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1.
Marcin Sielezniew Izabela Dziekańska Anna M. Stankiewicz-Fiedurek 《Journal of Insect Conservation》2010,14(2):141-149
Phengaris (=Maculinea) arion is an endangered social parasite of Myrmica ants, and for a very long time was considered as specific to Myrmica sabuleti. Previous studies carried out in Poland suggested some discrepancies within this assumption, and therefore a much more intensive
survey was undertaken. The host ant use of P. arion was studied at five sites in different types of biotopes in Poland, i.e. xerothermal grasslands where Thymus pulegioides was used as a larval food plant by the butterfly, and more or less sandy biotopes with Thymus serpyllum. Altogether nine Myrmica species were recorded, and considerable variation in species composition and density of nests was recorded. At four localities
M. sabuleti proved to be the most common ant. A total of 529 Myrmica nests were examined, and only 20 of them contained larvae and pupae of P. arion. Host ants belonged to five different species, i.e. M. sabuleti, Myrmica scabrinodis, Myrmica schencki, Myrmica lobicornis and Myrmica hellenica. Only at one site (NE Poland) was a significant heterogeneity in parasitation rates among Myrmica species detected. M. lobicornis was the most often infested ant there, which may suggest local specialisation of the butterfly. Overall low parasitism rates
may explain the vulnerability of P. arion in Central Europe but further studies are also necessary. 相似文献
2.
E. V. Bugdaeva 《Paleontological Journal》2010,44(10):1240-1251
Two new species of Sphenobaiera from the Baisa locality and Chernovskoe coal mine (Lower Cretaceous, Transbaikalia) are described. The cuticle of these plants
inhabiting different environments differs significantly. Leaves of S. starukhiniae sp. nov. have a very thin cuticle, almost not sunken, open, nonprotected stomata, while the leaves of S. vitimica sp. nov. have relatively thick and strong cuticle, well-developed papillae overhang the sunken stomata. Guard cells of both
species usually have fine radial striations. Apparently, the first plant dwelt in wet habitats, and the second, in the areas
with a temporary shortage of water. This reconstruction is confirmed by sedimentological data, coal-bearing sediments (where
S. starukhiniae sp. nov. was found) formed in swampy areas, carbonate deposits (S. vitimica sp. nov. was collected in marls of the Baisa locality), in the droughty one. It is not improbable that the cuticular features
revealed of these two species contributed to more efficient water exchange and allowed plants to exist in these different
environments. 相似文献
3.
The architecture of the musculature of the eutardigrade species Milnesium tardigradum Doyère, 1840, Hypsibius sp. and Ramazzottius oberhaeuseri (Doyère in Ann Sci Nat Zool Sér 2(14):269–369, 1840) is investigated by phalloidin staining and confocal laser scanning microscopy. There are methodological problems in staining
eutardigrades due to physiological alterations under stress (anhydrobiosis) and due to penetration problems of the cuticle.
It is helpful to fix specimens in the state of asphyxy, where animals are stretched following an oxygen shortage in their
environment. The musculatures of all three species correspond in their general architecture, but differ in detail, such as
in the number of muscles. All muscles are isolated muscle strands. There are on each body side two dorsal and one ventral
muscle strands, in addition to a system of dorsoventral, lateral and lateroventral muscles. Seven median ventral attachment
points give rise to dorsoventral, ventrolateral and appendage muscles. The appendages receive several muscles originating
dorsally and ventrally. The number of muscles and the arrangement differ in each appendage. The fourth appendage shows the
greatest differences with a far smaller number of muscles compared to other species. The musculature shows comparably few
strict segmental patterns, for example, the musculature of each appendage differs from the other ones. By comparison with
literature data on the same species and data of Macrobiotus hufelandi it can be shown that eutardigrades have a roughly comparable muscular architecture, but that there are several differences
in detail.
Dedicated to Professor Westheide on the occasion of his 70th birthday. 相似文献
4.
