New insights about cross-reactive epitopes of six trypanosomatid genera revealed that Crithidia and Leptomonas have antigenic similarity to L. (L.) chagasi

We investigated whether ELISA using crude antigens from insect and plant trypanosomatids, which are non-pathogenic and easily cultivated in large scale, has the same positivity data as Leishmania (Leishmania) chagasi, the etiological agent of human visceral leishmaniasis (VL) or canine leishmaniasis (CanL), or as Trypanosoma cruzi, the etiological agent of Chagas disease (CD). The antigens from Crithidia fasciculata, Crithidia luciliae, and Leptomonas seymouri showed 100% cross-reactivity with VL and CanL samples, with no statistically titers differences from L. (L.) chagasi, however, 34% (17/50) of VL samples revealed higher titers using the insect trypanosomatids than the homologous antigen. On the other hand, antigens from Strigomonas culicis, Angomonas deanei, and Phytomonas serpens showed low cross-reactivity with VL and CanL samples. The sera from patients with American tegumentary leishmaniasis showed low levels of cross-reactivity with all trypanosomatids investigated, even with L. (L) chagasi, without titers dissimilarity among them. These parasites were also worthless as antigen source for detection of CD cases, which required homologous antigens to reach 100% positivity. This study showed, by ELISA, that crude extract of Crithidia and Leptomonas have epitopes similar to L. (L.) chagasi, which supports the idea of using them as antigens source for the serodiagnosis of visceral leishmaniasis.     

Morphologic Differentiation of Viruses beyond the Family Level

Electron microscopy has been instrumental in the identification of viruses by being able to characterize a virus to the family level. There are a few cases where morphologic or morphogenesis factors can be used to differentiate further, to the genus level. These include viruses in the families Poxviridae, Reoviridae, Retroviridae, Herpesviridae, Filoviridae, and Bunyaviridae.     

The life cycle of Ascocotyle (Phagicola) longa (Digenea: Heterophyidae), a causative agent of fish-borne trematodosis

The complete life cycle of the trematode Ascocotyle (Phagicola) longa (Digenea: Heterophyidae) is elucidated by natural observation validated by experimental infections. The natural first intermediate host of A. (P.) longa, an agent of human heterophyiasis in Brazil, is the cochliopid snail Heleobia australis (new first intermediate host). Metacercariae were found encysted in the body musculature, heart, stomach, liver, kidney, spleen, gonads and mesentery of mullets Mugil liza. Hamsters Mesocricetus auratus were experimentally infected with metacercariae of A. (P.) longa obtained from the mullets, and the adults recovered were used to infect the snails H. australis. Rediae and cercariae of A. (P.) longa are described for the first time. The ultrastructure of the tegument of A. (P.) longa shows a change in spination pattern from the cercaria with single-pointed spines to the metacercaria and adult with multipointed, brush-shaped spines. The life cycle of A. (P.) longa is related to estuaries and coastal lagoons where the recruitment of mugilid juveniles occurs. The high prevalence (100%) of A. (P.) longa encysted in the mullets examined within the urban area of Rio de Janeiro indicates the potentially great public health impact of the consumption of raw mullets.     

A second wave of Sonic hedgehog expression during the development of the bat limb

Sonic hedgehog (Shh) plays an integral role in both the anterior-posterior (A-P) patterning and expansion of developing vertebrate limbs through a feedback loop involving Fgfs, Bmps, and Gremlin. In bat limbs A-P patterning and the size of the digital field are unique. The posterior digits of the forelimb are elongated and joined by tissue, whereas the thumb is short. The hindlimb digits often are uniform in length. Here, we reveal novel expression patterns for Shh and its target, Patched 1 (Ptc1), during limb development in two bat species. Early Shh expression in the zone of polarizing activity is wider in the bat forelimb than in the mouse forelimb, correlating with the reported expansion of Fgf8 expression in the apical ectodermal ridge and the early loss of symmetry in the bat forelimb. Later in limb development, Shh and Ptc1 expression is reinitiated in the interdigital tissue. Shh is graded along the A-P axis in forelimb and is expressed uniformly at a lower level across the hindlimb interdigital tissue. We also show that the reported Fgf8 expression in the interdigital tissue precedes the expression of Shh. We propose that the reinitiation of Shh and Fgf8 expression in bat limbs reactivates the Shh-Fgf feedback loop in the interdigital tissue of stage 16 bat embryos. The cell survival and proliferation signals provided by the Shh-Fgf signaling loop probably contribute to the lengthening of the posterior forelimb digits, the survival of the forelimb interdigital webbing, and the extension of the hindlimb digits to a uniform length.     

