块菌发育过程中伴生微生物多样性及其生态功能

块菌属Tuber是子囊菌门中一类珍贵的地下生外生菌根真菌,能与松科、壳斗科等多种树木形成菌根共生关系,在森林生态系统中扮演着重要的角色。同时,该属的一些种类因其独特的香味而备受国际食用菌市场推崇,具有极高的经济价值。在块菌属漫长的生活史中,菌丝的生长、菌根的形成、子囊果的产生和发育、特殊芳香化合物及活性物质的产生和积累均与其伴生微生物有着密切的关系。近年来,分子生物学技术的发展尤其是高通量测序技术的应用推动了对块菌属子囊果形成和发育机制的研究,为块菌生态学研究提供了有力的工具,使块菌伴生微生物相关研究取得重要突破。本文综述了近5年来国内外对块菌属生长发育过程中伴生细菌、真菌多样性及其生态功能的相关研究,并探讨了其中尚未清楚的问题及今后可能的研究方向,为块菌属生物学的研究及人工栽培奠定基础。     

Observations on post-fire black morel ascocarp development in an Israeli burnt forest site and their preferred micro-sites

Morchella species ascocarps (morels) are sought-after edible mushrooms that exhibit pyrophilous behavior, proliferating in fire-affected soils of certain types of forests. The factors governing fruiting in this habitat are poorly understood. An observational approach was used to determine the spatial distribution on preferred micro-sites of black morel fruiting in a forest after a summer fire, subjected to different post-fire forestry management activities. Clearing the burnt tree stumps from the site, compaction of the burnt soil by heavy machinery (bulldozers) and covering the soil with chopped wood created preferred micro-sites for black morel fruiting. Fewer fruit bodies developed on untouched burnt soil, and almost none on non-burnt soil at the same site. These observations enhance understanding the ecological principles underlying the distribution and abundance of morel ascocarp development in natural habitats; such an understanding could contribute to conservation and management of morel fruiting in the wild.     

Morphology of early fetal deaths and their chromosomal characteristics

The morphologic features of a consecutive series of 3,472 singleton spontaneous abortions are described. Of the total, 21% consisted of well-formed fetuses (over 30 mm long), 27.9% had no identifiable fetal tissues, 34.2% consisted of fetal membranes only, and the remainder, 16.8%, consisted of a variety of embryonic types. The rate of focal malformations among embryos over 10 mm in length and among fetuses was 16.4%. The overall rate of chromosome anomalies in the 1,356 karyotyped specimens was 39.8%. The vast majority, 94%, occurred in embryos less than 30 mm, and in specimens whose development had not proceeded beyond differentiation of fetal membranes. The rate of chromosome anomalies among nonmalformed fetuses (greater than 30 mm) was only 1.7%. However, the presence of limited embryonic development was not a good predictor of the presence of a chromosome anomaly. Slightly over half (56%) of all specimens less than 30 mm long had chromosome anomalies; for individual classes of such specimens the rate ranged from 45% to 81%. The morphologic category with the highest rate of karyotypic anomalies had an excess of monosomy X abortuses. A gradient of developmental level could be associated with the degree of intrauterine mortality of each chromosome anomaly; i.e., conceptuses with karyotypes that occur at term had a greater degree of embryonic development than karyotypes that are never seen among term births. Thus, trisomies 13, 18, and 21 were more often associated with fetuses, and less often with tissue fragments than other trisomies. Focal malformations were multiple and severe in abortuses with triploidy, trisomies 13 and 18, and monosomy X and mild in trisomy 21. With the exception of monosomy X the malformations were similar to, and not more severe than those reported from, term births with the same anomaly. The high rate of intrauterine mortality in conceptuses with chromosome anomalies could be ascribed to their failure to develop past the embryonic stages. However, the presence of an equally large fraction of chromosomally normal abortions with the same degree of rudimentary development suggests the existence of early and profound developmental problems that are not associated with anomalies of the chromosome complement.     

Morphology and locomotor adaptations of the foot in early Oligocene anthropoids

Newly discovered foot bones of Aegyptopithecus are described and compared to those of Apidium and Dolichocebus. Locomotor adaptations are inferred for African early Oligocene propliopithecids, parapithecids, and for Argentine early Oligocene Dolichocebus. All show an anthropoid grade of development in their foot anatomy. Tarsals of Aegyptopithecus compare best with those of Miocene hominoids. Apidium shares derived calcaneal features that link it with Old World monkeys. Dolichocebus exhibits a very generalized platyrrhine talar morphology akin to that seen in Saimiri, Callicebus, Cebus, and Aotus. The morphology of early Oligocene primate foot bones suggests that at least three quite distinct groups, corresponding to three recognized superfamilies, were present in the early Oligocene of South America and Africa.     