Stuart Maxwell Linton Benjamin J. Allardyce Wilhelm Hagen Petra Wencke Reinhard Saborowski 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(4):493-507
Both Engaeus sericatus and Cherax destructor are omnivorous crayfishes consuming a variety of food items. Materials identified in the faeces of both E. sericatus and C. destructor consisted of mainly plant material with minor amounts of arthropod animals, algae and fungi. The morphology of the gastric
mill of C. destructor suggests that it is mainly involved in crushing of food material while the gastric mill of E. sericatus appears to be better suited to cutting of food material. Given this, the gastric mill of E. sericatus may be better able to cut the cellulose and hemicellulose fibres associated with fibrous plant material. In contrast, the
gastric mill of C. destructor appears to be more efficient in grinding soft materials such as animal protein and algae. Both species accumulated high amounts
of lipids in their midgut glands (about 60% of the dry mass) which were dominated by triacylglycerols (81–82% of total lipids).
The dominating fatty acids were 16:0, 16:1(n-7), 18:1(n-9), 18:2(n-6), and 18:3(n-3). The two latter fatty acids can only
be synthesised by plants, and are thus indicative of the consumption of terrestrial plants by the crayfishes. The similarity
analysis of the fatty acid patterns showed three distinct clusters of plants and each of the crayfish species. The complement
of digestive enzymes, proteinases, total cellulase, endo-β-1,4-glucanase, β-glucosidase, laminarinase and xylanase within
midgut gland suggests that both C. destructor and E. sericatus are capable of hydrolysing a variety of substrates associated with an omnivorous diet. Higher activities of total cellulase,
endo-β-1,4-glucanase and β-glucosidase indicate that E. sericatus is better able to hydrolyse cellulose within plant material than C. destructor. In contrast to E. sericatus, higher total protease and N-acetyl-β-d-glucosaminidase activity in the midgut gland of C. destructor suggests that this species is better able to digest animal materials in the form of arthropods. Differences in total cellulase
and gastric mill morphology suggest that E. sericatus is more efficient at digesting plant material than C. destructor. However, the contents of faecal pellets and the fatty acid compositions seem to indicate that both species opportunistically
feed on the most abundant and easily accessible food items. 相似文献
5.
Morphology of the pronotal compound glands in <Emphasis Type="Italic">Tritoma bipustulata</Emphasis> (Coleoptera: Erotylidae) 总被引:1,自引:0,他引:1
Members of the cucujiform family Erotylidae possess a whole arsenal of compound integumentary glands. Structural details of
the glands of the pronotum of Tritoma bipustulata and Triplax scutellaris are provided for the first time. These glands, which open in the posterior and anterior pronotal corners, bear, upon a long,
usually unbranched excretory duct, numerous identical gland units, each comprising a central cuticular canal surrounded by
a proximal canal cell and a distal secretory cell. The canal cell forms a lateral appendix filled with a filamentous mass
probably consisting of cuticle, and the cuticle inside the secretory cell is strongly spongiose—both structural features previously
not known for compound glands of beetles. Additional data are provided for compound glands of the prosternal process and for
simple (dermal) glands of the pronotum. A combined defense plus anti-microbial function of the compound glands is tentatively
proposed. 相似文献
6.
7.
A. K. Rai R. Chakravorty Jaishree Paul 《World journal of microbiology & biotechnology》2008,24(12):2879-2887
This study was conducted to evaluate the load of three food- and water-borne parasites, namely, Giardia, Entamoeba, and Cryptosporidium on food items that are consumed either raw or in an unprocessed state in the northern parts of India. A two-step diagnostic
method was employed to assess the presence of Giardia and Cryptosporidium, the immunofluorescence assay (IFA) combined with the polymerase chain reactiion (PCR assay), whereas a Tech lab diagnostic
kit in combination with PCR assay was used for accurate detection of Entamoeba histolytica in the samples. The methods for isolation and enrichment of cysts/oocysts from the various food items were tested
and discussed here. Our results showed that the overall spectrum of incidence of the three parasites on food items in decreasing
order were Giardia > Entamoeba > Cryptosporidium. When data were subjected to the chi-square test, the prevalence of all three parasites was found to be independent of the
food items. To determine whether the presence of two types of parasites in a food item is uniform, a Poisson distribution
test was conducted. On comparing the intensity of occurrence of the different parasites in various food items, it was observed
that the occurrence of Giardia and Entamoeba was not of the same order at 5% level of significance only in case of samples of raw meat and milk. This confirmed that a
high number of raw or unpasteurized milk and meat samples are more likely to be contaminated with Giardia than with Entamoeba. Therefore, our observations point to the unhygienic practices of food handlers being a major contributor in the transmission
of parasites to unprocessed food products. 相似文献
8.
