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1.
Endosymbiotic Wolbachia bacteria are, to date, considered the most widespread symbionts in arthropods and are the cornerstone of major biological control strategies. Such a high prevalence is based on the ability of Wolbachia to manipulate their hosts' reproduction. One manipulation called cytoplasmic incompatibility (CI) is based on the death of the embryos generated by crosses between infected males and uninfected females or between individuals infected with incompatible Wolbachia strains. CI can be seen as a modification‐rescue system (or modresc) in which paternal Wolbachia produce mod factors, inducing embryonic defects, unless the maternal Wolbachia produce compatible resc factors. Transgenic experiments in Drosophila melanogaster and Saccharomyces cerevisiae converged towards a model where the cidB Wolbachia gene is involved in the mod function while cidA is involved in the resc function. However, as cidA expression in Drosophila males was required to observe CI, it has been proposed that cidA could be involved in both resc and mod functions. A recent correlative study in natural Culex pipiens mosquito populations has revealed an association between specific cidA and cidB variations and changes in mod phenotype, also suggesting a role for both these genes in mod diversity. Here, by studying cidA and cidB genomic repertoires of individuals from newly sampled natural C. pipiens populations harbouring wPipIV strains from North Italy, we reinforce the link between cidB variation and mod phenotype variation fostering the involvement of cidB in the mod phenotype diversity. However, no association between any cidA variants or combination of cidA variants and mod phenotype variation was observed. Taken together our results in natural C. pipiens populations do not support the involvement of cidA in mod phenotype variation.  相似文献   

2.
The morphological features and chromosome numbers were examined in cultures of five species of Cephaleuros; C. aucubae, C. biolophus, C. japonicus, C. microcellularis, and C. virescens, collected from Japan. On agar media of Bold's basal medium and CA medium, radial growth of the algal colonies was vigorous in C. virescens, moderate in C. aucubae, and poor in C. microcellularis, but varied from poor to moderate in isolates of C. biolophus and C. japonicus. Filaments of C. virescens branched at an angle less than 40° and just below the cross walls, while those of the other species branched at an angle greater than 40° without relation to the cross walls. The length of filamentous cells was significantly smaller in C. microcellularis than in the other species. The chromosome number differed with the species: n = 22 in C. aucubae, n = 34 in C. biolophus, n = 18 in C. japonicus, n = 12 in C. microcellularis, and n = 24 in C. virescens. The chromosome number did not vary between isolates from filaments and gametes in C. aucubae and C. biolophus and among those from filaments, gametes, and zoospores in C. japonicus and C. virescens.  相似文献   

3.
Pterisanthes (Vitaceae) is a genus of c. 20 species of scandent climbers endemic to Southeast Asia with unusual lamellate inflorescences. Molecular phylogenetic analysis supports its relationship in the well‐supported VitisAmpelocissusNothocissusPterisanthes clade (i.e. the AmpelocissusVitis clade). Shoot tips and floral buds were collected from wild and greenhouse‐grown P. eriopoda at different developmental stages and were examined using epi‐illumination, light and scanning electron microscopy. Inflorescence and floral ontogeny was studied to discover how the lamellate inflorescence evolved and to make morphological comparisons to infer relationships with closely related members of Vitaceae. The second‐order branches in P. eriopoda are racemose and develop helically around the inflorescence axis in a similar fashion to Vitis and Ampelocissus. Inflorescence branching is restricted to the second order in P. eriopoda, whereas in Vitis and most Ampelocissus species subsequent branching orders culminate in the typical vitaceous determinate dichasium. In P. eriopoda subsequent lateral growth of the second‐order branches combined with the inhibition of peduncle or pedicel formation and loss of dichasial branching results in the unique lamellae in Pterisanthes, on which the floral primordia arise directly in a helical pattern. Floral development in P. eriopoda is the same as in other genera of Vitaceae examined to date with initiation of floral whorls centripetally, the calyx ring developing first and calyx lobes fused to cover the petals and stamen primordia. Given the recent phylogenetic results that placed Pterisanthes firmly within Ampelocissus, the most likely scenario is that the Pterisanthes inflorescence is derived from the thyrse of an Ampelocissus‐like ancestor and that the thyrse is a morphological synapomorphy of the Ampelocissus–Vitis clade. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 725–741.  相似文献   

