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1.
Summary The coastline of the Salento Peninsula (Apulia region, Southern Italy) is characterized by a rocky shore with spectacular cliffs where the investigated fringing reef complex, the so called Castro Limestone, spectacularly outcrops for at least 40 km. As reconstructed from several measured sections, the Castro Limestone, which is Middle Chattian in age from our own data, disconformably mantles a tectonically deformed falaise of Cretaceous-Eocene rocks and is overlain by a remarkable erosional surface characterized by a very peculiar rhodolite rudstone. The Castro Limestone unit can be considered as a classic unconformity bounded depositional sequence representing, most probably, a shelf margin prograding complex, related to the major Middle Oligocene sea level lowstand. Stratigraphic and sedimentologic features, together with paleontological characters, allow recognition of a virtually complete range of reef environments across the reef profile. Several geomorphic zones and associated facies are described, from the most landward reef area (‘back reef’) across the reef flat and reef from downward to the fore reef slope, contributing to a better knowledge of the evolution of Oligocene reefs and reef communities in Italy and in the Mediterranean area.  相似文献   

2.
Summary The Bombaso Formation and basal Meledis Formation in the central Carnic Alps near Straniger Alm and Zollnersee (Austria/Italy) unconformably overlie the folded Variscan basement and consist of shallow marine clastic and carbonate sediments which are arranged to form two fining and deepening upward sequences. Particularly limestones and even breccias of the Bombaso Formation yielded a rich fusulinid fauna composed of 34 species which are attributed to the following zones:Quasifusulinoides quasifusulinoides-Protriticites ovatus; Protriticites pseudomontiparus, andMontiparus montiparus. Breccias of the Bombaso Formation west of Straniger Alm contain the oldest fusulinid fauna of the Carnic Alps, belonging to theQuasifusulinoides quasifusulinoides —Protriticites ovatus zone. The fauna is composed ofQuasifusulinoides quasifusulinoides, Q. fallax, Q. intermedius, Protriticites cf.ovoides, andPr. ovatus. This assemblage is most similar to that of the Peskovskaya Formation of the Myachkovian Horizon in the Moscow Basin indicating uppermost Moscovian age. Limestones from depositional sequence 1 at Zollnersee also contain fusulinids of the uppermost Moscovian which are characterized by a more diverse assemblage:Schubertella donetzica, Fusiella lancetiformis, Beedeina ulitinensis, B. consobrina, B. nytvica, B. siviniensis, Quasifusulinoides pakhrensis, Q. fallax, Q. kljasmicus, Q. quasifusulinoides, Fusulinella rara, andProtriticites ovatus. Limestones and calcareous sandstones-siltstones of the basal Meledis Formation of depositional sequence 2 near Zollnersee and at Cima Val di Puartis are characterized by fusulinids of theProtriticites pseudomontiparus zone (Protriticites globulus, Pr. pseudomontiparus, Pr. sphaericus, Pr. rotundatus, Pr. ovoides, Pr. lamellosus, andPraeobsoletes burkemensis) and byMontiparus paramontiparus zone (Praeobsoletes pauper, P. burkemensis, Obsoletes timanicus, O. obsoletes, Montiparus paramontiparus, M. umbonoplicatus, M. montiparus, M. likharevi, M. rhombiformis andM. priscus) indicating lower to middle Kasimovian age (Krevyakinskian and Khamovnicheskian Horizons of the Russian Platform). In memoriam FranzKahler (1900–1995)  相似文献   

