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1.
From a genomic library enriched for AG/TC repeats, eight polymorphic microsatellite markers were developed for Ceiba pentandra, a pan‐tropical forest tree. Polymorphism was evaluated using a panel of 74 adult trees. Using automated fluorescence detection, a total of 112 alleles was detected with an average of 14 alleles per locus. All microsatellite loci showed very high levels of genetic information content, with expected heterozygosity ranging from 0.814 to 0.895. These microsatellite markers represent a powerful tool to investigate refined questions of mating systems, gene flow, family structure and population dynamics in natural populations of C. pentandra.  相似文献   

2.
Abstract

Barbula munyensis R.S.Williams, a neglected moss species known only from the type material collected in central Peru in 1923, is newly reported for the moss floras of Argentina and Bolivia. The species is described, illustrated, mapped, and its habitat preferences are provided. Diagnostic characters and differentiation from some closely related South American taxa, with which it may be confused, are discussed. Barbula orizabensis Müll.Hal., a similar taxon, is excluded from the South American moss flora.  相似文献   

3.
Taxus chinensis var.mairei is an endangered and economically important tree species in China.Four polymorphic microsatellite markers were developed and characterized using the fast isolation by amplified fragment length polymorphism (AFLP) of sequences containing repeats (FIASCO) protocol.Polymorphism of each locus was quantified for five natural populations from Hubei Province,China.The number of alleles per locus varied from 6 to 24.The ranges of observed and expected heterozygosity were 0.493-1.000 and 0.440-0.845,respectively.These are the first microsatellites reported for the family of Taxaceae and will be helpful for the ongoing population and conservation genetics research of Taxus chinensis var.mairei.  相似文献   

4.
Larvae of the mud crab Panopeus lacustris were reared in laboratory from ovigerous females collected in the estuarine area of the Caeté River in the Amazonian region. The complete development of this species consisted of four zoeal and one megalopal stages, which were described and illustrated in detail. The results are compared with those of other previous studies on larval development of the species belonging to the genus Panopeus and then briefly discussed.  相似文献   

5.
Nerocila benrosei n. sp. is described from the hogfish, Lachnolaimus maximus (Walbaum), and the Spanish hogfish, Bodianus rufus (Linnaeus), (Perciformes: Labridae) from the northern Bahamas. Nerocila benrosei differs from all species of Nerocila by having the body of females 1.4-1.9 times as wide as long, instead of 2.0-3.0 times, and pleopods 1 and 2 lacking accessory lamellae. It differs from the only species of Nerocila with which it overlaps geographically, N. lanceolata (Say, 1818), by having the lateral margins of pleonites 1-5 strongly produced ventrally, coxae 5-7 manifestly shorter than the posterolateral projection of the respective pereonite, and a vaulted dorsal surface. The species of Nerocila in the northwestern Atlantic have almost mutually exclusive geographic ranges: New England to Panama, including Bermuda and the northern coast of Cuba (Nerocila lanceolata); Brazil to Trinidad and Tobago (Nerocila fluviatilis Schi?dte and Meinert, 1881); and the northern Bahamas and Bermuda (Nerocila benrosei). No species of Nerocila have been reported from the insular Caribbean. Nerocila benrosei appears to be highly host and site specific.  相似文献   

6.
Abstract  In this study we report the results from the first long-term (40 weeks) study of stick-insect fecundity and distribution under natural conditions of which we are aware. We used the number of eggs falling into 72 × 0.5 m2 traps to ask: 'Was egg production in Sipyloidea sp. uniform across the sample period'? and 'Was there evidence of host plant species preference or avoidance'? We collected a total of 213 Sipyloidea sp. eggs. The number of eggs caught per week was not uniform and an exponential decay model was the best-fit relationship between egg production and time, indicative of a steep decline from high to low (but continuous) egg production across the study period. Continuous egg production differs from other insect species in tropical areas that often show distinct seasonal differences between wet and dry seasons, timed to leaf production in host plants. The distribution of eggs within traps was aggregated, and more traps than expected from Poisson probabilities received no eggs, or six or more eggs. The concentration of eggs within particular traps was not related to the identity of canopy plant species, however. We suggest that continuous egg production in Sipyloidea sp. may be related to the wider range of plant species available as food resources for the polyphagous Sipyloidea , compared with other tropical insect species.  相似文献   