4.
Leishmania donovani and Leishmaniainfantum infections cause fatal visceral leishmaniasis, and Leishmaniamajor causes self healing cutaneous lesions. It is poorly understood what genetic differences between these Leishmania species are responsible for the different pathologies of infection. To investigate whether L.donovani species-specific genes are involved in visceral Leishmania infection, we have examined a L.donovani species-specific gene Ld1590 (ortholog of LinJ15_V3.0900) that is a pseudogene in L.major. We have previously shown that transgenic expression of L.donovani Ld1590 in L.major significantly increased the liver and spleen parasite burdens in infected BALB/c mice. In this study we report that Ld1590 potentially encodes a nucleotide sugar transporter (NST) which localizes in the L.donovani Golgi apparatus. Surprisingly, although transgenic expression of the Ld1590 NST increased L.major survival in visceral organs, deletion of Ld1590 NST in L.donovani had no significant effect on L.donovani survival in mice. These observations suggest that loss of the functional Ld1590 gene in L.major may have been associated with reduced virulence in visceral organs in its animal reservoir and could have contributed to L.major’s tropism for cutaneous infections.  相似文献   

5.
To evaluate the sectional classification in Carex, subgenus Vignea, the ITS region of 58 species of 20 sections was analyzed with Neighbor Joining (NJ) and Markov chain Monte Carlo (MCMC) methods. Sections Dioicae, Physodeae and Ovales are found to be monophyletic, with C. bohemica well integrated in the section Ovales. Section Heleonastes turns out to be monophyletic, if C. canescens is treated separately in section Canescentes. Section Elongatae is monophyletic, but C. remota is placed in section Remotae and C. bromoides in section Deweyanae. In both analyses, six representatives of section Arenariae cluster together in a terminal group, whereas C. disticha, C. repens and C. siccata form a basal cluster. C. maritima, as the only member of section Incurvae, shares this basal position. C. chordorrhiza is ascribed to section Chordorrhizeae and not ascribed to the paraphyletic section Divisae. C. vulpina and C. otrubae are assigned to section Vulpinae and separated from the heterogeneous section Stenorhynchae. The other members of sections Divisae, Muehlenbergianae, Multiflorae and Stenorhynchae are scattered throughout the trees. The representatives of section Foetidae are dispersed in both analyses, section Paniculatae appears to be non-monophyletic in the molecular results as well. The subgenus appears subdivided in at least four larger subgroups in all analyses. Whereas these subgroups are strongly supported, the relationships between these subgroups remain only poorly resolved.  相似文献   

6.
Macrolycus is a genus of net‐winged beetles with 69 species distributed in the eastern Palearctic and northernmost part of the Oriental region. The first molecular phylogeny of Macrolycus was produced using an rrnL + tRNA‐Leu + nad1 mtDNA fragment. The major lineages and species limits were identified with morphology and molecular data. We propose that Cerceros is a subgenus of Macrolycus to enable identification of all adult specimens in the genus without DNA sequencing. Two species groups are proposed in Macrolycus s. str. and six in Cerceros. Additionally, twelve Macrolycus species are newly described from China: M. aquilinus, M. baihualingensis, M. bicolor, M. guangxiensis, M. jianfenglingensis, M. kuatunensis, M. lizipingensis, M. parvus, M. phoeniceus, M. rhodoneurus, M. rosaceus and M. sichuanensis. Macrolycus holzschuhi is proposed to be a junior subjective synonym of M. jeanvoinei. The highest diversity of Macrolycus is found in southern China. The species from the main islands of Japan are placed in two species groups: M. excellens is a sister to remaining species of the M. murzini group and the M. flabellatus group is a monophylum of closely related species in a sister position to the M. bicolor group.  相似文献   