Comparison of the Virulence Markers of Helicobacter Pylori and their Associated Diseases in Patients from Pakistan and Afghanistan

Background/Aim:

Helicobacter pylori is a Gram-negative bacteria, which is associated with development of gastroduodenal diseases. The prevalence of H. pylori and the virulence markers cytotoxin-associated gene A and E (cagA, cagE) and vacuolating-associated cytotoxin gene (vacA) alleles varies in different parts of the world. H. pylori virulence markers cagA, cagE, and vacA alleles in local and Afghan nationals with H. pylori-associated gastroduodenal diseases were studied.

Patients and Methods:

Two hundred and ten patients with upper gastrointestinal symptoms and positive for H. pylori by the urease test and histology were included. One hundred and nineteen were local nationals and 91 were Afghans. The cagA, cagE, and vacA allelic status was determined by polymerase chain reaction.

Results:

The nonulcer dyspepsia (NUD) was common in the Afghan patients (P = 0.025). In Afghan H. pylori strains, cagA was positive in 14 (82%) with gastric carcinoma (GC) compared with 29 (45%) with NUD (P = 0.006), whereas cagE was positive in 11 (65%) with GC and 4 (67%) with duodenal ulcer (DU) compared with 12 (18%) with NUD (P < 0.001 and 0.021, respectively). The vacA s1a/b1 was positive in 10 (59%) of GC compared with 20 (31%) in NUD (P = 0.033). In Pakistani strains, cagE was positive in 12 (60%) with GC, 7 (58%) with GU, 12 (60%) with DU compared with 11 (16%) with NUD (P < 0.001, 0.004, and < 0.001, respectively). In Pakistani strains, cagA/s1a/m1 was 39 (33%) compared with Afghans in 17 (19%) (P = 0.022). Moderate to severe mucosal inflammation was present in 51 (43%) Pakistani patients compared with 26 (28%) (P = 0.033) in Afghans. It was also associated with grade 1 lymphoid aggregate development in Pakistani patients 67 (56%) compared with 36 (40%) (P = 0.016) in Afghans.

Conclusion:

Distribution of H. pylori virulence marker cagE with DU was similar in Afghan and Pakistan H. pylori strains. Chronic active inflammation was significantly associated with Pakistani H. pylori strains.     

Usefulness of rickettsial PCR assays for the molecular diagnosis of human rickettsioses

Background

The effectiveness of PCR methods to amplify rickettsiae from clinical samples has still not been evaluated. Our aim was to determine the sensitivity and usefulness for Rickettsia species identification by PCR methods, targeting 16S rDNA, htrA, gltA, ompA, and ompB genes for molecular diagnosis of rickettsioses.

Methods

A total of 72 clinical samples (EDTA-blood, skin biopsies and ticks) taken from 52 patients in the early phase of the illness with PCR-confirmed rickettsioses were included. Single [16S rDNA, gltA (5′ end), and htrA genes] and sequential (nested or semi-nested) PCR assays [ompB, gltA (central region) and ompA genes] were performed.

Results

For single-stage PCR assays, the greatest sensitivity (33.3%) was obtained using the gltA (5′ end), while for sequential assays, the most sensitive results were obtained using the ompB assay (83.3%). The highest sensitivity (100%) was achieved using the three sequential PCRs. The ompA PCR method was the most reliable for identifying Rickettsia species, according to clinical features.

Conclusions

PCR-based amplification methods are useful rickettsial diagnostic tools in the early phase of the illness. The three sequential PCR assays here investigated (ompB, gltA and ompA) appear to be useful tools for molecular diagnosis of rickettsioses. ompB PCR assay is effective for primary screening, since it detects a high percentage of positive samples. ompA assay is the most useful method to identify a Rickettsia species in human pathology. Nevertheless, epidemiology, clinical symptoms and the vector involved in the infection have to be taken into account for the diagnosis of rickettsioses.     