3.
Summary The fusulinacean faunal content of the Bombaso Fm. and lower part of the Auernig Group (Carnic Alps, Austria/Italy) is reviewed and completed by data on conodonts and algae. Four different faunal associations can be distinguished within this stratigraphic interval. The beginning of the postvariscan sedimentation in the investigated sections is diachronous, shifting in age from early Kasimovian (Krevyakinian) at Zollner Lake and Mt. Auernig, early to middle Kasimovian at Cima Val di Puartis to late Kasimovian (Dorogomilovian) at Mt. Ro?kofel. The sections analyzed consist of shallow-marine sediments, which differ in microfacies of limestones and partly in biotic assemblages. They are geographically isolated and could not be traced laterally for lithologic correlation in the field. The biostratigraphic correlation with the faunas of the stratotype sections in the Moscow Basin is hindered by the searceness of fusulinaceans in the critical levels, especially in the lowermost Kasimovian, and differences in the species composition. A biostratigraphic correlation of the Bombaso Fm. and basal part of the Auernig Group with the Peski Fm. (Myachkovian) of the Moscow Basin, as suggested byDavydov & Krainer (1999), is not confirmed by our results. Due to our taxonomic reinterpretation of the oldest fauna (Protriticites aff.permirus with distinct mural pores and largeBeedeina (Pseudotriticites) asiaticus) a lowermost Kasimovian (Lower Krevyakinian) age is more probable. This correlation is supported by the co-occurring conodont fauna, which is suggested to belong to the zone of “Streptognathodus subexcelsus”. This biozone reaches from the topmost Peski Fm. to the Suvorovo Fm. (Lower Krevyakinian) in the Moscow Basin, and may be correlated with the uppermost Desmoinesian of the Midcontinent North America. Fusulinaceans and conodonts of the overlying strata at Zollner Lake and from the sections at Cima Val di Puartis and Mt. Auernig most probably correspond to the upper Krevyakinian/lowermost Khamovnikian of the Russian platform (Lower Missourian of the Midcontinent North America). The algal associations (Dvinella, Beresella, Herakella) from these lowermost strata are unique for the Carnic Alps. Their stratigraphic range points to Moscovian-Kasimovian as well, and fits with the fusulinacean and conodont data. Sediments of the N?lbling Group (=“untere kalkreiche Schichtgruppe”) have their correlative levels in the upper Khamovnikian, but reach higher into the Dorogomilovian. More reliable correlations are possible with the fusulinacean faunas of the Cantabrian Mts. and Central Asia, based on the coincidence of several species. A revised biostratigraphic correlation with the different remote basins of the Paleotethyan realm and the Russian Platform is given, based on own data and recent results by the members of the SCCS Working group to define a GSSP close to the Moscovian/Kasimovian boundary. The sequence-stratigraphic scheme, the systematics, and the biostratigraphic correlation ofDavydov & Krainer (1999) are discussed.  相似文献   

4.
Summary Late Eocene sediments of the Upper Austrian Alpine Foreland Basin discordantly overlie Mesozoic and crystalline rocks, which are deeply eroded and form a distinct pre-Eocene relief. Late Eocene deposits contain red algal limestones with a remarkable lateral extent and a high diversity of sedimentary facies. Towards the south the algal limestones change into more clastic sediments, which are characterized by larger foraminifera and bryozoans. Main components are coralline algal branches and detritus, coralline crusts, rhodoliths, peyssonneliacean aggregates and crusts, nummulitid and orthophragminid foraminifera, corals, bryozoans, as well as terrigenous components. Rank correlation and factor analysis were calculated in order to obtain informations about relations between components. Hierarchical cluster analysis allowed the designation of 17 facies, most of them are dominated by coralline algae. Actualistic comparisons and correlations obtained from statistical analyses allowed the reconstruction of the depositional environments. Main features of the northern area are huge accumulations of unattached coralline algae (branches, rhodoliths, detritus), which are comparable to the present-day “Maerl”-facies. They formed loose frameworks cut by sand channels. The frequency of coralline detritus decreases upsection. Peyssonneliacean algae in higher parts of the profiles show growth-forms that are comparable to peyssonneliaceans of the Mediterranean circalittoral soft bottoms. This succession can be interpreted by an increasing relative sea level. Besides, crustose coralline algal frameworks were growing on morphological highs which are partially comparable to the present-day “Coralligéne de Plateau” of the Mediterranean Sea. In contrast to the northern area, sedimentation rate of the southern area is too low to keep up with rising sea level. The typical succession from nummulitid- to orthophragminid-and bryozoan-dominated facies can be interpreted by an increasing water depth from shallowest subtidal to the deeper photic zone and finally to the aphotic zone.  相似文献   