7.
The world's argasid tick fauna comprises 183 species in four genera, namely Argas, Carios, Ornithodoros and Otobius in the family Argasidae. The ixodid tick fauna consists of 241 species in the genus Ixodes and 442 species in the genera Amblyomma, Anomalohimalaya, Bothriocroton, Cosmiomma, Dermacentor, Haemaphysalis, Hyalomma, Margaropus, Nosomma, Rhipicentor and Rhipicephalus in the family Ixodidae, with the genus Boophilus becoming a subgenus of the genus Rhipicephalus. The family Nuttalliellidae is represented by the monospecific genus Nuttalliella. The species names of these ticks, based on seven previous complete or partial listings, as well as those of recently described new species, are presented in tabular format. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

8.
We discovered two new taxa of Achnanthidium and Encyonema occurring with high abundance in the upstream of the Yom River, which is one of four major rivers in Northern Thailand. Achnanthidium pseudoconspicuum var. yomensis var. nov. closely resembles Achnanthidium pseudoconspicuum var. pseudoconspicuum in scanning electron microscopy (SEM), but has clearly different valve morphometry under the light microscopy (LM). Achnanthidium pseudoconspicuum var. yomensis is also similar to A. japonicum in valve morphology under LM, but differs to this species based on SEM observation. Encyonema yuwadeeanum sp. nov. shows similarities to Encyonema leei and Encyonema subkukenanum, but differs in valve shape and/or polar fissure shape. We discuss the possible valve ontogenetic relationship between Achnanthidium and Cymbellales based on the detailed areolae structures of these two new taxa.  相似文献   

9.
Plagiochila cucullifolia Jack & Steph. var. anomala J. Heinrichs & Gradst. var. nov. is described and illustrated. The new variety is known from a single locality in southern Ecuador and differs from P. cucullifolia var. cucullifolia by the flat, not saccate leaves, somewhat smaller plant size and weaker leaf dentation. According to phylogenetic analyses of 35 nrDNA ITS1 and ITS2 sequences of Plagiochila, the two varieties of P. cucullifolia form a monophyletic lineage and are placed in a well supported clade together with five other species of Plagiochila sect. Hylacoetes: P. dimorpha Lindenb. & Gottsche var. ecuadorica (Inoue) J. Heinrichs, P. flabelliflora Steph., P. patriciae J. Heinrichs & H. Anton, P. macrostachya Lindenb. and P. turgida Herzog. Within Plagiochila, nrITS sequence variation is not concordant with morphological diversification. ITS sequences of Plagiochila cucullifolia s.str. and of P. dimorpha var. ecuadorica differ in only 23 aligned positions whereas two sequences of P. subplana Lindenb. differ in 86 aligned positions. Morphologically, P. cucullifolia s.str. and P. dimorpha var. ecuadorica differ in more than 20 characters and previously these two taxa were placed in separate genera. P. subplana phenotypes show considerable variation in leaf shape and dentation but the extremes are linked by numerous intermediates.  相似文献   

10.
The serological investigations support the opinion ofJanchen (1942) to combine the generaBunias, Isatis, andSisymbrium in the tribeSisymbrieae; Cheiranthus, Erysimum, andMatthiola in the tribeHesperideae; andBrassica, Crambe, Sinapis, andSuccowia in the tribeBrassiceae. They further underline the central position of theSisymbrieae and the isolated position of theHeliophileae. In accordance withEigner (1973) theBrassiceae are placed closer to theSisymbrieae than inJanchen; the same holds for thePringleeae. No serological justification could be found to uniteArabis andBarbarea in the tribeArabideae, andAlyssum andLunaria in theAlysseae. From the antigen-systems used among the representatives ofJanchen's Lepidieae the generaLepidium andNeslia show remarkable correspondence both toCamelina andThlaspi, but not toCochlearia which appears distant fromCamelina andThlaspi also.
Teil 1/Part 1.  相似文献   