The reproductive ecology of the gobiid fish Bathygobius fuscus was studied at Nobeoka, Miyazaki, Japan. Males of this species maintain small rock holes as a nest and females spawn an egg
mass on the wall of the nest. The males employed two forms of mating tactic: nest holding and sneaking. A nest holder stayed
in the nest and waited for a female to visit, whereas a sneaker intruded into a nest while a pair was engaged in reproduction.
Males larger than 55 mm standard length were always nest holders; those of smaller size employed both tactics. As the larger
males excluded the smaller males, the latter did not occupy a nest hole. With a decrease in the number of larger males, smaller
males changed their mating tactic from sneaking to nest holding. The results suggest that male Bathygobius fuscus adopt a conditional strategy whereby they change their tactic depending on their social status.
Electronic Publication 相似文献
9.
Andrew B. Shatrov 《Experimental & applied acarology》2011,53(3):263-285
The mouthparts of unfed larvae of Platytrombidium fasciatum (C. L. Koch, 1836) and Camerotrombidium pexatum (C. L. Koch, 1837) (Acariformes: Microtrombidiidae) were studied using both light optical (whole-mounted specimens, toluidine
blue stained semi-thin sections) and electron microscope (TEM, SEM) methods. The mouth apparatus incorporated within the gnathosoma
occupies an axial position and is covered from above by the arched dorsal shield, or scutum. The chelicerae are comparatively
long and separated, and the lateral lips form a permanent apomorphic sucker provided with an internal cuticular sclerite.
The pharynx is extremely wide and totally fused with the bottom of the infracapitulum. The pharyngeal dilators originate on
the posterior portions of the cervix (epistome) and on the capitular apodemes and run nearly parallel to the cervix to the
dorsal pharyngeal wall. Comparatively short sigmoid pieces serve as origin of the muscles—cheliceral levators inserting on
the posterior wall of the basal cheliceral segments. There are two sets of the extrinsic gnathosomal muscles originating on
the posterior portion of the scutum: retractors of chelicerae inserting on the posterior portions of the basal cheliceral
segments, and retractors of the gnathosoma inserting on the very posterior parts of the capitular apodemes. The labrum and
the cervix delimit the pharynx and the subcheliceral space. The labrum and the cervix for the most part are weakly sclerotized
cuticular plates and do not have own muscles. The larval mouth apparatus, in comparison with that of adult microtrombidiid
mites, is simply organized and more specialized for ingestion of large masses of liquid food. 相似文献
10.
ITS sequences determined for 53 Erysiphe specimens on Syringa and Ligustrum collected in Europe, East Asia, and North and South America were divided into two ITS groups, S and K types. Phylogenetic
analysis showed that these two ITS types do not share a common ancestor and form separate clades. The K type on Ligustrum was identified as Erysiphe ligustri based on the three-dimensional branching pattern of appendages. Morphological observations showed that there are some morphological
differences—pigmentation of appendages and number of ascospores per ascus—between the S and K types on Syringa. Based on these morphological observations, the S and K types on Syringa were identified as E. syringae and E. syringae-japonicae, respectively. The recent abundant production of chasmothecia by lilac powdery mildew in Europe was caused by E. syringae-japonicae introduced from East Asia. DNA sequence analyses of the rDNA ITS region and the 28S rDNA, tub2, CYP51, and Chs1 genes did not support an interspecific hybrid origin for E. syringae-japonicae. Haplotype analysis suggested that E. syringae originated in North America and independently migrated to East Asia and Europe/South America. 相似文献
11.
