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1.
The anatomy of Sphaerospira fraseri is described as a preliminaryto the revision of the larger eastern Australian Camaenidae.Sphaerospira agrees in many character states with the generaof American Camaenidae. The camaenid pallial configuration maybe unique to the family and the advanced helicoids cannot beconsidered simply as camaenids which have acquired a dart apparatus. *Present address, University Museum of Zoology, Downing Street,Cambridge CB2 3EJ (Received 19 July 1977;  相似文献   

2.
The monophyly of the land snail family Camaenidae has been in doubt due to a disjunct bihemispheric distributional pattern and to the lack of morphological synapomorphies. A cladistic analysis is presented using an ingroup composed of representatives of the three subfamilies distributed in Australia and 52 other species with American distribution. Bradybaenidae, Helicidae and Helminthoglyptidae were used as outgroups. Fifty morphological characters were treated as unordered and analysed using Pee-Wee ver. 2.9, a program for parsimony analysis using implied weights. The results of the analysis support Camaenidae as a monophyletic family (synapomorphies: oval genital orifice, absence of penial sheath). Two of the three Australasian subfamilies, Sinumeloninae and Camaeninae, are monophyletic in the strict consensus tree. The American taxa are classified in eight genera and arranged into two main clades. Caracolus is proposed as the sister group of the American Continental Camaenidae. The genus Solaropsis , previously excluded from this family by different authors, is reassigned to Camaenidae. Shell characters proved to be phylogenetically informative in defining Pleurodonte , Caracolus , Solaropsis , Isomeria and Labyrinthus . © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 138, 449–476.  相似文献   

3.
A phylogeny for Agelaius blackbirds was constructed using sequence data from an 890 base-pair (bp) region of the mitochondrial cytochrome-b gene in nine species of Agelaius and a single species from all but 1 of the 28 described blackbird genera and subgenera. The genus was found to be polyphyletic with the South American members of Agelaius more closely related to other South American blackbird genera. Application of bootstrap and jackknife manipulations supports this conclusion. That this relatively well-known genus is polyphyletic represents a warning to those attempting to construct phylogenies without first demonstrating monophyly of the ingroup. The conclusion that Agelaius is polyphyletic necessitates (1) the reinterpretation of previous studies that assumed monophyly and (2) the initiation of a variety of new comparative behavioral and ecological studies suggested by this finding.  相似文献   

4.
The river‐weed family Podostemaceae (c. 300 species in c. 54 genera) shows a number of morphological innovations to be adapted to its unusual aquatic habitat, and its unique or rare bauplan features have been reflected in the traditional (i.e. non‐molecular) classification recognizing numerous monotypic or oligospecific genera. The infrasubfamilial relationships of many genera remained unclear. The present study used molecular phylogenetic analysis of matK sequences for 657 samples (c. 132 species/c. 43 genera). The family was traditionally divided into three subfamilies (Podostemoideae, Tristichoideae and Weddellinoideae). American Podostemoideae were shown to be polyphyletic and divided into four clades, i.e. Ceratolacis, Diamantina, Podostemum and all other genera. Among the podostemoid clades, Diamantina was the first branching clade and a clade comprising Mourera and the Apinagia subclade was then sister to the remainder of the New World and Old World Podostemoideae with low statistic supports. The Old World Podostemoideae comprised four monophyletic clades, i.e. two African clades, one Madagascan clade and one Asian clade, although the relationships among these clades and American Ceratolacis and Podostemum were poorly resolved. African Podostemoideae were polyphyletic, with Saxicolella pro parte being weakly supported as sister to the remaining Old World Podostemoideae plus Ceratolacis and Podostemum. In contrast to the American and African clades, monophyly of four Asian subclades was well supported. Plants of Tristicha (Tristichoideae) and of Weddellina (Weddellinoideae), which are currently treated as monospecific, had great matK differentiation equivalent to at least interspecific variation. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 461–492.  相似文献   