5.
In order to improve the limited database on species inventories and ecology of Culicidae in Austria, we monitored hydrological and physico-chemical parameters of breeding habitats of the Culicidae species of Danubean wetlands from March to October 2011 in the National Park Donau-Auen (Lower Austria). A total of 34 eggrafts, 1022 larval, 80 pupal, and 221 adult Culicidae were collected. We detected 15 mosquito species belonging to the genera Anopheles Meigen, 1818, Culex Linnæus, 1758, Culiseta Felt, 1904, Coquillettidia Dyar, 1905, Aedes Meigen, 1818 and Ochlerotatus Lynch Arribalzaga, 1891. In the larval and pupal stage, Ochlerotatus geniculatus (Olivier, 1791) (64.1%) and Culex territans Walker, 1856 (18.7%) were most abundant. Based on abiotic and biotic parameters, sampling sites were grouped into four clusters. The results show that water level and -persistence, pH, conductivity, and phosphate concentrations had a significant influence on species distribution, and that floodplain dynamics are a key factor for the seasonal and spatial distribution of mosquito larvae in the National Park.  相似文献   

6.
Summary The Upper Rhaetian coral limestone of Adnet, southeast of Salzburg Austria has been repeatedly referred to as one of the most spectacular examples of an ancient ‘autochthonous’ coral reef structure. The ‘Tropfbruch’ quarry is probably the best outcrop for interpreting the distributional patterns of biotic successions and communities of a late Triassic patch reef. Our study is based on the interpretation of a) outcrop photographs, b) reef maps resulting from quadrat transects, and c) the analysis of quantitative data describing the distribution and frequency of reef organisms and sediment. A new methodological approach (combination of reef mapping and photo-transects) is used to obtain quantitative field data which can be compared in greater detail with data from modern coral reefs investigated by corresponding quantitative surveys. Three unconformities and three well-defined ‘reef growth stages’ reflecting the vertical and lateral development of the reef structure were differrentiated using transects: Stage 1, representing the reef growth optimum, is characterized by laterally differentiated coral reef knobs with corals in growth position. Criteria supporting this interpretation are the extraordinary size of the corals, their preservation in situ and the great thickness of this interval. The massive coralPamiroseris grew under higher energy conditions at the rim of the reef knob, whereas branchingRetiophyllia colonies preferred less agitated water in the center. Vertical changes are reflected by an increase in frequency of the dasycladacean algaDiplopora adnetensis and by the decreasing size ofRetiophyllia. These sedimentological and biological criteria together with the unconformity above indicate a fall in the sea level as a major control mechanism. Stage 2, separated from stage 1 by an unconformity caused by partial subaerial exposure and karstification, is characterized by vertically stacked coral successions with diverse reef debris. Facies heterogeneity is reflected by differences in the diversity, taphonomy and packing density of reef-building organisms as well as by differences in sediment input from the platform. Water depths and accommodation space were lower, therefore minor sea level fluctuations had a stronger effect on the biotic composition. The high percentage of coral debris and corals reworked by storms and the increase in the input of platform sediment led to a reduction of reef growth. Stage 3, again separated at the base by an unconformity associated with karstification, is characterized by bioclastic sediments with isolated reefbuilders forming a level-bottom community. The distribution of different coral morphotypes suggests that sea level fluctuations were not the only controlling factor. Variations in the substrate were caused by differences in the input of platform sediment. The three-step development seen in Adnet documents the response of low-diverse coral associations to variations caused by small-scale sea level changes, storm activity and sedimentation. The vertical changes in reef community structures correspond to a sequence of ‘allogenic replacements’. The Adnet reef structure should not be regarded as a general model of Alpine Upper Rhaetian reefs, because of the particular setting of the patch reef. Only the ‘capping beds’ of the Upper Rhaetian Reef Limestone of the Steinplatte exhibit criteria similar to Adnet. Potential modern analogues of features seen in the coral communities of Adnet are the internal structure of theRetiophyllia thickets, the key role of branching corals within the communities, the scattered distribution and low and even diversity of corals subsequent to breaks in settlement, segration patterns of corals indicating ‘contact avoidance’, toppling of large coral colonies by intensive boring, and decreasing coral coverage from deeper and sheltered settings to more shallower water depths.  相似文献   

