Comparative genomic analysis of Leishmania (Viannia) peruviana and Leishmania (Viannia) braziliensis

Background

The Leishmania (Viannia) braziliensis complex is responsible for most cases of New World tegumentary leishmaniasis. This complex includes two closely related species but with different geographic distribution and disease phenotypes, L. (V.) peruviana and L. (V.) braziliensis. However, the genetic basis of these differences is not well understood and the status of L. (V.) peruviana as distinct species has been questioned by some.Here we sequenced the genomes of two L. (V.) peruviana isolates (LEM1537 and PAB-4377) using Illumina high throughput sequencing and performed comparative analyses against the L. (V.) braziliensis M2904 reference genome. Comparisons were focused on the detection of Single Nucleotide Polymorphisms (SNPs), insertions and deletions (INDELs), aneuploidy and gene copy number variations.

Results

We found 94,070 variants shared by both L. (V.) peruviana isolates (144,079 in PAB-4377 and 136,946 in LEM1537) against the L. (V.) braziliensis M2904 reference genome while only 26,853 variants separated both L. (V.) peruviana genomes.Analysis in coding sequences detected 26,750 SNPs and 1,513 indels shared by both L. (V.) peruviana isolates against L. (V.) braziliensis M2904 and revealed two L. (V.) braziliensis pseudogenes that are likely to have coding potential in L. (V.) peruviana. Chromosomal read density and allele frequency profiling showed a heterogeneous pattern of aneuploidy with an overall disomic tendency in both L. (V.) peruviana isolates, in contrast with a trisomic pattern in the L. (V.) braziliensis M2904 reference.Read depth analysis allowed us to detect more than 368 gene expansions and 14 expanded gene arrays in L. (V.) peruviana, and the likely absence of expanded amastin gene arrays.

Conclusions

The greater numbers of interspecific SNP/indel differences between L. (V.) peruviana and L. (V.) braziliensis and the presence of different gene and chromosome copy number variations support the classification of both organisms as closely related but distinct species.The extensive nucleotide polymorphisms and differences in gene and chromosome copy numbers in L. (V.) peruviana suggests the possibility that these may contribute to some of the unique features of its biology, including a lower pathology and lack of mucosal development.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1928-z) contains supplementary material, which is available to authorized users.     

Mucosal Leishmaniasis caused by Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in the Brazilian Amazon

Background

Leishmania (Viannia) braziliensis is a parasite recognized as the most important etiologic agent of mucosal leishmaniasis (ML) in the New World. In Amazonia, seven different species of Leishmania, etiologic agents of human Cutaneous Leishmaniasis, have been described. Isolated cases of ML have been described for several different species of Leishmania: L. (V.) panamensis, L. (V.) guyanensis and L. (L.) amazonensis.

Methodology

Leishmania species were characterized by polymerase chain reaction (PCR) of tissues taken from mucosal biopsies of Amazonian patients who were diagnosed with ML and treated at the Tropical Medicine Foundation of Amazonas (FMTAM) in Manaus, Amazonas state, Brazil. Samples were obtained retrospectively from the pathology laboratory and prospectively from patients attending the aforementioned tertiary care unit.

Results

This study reports 46 cases of ML along with their geographical origin, 30 cases caused by L. (V.) braziliensis and 16 cases by L. (V.) guyanensis. This is the first record of ML cases in 16 different municipalities in the state of Amazonas and of simultaneous detection of both species in 4 municipalities of this state. It is also the first record of ML caused by L. (V.) guyanensis in the states of Pará, Acre, and Rondônia and cases of ML caused by L. (V.) braziliensis in the state of Rondônia.

Conclusions/Significance

L. (V.) braziliensis is the predominant species that causes ML in the Amazon region. However, contrary to previous studies, L. (V.) guyanensis is also a significant causative agent of ML within the region. The clinical and epidemiological expression of ML in the Manaus region is similar to the rest of the country, although the majority of ML cases are found south of the Amazon River.