猫视网膜多巴胺能神经元的形态和发育

Morphology and development of dopaminergic neurons has been studied in the kitten retina, using tyrosine hydroxylase (TH) immunocytochemistry. TH immunoreactive (TH+) cells are already presented in whole amount and sectioned retina at first postnatal day (P1). According to soma size, shape, dendritic process pattern and immunoreactivity, two classes, type I or large dark staining TH+ cells and type II or small light staining TH+ cells are recognized. The TH I cells which consisting of normal placed DA amacrine cells, displaced DA amacrine cells and DA interplex-form-like cells, gradually mature during postnatal development, while TH II cells decrease quickly and through disappear at P30. After eye opening TH I amacrine cells, especially their dendrites develop quickly. The soma diameters increase from 11.8 microns (P1) to 14.2 microns (P30). The dendritic fields increase in size and complexity. At P1 the thick radiating dendrites emerge from the cell body with small or large "spines" and many growth cones. At P13 the dendritic field is markedly enlarged and only a few growth cones can be seen on some stained dendrites. In addition, the dendritic spines are no longer apparent and they are a part of rudimentary rings. By P30 the dendritic plexus of TH+ dendrites and rings in the out most part of IPL, typical of the adult cells, are complete. The influence of light on the development of DA cells after eye opening and the possibility of neurotransmitter changing are discussed.     

Morphology and behaviour: functional links in development and evolution

Development and evolution of animal behaviour and morphology are frequently addressed independently, as reflected in the dichotomy of disciplines dedicated to their study distinguishing object of study (morphology versus behaviour) and perspective (ultimate versus proximate). Although traits are known to develop and evolve semi-independently, they are matched together in development and evolution to produce a unique functional phenotype. Here I highlight similarities shared by both traits, such as the decisive role played by the environment for their ontogeny. Considering the widespread developmental and functional entanglement between both traits, many cases of adaptive evolution are better understood when proximate and ultimate explanations are integrated. A field integrating these perspectives is evolutionary developmental biology (evo-devo), which studies the developmental basis of phenotypic diversity. Ultimate aspects in evo-devo studies--which have mostly focused on morphological traits--could become more apparent when behaviour, 'the integrator of form and function', is integrated into the same framework of analysis. Integrating a trait such as behaviour at a different level in the biological hierarchy will help to better understand not only how behavioural diversity is produced, but also how levels are connected to produce functional phenotypes and how these evolve. A possible framework to accommodate and compare form and function at different levels of the biological hierarchy is outlined. At the end, some methodological issues are discussed.     

Morphology and development of teeth and epidermal brushes in loricariid catfishes

Loricariidae or suckermouth armored catfishes are one of several aquatic taxa feeding on epilithic and epiphytic algae. Their upper and lower jaws bear exquisitely curved teeth, which usually are asymmetrically bicuspid. The enlarged lower lip carries papillae with keratinous unicellular epidermal brushes or unculi. Teeth, and probably unculi too, assist in scraping food off substrates. Their morphology, growth, and replacement is examined and compared among several loricariid species, using cleared and stained specimens, serial sections, and SEM. Apart from the general tooth form and crown shape, the anterior layer of soft tissue on the lower shaft region, present in several species, appears to be a specialization for enhancing the mobility of individual teeth when scraping on uneven surfaces. During early ontogeny, a transition from simple conical to mature tooth occurs. The first unculi appear together with the first teeth carrying a bicuspid crown, 2 days after the first exogenous feeding, but synchronous with the complete resorption of the yolk sac.     

Morphology and development of floral shoots and organs in certain Zannichelliaeeae

Development of reproductive shoots and associated organs in Vleisia aschersoniana, Althenia filiformis, Lepilaena bilocularis and L. cylindrocarpa (Zannichelliaeeae, sensu Dumortier) has been examined using an epi-illumination technique to provide photographic documentation. Floral shoots share a similar basic developmental pattern. The vegetative shoot is terminated by a unisexual flower, but growth is continued from the axils of leaves immediately below so that fairly regular sympodia develop. Vleisia is most variable in the expression of this pattern. The flowers are simple, consisting of a single stamen or three carpels (one in Vleisia) and show marked similarity in development. Short scale-like appendages, reminiscent of a perianth, develop at the base of the stamen in Althenia and Lepilaena. An outgrowth at the tip of the connective in Lepilaena bilocularis and two at its middle part in Vleisia are initiated at late stages of stamen development. Carpels are subtended by membranous tepal-like appendages that are initiated at the same time as the carpel primordia. Each carpel primordium becomes peltate and develops a bitegmic ovule on the adaxial portion of the carpel wall which in turn overgrows the ovule and ultimately forms a long thin style with either a funnel-shaped (Vleisia, L. cylindrocarpa) , peltate (L. bilocularis) or feathery (Althenia) stigma. Relationships with other Alismatales are discussed.     