7.
A characteristic microfacies of the Late Jurassic to Early Cretaceous allodapic Barmstein Limestone of the Northern Calcareous Alps are clasts of wackestones with numerous fragments of calcareous algae (“algal debris-facies”). According to dasycladale palaeocoenoses, several subtypes comprising different associations can be distinguished. One association is characterized by the debris of an unknown large dasycladalean alga reported as dasycladalean alga indet. sp. 1 from different localities in the Northern Calcareous Alps, typically forming a monospecific assemblage. Another microfacies type contains star-like calcitic bodies tentatively referred to the morphospecies Coptocampylodon pantici Ljubović-Obradović and Radoičić, originally described as being from the Turonian of NW-Serbia. Other Coptocampylodon-like bodies represent the calcified tufts of the laterals of Selliporella neocomiensis (Radoičić). The occurrence of Coptocampylodon pantici-like microfossils in the Late Tithonian to Early Berriasian, shows that obviously different species of dasycladaleans display identical to similar shaped tufts of laterals in transverse sections when becoming fragmented. Coptocampylodon pantici Ljubović-Obradović and Radoičić was observed only from different occurrences of Barmstein Limestone, but not from the autochthonous platform carbonates of the Plassen carbonate platform. The Coptocampylodon algal debris-facies is also reported from the Late Jurassic of Albania, Mirdita zone. Occurrences of different types of algal debris-facies in components of mass-flow deposits can be used as a tool to reconstruct eroded carbonate platforms and tectonics, as demonstrated in the Northern Calcareous Alps and the Albanides. Finally, the general occurrences of algal debris-facies in both settings—intra-Tethyan mostly isolated platforms (Alps, Albanides) vs. extended epeiric platforms (Middle East)—are compared and discussed.  相似文献   

8.
Forke  Holger C. 《Facies》2002,47(1):201-275
Summary In order to establish a refined biostratigraphic subdivision and correlation of the Uppermost Carboniferous/Lower Permian deposits of the Southern Alps (Carnic Alps, Karavanke Mountains; Austria/Italy/Slovenia), two major microfossil groups (fusulinoideans, conodonts) were investigated within the same sample. The fusulinoidean species diversity (71 species, including five new species and three new subspecies) and generic composition were reviewed and complemented. Additionally, the data on fusulinoidean assemblages were supplemented by co-occurring conodont faunas (seven species). Accompanying studies on material from the type sections of the Southern Urals (Russia) were made to improve the biostratigraphic correlation with the Russian standard zonation and to discuss paleobiogeographical aspects of the faunal associations. An integrated microfacies analysis of the sampled material in the Southern Alps serves to evaluate the relationships between certain genera and specific microfacies types. The fusulinoidean fauna of the Lower “Pseudoschwagerina” Limestone is of late Gzhelian age. The Carboniferous/Permian boundary is close to the base of the Grenzland Formation, which covers the entire Asselian and a part of the Sakmarian. The Upper “Pseudoschwagerina” Limestone and Trogkofel Limestone are Lake Sakmarian to Artinskian. The studies sequences in the Karavanke Mountains. formerly known as “carbonate and clastic Trogkofel beds”, correlate to the Lower “Pseudoschwagerina” Limestone, respectively with parts of the Grenzland Formation. Due to the lithologic differences, new formation names (Dolzanova Soteska Fm., Born Fm.) were introduced for the so-called “Trogkofel” Limestone along the Dolzanova Soteska. Whereas late Gzhelian/Asselian fusulinoidean faunas of the Southern Alps correspond to the Southern Uralian faunas to a large extent, Sakmarian and Artinskian faunas reveal an increasing divergence in species and genus composition. Climatic as well as geographic barriers may have prevennted the dispersal of Paleotethyan taxa into the Southern Urals. Biostratigraphic correlation of Sakmarian to Artinskian deposits is therefore possible only on the basis of the sparse conodont faunas.  相似文献   