Author Summary

Leishmaniasis is considered a neglected disease with 1.5 million new cases of cutaneous leishmaniasis (CL) occurring each year. In the Amazon region and in the Americas in general, ML is caused by Leishmania (Viannia) braziliensis, though in rare cases it has been related to other species. ML, which is associated with inadequate treatment of CL, normally manifests itself years after the occurrence of CL. Clinical features evolve slowly and most often affect the nasal cavity, in some cases causing perforation, or even destruction, of the septum. Diagnosis is made using the Montenegro skin test, serology and histopathology of the patients'' mucosal tissues, or by isolation of the parasites. PCR is the best way to identify the species of leishmaniasis and is therefore the diagnostic method of choice. This paper describes 46 cases of ML and their geographical origin, 30 cases associated with L. (V.) braziliensis and 16 with L. (V.) guyanensis. The species of leishmaniasis was identified using mucosal biopsies taken from Amazonian patients who were diagnosed and treated for ML in the tertiary care unit, in Manaus, Amazonas state, Brazil. This is the highest number of ML cases caused by L. (V.) guyanensis that has ever been reported.     

Bryophytes from the southeastern Yukon Territory,Canada

One hundred and forty-five taxa of bryophytes are reported from the extreme southeastern Yukon. Eight species of Hepaticae and 13 of mosses represent new records for the Yukon, which are Calypogeia suecica (S. Arnell & Perss.) K. Müll., Chiloscyphus pallescens (Ehrh.) Dum., Conocephalum conicum (L.) Dum., Jamesoniella autumnalis (DC.) Steph., Pellia neesiana (Gott.) Limpr., Ptilidium pulcherrimum (Web.) Hampe, Riccardia palmata (Hedw.) Carruth., Tritomaria exsecta (Schmid.) Schiffn., Amblystegium varium (Hedw.) Lindb., Brachythecium rivulare B.S.G., B. rutabulum (Hedw.) B.S.G., Bryum blindii B.S.G., Didymodon rigidulus Hedw., D. tophaceus (Brid.) Lisa, Drepanocladus trichophyllus (Warnst.) Podp., Hygroamblystegium noterophilum (Sull. & Lesq. ex Sull.) Warnst., Hygrohypnum molle (Hedw.) Loeske, Plagiomnium ciliare (C. Müll.) Kop., P. cuspidatum (Hedw.) Kop., Platydictya minutissimum (Sull. & Lesq. ex Sull.) Crum, and Pylaisiella selwynii (Kindb.) Crum, Steere & Anderson. Many of the other collections represent wide extensions of range within the Yukon Territory.     

Checklist of the Braulidae,Camillidae, Diastatidae and Drosophilidae of Finland (Diptera,Ephydroidea)

A checklist of the Braulidae (1 species), Camillidae (3 spp.), Diastatidae (10 spp.) and Drosophilidae (67 spp.) of Finland is presented. Campichoetinae is included as a subfamily of Diastatidae.     

Three new species of the subgenus Neoribates (Neoribates) (Acari,Oribatida, Parakalummidae) from Nepal

Three new parakalummid mites of the subgenus Neoribates (Neoribates), N. (N.) parabulanovae sp. n., N. (N.) paramacrosacculatus sp. n. and N. (N.) pararotundus sp. n., are described from Nepalese soils. Neoribates (Neoribates) parabulanovae sp. n. is morphologically most similar to N. (N.) bulanovae Grishina, 2009, N. (N.) rotundus Aoki, 1982 and N. (N.) setiger Balogh & Mahunka, 1978, however, it differs from N. (N.) bulanovae by the body length, body and leg integument, morphology of bothridial setae, absence of aggenital setae, length of interlamellar setae and location of adanal setae ad₃; from N. (N.) rotundus by the body size, body integument, morphology of bothridial setae and length of interlamellar setae; from N. (N.) setiger by the body size, number of genital setae and absence of aggenital setae. Neoribates (Neoribates) paramacrosacculatus sp. n. is morphologically most similar to N. (N.) macrosacculatus Aoki, 1966, however, it differs from the latter by the body size, body integument, length and morphology of bothridial setae, number of genital setae, absence of lamellar setae and length of interlamellar setae. Neoribates (Neoribates) pararotundus sp. n. is morphologically most similar to N. (N.) rotundus, however, it differs from the latter by the number of notogastral setal alveoli, body integument and length of interlamellar setae.     