5.
Identification of adult fruit flies primarily involves microscopic examination of diagnostic morphological characters, while immature stages, such as larvae, can be more problematic. One of the Australia’s most serious horticultural pests, the Queensland Fruit Fly (Bactrocera tryoni: Tephritidae), is of particular biosecurity/quarantine concern as the immature life stages occur within food produce and can be difficult to identify using morphological characteristics. DNA barcoding of the mitochondrial Cytochrome Oxidase I (COI) gene could be employed to increase the accuracy of fruit fly species identifications. In our study, we tested the utility of standard DNA barcoding techniques and found them to be problematic for Queensland Fruit Flies, which (i) possess a nuclear copy (a numt pseudogene) of the barcoding region of COI that can be co‐amplified; and (ii) as in previous COI phylogenetic analyses closely related B. tryoni complex species appear polyphyletic. We found that the presence of a large deletion in the numt copy of COI allowed an alternative primer to be designed to only amplify the mitochondrial COI locus in tephritid fruit flies. Comparisons of alternative commonly utilized mitochondrial genes, Cytochrome Oxidase II and Cytochrome b, revealed a similar level of variation to COI; however, COI is the most informative for DNA barcoding, given the large number of sequences from other tephritid fruit fly species available for comparison. Adopting DNA barcoding for the identification of problematic fly specimens provides a powerful tool to distinguish serious quarantine fruit fly pests (Tephritidae) from endemic fly species of lesser concern.  相似文献   

6.
Electron microscopic observations on the euspermatozoa (fertilizingsperm) and paraspermatozoa (infertile sperm) of Serpulorbissp. and Dendropoma sp. suggest that the family Vennetidae (sensustricto) is not closely allied to any true cerithioidean family.Vermetid euspermatozoa strongly resemble those of a number ofother mesogastropod superfamilies including the Stromboidea,Epitonioidea, Naticoidea, Calyptraeoidea, Cypraeoidea, somerissooideans and littorinoideans, and even some neogastropodtaxa. Vermetid paraspermatozoa are anudeate, with one or moretails extending from both ends of a central body region. Incontrast, paraspermatozoa of true cerithioideans: (1) have tailsextending from only the posterior region of the ‘head’(2) usually retain a condensed nuclear remnant and (3) sometimespossess an acrosome-like structure at the head apex. These results,in conjunction with anatomical work by Morton, suggest thatthe Vennetidae should be removed from the Cerithioidea and placedprobably in its own superfamily (Vermetoidea Raphinesque, 1815)as practised by some recent workers. The Vermetoidea possiblyare associable with the Stromboidea/Calyptraeoidea/Hipponicoidea/Xeno-phoroideablock within the Mesogastropoda *Present address: Department of Zoology, University of Queensland,St. Lucia, 4067, Queensland, Australia  相似文献   

7.
Pyruvate was converted into acetyl-CoA by the cytosol enzymefraction prepared from sweet potato root tissue infected withCeratocystis fimbriata. The conversion was dependent on thiaminepyrophosphate, NAD+, ATP and CoA. Activities of pyruvate decarboxylase,aldehyde dehydrogenase and acetyl CoA synthetase increased indiseased tissue. These results indicate the operation of thecytosol pathway of acetyl-CoA supply for terpene biosynthesisin C. fimbriata-infected tissue which consists of the abovethree enzymes. 1This paper constitutes Part 135 of the Phytopathological Chemistryof Sweet Potato with Black Rot and Injury. This work was supportedin part by a Grant-in-Aid from the Ministry of Education, Scienceand Culture. 2Present address: Biochemistry Department, University of Queensland,St. Lucia 4067, Queensland, Australia. (Received April 21, 1980; )  相似文献   

8.
SYNOPSIS. The anterior (ileum) and posterior (rectum) segmentsof the locust hindgut constitute the reabsorptive regions ofthe excretory system, which conserves or eliminates body waterand solutes as required for osmotic homeostasis. Hindgut transportmechanisms in the desert locust have previously been well describedbut the neuropeptide hormones that may naturally control theseprocesses are only now being identified. Ion Transport Peptide(ITP) has been isolated from locust corpus cardiacum (CC) andits full sequence of 72 amino acids deduced from its cDNA. NativeITP has the same actions as crude CC extracts in stimulatingCl , Na+, K+, and fluid absorption and inhibiting H+secretion (i.e., influencing pH regulation). The deduced aminoacid sequence of ITP was confirmed by showing biological activityof expressed and synthetic forms of this peptide. ITP has highsequence homology with a large family of crustacean hormonesthat include hyperglycaemic (CHH) and moult-inhibiting hormones(MIH) and is the first member reported outside crustaceans.  相似文献   

9.
10.
In the absence of knowledge about its anatomy, the systematic position of the genus Chalepotaxis, which inhabits a large part of South East Asia, has been historically dubious. The genitalia, sole of the foot and the caudal region of the type species, Chalepotaxis infantilis (Gredler, V. 1881. Zur Conchylien-Fauna von China. III. Stück. Jahrbücher der Deutschen Malakozoologischen Gesellschaft 8, 110–128), are described, which place this genus into the Helicarionidae family. DNA markers (cytochrome oxidase subunit I [COI] and 28S rRNA genes) corroborate this assignment and unequivocally remove the species from the Camaenidae (=Bradybaenidae) and Ariophantidae, where it had previously been placed. Radular morphology of the type species is also re-described and illustrated.  相似文献   