7.
ABSTRACT. A marine kinetoplastid flagellate, Cryptobia eilatica n. sp., is described from the gills of cultured gilt-head sea bream Sparus aurata L. and wild black-spot sea bream Diplodus noct (Valenciennes) in the Red Sea. The trophozoite is elongated and lacks a contractile vacuole and undulating membrane. The body averages 13.5 × 4.1 μm, anterior flagellum 9.7 μm, and free portion of recurrent flagellum 15.2 μm. The ultrastructural features of the species exhibit great similarity to various previously studied Cryptobiids. Cryptobia eilatica trophozoites feed on bacteria, show a preference for the branc hial interlamellar crypts, and attach to the host epithelium by means of the recurrent flagellum. Neither penetration into the epithelial cells, nor any direct damage to host tissue was observed. Cryptobia eilatica inhabits a purely marine habitat, but its trophozoite tolerates salinities as low as 10 ppt.  相似文献   

8.
A new anisakid nematode, Raphidascaroides brasiliensis n. sp., is described from the intestine of the freshwater thorny catfish Pterodoras granulosus (Valenciennes) (Doradidae, Siluriformes) from Amazonia (Manaus), Brazil. It is characterised mainly by the smooth, almost rounded tail tip in both sexes, the length of the spicules (0.952–1.183 mm) and by the number and arrangement of the caudal papillae (24–34 pre-anal, 1 adanal and 5 postanal pairs and 1 median pre-anal papilla) in the male. It is the first Raphidascaroides species described from South America and the second species of this genus reported from a freshwater fish.  相似文献   

9.
ABSTRACT

C. emeriflorus is an endemic species occurring in two disjunct areas some 200 km apart: the Pre-Alps of Lombardia and the Pre-Alps of Friuli. Four populations from the western area and five populations from the eastern area were sampled in order to ascertain the amount and the distribution of variation throughout the range of the species. Phenetic measures of isozyme polymorphism were used. Diversity values showed that the species is polymorphic, despite its restricted distribution and the small population size; phenetic distances revealed that partitioning of diversity was largely within rather than among populations. Moreover, little differentiation was found between the two disjunct areas, although the western populations exhibited a slightly higher diversity compared with the eastern ones. The high level of polymorphism and the overall similarity between populations from the two areas may be ascribed to past contacts, and indicate that, despite the present widespread disjunction, the two areas have not evolved independently long enough for divergence to have occurred. There is no evidence that C. emeriflorus is at present genetically depauperated, although its range of distribution must have been much broader in the past; its present reduced distribution area and the small population size may be mainly due to ecological factors.  相似文献   

10.
Noctuidonema dibolia n. sp., an ectoparasite of adults of the noctuid moth Mocis latipes (Guenée) is described. The differentiating characters are a club-shaped body with a subterminal vulva in the female, spicules with a reduced matrix and sheath and closely apposed dorsal and ventral arms in the male, very long stylet and conus, moderately prominent stylet knobs, a bluntly rounded head, and a large renette cell in both sexes. Lateral fields, rectum, anus, bursa, and gubernaculum are absent. Noctuidonema dibolia differs from the other species of the subfamily Noctuidonematinae in the size and robustness of the body, the length of the stylet and conus, the length of the tail, and the shape of the spicules.  相似文献   

11.
12.
Eimeria ornata n. sp. is described from the feces of 6/16 (37.5%) ornate box turtles, Terrapene ornata ornata , in northcentral Texas. Endogenously sporulated oocysts are ellipsoid 17.9 × 15.7(16-21 × 14-18) μm, with a thin, single-layered wall; shape index 1.14 (1.0-1.3). A micropyle is absent but a polar granule was present in one third of the oocysts. An oocyst residuum was present, consisting of numerous small globules situated either in a distinct mass or scattered within the oocyst. The sporocysts are elongate, 11.1 × 5.4 (9-13 × 5-6) μm, with an indistinct Stieda body at 1 pole. A sporocyst residuum is present, consisting either as a compact mass or as scattered granules. The sporozoites are elongate, 9.5 × 2.0 (8-12 × 2) μm, in situ, with spherical anterior and posterior refractile bodies. The new species is distinguished from the similar Eimeria carri Ernst & Forrester, 1973, from eastern box turtles, T. Carolina , by slight differences in oocyst morphology and endogenous sporulation.  相似文献   