Chemotherapeutic Potential of 17-AAG against Cutaneous Leishmaniasis Caused by Leishmania (Viannia) braziliensis

Background

Leishmaniasis remains a worldwide public health problem. The limited therapeutic options, drug toxicity and reports of resistance, reinforce the need for the development of new treatment options. Previously, we showed that 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), a Heat Shock Protein 90 (HSP90)-specific inhibitor, reduces L. (L.) amazonensis infection in vitro. Herein, we expand the current knowledge on the leishmanicidal activity of 17-AAG against cutaneous leishmaniasis, employing an experimental model of infection with L. (V.) braziliensis.

Methodology/Principal findings

Exposure of axenic L. (V.) braziliensis promastigotes to 17-AAG resulted in direct dose-dependent parasite killing. These results were extended to L. (V.) braziliensis-infected macrophages, an effect that was dissociated from the production of nitric oxide (NO), superoxide (O⁻²) or inflammatory mediators such as TNF-α, IL-6 and MCP-1. The leishmanicidal effect was then demonstrated in vivo, employing BALB/c mice infected with L. braziliensis. In this model, 17-AAG treatment resulted in smaller skin lesions and parasite counts were also significantly reduced. Lastly, 17-AAG showed a similar effect to amphotericin B regarding the ability to reduce parasite viability.

Conclusion/Significance

17-AAG effectively inhibited the growth of L. braziliensis, both in vitro and in vivo. Given the chronicity of L. (V.) braziliensis infection and its association with mucocutaneous leishmaniasis, 17-AAG can be envisaged as a new chemotherapeutic alternative for cutaneous Leishmaniasis.     

In vitro and in vivo activity of a palladacycle complex on Leishmania (Leishmania) amazonensis

Background

Antitumor cyclopalladated complexes with low toxicity to laboratory animals have shown leishmanicidal effect. These findings stimulated us to test the leishmanicidal property of one palladacycle compound called DPPE 1.2 on Leishmania (Leishmania) amazonensis, an agent of simple and diffuse forms of cutaneous leishmaniasis in the Amazon region, Brazil.

Methodology/Principal Findings

Promastigotes of L. (L.) amazonensis and infected bone marrow-derived macrophages were treated with different concentrations of DPPE 1.2. In in vivo assays foot lesions of L. (L.) amazonensis-infected BALB/c mice were injected subcutaneously with DPPE 1.2 and control animals received either Glucantime or PBS. The effect of DPPE 1.2 on cathepsin B activity of L. (L.) amazonensis amastigotes was assayed spectrofluorometrically by use of fluorogenic substrates. The main findings were: 1) axenic L. (L.) amazonensis promastigotes were destroyed by nanomolar concentrations of DPPE 1.2 (IC50 = 2.13 nM); 2) intracellular parasites were killed by DPPE 1.2 (IC50 = 128.35 nM), and the drug displayed 10-fold less toxicity to macrophages (CC50 = 1,267 nM); 3) one month after intralesional injection of DPPE 1.2 infected BALB/c mice showed a significant decrease of foot lesion size and a reduction of 97% of parasite burdens when compared to controls that received PBS; 4) DPPE 1.2 inhibited the cysteine protease activity of L. (L.) amazonensis amastigotes and more significantly the cathepsin B activity.

Conclusions/Significance

The present results demonstrated that DPPE 1.2 can destroy L. (L.) amazonensis in vitro and in vivo at concentrations that are non toxic to the host. We believe these findings support the potential use of DPPE 1.2 as an alternative choice for the chemotherapy of leishmaniasis.     

Comparative anatomy of the nectary spur in selected species of Aeridinae (Orchidaceae)

Background and Aims

To date, the structure of the nectary spur of Aeridinae has not been studied in detail, and data relating to the nectaries of ornithophilous orchids remain scarce. The present paper compares the structural organization of the floral nectary in a range of Aeridinae species, including both entomophilous and ornithophilous taxa.