11.
K+ channels are differentially expressed throughout oligodendrocyte (Olg) development. KV1 family voltage-sensitive K+ channels have been implicated in proliferation and migration of Olg progenitor cell (OPC) stage, and inward rectifier K+ channels (KIR)4.1 are required for OPC differentiation to myelin-forming Olg. In this report we have identified a Shaw family K+ channel, KV3.1, that is involved in proliferation and migration of OPC and axon myelination. Application of anti-KV3.1 antibody or knockout of Kv3.1 gene decreased the sustained K+ current component of OPC by 50% and 75%, respectively. In functional assays block of KV3.1-specific currents or knockout of Kv3.1 gene inhibited proliferation and migration of OPC. Adult Kv3.1 gene-knockout mice had decreased diameter of axons and decreased thickness of myelin in optic nerves compared with age-matched wild-type littermates. Additionally, KV3.1 was identified as an associated protein of Olg-specific protein (OSP)/claudin-11 via yeast two-hybrid analysis, which was confirmed by coimmunoprecipitation and coimmunohistochemistry. In summary, the KV3.1 K+ current accounts for a significant component of the total K+ current in cells of the Olg lineage and, in association with OSP/claudin-11, plays a significant role in OPC proliferation and migration and myelination of axons. membrane potential; tight junction; myelin; progenitor cell  相似文献   

12.
A new opecoelid cercaria, Cercaria capricornia XII, is reported from Nassarius olivaceus in Capricornia, Central Queensland, Australia. Combined molecular and morphological data indicate that this cercaria is a member of the subfamily Opecoelinae. Cercaria capricornia XII is the first known opecoeline cercaria reported from a nassariid gastropod. Cercaria capricornia XII can be distinguished from other opecoelid cercariae by the combination of the presence of a 2-pointed stylet, body length and width, and the size of the tail. The emergence pattern for C. capricornia XII in captivity was erratic; rapid emergences of thousands of cercariae were interspersed by periods that sometimes exceeded a month in which no emergence occurred. There was no detectable pattern to or stimulus of the emergence. The molluscan host range of opecoelids is analysed in detail. Gastropods from the Buccinoidea, Cerithioidea and Rissooidea are hosts to both opecoeline and plagioporine cercariae, but the dominant subfamily infecting the Cerithioidea and Rissooidea is the Plagioporinae. The dominant marine host gastropod superfamily for opecoeline cercariae is the Buccinoidea; the family Nassariidae is contained in the Buccinoidea. The range of gastropod superfamilies known as hosts of plagioporines is much broader than that for opecoelines, which may be explained by the relative size of the two opecoelid families and perhaps by indications that the Plagioporinae is polyphyletic.  相似文献   

13.
Tandem repeats belonging to three DNA sequence families (OeTaq80, OeTaq178, and OeGEM86) were isolated from the nuclear DNA of Olea europaea cv. Carolea and dot-hybridized to the genomic DNA of 14 hypothetically different Olea species, 78 olive cultivars, and 14 wild olives. The copy number per unreplicated haploid genome of OeTaq80- and OeTaq178-related sequences was in the 107-106 range and that of OeGEM86-related sequences was in the 105 range in cultivars, wild olives and some Olea species. A large variation in the frequency of repeats belonging to each sequence family was observed within each group of plants. Positive correlations existed in each genome between the frequencies of repeats belonging to each family, and their overall frequency was positively correlated to the genome size. Duncan grouping showed that the frequency variation of tandem repeats within each group of plants was not continuous. Two main groups and several subgroups of genotypes could be separated within both the olive cultivars and the wild olives. Discrete areas in the Mediterranean Basin could be delimited by the geographic distribution of cultivated olives with different genotypes and the wild plants were associated with the cultivars in these areas according to genotypic similarity. The Olea species could be divided into four genotypic groups. Three of these, comprising accessions from Asia and North Africa, showed similarity with the genotypes of cultivars and wild olives. These results suggest a polyphyletic origin of cultivated olives from different wild Olea forms distributed throughout the Mediterranean Basin.  相似文献   