11.
A taxonomic review of the Korean Lymantria Hübner, 1819 was conducted. A total of nine species of five subgenera with two unrecorded species are listed: Lymantria (Porthetria) dispar Linnaeus 1758, L. (P.) xylina Swinhoe 1903, L. (Lymantria) monacha (Linnaeus 1758), L. (L.) minomonis Matsumura 1933 (new to Korea), L. (L.) similis monachoides Schintlimeister 2004 (new to Korea), L. (L.) lucescens (Butler 1881), L. (Nyctria) mathura Moore 1865, L. (Collentria) fumida Butler 1877, and L. (Spinotria) bantaizana Matsumura 1933. Lymantria (Lymantria) minomonis and L. (L.) similis monachoides are newly added to the Korean fauna. Lymantria (L.) minomonis was found only on Bogildo Island of Jeollanam‐do in the southern part of Korea, and L. (L.) similis monachoides was collected in central Korea. Lymantria (Porthetria) xylina and L. (Collentria) fumida were not examined in this study, and it is considered that the previous records were due to misidentification or they are only distributed in the northern part of the Korean Peninsula. We provide diagnoses of two unrecorded species and adult habitus and genitalia photos of the Korean Lymantria species.  相似文献   

12.
The closely related genera Carestiella, Schizoxylon and Stictis (Stictidaceae, Ostropales, Ascomycota) are revised in northern Scandinavia, and a revised phylogenetic hypothesis, including all seven species of this group in the area, is presented. A key to the species of Stictis s. lat. (including Carestiella, Schizoxylon and Stictis) in Northern Scandinavia is presented. S. albescens and S. confusum are described as new to science, and the new name S. brunnescens is introduced for S. mollis ssp. populorum, when treated as a distinct species. C. socia and S. albescens are the only representatives of their genera in northern Scandinavia, but a total of five species of Stictis are present in the area (S. brunnescens, S. confusum, S. mollis, S. populorum and S. radiata). Substantial within-species variation in ascoma morphology and wall pigmentation is revealed and discussed, and found to correlate with fungal lifestyles; optional lichenization apparently affects several details in fungal anatomy and morphology.  相似文献   

13.
Crinkled is associated with embryonic denticle formation and auditory organ development in Drosophila melanogaster. However, the functions of Crinkled have not been fully investigated. Additionally, the genes that participate in the Crinkled pathway are unknown. Phylogenetic analysis indicates that crinkled exhibits a one‐to‐one orthologous relationship in insects. In Tribolium castaneum, the crinkled gene is 6,498 bp in length and consists of six exons. Crinkled expression peaked during two phases in Tribolium: late embryonic and pupal stages. High levels of crinkled mRNA were detected in the fat body, head, epidermis, ovary, and accessory gland of late adults. Knockdown of crinkled using RNA interference (RNAi) severely affected wing morphogenesis in T. castaneum. We further showed that crinkled silencing reduced forked expression through wingless and shaven‐baby, and RNAi of forked phenocopied the effects of crinkled knockdown in T. castaneum. This study investigated the development role of crinkled in postembryonic stages and indicated that forked mediates the functions of crinkled during wing morphogenesis in T. castaneum.  相似文献   