9.
Summary An integrated study of the early Messinian reef complex cropping out along the eastern coast of the Salento Peninsula (southern Italy), including stratigraphy, facies analysis and paleoecological aspects, is here presented. Fourteen facies types belonging to three main facies associations (back reef and shelf, shelf-edge, slope) have been recognized. They document a wide spectrum of depositional environments, reef building organisms and growth fabrics, in response to depth and other environmental factors in different parts of the reef complex. The biotic structure of the reef is also described and discussed in detail. It consists of different types of reef building organisms and of their bioconstructions (mainlyPorites coral reefs,Halimeda bioherms and vermetidmicrobial “trottoirs”), that differ in composition and structure according to their position on the shelf edge-toslope profile. Results indicate that the reef complex of the Salento Peninsula has strong similarities with the typical early Messinian reefs of the Mediterranean region. However, the recognition of some peculiar features, i.e. the remarkable occurrence ofHalimeda bioherms and of vermetid-microbial “trottoirs”, gives new insights for better understanding reef patterns and development of the reef belt during the Late Miocene in the Mediterranean.  相似文献   

10.
Charcoal analysis was carried out as part of an interdisciplinary project focusing on the copper mining history of the former mining area of Schwaz and Brixlegg, a region pivotal as a copper source in prehistoric Europe. The goal was to use remains of carbonised wood to investigate environmental implications of prehistoric mining, as well as to gain new insight about the ancient mining technique of fire-setting. Charcoal samples from seven copper mining sites (Late Bronze Age to Early Iron Age) were analysed. The results reveal a strong preference for coniferous wood as fuel in fire-setting, but not in ore smelting/roasting processes. Species composition at the ore-processing sites indicates moderate forest degradation processes caused by human intervention.  相似文献   

11.
Middle to Upper Oxfordian reefs of a shallow marine carbonate platform located in northeastern France show important facies changes in conjunction with terrigeneous contents. The Pagny-sur-Meuse section shows coral-microbialite reefs that developed both in pure carbonate limestones and in mixed carbonate-siliciclastic deposits. Phototrophic coral associations dominated in pure carbonate environments, whereas a mixed phototrophic/heterotrophic coral fauna occurred in more siliciclastic settings. Microbialites occur in pure carbonate facies but are more abundant in mixed carbonate-siliciclastic settings. Reefs seem to have lived through periods favourable for intense coral growth that was contemporaneous with a first microbialitic layer and periods more favourable for large microbialitic development (second microbialitic layer). The first microbialitic crust probably developed within the reef body and thus appears to be controlled by autogenic factors. The second generation of microbialites tended to develop over the entire reef surface and was probably mainly controlled by allogenic factors. Variations in terrigeneous input and nutrient content, rather related to climatic conditions than to water depth and accumulation rate, were major factors controlling development of reefs and their taxonomic composition.  相似文献   

12.
During the last 15 years, European stone fruit yellows (ESFY) has become a major concern in Austrian fruit production. Therefore, presence and temporal dynamics of its vector Cacopsylla pruni were investigated using a beating tray method and yellow sticky traps on Prunus armeniaca, Prunus domestica, Prunus spinosa and P. cerasifera nigra. Infection rates of C. pruni and Prunus spp. trees were assessed by direct, nested and real‐time PCR. Movement of remigrants in a model apricot orchard was tracked by aid of a mark, release and recapture study. Insects were marked by fluorescent dyes. Movement of the marked insects and presence of naturally occurring insects were monitored by yellow sticky traps. In 2011, remigration of C. pruni to Prunus spp. started in calendar week 10 (8th of March) and in 2012, in calendar week 12 (18th of March). Remigrants were observed until calendar week 20 (middle of May), significant numbers of the springtime generation adults were present until week 26 (end of June). The phytoplasma was ascertained in 0–11.5% of the remigrants and in 0–3.44% of the springtime generation insects. About 9.8–63.3% of the apricot samples, 20–40% of the plum samples and single blackthorn samples were infected. The mark, release and recapture study proved a fast and frequent tree‐to‐tree movement of remigrated C. pruni adults. Insects easily covered distances from row to row or even farther (ca. 13 m) within 24 h after release and were present in a large part of the model orchard after 8 days (up to 24 m from release point).  相似文献   