14.
Desensitization of ANG II tonic contractile response of theguinea pig ileum is related to membrane repolarization determined byCa2+-activatedK+(maxi-K+) channelopening. ANG II-stimulated depolarized myocytes presented sustainedactivation of maxi-K+ channels,characterized by reduction from 415 to 12 ms of the closed timeconstant. ANG II desensitization was prevented by 100 nM iberiotoxin,being reversible within 30 min. Depolarization by KCl, higher than 4 mM, impaired desensitization, suggesting that the membrane potentialmust attain a threshold to counteract the repolarization induced bymaxi-K+ channel opening. Once thisvalue is attained, there is no time dependency because thedesensitization process was shut off by addition of KCl along the timecourse of the tonic response. In contrast, the sustained ACh toniccomponent was not altered by these maneuvers. We conclude thatdesensitization of the ANG II tonic component is foremost due to theopening of maxi-K+ channels,leading to membrane repolarization, thus closing the voltage-dependentCa2+ channels responsible for theCa2+ influx that sustains thetonic component in this muscle.

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15.
Epidermal-cell protoplasts from rye (Secale cereale L.) rootswere voltage-clamped in both the whole-cell and outside-outmembrane-patch modes. Time-dependent inwardly-rectified (IR)and outwardly-rectified (OR) K+-currents were recorded, as wellas a ubiquitous, timeindependent (instantaneous) K+-current. The IR current activated at voltages more negative than —100mVwith two exponentially rising components. The time-constantof the shorter component was voltage-independent, whereas thetime-constant of the longer component was voltage-dependent,increasing as the activating voltage became more negative. TheIR current showed no inactivation. The IR current deactivatedwith a single exponential timecourse. The steady-state IR currentcould be fitted to a Boltzmann function with —135 mV asthe voltage at which the current was half-maximal and a minimalgating charge of 1.93. These parameters were insensitive tochanges in EK. One component of the IR current was K + , butother ions were also permeable. The IR current was inhibitedby extracellular Ca2+ , Ba2+ , Cs+, and TEA+, but was insensitiveto quinine. Single channels with unitary conductances of 56pS and 110 pS (in c.100 mM K+) were recorded at negative voltages. Two OR currents were observed. One had sigmoidal activationkinetics and activated at low positive voltages. The other activatedmore rapidly, with apparently exponential kinetics, at voltages50–100 mV more positive than the first. Neither currentshowed inactivation and deactivation of OR currents followeda double exponential time-course. Unitary-conductances of thechannels mediating these OR currents were 24 pS and 57 pS (inc.100 mM K+), respectively. Only the first type of OR currentwas studied in detail. This current activated with a sigmoidaltime-course, which could be described using a Hodgkin-Huxleyfunction with the activation variable raised to the second power.Its voltage-dependence was modulated in response to changesin EK and analysis of single-channel recordings indicated thatthe channel was K+-selective. The current was inhibited by Ba2+and TEA+, but not Ca2+, Cs+ or quinine. The instantaneous current was selective for monovalent cationsand K+ , Na+ and Cs+ were all permeant. It was inhibited byextracellular quinine and the instantaneous inward K+-currentwas reduced by extracellular Ca2+, Ba2+ and TEA+, as well asby competing permeant monovalent cations. The kinetics and pharmacology of these currents are comparedwith K+-currents across the plasma membrane of protoplasts fromother root-derived cells and with K+ channels in the plasmamembrane of rye roots studied following incorporation into artificial,planar lipid bilayers. Key words: Ionic currents, patch-clamp, pharmacology, potassium, K+, rye, Secale cereale L  相似文献   

16.
Several species of the family Petraliellidae were first described from the coast of Queensland, including the type species of Sinupetraliella, S. litoralis. These species are redescribed from type, or topotype specimens, and include Petraliella concinna, which has not been certainly found since its introduction in 1891; lectotype material is designated for P. buski and P. magna. Six other species are described from Queensland, P. crassocirca, P. dentilabris, P. dorsiporosa, Mucropetraliella bennetti, M. serrata and M. tuberosa. The species Mucropetraliella tuberosa is a new addition to the Queensland fauna and is described and illustrated here for the first time since its introduction in 1884. The characters of the family Petraliellidae are briefly discussed and the genera to which the Queensland species are assigned is reviewed. A taxonomic key to the ten Queensland petraliellid species described is also provided.  相似文献   