First human cases of Leishmania (Viannia) naiffi infection in Ecuador and identification of its suspected vector species

Epidemiological surveillance of leishmaniasis was conducted in a northern Amazonian region of Ecuador, in which cutaneous leishmaniasis cases were recently reported. Sand flies were captured in the military training camp, and the natural infection of sand flies by Leishmania species was examined. Out of 334 female sand flies dissected, the natural infection by flagellates was microscopically detected in 3.9% of Lutzomyia yuilli yuilli and 3.7% of Lutzomyia tortura, and the parasite species were identified as Endotrypanum and Leishmania (Viannia) naiffi, respectively. After the sand fly surveillance, specimens from cutaneous leishmaniasis (CL) patients considered to have acquired the infection in the training camp area were obtained, and the infected parasite species were identified as L. (V.) naiffi. The present study reported first cases of CL caused by L. (V.) naiffi infection in Ecuador. In addition, a high ratio of infection of Lu. tortura by L. (V.) naiffi in the same area strongly suggested that Lu. tortura is responsible for the transmission of L. (V.) naiffi in this area.     

First report of the activity of predatory fungi on Angiostrongylus cantonensis (Nematoda: Angiostrongylidae) first-stage larvae

The nematode Angiostrongylus cantonensis causes eosinophilic meningoencephalitis in humans and thus alternative methods of control should be studied. The objective of this work was to evaluate the predatory capacity of eight fungal isolates of the species Duddingtonia flagrans (AC001, CG768 and CG722), Monacrosporium thaumasium (NF34), M. sinense (SF53) and Arthrobotrys robusta (I31), A. cladodes (CG719) and A. conoides (I40) on first-stage larvae (L₁) of A. cantonensis under laboratory conditions. The treated groups contained 1000 conidia of the fungal isolates and 1000 A. cantonensis L₁ in Petri dishes containing 2% water-agar medium (2% WA). The control group (without fungi) contained only 1000 A. cantonensis L₁ in 2% WA. Evidence of predation was observed at the end of 7 days. Percentage reductions in L₁ were: AC001, 82.8%; CG768, 71.0%; CG722, 72.8%; NF34, 86.7%; SF53, 89.7%; I40, 48.3%; CG719, 84.7%; and I31, 80.4%. No significant difference was observed (p > 0.01) between the actions of the isolates used; however, a difference was noted (p < 0.01) in relation to the control group. The results of the present work, confirm previous reports of the effectiveness of the fungi D. flagrans, M. thaumasium, M. sinense and A. robusta in controlling larvae of potentially zoonotic nematodes, this being the first report on A. cantonensis L₁.     

The isolation and molecular characterization of Leishmania spp. from patients with American tegumentary leishmaniasis in northwest Argentina

American tegumentary leishmaniasis (ATL) is a group of zoonotic diseases caused by kinetoplastid flagellates of the genus Leishmania. A total of 66 patients diagnosed as positive ATL cases from northwest Argentina were included in this study. Leishmania stocks were isolated in vitro and analyzed over promastigote cultures sown on FTA through nested PCR and sequence of cytochrome b (cyt b). The molecular analysis resulted in the incrimination of L. (Viannia) braziliensis as the predominant species in the studied area, identifying two genotypes of L. (V.) braziliensis, 24 cases of Ab-1 cyt b and 41 cases of Ab-2 cyt b. One L. (V.) guyanensis strain was obtained from a traveler from the Brazilian Amazon. The prevalence of different genotypes was in agreement with previous studies, suggesting the necessity for new systems to study the genetic diversity in more detail. Most of the cases typified in this study were registered in the area of Zenta Valley (Orán, Hipólito Yrigoyen, and Pichanal cities), pointing a link between genotype and geographical origin of the sample. Sex and age distribution of the patients indicate that the transmission was predominantly associated with rural areas or rural activities, although the results might not exclude the possibility of peri-urban transmission. This work represents, so far, the largest isolation and molecular characterization of ATL cases in Argentina.     