14.
Two sequenced nodulation regions of lupin Bradyrhizobium sp. WM9 carried the majority of genes involved in the Nod factor production. The nod region I harbored: nolA, nodD, nodA, nodB, nodC, nodS, nodI, nodJ, nolO, nodZ, fixR, nifA, fixA, nodM, nolK and noeL. This gene arrangement resembled that found in the nodulation region of Bradyrhizobium japonicum USDA110, however strain WM9 harbored only one nodD gene copy, while the nodM, nolK and noeL genes had no counterparts in the 410 kb symbiotic region of strain USDA110. Region II harbored nolL and nodW, but lacked an nodV gene. Both regions carried ORFs that lacked similarity to the published USDA110 sequences, though they had homologues in symbiotic regions of Rhizobium etli, Sinorhizobium sp. NGR234 and Mesorhizobium loti. These differences in gene content, as well as a low average sequence identity (70%) of symbiotic genes with respect to B. japonicum USDA110 were in contrast with the phylogenetic relationship of USDA110 and WM9 revealed by the analysis of 16S rDNA and dnaK sequences. This most likely reflected an early divergence of symbiotic loci, and possible co-speciation with distinct legumes. During this process the loss of a noeI gene and the acquisition of a nolL gene could be regarded as an adaptation towards these legumes that responded to Nod factors carrying 4-O-acetylfucose rather than 2-O-methylfucose. This explained various responses of lupins and serradella plants to infection by mutants in nodZ and nolL genes, knowing that serradella is a stringent legume while lupins are more promiscuous legumes. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

15.
Franks  Steven J. 《Plant Ecology》2003,168(1):1-11
Garden experiments focused on vegetative regeneration were carried out with four invasive taxa of the genus Reynoutria (R. japonica var. japonica, R. japonica var. compacta, R. sachalinensis and a hybrid between R. sachalinensis and R. japonica var. japonica, R. ×bohemica). Regeneration ability of stems and rhizomes, timing of shoot emergence and biomass production were studied under the following treatments: laid horizontally on the soil surface; placed upright; buried in the soil; floating in water. Two different soils (sand and garden loam) representing contrasting nutrient levels were applied. Differences were found in the capability and speed of regeneration, as well as in the quality of shoots produced. Regeneration from stems was less efficient than that from rhizomes in all taxa except R. sachalinensis. R. ×bohemica exhibits higher regeneration potential (61%) than all other taxa and can be considered as the most successful taxon of the Czech representatives of the genus Reynoutria in terms of regeneration and establishment of new shoots. High regeneration capacity was also exhibited by R. japonica var. compacta (52%). Other taxa showed generally lower regeneration rates (R. japonica var. japonica 39% and R. sachalinensis 21%), but under some treatments the percentage of regenerated segments was high, too. R. japonica var. japonica rhizomes regenerated successfully in all three soil treatments but not in the water. An opposite pattern was found for its stems: they regenerated well if exposed to water treatment but in the soil, they did not regenerate at all. Particular taxa responded to the soil type in a contrasting way. R. sachalinensis and R. ×bohemica regenerated better in loam while the opposite was true in R. japonica var. japonica. R. japonica var. compacta produced the tallest and R. ×bohemica the heaviest and most robust shoots. It is concluded that rhizomes are more crucial than stems for the spread of knotweeds through fragmentation and clonal growth, suggesting the importance of soil disturbance.  相似文献   

16.
Although quantitative disease resistance (QDR) is a durable and broad‐spectrum form of resistance in plants, the identification of the genes underlying QDR is still in its infancy. RKS1 (Resistance related KinaSe1) has been reported recently to confer QDR in Arabidopsis thaliana to most but not all races of the bacterial pathogen Xanthomonas campestris pv. campestris (Xcc). We therefore explored the genetic bases of QDR in A. thaliana to diverse races of X. campestris (Xc). A nested genome‐wide association mapping approach was used to finely map the genomic regions associated with QDR to Xcc12824 (race 2) and XccCFBP6943 (race 6). To identify the gene(s) implicated in QDR, insertional mutants (T‐DNA) were selected for the candidate genes and phenotyped in response to Xc. We identified two major QTLs that confer resistance specifically to Xcc12824 and XccCFBP6943. Although QDR to Xcc12824 is conferred by At5g22540 encoding for a protein of unknown function, QDR to XccCFBP6943 involves the well‐known immune receptor pair RRS1/RPS4. In addition to RKS1, this study reveals that three genes are involved in resistance to Xc with strikingly different ranges of specificity, suggesting that QDR to Xc involves a complex network integrating multiple response pathways triggered by distinct pathogen molecular determinants.  相似文献   

