mitt.）X.R.Wang&J.C.Zhao]和中华拟缺齿藓[H.sinensis（Dix.）X.R.Wang&J.C.Zhao]。笔者对中国拟缺齿藓属3种植物的形态学特征绘制了墨线图,在光学显微镜和电子显微镜下拍摄显微形态照片,并对每种的主要识别特征、生境和地理分布以及与相似种的形态学比较进行了讨论。     

小菇属三新种

本文报道了产自吉林省的小菇属(Myceno)三个新种:具核小菇(M.nucleata X.He et X.D.Fang),黄囊小菇(M.xanthocystidium X.He et.X.D.Fang)和棘囊小菇(M.brevispina X.He et X.D.Fang)。     

Chromosome evolution in the erythrinid fish, Erythrinus erythrinus (Teleostei: Characiformes)

The genus Erythrinus belongs to the family Erythrinidae, a neotropical fish group. This genus contains only two described species, Erythrinus erythrinus being the most widely distributed in South America. Six samples of this species from five distinct Brazilian localities and one from Argentina were studied cytogenetically. Four groups were identified on the basis of their chromosomal features. Group A comprises three samples, all with 2n = 54 chromosomes, a very similar karyotypic structure, and the absence of chromosome differentiation between males and females. One sample bears up to four supernumerary microchromosomes, which look like 'double minute chromosomes' in appearance. Groups B-D comprise the three remaining samples, all sharing an X(1)X(1)X(2)X(2)/X(1)X(2)Y sex chromosome system. Group B shows 2n = 54/53 chromosomes in females and males, respectively, and also shows up to three supernumerary microchromosomes. Groups C and D show 2n=52/51 chromosomes in females and males, respectively, but differ in the number of metacentric, subtelocentric, and acrocentric chromosomes. In these three groups (B-D), the Y is a metacentric chromosome clearly identified as the largest in the complement. The present results offer clear evidence that local samples of E. erythrinus retain exclusive and fixed chromosomal features, indicating that this species may represent a species complex.     

Mouse ferritin H multigene family is polymorphic and contains a single multiallelic functional gene located on chromosome 19.

Multiple ferritin H subunit sequences are present in the genome of higher vertebrates, but it is not yet known with certainty if more than one is expressed. In this paper, we provide evidence that there is only one functional ferritin H gene in the mouse. We screened a mouse genomic library using a mouse ferritin H cDNA as a probe and characterized five clones. These genomic clones proved to contain three pseudogenes and two allelic forms of a unique functional gene. These two alleles differed by only two point mutations in the promoter and three in the first intron and by a 31-bp insertion in the first intron. They were equally expressed when transiently transfected in HeLa cells. These five genomic clones account for all the bands observed on a Southern blot of mouse genomic DNA hybridized with a ferritin H cDNA, and these bands present a restriction fragment length polymorphism between various representatives of the genus Mus. Using a DNA panel prepared from the backcross progeny (C57BL/6 X Mus spretus)F1 X C57BL/6, we localized the functional ferritin H gene (Fth) in region B of mouse chromosome 19 and established cen-Ly-1-Fth-Pax-2 as the most likely gene order, thus defining a conserved syntenic fragment with human chromosome 11q.     

Microtetraspora malaysiensis sp. nov., isolated from Malaysian primary dipterocarp forest soil

The taxonomic position of three actinomycete strains isolated from Malaysian soil was established by using a polyphasic approach. The isolates formed chains composed of four spores on the tip of sporophores branching from the aerial mycelium, and their chemotaxonomic properties were common to those of members of the family Streptosporangiaceae. These phenotypic properties as well as a phylogenetic analysis based on 16S rRNA gene sequences indicated that they should be classified in the genus Microtetraspora. The three isolates showed a unique pattern of cultural, physiological and biochemical properties that distinguished them from previously described species of the genus Microtetraspora. The isolates showed more than 72% DNA relatedness to each other, but only 58% or less relatedness to any previously described species. On the basis of the data presented, a new species of the genus Microtetraspora, Microtetraspora malaysiensis, is proposed. The type strain of the new species is strain H47-7(T) (=JCM 11278(T)=DSM 44579(T)).     