Anthropophilic mosquitoes and malaria transmission in the eastern foothills of the central highlands of Madagascar

Malaria remains a major public health problem in Madagascar, as it is the first cause of morbidity in health care facilities. Its transmission remains poorly documented. An entomological study was carried out over 1 year (October 2003-September 2004) in Saharevo, a village located at an altitude of 900 m on the eastern edge of the Malagasy central highlands. Mosquitoes were sampled weekly upon landing on human volunteers and in various resting-places. Out of 5515 mosquitoes collected on humans, 3219 (58.4%) were anophelines. Eleven anopheline species were represented, among which Anopheles funestus, Anopheles gambiae, Anopheles arabiensis and Anopheles mascarensis. Out of 677 mosquitoes collected in bedrooms by pyrethrum spray catches and in Muirhead-Thomson pits, 656 (96.9%) were anopheline belonging to these four latter species. The proportion of mosquitoes that fed on human varied according to the resting-places and the mosquito species: 86% of An. funestus resting in bedrooms fed on humans, whereas only 16% of An. funestus and 0% of An. mascarensis resting in pits fed on humans. The proportion of anopheline mosquitoes infected with human Plasmodium was measured by circumsporozoite protein-ELISA: 10/633 An. funestus (1.58%), 1/211 An. gambiae s.l. (0.48%) and 2/268 An. mascarensis (0.75%). The annual entomological inoculation rate (number of bites of infected anophelines per adult) was estimated at 2.78. The transmission was mainly due to An. funestus and only observed in the second half of the rainy season, from February to May. These results are discussed in the context of the current malaria vector control policy in Madagascar.     

Molecular evidence of misidentification of Anopheles minimus as Anopheles fluviatilis in Assam (India)

Anophelesminimus s.l. and Anophelesfluviatilis s.l., two closely related taxa, are reported vectors of malaria in Assam state of India. We determined the DNA sequences of morphologically identified A. minimus s.l. and A. fluviatilis s.l. collected from the Kamrup district in Assam, for two rDNA loci—internal transcribed spacer 2 (ITS2) and D3 domain of 28S rDNA (28S-D3). Analysis of rDNA data revealed that the sequences of both the morphologically identified A. minimus s.l. and A. fluviatilis s.l. from Assam are identical, homologous to the sequences of A. minimus s.s. (former species A) and different from that of all the reported members of the Fluviatilis Complex (species S, T and U). This indicates that A. fluviatilis s.l. being reported in Kamrup district, Assam, in low density, mostly during January to April, is actually a hypermelanic and seasonal variant of A. minimus. It was also found that the banding pattern on chromosome arm 2 (which bears species-diagnostic inversions for the Fluviatilis Complex) of A. minimus and of A. fluviatilis s.l. from Assam is homosequential with A. fluviatilis species U suggesting that probably previously described A. fluviatilis U from Assam were also A. minimus.     

Comparison of the effects of extracts from three Vitex plant species on Anopheles gambiae s.s. (Diptera: Culicidae) larvae

Acetone and methanol extracts of different parts of three Vitex species (leaves and stem bark of Vitex trifolia, leaves, stem bark and root bark of Vitex schiliebenii and stem and root bark of Vitex payos) were evaluated for their potential to control Anopheles gambiae Giles s.s. larvae (Diptera: Culicidae). The extracts gave different levels and rate of mortality of the larvae. Some (methanol extract of V. trifolia leaves, acetone extracts of stem bark and leaves of V. schiliebenii, acetone extract of root bark of V. payos) caused 100% mortality at 100 ppm in 72 h, with those of V. schiliebenii and V. payos showing faster rate of mortality (LT₅₀ = 8 h) than that of V. trifolia (LT₅₀ = 14 h). At lower doses of these extracts (≤50 ppm), most of the larvae failed to transform to normal pupae but gave larval–pupal intermediates between 4 and 14 days of exposure. Some pupated normally but the adults that emerged appeared to be weak and died within 48 h. Extracts of the stem bark of V. payos showed interesting effects on the larvae. Initially, the larvae were relatively hyperactive compared to those in control treatments. Later, the ones that did not transform to larval–pupal intermediates became stretched and inactive and died and floated in clusters on the surface. These observations suggest some interesting growth-disrupting constituents in the plants, with possible application in the practical control of mosquito larvae in aquatic ecosystems.     