17.
Hemiodus bimaculatus sp. nov., is described from tributaries of the Rio Juruena and Rio Teles Pires in the upper Rio Tapajós basin. The new species is diagnosed from most congeners, except Hemiodus jatuarana, by having a conspicuous circular or horizontally elongate dark blotch on the caudal peduncle (v. inconspicuous in H. iratapuru and absent in the other species). The new species differs from H. jatuarana by having a round midlateral spot on the flank (v. absent in H. jatuarana), 98–121 perforated scales in the lateral line (v. 66–72 in H. jatuarana), 23–28 scale series above and 14–19 below lateral line (v. 12–13 above and 6–7 below in H. jatuarana). Hemiodus bimaculatus is hypothesised to be related to species of the H. microlepis group, from which it also differs by having 11–25 epibranchial (v. 26–34 in H. argenteus, 29–39 in H. microlepis, 21–42 in H. orthonops and 27–35 in H. parnaguae) and 18–31 ceratobranchial (v. 38–50 in H. argenteus, 43–58 in H. microlepis, 32–52 in H. orthonops and 34–48 in H. parnaguae) gill rakers in the first arch.  相似文献   

18.
The structural organization of the nuclear ribosomal DNA (rDNA) of Humulus lupulus, H. japonicus and Cannabis sativa was determined by restriction site mapping. A high degree of DNA sequence similarity was evident in the coding regions of the rDNA repeats of the taxa and supports the placement of Cannabis and Humulus in one family, Cannabaceae. However, the presence of a BstEII site, an additional SacI site, absence of the SpeI site and positional differences of the SspI sites in the 25 S gene distinguished H. japonicus from H. lupulus. Humulus lupulus has an additional EcoRV site in the IGS region. A XhoI site in the 18S region of C. sativa distinguishes it from the two hop species. The diagnostic differences in the IGS of C. sativa include the EcoRI, HindIII and XhoI sites. These sites were not detected in the IGS of the two hop species.  相似文献   

19.
The Chinese species of the subgenus Microchelonus Szépligeti of the genus Chelonus Panzer with the female carapace having an incised apex in dorsal view and/or in posterior view are revised. Two new species, Chelonus (Microchelonus) rhagius sp. n. and Chelonus (Microchelonus) tobiasi sp. n. are described. Chelonus (Microchelonus) elegantulus Tobias and Chelonus (Microchelonus) volgensis Tobias are recorded in China for the first time.  相似文献   

20.
Functions of α‐ and β‐branch carotenoids in whole‐plant acclimation to photo‐oxidative stress were studied in Arabidopsis thaliana wild‐type (wt) and carotenoid mutants, lut ein deficient (lut2, lut5), n on‐p hotochemical q uenching1 (npq1) and s uppressor of z eaxanthin‐l ess1 (szl1) npq1 double mutant. Photo‐oxidative stress was applied by exposing plants to sunflecks. The sunflecks caused reduction of chlorophyll content in all plants, but more severely in those having high α‐ to β‐branch carotenoid composition (α/β‐ratio) (lut5, szl1npq1). While this did not alter carotenoid composition in wt or lut2, which accumulates only β‐branch carotenoids, increased xanthophyll levels were found in the mutants with high α/β‐ratios (lut5, szl1npq1) or without xanthophyll‐cycle operation (npq1, szl1npq1). The PsbS protein content increased in all sunfleck plants but lut2. These changes were accompanied by no change (npq1, szl1npq1) or enhanced capacity (wt, lut5) of NPQ. Leaf mass per area increased in lut2, but decreased in wt and lut5 that showed increased NPQ. The sunflecks decelerated primary root growth in wt and npq1 having normal α/β‐ratios, but suppressed lateral root formation in lut5 and szl1npq1 having high α/β‐ratios. The results highlight the importance of proper regulation of the α‐ and β‐branch carotenoid pathways for whole‐plant acclimation, not only leaf photoprotection, under photo‐oxidative stress.  相似文献   

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