13.
Unadenylylated glutamine synthetase (EC 6.3.1.2) was isolated and purified to homogeneity from Salmonella typhimurium. The enzyme molecule is a symmetrical aggregate of 12 subunits arranged in two hexagonal layers, as is evident from electron micrographs. The subunit molecular weight of the enzyme was found to be approximately 50,000 by polyacrylamide gel electrophoresis in sodium dodecyl sulfate when compared to Escherichia coli glutamine synthetase and other protein standards. A long tube of glutamine synthetase was formed as a single-stranded coil resulting from incubation of the enzyme in a low ionic strength buffer. A study of Mn(II) binding to the unadenylylated enzyme at 25 °C was conducted as a function of pH. At pH 7.1 two classes of metal ion sites per subunit were found with KD values of 3.7 × 10?6 and 1.7 × 10?4m, while at pH 6.8 these values were 1.1 × 10?5 and 1.0 × 10?4m, respectively. Only one set of binding sites was observed at pH 6.2 with a KD value of 1.0 × 10?4m. The metal ion binding sites were further investigated by monitoring proton relaxation rates (prr) and the epr spectrum of enzyme-bound Mn(II). The longitudinal prr of water protons at pH 7.1 indicate that protons interacting with enzyme-Mn(II) at the “tight” site (KD = 3.7 × 10?6) are de-enhanced (?b1 = 0.42) and result from water protons beyond the inner coordination sphere. The second Mn(II) site has a value of ?b2 = 35 for the binary enhancement, suggesting that this site probably has two to three rapidly exchanging water molecules in its coordination sphere. The epr spectrum of enzyme-bound Mn(II) at the “tight” site is isotropic and is dramatically sharpened by adding the substrate analog methionine sulfoximine. Subsequent addition of ATP or the ATP analog, AMP-PCP (adenylyl methylene diphosphate) produced anisotropic spectra that were similar, suggesting that both ATP and AMP-PCP bind similarly on the enzyme surface. However, a marked change in the Mn(II) environment from anisotropic to near cubic results from the addition of ADP to the quaternary enzyme-Mn(II)-sulfoximine- (AMP-PCP) complex, indicating that ADP displaces AMP-PCP. No change in the anisotropic spectrum due to the enzyme-Mn(II)-sulfoximine-ATP complex is seen by the addition of ADP. This experimental result supports the experimental findings of Ronzio and Meister [Proc. Nat. Acad. Sci. USA59, 164 (1968)], who established that ATP phosphorylates methionine sulfoximine, thereby producing an inactive enzyme. The allosteric effectors, AMP and Trp, have little effect on the epr spectrum of the complex formed from Mn(II), enzyme, sulfoximine, and ADP, suggesting the absence of direct coordination of AMP or Trp to the bound Mn(II). The prr and epr results reported herein with glutamine synthetase from S. typhimurium when compared to those seen for the enzyme from E. coli [Villafranca et al., Biochemistry15, 544 (1976)] demonstrate some similarities but also many substantial differences between the enzymes from these two bacterial sources.  相似文献   

14.
The stem anatomy and internal organisation of a newly collected sphenophyte trunk is studied from the type locality of Arthropitys, the Lower Permian petrified forest of Chemnitz, Germany. The trunk was found nearly in situ, still standing upright, and embedded in coarse-grained pyroclastics of the Zeisigwald Tuff Horizon (Leukersdorf Formation, Erzgebirge Basin). This specimen – the basal portion of a huge woody tree measuring up to 60 cm in diameter – represents the largest anatomically preserved calamite trunk ever found. On the basis of current investigation the exceptional find has been attributed to Arthropitys ezonata Goeppert, which is more completely characterised and emended herein. This species is characterised by its rather homogeneous loose wood without clearly distinct interfascicular rays and fascicular wedges. For the first time we are able to show details of the primary body of this poorly understood species such as vascular strands and pith parenchyma. Comparisons are made with the generitype Arthropitys bistriata (Cotta) Goeppert and other species of the genus Arthropitys.  相似文献   