Ethnicity association of Helicobacter pylori virulence genotype and metronidazole susceptibility

AIM:To characterise the cag pathogenicity island in Helicobacter pylori(H.pylori) isolates by analysing the strains’ vacA alleles and metronidazole susceptibilities in light of patient ethnicity and clinical outcome.METHODS:Ninety-five H.pylori clinical isolates obtained from patients with dyspepsia living in Malaysia were analysed in this study.Six genes in the cagPAI region(cagE,cagM,cagT,cag13,cag10 and cag67) andvacA alleles of theH.pylori isolates were identified by polymerase chain reaction.The isolates’ metronidazole susceptibility was also determined using the E-test method,and the resistant gene was characterised by sequencing.RESULTS:More than 90% of the tested isolates had at least one gene in the cagPAI region,and cag67 was predominantly detected in the strains isolated from the Chinese patients,compared with the Malay and Indian patients(P < 0.0001).The majority of the isolates(88%) exhibited partial deletion(rearrangement) in the cagPAI region,with nineteen different patterns observed.Strains with intact or deleted cagPAI regions were detected in 3.2% and 8.4% of isolates,respectively.The prevalence of vacA s1m1 was significantly higher in the Malay and Indian isolates,whereas the isolates from the Chinese patients were predominantly genotyped as vacA s1m2(P = 0.018).Additionally,the isolates from the Chinese patients were more sensitive to metronidazole than the isolates from the Malay and Indian patients(P = 0.047).Although we attempted to relate the cagPAI genotypes,vacA alleles and metronidazole susceptibilities to disease outcome,no association was observed.The vacA alleles were distributed evenly among the strains with intact,partially deleted or deleted cagPAI regions.Interestingly,the strains exhibiting an intact cagPAI region were sensitive to metronidazole,whereas the strains with a deleted cagPAI were more resistant.CONCLUSION:Successful colonisation by different H.pylori genotypes is dependent on the host’s genetic makeup and may play an important role in the clinical outcome.     

Genetic suppression of the circadian Clock mutation by the melatonin biosynthesis pathway

Most laboratory mouse strains including C57BL/6J do not produce detectable levels of pineal melatonin owing to deficits in enzymatic activity of arylalkylamine N-acetyltransferase (AANAT) and N-acetylserotonin O-methyl transferase (ASMT), two enzymes necessary for melatonin biosynthesis. Here we report that alleles segregating at these two loci in C3H/HeJ mice, an inbred strain producing melatonin, suppress the circadian period-lengthening effect of the Clock mutation. Through a functional mapping approach, we localize mouse Asmt to chromosome X and show that it, and the Aanat locus on chromosome 11, are significantly associated with pineal melatonin levels. Treatment of suprachiasmatic nucleus (SCN) explant cultures from Period2^Luciferase (Per2^Luc) Clock/+ reporter mice with melatonin, or the melatonin agonist, ramelteon, phenocopies the genetic suppression of the Clock mutant phenotype observed in living animals. These results demonstrate that melatonin suppresses the Clock/+ mutant phenotype and interacts with Clock to affect the mammalian circadian system.     