Background
In C. elegans and other nematode species, body size is determined by the composition of the extracellular cuticle as well as by the nuclear DNA content of the underlying hypodermis. Mutants that are defective in these processes can exhibit either a short or a long body size phenotype. Several mutations that give a long body size (Lon) phenotype have been characterized and found to be regulated by the DBL-1/TGF-β pathway, that controls post-embryonic growth and male tail development. 相似文献12.
Background
The protective external cuticle of insects does not accommodate growth during development. To compensate for this, the insect life cycle is punctuated by a series of molts. During the molt, a new and larger cuticle is produced underneath the old cuticle. Replacement of the smaller, old cuticle culminates with ecdysis, a stereotyped sequence of shedding behaviors. Following each ecdysis, the new cuticle must expand and harden. Studies from a variety of insect species indicate that this cuticle hardening is regulated by the neuropeptide bursicon. However, genetic evidence from Drosophila melanogaster only supports such a role for bursicon after the final ecdysis, when the adult fly emerges. The research presented here investigates the role that bursicon has at stages of Drosophila development which precede adult ecdysis. 相似文献13.
There are three most important bacterial causative agents of serious infections that could be misused for warfare purposes:
Bacillus anthracis (the causative agent of anthrax) is the most frequently mentioned one; however, Fracisella tularensis (causing tularemia) and Yersinia pestis (the causative agent of plague) are further bacterial agents enlisted by Centers for Disease Control and Prevention into the category A of potential biological weapons. This review intends to summarize basic information about these bacterial
agents. Military aspects of their pathogenesis and the detection techniques suitable for field use are discussed. 相似文献
14.
The CONSTANS (CO) gene is a key regulator of the response to photoperiod in the model plant Arabidopsis thaliana, and its homologues are present in many plant species. We describe here the isolation of the CO homologue for zinc finger protein gene GmCOL10 (Glycine max CONSTANS-Like 10) from the soybean cultivar Kennong18. Sequence comparisons showed that the closest A. thaliana gene to GmCOL10 is COL5. The expression of GmCOL10 was regulated in a circadian manner, especially under short-day conditions. The expression of GmCOL10 was concentrated in vegetative organs, and in particular in the unifoliolates and cotyledons. An analysis of subcellular
localization found GmCOL10 in the nucleus. Our data suggested that GmCOL10 was not related to the photoperiodic pathway of floral transition as Arabidopsis CO does. 相似文献
15.
W. Chapple 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2002,188(10):753-766
Mechanoreceptors in the soft cuticle of the 4th abdominal segment of the hermit crab, Pagurus pollicarus, that are associated with reflex activation of abdominal postural motoneuron, were studied to determine whether their properties are consistent with a feedback control of abdominal stiffness. Three classes of receptors were identified: (1) setal dome receptors, (2) hypodermal receptors, and (3) funnel-canal receptors. The hypodermal receptors, which have the largest extracellular action potentials, were selected for further study. Their axons innervate the entire ipsilateral half of a segment; receptive fields of receptors with different amplitudes show extensive overlap. They are phasic and show significant adaptation; at higher frequencies they signal displacement rather than velocity. Although they are activated by changing muscle tension, their threshold for cuticular displacement is much lower than for forces generated by postural muscles. These features suggest that they are primarily involved in signaling cuticular displacement and shearing forces as they contact the columella of the shell in which the hermit crab lives. 相似文献
16.