Revision for the swordtail cricket genus Homoeoxipha (Grylloidea: Trigonidiidae: Trigonidiinae) from China

Species of Homoeoxipha are very small and always live on leaves of shrubs and grasses. This genus contains ten species worldwide and is distributed across five zoological regions, from Africa to New Guinea. Homoeoxipha lycoides is the type species of this genus and possesses the characteristic coloration for the genus. These coloration features resulted in some synonyms and disputes over species, because most Homoeoxipha species are ornamented with a similar coloration pattern. We compared and documented the differences between H. lycoides and its relatives in China. A new important character, the epiphallic transversal suture, is used to distinguish them. Based on this work, all of the Chinese species, H. lycoides, H. obliterata and H. nigripes, and one new species, H. eurylobus, with similar coloration to H. lycoides, are described and illustrated.     

Dosage Compensation Regulatory Proteins and the Evolution of Sex Chromosomes in Drosophila

In the fruitfly Drosophila melanogaster, the four male-specific lethal (msl) genes are required to achieve dosage compensation of the male X chromosome. The MSL proteins are thought to interact with cis-acting sites that confer dosage compensation to nearby genes, as they are detected at hundreds of discrete sites along the length of the polytene X chromosome in males but not in females. The histone H4 acetylated isoform, H4Ac16, colocalizes with the MSL proteins at a majority of sites on the D. melanogaster X chromosome. Using polytene chromosome immunostaining of other species from the genus Drosophila, we found that X chromosome association of MSL proteins and H4Ac16 is conserved despite differences in the sex chromosome karyotype between species. Our results support a model in which cis-acting regulatory sites for dosage compensation evolve on a neo-X chromosome arm in response to the degeneration of its former homologue.     

The biology and systematics of a new species of Xenopus (Anura: Pipidae) from the highlands of Central Africa

A new species of clawed toad, Xenopus wittei sp. nov. is described from highland areas overlapping the borders of Rwanda, Uganda and Zaire. A comprehensive morphological analysis of the species has been carried out. X. wittei sp. nov. is very closely related to X. vestitus and both have a tetraploid chromosome complement (2 n = 72), the only examples within the genus. Nevertheless, the two species may be distinguished by easily observed features, including head morphology and dorsal body colours and patterns, and are also identified by their karyotypes and mating calls.
Data on distribution, ecology and parasite infection are derived from both museum collections and fieldwork in Central Africa. X. wittei sp. nov. is sympatric in parts of its range with X. vestitus, X. laevis victorianus and X. I. bunyoniensis , with up to three of the taxa sharing the same habitats. The implications of potential species interactions are discussed. Experimental hybridization has confirmed the reproductive isolation of the two tetraploid species. Parasitological studies show that they may be distinguished from one another by host specific species of the nematode Chitwoodchabaudia and from other Xenopus species by the absence of the tapeworm genus Cephalochlamys . Large scale population movements of the Xenopus species have apparently occurred in the Central African highlands during the period of available records. Sympatry observed amongst the present day representatives of Xenopus may have been an important factor in the evolution of these toads since X. wittei sp. nov. and X. vestitus are interpreted as allopolyploids, the products of interspecies hybridization.     

A review of Asian Hediste species complex (Nereididae, Polychaeta) with descriptions of two new species and a redescription of Hediste japonica (Izuka, 1908)