17.
VE-cadherin: adhesion at arm's length   总被引:8,自引:0,他引:8  
VE-cadherin was first identified in the early 1990s and quickly emerged as an important endothelial cell adhesion molecule. The past decade of research has revealed key roles for VE-cadherin in vascular permeability and in the morphogenic events associated with vascular remodeling. The details of how VE-cadherin functions in adhesion became apparent with structure-function analysis of the cadherin extracellular domain and with the identification of the catenins, a series of cytoplasmic proteins that bind to the cadherin tail and mediate interactions between cadherins and the cytoskeleton. Whereas early work focused on the armadillo family proteins -catenin and plakoglobin, more recent investigations have identified p120-catenin (p120ctn) and a related group of armadillo family members as key binding partners for the cadherin tail. Furthermore, a series of new studies indicate a key role for p120ctn in regulating cadherin membrane trafficking in mammalian cells. These recent studies place p120ctn at the hub of a cadherin-catenin regulatory mechanism that controls cadherin plasma membrane levels in cells of both epithelial and endothelial origin. endothelial cell; cytoskeleton; -catenin; p120ctn; cell adhesion; vascular endothelial cadherin  相似文献   

18.
Although several investigators have presented data suggesting that the Caprifoliaceae is polyphyletic in origin, the family has been retained as a taxon in recent classifications. Serological analyses of the taxa included within the family have been undertaken to provide additional taxonomic data. Precipitin techniques of double diffusion (Ouchterlony) and nephelometry (Boyden Procedure) were used to analyse serological similarities of seed proteins from representatives of the family. Three distinct groupings were detected for the taxa included in the Caprifoliaceae. AlthoughViburnum exhibited greatest serological similarity withSambucus, Viburnum was quite distinct from all members of the family investigated.Sambucus also was somewhat distinct from the other genera and exhibited about as much serological correspondence withCornus of the Cornaceae as with any tested member of the Caprifoliaceae. The remaining species examined formed a very close serological grouping. These data can be interpreted as supporting either a monophyletic or polyphyletic origin of the family as presently composed, because of the different arrangements of the families Caprifoliaceae and Cornaceae in the various systems of classification.  相似文献   

19.
Some debated issues of the genus Malus (apple) taxonomy were examined using a variety of species from the collection of the Maikop Experimental Station, Vavilon Research Institute of Plant Industry (Krasnodar krai). Phylogenetic relationships among these species were studied using traditional analysis of morphological traits, RAPD, and complete sequencing of the 5"- internal transcribed spacer (ITS1), 5.8S rRNA, 3"- internal transcribed spacer (ITS2) (constituting a cluster of the rRNA genes), and the terminal fragment of the matK gene encoding chloroplast maturase. The results showed that the Sorbomalussection was polyphyletic; the American apple M. fusca was closely related to the species contributing to the East Asian center of the genus origin, and the American speciesM. angustifolia, M. coronaria, and M. ioensis were closely related to the M. trilobata relict species, whose assignment to the genus Malus is debated by some authors. Molecular analysis of the species relationships showed that the Middle Asian apple M. sieversii is the species from which apple domestication started.  相似文献   

20.
Phylogenetic analysis of plastid DNA restriction site and rearrangement mutations suggests a number of major revisions to taxonomy and phylogenetic concepts in the hard pines. Total genomic DNA from 18 species that sampled all nine subsections was digested with 19 restriction enzymes, blotted, and probed with 70% of the Douglas-fir (Pseudotsuga menziesii) chloroplast genome, or, with clones encompassing the entire chloroplast genome of Pinus contorta. A total of 204 site mutations and five rearrangement mutations were generated, of which 126 were phylogenetically informative. Wagner parsimony analyses revealed 11 clades that were strongly supported by bootstrap and decay index analyses. All North American species except P. resinosa formed a distinct monophyletic group that was strongly separated from the Eurasian species. Within the Eurasian clade subsect. Sylvestres was polyphyletic; its Mediterranean species were closely allied with members of sect. Pinea. Sect. Pinea appeared polyphyletic as well; both species of its subsect. Leiophyllae showed a close affinity to Mesoamerican pines of subsect. Oocarpae in sect. Pinus. Within the North American pines subsects. Ponderosae and Oocarpae were polyphyletic. Despite its shallow fossil record, subsect. Contortae emerged as a sister group to all of the North American pines apart from P. resinosa, which was allied with Eurasian species of subsect. Sylvestres. The remaining North American subsections formed two groups: a poorly resolved clade with subsects. Ponderosae and Sabinianae, and sequentially nested clades represented by: P. radiata; P. taeda; representatives of subsects. Oocarpae and Ponderosae from Mesoamerica, and subsect. Leiophyllae. We present estimates of divergence times for each of these major clades based on molecular clocks calibrated using two hard pine fossil observations.  相似文献   

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