15.
Ecosystem health is a key principle which underlies the Canadian Environmental Protection Act (CEPA). This act is designed to protect human health and the environment from harmful and/or irreversible effects by providing a cradle-to-grave regulation of toxic substances.As an example of the application of this act, this contribution considers the most toxic dioxins and furans which are generally associated with Kraft pulp mill effluents. These are some of the first substances to come under the CEPA legislation. The proposed CEPA regulations for dioxins and furans are based on end-of-pipe control, which would effectively limit their concentrations in effluent to something close to measurable levels. Depending on sample matrix and methodology, however, measurable levels may differ considerably.Evidence presented at the Alberta-Pacific (ALPAC) pulp mill hearings in Alberta and the Northwest Territories during 1989 demonstrated that total loading are particularly important in dealing with the far-field effects of these extremely toxic, persistent, and bioaccumulating substances. Further, it was reported that there might be no threshold of effect for tetrachlorodibenzo-para-dioxin (2, 3, 7, 8, TCDD) or the companion furan. If such evidence is correct, the CEPA regulations should be designed to achieve zero discharge of these contaminants. Measurable levels, as presently defined in the CEPA regulations, may be in excess of zero discharge requirements.Clearly, such inconsistency may cause problems and should be addressed directly. Unfortunately, the first draft of the CEPA regulations represents a piecemeal approach. In this, it is unfair to industry, it is scientifically inadequate, and it may not be enforceable. The application of CEPA regulations for the pulp and paper industry will set a new precedent for Canada's approach to ecosystem health. It is therefore essential to base decisions on a good under-standing of the dynamics and effects of chemicals in ecosystems and to re-evaluate, carefully, the toxicities of key contaminants. Interim measures are likely appropriate.  相似文献   

16.
17.
Rick Hochberg 《Zoomorphology》2007,126(4):245-264
The neuropeptide FMRFamide (Phe–Met–Arg–Phe–NH2) is part of a large and diverse family of peptidergic neurotransmitters present throughout the animal kingdom. To date, no such neuropeptides have been demonstrated in gastrotrichs despite their presence in closely related invertebrates such as nematodes. Here, the FMRFamidergic nervous system of three marine gastrotrichs is investigated with immunofluorescence, CLSM, and 3D computer imaging to gain insight into structure of the cerebral ganglion and test various phylogenetic hypotheses on its organization. Results reveal that FMRFamide-like immunoreactivity (IR) is present throughout the nervous systems of three species: Neodasys cirritus (Chaetonotida), Xenodasys riedli and Turbanella cf. hyalina (Macrodasyida). Both macrodasyidans possess FMRFamide-like IR in the central, peripheral- and stomatogastric-nervous systems, while FMRFamide-like IR is restricted to the CNS in N. cirritus. In all three species, the cerebral ganglion is dumbbell-shaped and bordered bilaterally by cerebral perikarya: numerous perikarya are present in X. riedli and N. cirritus, while few perikarya are present in T. cf. hyalina. Cerebral perikarya flank the nerve ring neuropil, which contains IR fibers in the supra- and subpharyngeal commissures of both macrodasyidans, but in N. cirritus, only contains IR fibers in the suprapharyngeal commissure. Together, these results confirm the peripharyngeal nature of the gastrotrich cerebral ganglion, but are equivocal on hypotheses of its tripartite structure. Still, the neural organization of gastrotrichs, in particular, the architecture of the cerebral ganglion, is expected to hold valuable information for future assessments of gastrotrich phylogeny, and may yet provide key insights into the evolution of this enigmatic taxon.  相似文献   

18.
SYNOPSIS. Thirty-two of 48 raccoons examined were infected with a previously undescribed species of Eimeria which is herein named E. procyonis. Of the 32 infected animals, 10 also harbored E. nuttalli and 1 had Isospora sp. oocysts.
The ellipsoid to ovoid oocysts of E. procyonis measured 23.4 × 18.0 (16–29 × 13–24) μm; its sporocysts measured 12.1 × 9.3 (11.5–15 × 7–10) μm, each containing a slightly flattened substiedal body. The sporocyst residuum consisted of numerous scattered granules each ∼1 μm in diameter. The oocyst wall was double-layered. The outer layer appeared rough and pitted, measuring 1.5 μm, except at the micropyle where it was 1 μm thick.
The oocysts of the Isospora sp. measured 16.8 × 13.7 (16–18.5 × 12.5–15.5) μm. The wall consisted of a single layer ∼0.5 μm thick. The sporocysts measured 11.2 × 9.1 (9.5–11.5 × 8–10) μm, and each contained 4 elongate sporozoites. The oocysts of E. nuttalli measured 17.5 × 13.6 (12-21 × 11-15) μm, with a smooth single-layered wall approximately 0.7 μm thick. The sporocysts measured 12.2 × 7.1 (9-13 × 5.5–11) μm. Each sporocyst had a thin, dark, Stieda body and the sporocyst residuum consisted of many fine granules.  相似文献   

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