13.
The Early to Middle Pleistocene Dandiero rift basin is located near the Buia village, 110 km south of Massawa (Eritrea), and is filled by about 1000 m of continental deposits bearing 1 My erectus-like human remains. The basin fill consists of six formations (from bottom up): Bukra sand and gravels (fluvial), Alat formation (fluvio-lacustrine), Wara sand and gravel (fluvial), Goreya formation (lacustrine), Aro sand (fluvio-deltaic) and Addai fanglomerate (alluvial fan). This paper is focused on the Homo-bearing deposits of the Alat formation. The Alat formation records several episodes of changing accommodation space, with repeated shifts from fluvial to lacustrine conditions. The first episode points to rapid lake formation followed by a progressive shallowing. The second episode records fluvial aggradation above a sequence boundary, followed by the development and progressive infill of a second lake. The third episode points to a rapid lake formation followed by deposition of deltaic and fluvial sediments. The last episode is characterised by fluvial deposition under low-accommodation conditions. The development of the lacustrine environments was probably controlled by tectonics, in accordance with its formation during regionally dry climatic conditions, although minor shifts toward wetter conditions cannot be excluded. Human remains occur in the upper Alat formation, where the transition from a deltaic to alluvial setting is characterised by high frequency, potentially millennial-scale, lake-level oscillations. The palaeoanthropological record in the Buia area seems to be correlated with water availability (lacustrine coastal plains and floodplains) in a relatively open and grassy environment (grassland- and savannah-dominated). The increase in fluvial discharge that occurred at the top of the Alat formation led to erosion and winnowing of the underlying fossil-bearing, fluvio-deltaic deposits. A large number of bones and artefacts were consequently accumulated at the base of channel fills, which represent a preferential horizon for fossil searching.  相似文献   

14.
Since the beginning of the 1990s, the largest lakes south of the Alps (Garda, Iseo, Como and Maggiore) showed a progressive colonization of Dolichospermum lemmermannii (Cyanobacteria). The appearance of surface blooms of this species raised serious concerns because of the impacts on the tourist economy and the potential toxigenic effects. Nevertheless, no detailed investigations were done to clarify the taxonomic position, ecology and toxicity of this species. In this work, phylogenetic analyses based on the 16S rRNA and rpoB genes demonstrated how the strains isolated from the Italian lakes were clustered together with other D. lemmermannii strains isolated in Northern Europe. The expansion of this species in the southern subalpine lakes contrasted with the prevailing south to north dispersion paths typical of other Nostocales (e.g. Cylindrospermopsis and Aphanizomenon). Conversely, the spread was consistent with the geographical areal of this cyanobacterium, which appears circumscribed between the 40th parallel and the Arctic Circle. This aspect highlights the ecological heterogeneity that characterizes the order Nostocales. In Lake Garda, D. lemmermannii always developed in the warmest months (>15 °C) with low abundances (generally <200 cell mL−1). Nevertheless, owing to its ability to form surface water blooms, this species is considered as one of the most nuisance algae in the subalpine lake district. From the other side, different strains isolated from these large lakes tested negative for the biosynthesis of microcystins, anatoxin-a, nodularins and cylindrospermopsins, and for the presence of mcyE and anaC genes of the microcystins and anatoxin-a gene clusters.  相似文献   

15.
Summary During the Late Albian, Early and Middle Cenomanian in the NW part of the Adriatic Carbonate Platform (presentday Istria) specific depositional systems characterised by frequent lateral and vertical facies variations were established within a formerly homogeneous area, ranging from peritidal and barrier bars to the offshore-transition zone. In southern Istria this period is represented by the following succession: thin-bedded peritidal peloidal and stromatolitic limestones (Upper Albian); well-bedded foreshore to shoreface packstones/grainstones with synsedimentary dliding and slumping (Vraconian-lowermost Cenomanian); shoreface to off-shore storm-generated limestones (Lower Cenomanian); massive off-shore to shoreface carbonate sand bodies (Lower Cenomanian); prograding rudist bioclastic subaqueous dunes (Lower to Middle Cenomanian); rudist biostromes (Lower to Middle Cenomanian), and high-energy rudist and ostreid coquina beds within skeletal wackestones/packstones (Middle Cenomanian). Rapid changes of depositional systems near the Albian/Cenomanian transition in Istria are mainly the result of synsedimentary tectonics and the establishment of extensive rudist colonies producing enormous quantities of bioclastic material rather than the influence of eustatic changes. Tectonism is evidenced by the occurrence of sliding scars, slumps, small-scale synsedimentary faults and conspicuous bathymetric changes in formerly corresponding environments. Consequently, during the Early Cenomanian in the region of southern Istria, a deepening of the sedimentary environments occurred towards the SE, resulting in the establishment of a carbonate ramp system. Deeper parts of the ramp were below fair-weather wave base (FWWB), while the shallower parts were characterised by high-energy environments with extensive rudist colonies, and high organic production leading to the progradation of bioclastic subaqueous dunes. This resulted in numerous shallowing- and coarsening-upwards clinostratified sequences completely infilling formerly deeper environments, and the final re-establishment of the shallow-water environments over the entire area during the Middle Cenomanian.  相似文献   