Methods

Nectary spurs of Ascocentrum ampullaceum (Roxb.) Schltr. var. aurantiacum Pradhan, A. curvifolium (Lindl.) Schltr., A. garayi Christenson, Papilionanthe vandarum (Rchb.f.) Garay, Schoenorchis gemmata (Lindl.) J.J. Sm., Sedirea japonica (Rchb.f.) Garay & H.R. Sweet and Stereochilus dalatensis (Guillaumin) Garay were examined by means of light microscopy, scanning electron microscopy and transmission electron microscopy.

Key Results and Conclusions

The diverse anatomy of the nectary is described for a range of Aeridinae species. All species of Ascocentrum investigated displayed features characteristic of ornithophilous taxa. They have weakly zygomorphic, scentless, red or orange flowers, display diurnal anthesis, possess cryptic anther caps and produce nectar that is secluded in a relatively massive nectary spur. Unicellular, secretory hairs line the lumen at the middle part of the spur. Generally, however, with the exception of Papilionanthe vandarum, the nectary spurs of all entomophilous species studied here (Schoenorchis gemmata, Sedirea japonica, Stereochilus dalatensis) lack secretory trichomes. Moreover, collenchymatous secretory tissue, present only in the nectary spur of Asiatic Ascocentrum species, closely resembles that found in nectaries of certain Neotropical species that are hummingbird-pollinated and assigned to subtribes Maxillariinae Benth., Laeliinae Benth. and Oncidiinae Benth. This similarity in anatomical organization of the nectary, regardless of geographical distribution and phylogeny, indicates convergence.     

Population Structure and Evidence for Both Clonality and Recombination among Brazilian Strains of the Subgenus Leishmania (Viannia)

Background/Objectives: Parasites of the subgenus Leishmania (Viannia) cause varying clinical symptoms ranging from cutaneous leishmaniases (CL) with single or few lesions, disseminated CL (DL) with multiple lesions to disfiguring forms of mucocutaneous leishmaniasis (MCL). In this population genetics study, 37 strains of L. (V.) guyanensis, 63 of L. (V.) braziliensis, four of L. (V.) shawi, six of L. (V.) lainsoni, seven of L. (V.) naiffi, one each of L. (V.) utingensis and L. (V.) lindenbergi, and one L. (V.) lainsoni/L. naiffi hybrid from different endemic foci in Brazil were examined for variation at 15 hyper-variable microsatellite markers. Methodology/Principal findings: The multilocus microsatellite profiles obtained for the 120 strains were analysed using both model- and distance-based methods. Significant genetic diversity was observed for all L. (Viannia) strains studied. The two cluster analysis approaches identified two principal genetic groups or populations, one consisting of strains of L. (V.) guyanensis from the Amazon region and the other of strains of L. (V.) braziliensis isolated along the Atlantic coast of Brazil. A third group comprised a heterogeneous assembly of species, including other strains of L. braziliensis isolated from the north of Brazil, which were extremely polymorphic. The latter strains seemed to be more closely related to those of L. (V.) shawi, L. (V.) naiffi, and L. (V.) lainsoni, also isolated in northern Brazilian foci. The MLMT approach identified an epidemic clone consisting of 13 strains of L. braziliensis from Minas Gerais, but evidence for recombination was obtained for the populations of L. (V.) braziliensis from the Atlantic coast and for L. (V.) guyanensis. Conclusions/Significance: Different levels of recombination versus clonality seem to occur within the subgenus L. (Viannia). Though clearly departing from panmixia, sporadic, but long-term sustained recombination might explain the tremendous genetic diversity and limited population structure found for such L. (Viannia) strains.     