Joha W. Grobbelaar Z. Wilhelm de Beer Paulette Bloomer Michael J. Wingfield Xu Dong Zhou Brenda D. Wingfield 《Mycoscience》2011,52(2):111-118
Ophiostoma species such as O. quercus are the most frequent causal agents of sapstain of freshly felled hardwood timber and pulpwood. Many species are regarded
as economically important agents of wood degradation. The aim of this study was to identify a collection of Ophiostoma isolates, resembling O. quercus, found on stained Eucalyptus pulpwood chips in China. DNA sequences of the internal transcribed spacer regions, including the 5.8S region, of the ribosomal
DNA, and parts of the β-tubulin and elongation factor-1α genes, revealed that the isolates were not O. quercus. Surprisingly, they represented O. tsotsi, a wound-infesting fungus recently described from hardwoods in Africa. In addition, sequence data from an isolate from agarwood
in Vietnam, identified in a previous study as belonging to an unknown Pesotum species, were also shown to represent O. tsotsi. A high level of genetic variability was observed among isolates of both O. quercus and O. tsotsi. This was unexpected and suggests that both species have been present in Asia for a significant amount of time. 相似文献
17.
Quantitative trait loci (QTL) detection was carried out for adventitious rooting and associated propagation traits in a second-generation
outbred Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid family (n = 186). The parental species of this cross are divergent in their capacity to develop roots adventitiously on stem cuttings
and their propensity to form lignotubers. For the ten traits studied, there was one or two QTL detected, with some QTL explaining
large amounts of phenotypic variation (e.g. 66% for one QTL for percentage rooting), suggesting that major effects influence
rooting in this cross. Collocation of QTL for many strongly genetically correlated rooting traits to a single region on linkage
group 12 suggested pleiotropy. A three locus model was most parsimonious for linkage group 12, however, as differences in
QTL position and lower genetic correlations suggested separate loci for each of the traits of shoot production and root initiation.
Species differences were thought to be the major source of phenotypic variation for some rooting rate and root quality traits
because of the major QTL effects and up to 59-fold larger homospecific deviations (attributed to species differences) relative
to heterospecific deviations (attributed to standing variation within species) evident at some QTL for these traits. A large
homospecific/heterospecific ratio at major QTL suggested that the gene action evident in one cross may be indicative of gene
action more broadly in hybrids between these species for some traits. 相似文献
18.
19.
Invasive species are often hypothesized to have superior performance traits. We compared stress tolerance (as change in biomass)
of the invasive macroalgae Codium fragile ssp. tomentosoides and Gracilaria vermiculophylla to the native macroalgae Fucus vesiculosus, Agardhiella subulata, Hypnea musciformis and Ulva curvata in Hog Island Bay, a shallow lagoon in Virginia, USA. We hypothesized that the success of the two aliens is due to their
high tolerances of turbidity, sedimentation, desiccation, grazing and nutrient enrichment. Like many lagoons, Hog Island Bay
is characterized by extensive intertidal mudflats, high turbidity and sedimentation, and high densities of omnivorous mud
snails. Nutrient enrichment may also become a problem as land use practices in adjacent watersheds change. Contrary to our
hypothesis, C. fragile was less resistant to sedimentation, desiccation and grazing than other algae and had low growth at all light and nutrient
levels. This suggests that any superior performance of this invasive species compared to native algae is probably limited
to microhabitats where stress is minimal and where bivalve shells facilitate recruitment and long-term persistence. In contrast,
G. vermiculophylla was resistant to desiccation, burial and grazing, and was not negatively influenced by either high or low light or nutrient
levels. These traits reflect the current success of G. vermiculophylla in already invaded lagoons and estuaries, and indicates that it will likely continue its spread in European and North American
turbid and tidal soft-sediment systems. 相似文献
20.
Philomena Bodensteiner 《Mycological Progress》2007,6(4):221-228
Maireina afibulata and M. attenuatipilis are proposed as new members of the recently revised genus Maireina, one of the few anatomically well-studied cyphelloid groups in the Basidiomycota. Maireina species have brownish basidiomes, smooth, parietally unpigmented spores, and are characterized by non-ramified external hyphae
with more or less thick, yellow to brown cell walls and distinct crystalline incrustations that always include their distal
ends. A key to the species of the genus Maireina is presented, and M. afibulata as well as M. attenuatipilis are described and discussed in detail.
Taxonomic novelties: Maireina afibulata Bodensteiner, M. attenuatipilis Bodensteiner 相似文献