Birth of a new gene on the Y chromosome of Drosophila melanogaster

Contrary to the pattern seen in mammalian sex chromosomes, where most Y-linked genes have X-linked homologs, the Drosophila X and Y chromosomes appear to be unrelated. Most of the Y-linked genes have autosomal paralogs, so autosome-to-Y transposition must be the main source of Drosophila Y-linked genes. Here we show how these genes were acquired. We found a previously unidentified gene (flagrante delicto Y, FDY) that originated from a recent duplication of the autosomal gene vig2 to the Y chromosome of Drosophila melanogaster. Four contiguous genes were duplicated along with vig2, but they became pseudogenes through the accumulation of deletions and transposable element insertions, whereas FDY remained functional, acquired testis-specific expression, and now accounts for ∼20% of the vig2-like mRNA in testis. FDY is absent in the closest relatives of D. melanogaster, and DNA sequence divergence indicates that the duplication to the Y chromosome occurred ∼2 million years ago. Thus, FDY provides a snapshot of the early stages of the establishment of a Y-linked gene and demonstrates how the Drosophila Y has been accumulating autosomal genes.The mammalian Y chromosome has the lowest gene density of any chromosome, and most of its genes have a homolog on the X. This pattern is consistent with the mammalian sex chromosomes having originated from an ordinary pair of chromosomes, followed by massive gene loss from the Y (1–4). In contrast, the closest homologs of all Drosophila melanogaster Y-linked protein-encoding genes are autosomal, strongly suggesting that its Y chromosome has been acquiring genes from the autosomes (5–7). Indeed, gene gains, and not gene losses, have played the major role in shaping the gene content of the Drosophila Y, at least in the last ∼63 million years (My) (8, 9). Hence, the Drosophila Y chromosome seems to be evolving noncanonically (10) and is an ideal model to investigate the dynamics of gene gain on a nonrecombining Y chromosome.The Drosophila Y chromosome has long been known to contain genes essential for male fertility (11, 12). Due to its heterochromatic state, progress in the molecular identification of the Y-linked single-copy genes has been slow. male fertility factor kl5 (kl-5), the first single-copy gene identified, was found serendipitously; it encodes a motor protein (dynein heavy chain) required for flagellar beating (13). More recently, a combination of computational and experimental methods identified 11 single-copy Y-linked genes among the unmapped sequence scaffolds produced by the Drosophila Genome Project (5–7). These genes have two striking features: (i) their closest paralogs are autosomal and not X linked, and (ii) they have male-specific functions, such as the beating of sperm flagella reported for the kl-5 gene (14). The most likely explanation for this pattern is that Y-linked genes were acquired from the autosomes and have been retained because they confer a specific fitness advantage to their carriers. An autosomal origin has previously been reported for a few Y-linked genes in humans and a repetitive gene on the Drosophila Y (4, 15). However, unequivocal evidence of the autosomal origin of Drosophila Y-linked genes, and of the specific mechanism that originated them, is lacking due to their antiquity. The 11 known single-copy genes (kl-2, kl-3, kl-5, ARY, WDY, PRY, Pp1-Y1, Pp1-Y2, Ppr-Y, ORY, and CCY) represent ancient duplications, with amino acid identities to the putative ancestors ranging from 30% to 74%, and poor (if any) alignment at the nucleotide level. Most of them have introns in conserved positions compared with their autosomal paralogs, ruling out retrotransposition and suggesting DNA-based duplication as the mechanism. The original size of these putative duplications is unknown, because the similarity between autosomal and Y-linked regions is restricted to one gene in each case. Flanking sequences and contiguous genes either were not duplicated or were subsequently mutated and deleted beyond recognition.Here we describe flagrante delicto Y (FDY), a single copy Y-linked gene present only in D. melanogaster, and which is 98% identical at the nucleotide level to the autosomal gene vig2. Because its origin is very recent (it occurred after the split between D. melanogaster and Drosophila simulans, ∼4 Mya), it was possible to demonstrate that FDY arose from a DNA-based duplication of chromosome 3R to the Y: the duplicated segment spans 11 kb of autosomal sequence and includes five contiguous genes (vig2, Mocs2, CG42503, Clbn, and Bili); the last four genes became pseudogenes by rapid accumulation of deletions, point mutations, and transposable element insertions or by lack of expression. Thus, FDY unequivocally demonstrates that the Drosophila Y has acquired genes from autosomes. Several Y-linked genes such as kl-2, kl-3, and PRY are shared by distant Drosophila species that diverged ∼60 Mya, implying ancient acquisitions. FDY dates the more recent acquisition to ∼2 My, and hence strongly suggests that Drosophila Y has been continuously acquiring autosomal genes.     

Laboratory and field efficacy of Pedalium murex and predatory copepod,Mesocyclops longisetus on rural malaria vector,Anopheles culicifacies

Objective

To test the potentiality of the leaf extract of Pedalium murex (P. murex) and predatory copepod Mesocyclops longisetus (M. longisetus) in individual and combination in controlling the rural malarial vector, Anopheles culicifacies (An. culicifacies) in laboratory and field studies.

Methods

P. murex leaves were collected from in and around Erode, Tamilnadu, India. The active compounds were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus. Laboratory studies on larvicidal and pupicidal effects of methanolic extract of P. murex tested against the rural malarial vector, An. culicifacies were significant.