Carbon isotope ratios demonstrate carbon flux from c(4) host to c(3) parasite

Carbon isotope ratios of mature leaves from the C₃ angiosperm root hemiparasites Striga hermonthica (Del.) Benth (−26.7‰) and S. asiatica (L.) Kuntze (−25.6‰) were more negative than their C₄ host, sorghum (Sorghum bicolor [L.] Moench cv CSH1), (−13.5‰). However, in young photosynthetically incompetent plants of S. hermonthica this difference was reduced to less than 1‰. Differences between the carbon isotope ratios of two C₃-C₃ associations, S. gesnerioides (Willd.) Vatke—Vigna unguiculata (L.) Walp. and Oryza sativa L.—Rhamphicarpa fistulosa (Hochst.) Benth differed by less than 1‰. Theoretical carbon isotope ratios for mature leaves of S. hermonthica and S. asiatica, calculated from foliar gas exchange measurements, were −31.8 and −32.0‰, respectively. This difference between the measured and theoretical δ¹³C-values of 5 to 6‰ suggests that even in mature, photosynthetically active plants, there is substantial input of carbon from the C₄ host. We estimate this to be approximately 28% of the total carbon in S. hermonthica and 35% in S. asiatica. This level of carbon transfer contributes to the host's growth reductions observed in Striga-infected sorghum.     

Neutrophils reduce the parasite burden in Leishmania (Leishmania) amazonensis-infected macrophages

Background

Studies on the role of neutrophils in Leishmania infection were mainly performed with L. (L) major, whereas less information is available for L. (L) amazonensis. Previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to L. (L.) amazonensis (C3H/HePas). In contrast, the susceptible strain (BALB/c) displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. These findings led us to investigate the interaction of inflammatory neutrophils with L. (L.) amazonensis-infected macrophages in vitro.

Methodology/Principal Findings

Mouse peritoneal macrophages infected with L. (L.) amazonensis were co-cultured with inflammatory neutrophils, and after four days, the infection was quantified microscopically. Data are representative of three experiments with similar results. The main findings were 1) intracellular parasites were efficiently destroyed in the co-cultures; 2) the leishmanicidal effect was similar when cells were obtained from mouse strains resistant (C3H/HePas) or susceptible (BALB/c) to L. (L.) amazonensis; 3) parasite destruction did not require contact between infected macrophages and neutrophils; 4) tumor necrosis factor alpha (TNF-α), neutrophil elastase and platelet activating factor (PAF) were involved with the leishmanicidal activity, and 5) destruction of the parasites did not depend on generation of oxygen or nitrogen radicals, indicating that parasite clearance did not involve the classical pathway of macrophage activation by TNF-α, as reported for other Leishmania species.

Conclusions/Significance

The present results provide evidence that neutrophils in concert with macrophages play a previously unrecognized leishmanicidal effect on L. (L.) amazonensis. We believe these findings may help to understand the mechanisms involved in innate immunity in cutaneous infection by this Leishmania species.     

中国兰科二新记录种

报道了中国西藏兰科植物二新记录种:无叶沼兰(Crepidium aphyllum(King&Pantl.)A.N.Rao)和矮生白点兰Thrixspermum pygmaeum(King&Pantl.)Holttum。无叶沼兰和本属另一腐生种C.saprophytum(King&Pantl.)A.N.Rao的主要区别为假鳞茎圆柱形,唇瓣平展,顶端圆形,中萼片直立。矮生白点兰与T.masciflorum A.S.Rao&J.Joseph相似,但本种花序短于叶,苞片螺旋排列、花瓣匙形、唇瓣下凹且3裂、中裂片顶端下凹、胼胝体有毛。     

Taxonomic notes on some species of the Cercospora complex (VI)

The new species Cercosporella pergulariae sp. nov., Pseudocercospora catalpicola sp. nov., Sirosporium rhamnigenum sp. nov., and Spiropes desmodiicola sp. nov. are described and Cercospora commelinicola Chupp is validated. Cercostigmina curta (Syd.) comb, nov., Eriocercosporella vitis-heterophyllae (Henn.) comb, nov., Mycovellosiella lactucae (Henn.) comb, nov., M. trichostemmatis (Henn.) comb, nov., M. tylophorae (Hansf.) comb, nov., Passalora caespitosa (Ellis & Everh.) comb, nov., P. chionanthi (Ellis & Everh.) comb, nov., Prathigada condensata (Ellis & Kellerm.) comb, nov., Pseudocercospora carrii (Barthol.) comb, nov., P. glaucescens (G. Winter) comb, nov., P. pamelae-ellisiae (G.P. Agarwal & N.D. Sharma) comb, nov., Pseudophaeoramularia angolensis (T. Cavalho &O. Mendes) comb, nov., Sporidesmium seminale (Ellis & Everh.) comb, nov., and Stenella praelonga (Syd.) comb. nov. are introduced. Cercospora litseae Henn. is reduced to synonym with Mycovellosiella litseae Meenu et al., and a second collection of Cercosporella indica from Vietnam is recorded.     