16.
朴冬花  姚磊  王玲  樊东 《昆虫学报》2008,51(3):342-348
利用昆虫几丁质酶对几丁质的调控作用破坏几丁质新陈代谢的平衡来防治害虫, 在生物防治策略中具有很大的发展潜力。从处于预蛹期的小地老虎Agrotls ipsilon (Hufnagel)体中肠内提取总的RNA, 经反转录, 利用cDNA末端快速扩增技术(RACE)获得了几丁质酶基因的cDNA序列。该基因序列已经登录GenBank并获得登录号为EU035316。该序列长度为2 823个碱基, 含有一个1 674个碱基的开放读码框。开放读码框编码558个氨基酸残基, 预测的分子量为62.5 kDa, 等电点5.12。推导得到的氨基酸序列含有2个N-位糖基化位点,20个O-位糖基化位点, 含有2个几丁质酶所具有的保守序列:N-端的催化区和C-端的几丁质结合区。氨基酸序列与其他昆虫, 特别是鳞翅目昆虫的几丁质酶高度同源。  相似文献   

17.
为了研究蜕皮激素受体(EcR)在麦红吸浆虫Sitodiplosis mosellana (Géhin)滞育活动中的作用, 利用RT PCR和RACE技术克隆得到了麦红吸浆虫蜕皮激素受体基因cDNA全长, 并通过Real-time quantitative PCR研究了其表达情况。该cDNA全长序列被命名为SmEcR (GenBank登录号: KC491135), 其开放阅读框长1 386 bp, 编码461个氨基酸残基。其蛋白预测分子量52.90 kD, 理论等电点6.24。该蛋白与其他已报道的昆虫EcR蛋白具有很高的同源性, 其中与迟眼蕈蚊Bradysia coprophila中相应蛋白的氨基酸序列一致性高达92%。SmEcR在麦红吸浆虫不同滞育时期和不同虫态中均有表达, 且在不同滞育时期、 不同虫态中的表达量差异很大。在滞育不同时期以11月表达量最高, 12月表达量最低; 在不同虫态以麦穗幼虫中的表达量较低, 而成虫中的表达水平很高。本研究为进一步明确SmEcR在麦红吸浆虫滞育调控中的作用奠定了基础。  相似文献   

18.
小菜蛾热休克蛋白基因的鉴定及其表达模式分析   总被引:3,自引:0,他引:3  
热休克蛋白(heat shock protein, HSP)在昆虫应对外界胁迫刺激时起着重要作用。为了系统研究小菜蛾Plutella xylostella HSP基因家族, 根据家蚕的HSP蛋白序列, 采用本地Blast程序对小菜蛾全基因组数据库进行同源序列检索, 从小菜蛾基因组数据库中鉴定了25个HSP基因, 包括2个HSP90、 8个HSP70和15个sHSP(small heat shock protein, sHSP)基因。小菜蛾、 家蚕Bombyx mori、 黑腹果蝇Drosophila melanogaster和赤拟谷盗Tribolium castaneum的HSP系统进化分析显示, 昆虫的小分子量热休克蛋白sHSP具有很强的种属特异性, HSP70家族的保守性比sHSP强。小菜蛾HSP基因表达模式分析显示, 与敏感品系对比, 抗性品系(抗毒死蜱和抗氟虫氰品系)中HSP基因具有不同的表达模式。小菜蛾1, 2和3龄幼虫HSP基因表达模式较为接近, 而与4龄幼虫中的表达模式相差较大; 4龄幼虫和蛹中的表达模式相近; 雌成虫和雄成虫中的表达模式显著不同, 与果蝇精子形成有关的两个热休克蛋白HSP23和HSP27基因[分别为CCG003980.1 (Px23.5)和CCG005412.2 (Px27.5)], 在小菜蛾雄成虫中的表达量显著高于雌成虫。研究结果表明小菜蛾HSP基因不仅在杀虫剂抗性、 发育分化, 甚至在生殖上均可能起着重要的作用。本研究为深入研究小菜蛾HSP与生长发育、 抗逆行为的相互关系奠定了基础。  相似文献   