Three Asian species of the genus Hediste (Nereididae, Polychaeta, Annelida), including two new species, are reviewed. Hediste japonica (Izuka, 1908) was redescribed based on recently discovered type material and on additional specimens newly collected from the Ariake Sea in Japan and the west coast of Korea. Two new species, H .  diadroma and H. atoka , were described based on specimens collected from Japan. These three species are morphologically similar, but distinguishable by some differences in parapodial and chaetal morphology, at least at the sexually mature stage. The presence of homogomph falcigers and the absence of heterogomph spinigers are unique characteristics of H. japonica among this genus. Inconspicuous epitokous metamorphosis occurred as a slight enlargement of the eyes and parapodial ligules in mature adults of H. diadroma sp. nov. and H. japonica in combination with their reproductive swarming and pelagic larval development. The epitoke-specific sesquigomph spinigers were added in mature adults of H. diadroma sp. nov., while the number of ordinary homogomph spinigers increased in some adults of H. japonica. Epitokous metamorphosis in the Hediste species was compared with that in other nereidid genera. No epitokous metamorphosis was observed in H. atoka sp. nov., corresponding to its reproduction without swarming and to its development without a planktonic larval stage. Significant differences in paragnath numbers in the maxillary ring of the proboscis were found among the three species, suggesting different feeding habits. In Japan, the present distribution of H. japonica is restricted to muddy tidal flats in the inner part of the Ariake Sea, probably due to recent human impact, while the other two species are widespread.  © 2003 The Linnean Society of London. Zoological Journal of the Linnean Society, 2003, 137, 403−445     

Molecular systematics of bats of the genus Myotis (Vespertilionidae) suggests deterministic ecomorphological convergences.

Based on extensive phenetic analyses, bats of the genus Myotis have been classically subdivided into four major subgenera each of which comprise many species with similar morphological and ecological adaptations. Each subgenus thus corresponds to a distinct "ecomorph" encompassing bat species exploiting their environment in a similar fashion. As three of these subgenera are cosmopolitan, regional species assemblages of Myotis usually include sympatric representatives of each ecomorph. If species within these ecomorphs are monophyletic, such assemblages would suggest extensive secondary dispersal across geographic areas. Conversely, these ecomorphological adaptations may have evolved independently through deterministic processes, such as adaptive radiation. In this case, phylogenetic reconstructions are not expected to sort species of the same ecomorph into monophyletic clades. To test these predictions, we reconstructed the phylogenetic history of 13 American, 11 Palaearctic, and 6 other Myotis species, using sequence data obtained from nearly 2 kb of mitochondrial genes (cytochrome b and nd1). Separate or combined analyses of these sequences clearly demonstrate the existence of several pairs of morphologically very similar species (i.e., sibling species) which are phylogenetically not closely related. None of the three tested subgenera constitute monophyletic units. For instance, Nearctic and Neotropical species currently classified into the three subgenera were clustered in a single, well-supported monophyletic clade. These species thus evolved independently of their ecological equivalents from the Palaearctic region. Independent adaptive radiations among species of the genus Myotis therefore produced strikingly similar evolutionary solutions in different parts of the world. Furthermore, all phylogenetic reconstructions based on mtDNA strongly supported the existence of an unsuspected monophyletic clade which included all assayed New World species plus M. brandtii (from the Palaearctic Region). This "American" clade thus radiated into a morphologically diverse species assemblage which evolved after the first Myotis species colonized the Americas. Molecular reconstructions support paleontological evidence that species of the genus Myotis had a burst of diversification during the late Miocene-early Pliocene epoch.     

Molecular systematics of Ceratostomella sensu lato and morphologically similar fungi

The systematic position and phylogenetic relationships of Ceratostomella sensu lato and phenotypically similar fungi using comparative morphological and culture studies and phylogenetic analyses of the nuclear large- and small-subunit ribosomal DNA were explored. In the light of inferred phylogenies and morphological data the genus Ceratostomella is redescribed, the generic concept is emended and four species are accepted (viz. C. cuspidata, C. pyrenaica, C. rhynchophora and C. rostrata). A new genus Xylomelasma is introduced and delimited from Ceratostomella, with two new species described (viz. X. novaezelandiae and X. sordida). In culture species of both Ceratostomella and Xylomelasma produced sterile mycelium. The genus Lentomitella with a phaeoisaria-like anamorph formed in vitro is reinstated to encompass taxa formerly attributed to the broadly perceived Ceratostomella with three accepted species (viz. L. cirrhosa, L. crinigera and L. tomentosa). Lentomitella and Ceratostomella are clearly distinguishable by the morphology of asci, ascospores and centrum. Lentomitella is compared to phenotypically similar Ceratosphaeria, which formed a harpophora-like anamorph in vitro. In the present phylogenies Ceratostomella, Ceratosphaeria, Lentomitella and Xylomelasma are shown as clearly separate genera belonging to three different groups of perithecial ascomycetes. Ceratostomella, Lentomitella and Xylomelasma reside within a large unsupported clade consisting of members the Ophiostomatales, the freshwater Annulatascaceae and a group of nonstromatic, terrestrial taxa. Ceratosphaeria is well supported within the Magnaporthaceae. The systematic value of morphological characters of ascospores, paraphyses, asci, centrum and conidiogenesis in segregating taxa from Ceratostomella sensu lato and their relatives is discussed.     