Pollen morphology of Lathyrus (Fabaceae) taxa in the Platystylis section from Turkey

In this study, the pollen morphology of 18 wild taxa of Lathyrus L. grown in Turkey: L. pallescens (Bieb.) Koch, L. brachypterus Cel., L. haussknechtii Sirj., L. karsianus P. H. Davis, L. satdaghensis P. H. Davis, L. nivalis Hand.-Mazz, L. atropatanus (Grossh.) Sir., L. armenus (Boiss. and Huet) Sirj., L. cyaneus (Stev.) Koch var. cyaneus, L. cyaneus var. pinnatus?Davis, L. digitatus (Bieb.) Fiori, L. tukhtensis Czecz., L. variabilis (Boiss. and Ky.) Maly, L. spathulatus Cel. L. elongatus (Bornm.) Sirj., L. cilicicus Hayek and Siehe, L. boissieri Sirj., and L. bitlisicus Pe?men was examined by light microscopy and scanning electron microscopy. The pollen grains were 3-zonocolporate, of spheroidal-subprolate-prolate (P/E?=?0.957?C1.252) types, and medium in size. Equatorial view: rectangular or elliptical-obtuse-convex, polar view: circular, triangular or quinquangular-obtuse-convex. The smallest pollen grains belonged to L. elongatus (P?=?36.972/E?=?38.636) and the largest to L. cyaneus var. cyaneus (P?=?46.332/E?=?32.864). The ornamentation was perforate-foveolate or slightly reticulate. Some photographs included in this work were taken using both light microscopy and scanning electron microscopy.     

The Genome Sequence of Leishmania (Leishmania) amazonensis: Functional Annotation and Extended Analysis of Gene Models

We present the sequencing and annotation of the Leishmania (Leishmania) amazonensis genome, an etiological agent of human cutaneous leishmaniasis in the Amazon region of Brazil. L. (L.) amazonensis shares features with Leishmania (L.) mexicana but also exhibits unique characteristics regarding geographical distribution and clinical manifestations of cutaneous lesions (e.g. borderline disseminated cutaneous leishmaniasis). Predicted genes were scored for orthologous gene families and conserved domains in comparison with other human pathogenic Leishmania spp. Carboxypeptidase, aminotransferase, and 3′-nucleotidase genes and ATPase, thioredoxin, and chaperone-related domains were represented more abundantly in L. (L.) amazonensis and L. (L.) mexicana species. Phylogenetic analysis revealed that these two species share groups of amastin surface proteins unique to the genus that could be related to specific features of disease outcomes and host cell interactions. Additionally, we describe a hypothetical hybrid interactome of potentially secreted L. (L.) amazonensis proteins and host proteins under the assumption that parasite factors mimic their mammalian counterparts. The model predicts an interaction between an L. (L.) amazonensis heat-shock protein and mammalian Toll-like receptor 9, which is implicated in important immune responses such as cytokine and nitric oxide production. The analysis presented here represents valuable information for future studies of leishmaniasis pathogenicity and treatment.     

Early colonization with a group of Lactobacilli decreases the risk for allergy at five years of age despite allergic heredity

Background

Microbial deprivation early in life can potentially influence immune mediated disease development such as allergy. The aims of this study were to investigate the influence of parental allergy on the infant gut colonization and associations between infant gut microbiota and allergic disease at five years of age.