19.
【目的】卵黄原蛋白受体(vitellogenin receptor,VgR)属于低密度脂蛋白受体,通过介导内吞作用为发育中的卵母细胞摄取卵黄原蛋白,为胚胎发育提供营养物质,在昆虫生殖过程中发挥关键作用。为研究黑尾叶蝉Nephotettix cincticeps VgR(NcVgR)基因的生理功能及其在生殖中的作用,本研究克隆并解析了NcVgR基因的序列,并对其时空表达进行了研究。【方法】根据黑尾叶蝉转录组数据信息,利用RT-PCR克隆了NcVgR基因,并进行了生物信息学分析;利用实时荧光定量PCR研究了不同发育时期、成虫不同组织NcVgR的表达水平。【结果】NcVgR c DNA序列全长6 676 bp,开放阅读框长度5 568 bp,编码1 855个氨基酸,预测编码蛋白的分子量为206 k D,N端前17个氨基酸为信号肽。序列分析显示,NcVgR具有低密度脂蛋白家族的5个经典保守域,即:配体结合域(ligand-binding domain,LBD)、表皮生长因子前体同源域(EGF-precursor homology domain,EGFP)、O-糖链结构域(O-linked sugar domain,OLSD)、跨膜域(transmembrane domain,TMD)和胞质尾域(cytoplasmic domain)。系统发育分析表明,NcVgR与褐飞虱N.lugens VgR亲缘关系最近。实时荧光定量PCR结果显示,NcVgR转录起始时间为5龄若虫,羽化后转录水平逐渐上升,至羽化后8 d达到峰值,随后下降。有意思的是,随着黑尾叶蝉产卵,NcVgR转录水平再次上升,至羽化后16 d达到最高水平。组织定位结果显示,NcVgR在黑尾叶蝉雌成虫卵巢中特异性高表达,而在雌成虫脂肪体和肠道中微量表达,在雌成虫脑及雄成虫中均未检测到表达。【结论】NcVgR在黑尾叶蝉雌成虫卵巢中特异性表达,并且不同发育时期具有不同的表达量,这为研究黑尾叶蝉的生殖调控机理提供了分子信息。  相似文献   

20.
胡振  左洪亮  李亚楠  黄劲飞  胡美英 《昆虫学报》2011,54(11):1249-1257
过氧化氢酶 (catalase, CAT)作为生物体内的重要物质, 其主要功能是参与活性氧代谢过程, 在清除H2O2、 超氧自由基和过氧化物以及阻止羟基自由基形成等方面发挥着重要作用。本研究利用RT-PCR技术和RACE方法首次克隆和分析了甜菜夜蛾Spodoptera exigua (Hübner)CAT基因, 命名为SexiCAT, GenBank登录号为JN051294, 其cNDA序列全长为1 755 bp, 开放阅读框长1 524 bp, 推测编码507个氨基酸。经氨基酸序列比对, 此多肽序列具有高度保守性, 与其他昆虫CAT的序列一致性分别为: 家蚕Bombyx mori (87%)、 黑腹果蝇Drosophila melanogaster (73%)、 埃及伊蚊Aedes aegypti (71%)和赤拟谷盗Tribolium castaneum (70%)。对该基因在甜菜夜蛾各个发育时期以及不同组织表达量的荧光定量PCR分析表明, SexiCAT基因在甜菜夜蛾各个发育阶段的表达水平存在显著差异, 其中成虫期的表达量最高, 是卵期表达量的7倍, 幼虫期次之, 卵期最低; SexiCAT基因在5龄幼虫体壁、 中肠、 脂肪体和马氏管组织中都有表达, 但在脂肪体中表达量最高。甜菜夜蛾SexiCAT基因的成功克隆及同源建模将为今后对其功能研究以及作为靶标设计新型氧化酶抑制剂提供了基础。  相似文献   

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