Morphology and development of mirror-image doublets of Stylonychia mytilus

This paper describes the cortical anatomy and development of mirror-image doublets of Stylonychia mytilus, analyzed using the protargol technique. The reversed, or "left-handed" (LH) component of these doublets is a mirror image of the normal or "right handed" (RH) component with regard to the arrangement of cortical structures. The mirror-image patterning is imperfect, however, as the individual ciliary structures of the LH component all are of normal internal asymmetry, and the orientation of membranelles is inverted. Certain structures that would be expected to form near the line of symmetry are absent. During cell division and cortical reorganization, ciliary primordia arise and become arranged in a mirror-image pattern that is more perfect than that exhibited by the mature structures. Deviations from a mirror-image pattern appear at late stages when organelle sets differentiate within ciliary primordia: for example, the membranelle set differentiates within the oral primordium of the LH component in a sequence that is an inversion rather than a mirror image of the corresponding sequence of the RH component. This mixed control of oral development by different cortical "informational systems" accounts for some of the characteristic abnormalities of the mature oral structures of the LH component.     

Substrate type and microbial interactions as factors affecting ascocarp formation by mangrove fungi

The growth and ascocarp formation of Aigialus parvus, Lignincola laevis and Verruculina enalia in single and mixed cultures on wood of Avicennia alba, Bruguiera cylindrica and Rhizophora apiculata was studied. In pure cultures, these fungi grew well on all three species of wood. Except for Aigialus parvus on B. cylindrica, all three fungi also formed abundant ascocarps. The time needed for ascocarp formation after inoculation ranged from six to eight weeks for L. laevis on all wood species, and for V. enalia on Avicennia alba; to ten weeks for V. enalia on B. cylindrica and R. apiculata; and 12 weeks for Aigialus parvus on Avicennia alba and R. apiculata.Mixed cultures involving two or three of the test fungi delayed the onset of sporulation and affected the abundance of ascocarps formed. Sporulation by Aigialus parvus on Avicennia alba and R. apiculata was markedly reduced by L. laevis alone or in combination with V. enalia. Likewise, sporulation by L. laevis was suppressed by Aigialus parvus and/or V. enalia. In contrast, the presence of L. laevis enhanced ascocarp formation by V. enalia on all types of wood. These observations suggest the presence of interference competition among the test fungi.     

Morphology and development of floral features recognised by pollinators

The diversity of angiosperm flowers is astounding. The conventional explanation for this diversity is that it represents the great variety of ways in which flowers have adapted to attract an even greater diversity of animal pollinators. Many animal behaviourists are therefore interested in how changes in floral morphology affect pollinator behaviour. The establishment of well-characterised model plant species has greatly furthered our understanding of how floral morphology is generated and varied. Many of these model species are pollinated by animals and attract their pollinators through the production of colour, shape, scent, size and rewards. An understanding of the developmental plasticity of floral morphology, and the constraints upon it, should inform research into animal responses to flowers. The use of genetically characterised model species, and the isogenic and near-isogenic lines available in them, will allow dissection of the different components of floral attraction and reward in natural systems. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Handling editor: Heikki Hokkanen     

Morphology,development and cytology of Taphrina maculans Butler

Morphology, development and nuclear behavior of the ascogenous stroma and asci in the infection spots have been described inTaphrina maculans Butler. The fungus forms subcuticular and intercellular mycelium in the leaf tissues and the ascogenous layers originate through division of the subcuticular hyphal cells in the infection sites. Germination of ascogenous cells starts with their elongation in the uppermost layer forming asci and ascospores without formation of stalk cells. Meiosis of the fusion (diploid) nucleus occurs in the young ascus as in otherTaphrina species devoid of stalk cells. The haploid chromosome complement in this species consists of 3 chromosomes (n=3). All the cells in the stromatic layer are potential ascogenous cells and ascus formation continues, until all of them are exhausted in the infection spot. Eight ascospores are normally formed in each ascus, but multi-plication of ascospores may occurin situ later. Three morphologically distinct types of ascus opening are encountered, which are apparently not correlated with prevalent environment. Multiplication of ascospores after their discharge from mature asci occurs by budding proceded by a mitotic division of the spore nucleus. Blastospores (budded cells) germinate into short hyphae and binucleate condition of cells originates by mitotic division of the nucleus. Occurrence of giant cells containing 2 nuclei is often observed. Possible origin of Uredinales fromTaphrina-like ancestors has been indicated due to their close resemblance.