Methods and Findings

Fecal samples were collected from 58 infants, with allergic or non-allergic parents respectively, at one and two weeks as well as at one, two and twelve months of life. DNA was extracted from the fecal samples and Real time PCR, using species-specific primers, was used for detection of Bifidobacterium (B.) adolescentis, B. breve, B. bifidum, Clostridium (C.) difficile, a group of Lactobacilli (Lactobacillus (L.) casei, L. paracasei and L. rhamnosus) as well as Staphylococcus (S.) aureus. Infants with non-allergic parents were more frequently colonized by Lactobacilli compared to infants with allergic parents (p = 0.014). However, non-allergic five-year olds acquired Lactobacilli more frequently during their first weeks of life, than their allergic counterparts, irrespectively of parental allergy (p = 0.009, p = 0.028). Further the non-allergic children were colonized with Lactobacilli on more occasions during the first two months of life (p = 0.038). Also, significantly more non-allergic children were colonized with B. bifidum at one week of age than the children allergic at five years (p = 0.048).

Conclusion

In this study we show that heredity for allergy has an impact on the gut microbiota in infants but also that early Lactobacilli (L. casei, L. paracasei, L. rhamnosus) colonization seems to decrease the risk for allergy at five years of age despite allergic heredity.     

Gibberellin-sensitive Suspension Cultures

Suspension cultures were incubated in the presence and absence of gibberellic acid (GA₃) in an attempt to define a new experimental system for study of the molecular action of gibberellins upon growth. Unlike many suspension cultures, an auxin-independent green clone from spinach (Spinacia oleracea L.) and an auxin-dependent line of “Paul's Scarlet” rose (Rosa sp.) were promoted in expansion growth by GA₃ at 10⁻¹¹ to 10⁻⁶ molar. In Rosa the cells also elongated upon GA₃ treatment whereas in Spinacia they remained isodiametric.     

Review of genus Pseudorthocladius Goetghebuer, 1943 (Diptera,Chironomidae) from China

The genus Pseudorthocladius Goetghebuer, 1943 from China, including 12 species, is reviewed. Five new species, P. (P.) binarius sp. n., P. (P.) cylindratus sp. n., P. (P.) digitus sp. n., P. (P.) ovatus sp. n. and P. (P.) paucus sp. n. are described and illustrated as adult males. P. (P.) cristagus Stur & Sæther, 2004, P. (P.) jintutridecima (Sasa, 1996), P. (P.) macrovirgatus Sæther & Sublette, 1983, P. (P.) morsei Sæther & Sublette, 1983, P. (P.) uniserratus Sæther & Sublette, 1983, P. (L.) wingoi Sæther & Sublette, 1983 are newly recorded in Oriental Region. A key to the males of Pseudorthocladius in China is presented.     

Promotive effect of chrysanthemic acids on adventitious root formation in some plants

Adventitious root formation in excised cucumber (Cucumis sativus L.) cotyledons was significantly promoted by (±)-cis-chrysanthemic acid at 0.006–1.8 mM. The effect of (±)-cis-chrysanthemic acid on indole-3-acetic acid (IAA)-induced rooting was additive. Rooting in excised cucumber cotyledons was significantly promoted by several isomers of chrysanthemic acid and sodium (±)-cis-chrysanthemate at 0.18 mM. Rooting in mung bean (Phaseolus radiatus L.) hypocotyls was also stimulated by the sodium salt at 0.06–0.6 mM. Rooting of kidney bean (Phaseolus vulgaris L.) hypocotyls was also clearly enhanced by sodium (±)-cis-chrysanthemate at 0.18–6 mM.     

Comparative morphology of annual shoots in seedlings of five Nothofagus species from Argentinian Patagonia

Morphological features of seedlings were compared between five Nothofagus species from Patagonia: N. antarctica (Forst. F.) Oerst., N. dombeyi (Mirb.) Oerst, N. nervosa (Phil.) Dim. et Mil., N. obliqua (Mirb.) Oerst. and N. pumilio (Poepp. et Endl.) Krasser. Annual shoots of 1- to 3-year-old seedlings collected from natural communities were observed and the distribution of their length and number of internodes analysed. Each seedling produced one shoot each year. Leaves are alternate in all cases except for the cotyledons (which are always opposite) and the first two leaves after the cotyledons (which have, depending on the species, a high or low probability of being opposite to each other). Shoot length and number of internodes depended on the year and on the species concerned. Shoot length was more variable than internode number both within and between species. The probability of shoot apex death after shoot elongation may be high or low depending on the species and the age of the seedling.