Results

Evaluated lethal concentrations (LC₅₀) of P. murex extract were 2.68, 3.60, 4.50, 6.44 and 7.60 mg/L for I, II, III, IV and pupae of An. culicifacies, respectively. Predatory copepod, M. longisetus was examined for their predatory efficacy against the malarial vector, An. culicifacies. M. longisetus showed effective predation on the early instar (47% and 36% on I and II instar) when compared with the later ones (3% and 1% on III and IV instar). Predatory efficacy of M. longisetus was increased (70% and 45% on I and II instar) when the application was along with the P. murex extract.

Conclusions

Predator survival test showed that the methanolic extract of P. murex is non-toxic to the predatory copepod, M. longisetus. Experiments were also conducted to evaluate the efficacy of methanolic extract of P. murex and M. longisetus in the direct breeding sites (paddy fields) of An. culicifacies. Reduction in larval density was very high and sustained for a long time in combined treatment of P. murex and M. longisetus.     

Zoonotic infections in communities of the James Bay Cree territory: An overview of seroprevalence

The Cree communities of James Bay are at risk for contracting infectious diseases transmitted by wildlife. Data from serological testing for a range of zoonotic infections performed in the general population (six communities), or trappers and their spouses (one community), were abstracted from four population-based studies conducted in Cree territory (Quebec) between 2005 and 2009. Evidence of exposure to Trichinella species, Toxoplasma gondii, Toxocara canis, Echinococcus granulosus, Leptospira species, Coxiella burnetii and Francisella tularensis was verified in all communities, whereas antibodies against Sin Nombre virus and California serogroup viruses (Jamestown Canyon and snowshoe hare viruses) were evaluated in three and six communities, respectively. Seroprevalence varied widely among communities: snowshoe hare virus (1% to 42%), F tularensis (14% to 37%), Leptospira species (10% to 27%), Jamestown Canyon virus (9% to 24%), C burnetii (0% to 18%), T gondii (4% to 12%), T canis (0% to 10%), E granulosus (0% to 4%) and Trichinella species (0% to 1%). No subject had serological evidence of Sin Nombre virus exposure. These data suggest that large proportions of the Cree population have been exposed to at least one of the targeted zoonotic agents. The Cree population, particularly those most heavily exposed to fauna, as well as the medical staff living in these regions, should be aware of these diseases. Greater awareness would not only help to decrease exposures but would also increase the chance of appropriate diagnostic testing.     

A hyperactive quantitative trait locus allele of Arabidopsis BRX contributes to natural variation in root growth vigor

Quantitative trait loci analysis of natural Arabidopsis thaliana accessions is increasingly exploited for gene isolation. However, to date this has mostly revealed deleterious mutations. Among them, a loss-of-function allele identified the root growth regulator BREVIS RADIX (BRX). Here we present evidence that BRX and the paralogous BRX-LIKE (BRXL) genes are under selective constraint in monocotyledons as well as dicotyledons. Unexpectedly, however, whereas none of the Arabidopsis orthologs except AtBRXL1 could complement brx null mutants when expressed constitutively, nearly all monocotyledon BRXLs tested could. Thus, BRXL proteins seem to be more diversified in dicotyledons than in monocotyledons. This functional diversification was correlated with accelerated rates of sequence divergence in the N-terminal regions. Population genetic analyses of 30 haplotypes are suggestive of an adaptive role of AtBRX and AtBRXL1. In two accessions, Lc-0 and Lov-5, seven amino acids are deleted in the variable region between the highly conserved C-terminal, so-called BRX domains. Genotyping of 42 additional accessions also found this deletion in Kz-1, Pu2-7, and Ws-0. In segregating recombinant inbred lines, the Lc-0 allele (AtBRX^Lc-0) conferred significantly enhanced root growth. Moreover, when constitutively expressed in the same regulatory context, AtBRX^Lc-0 complemented brx mutants more efficiently than an allele without deletion. The same was observed for AtBRXL1, which compared with AtBRX carries a 13 amino acid deletion that encompasses the deletion found in AtBRX^Lc-0. Thus, the AtBRX^Lc-0 allele seems to contribute to natural variation in root growth vigor and provides a rare example of an experimentally confirmed, hyperactive allelic variant.