Euchromatic domains in plant chromosomes as revealed by H4 histone acetylation and early DNA replication.

Using specific polyclonal antisera raised against acetylated isoforms of histone H4, we have analyzed their distribution in the dioecious plant Silene latifolia (syn. Melandrium album) possessing heteromorphic sex chromosomes. Our previous studies on this species have shown that one of the two X chromosomes in homogametic female cells is heavily methylated and late replicating, as a possible consequence of dosage compensation. Here we report that there are no detectable differences in intensity and distribution of H4 acetylation between these two X chromosomes. In S. latifolia only distal-subtelomeric chromosome regions, on both the sex chromosomes and autosomes, display strong signals of H4 acetylation at N-terminal lysines 5, 8, and 12. These acetylated domains correspond to the very early replicating distal chromosome regions as revealed by 5-bromodeoxyuridine pulses followed by the indirect immunofluorescence microscopy. The distribution of H4 acetylated at lysine 16 was uniform along the chromosomes. The unique distal-subtelomeric H4 acetylation signals were also observed in three other Silene species (S. vulgaris, S. pendula, and S. chalcedonica), but not in two non-related plant species tested (Allium cepa and Nicotiana tobacum). The presented data as well as our recent studies on the structure of S. latifolia chromosome ends indicate that Silene species possess the specific distal-subtelomeric location of euchromatin, gene-rich regions on chromosomes.     

Wood and bark anatomy of Hypocalyptus support its isolated taxonomic position in Leguminosae

The wood and bark anatomy of all three species of Hypocalyptus from the monotypic South African endemic tribe Hypocalypteae were studied. Despite large morphological differences (especially in habit) the species were found to be similar in wood and bark structure. Discontinuities are quantitative only, relating mainly to differences in growth form between H. oxalidifolius, a short-lived shrublet, and the two other species, H. coluteoides and H. sophoroides, both of which are erect shrubs or small trees of up to 6 m tall. Hypocalyptus wood has a mesomorphic structure with vessels solitary or in small groups, reflecting relatively moist habitats in fynbos vegetation. In contrast to many genera of Leguminosae for which data are available, crystals are absent from the wood. This is the first report of tanniniferous tubes in the wood of Leguminosae (previously reported only in Myristicaceae and a genus from Ulmaceae). The presence of tanniniferous tubes and the absence of crystals in all three species of Hypocalyptus underline the isolated position of the genus and support its tribal status.     

Pattern of X-Y chromosome pairing in the Taiwan vole, Microtus kikuchii.

Pairing of X and Y chromosomes at meiotic prophase and the G- and C-banding patterns and nucleolar organizer region (NOR) distribution were analyzed in Microtus kikuchii. M. kikuchii is closely related to M. oeconomus and M. montebelli, karyologically and systematically. The formation of a synaptonemal complex between the X and Y chromosomes at pachytene and end-to-end association at diakinesis--metaphase I are only observed in three species in the genus Microtus; M. kikuchii, M. oeconomus, and M. montebelli. All the other species that have been studied so far have had asynaptic X-Y chromosomes. These data confirm that M. kikuchii, M. oeconomus, and M. montebelli are very closely related, and support the separation of asynaptic and synaptic groups on the phylogenetic tree.