Analysis of helminth genetic data: comparative examples with Haemonchus contortus isozymes using exact tests or resampling procedures

Bentounsi, B.; Cabaret, Jacques

doi:10.1007/s004360050645

Cited by 11 publications

(5 citation statements)

References 8 publications

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“…STR repeat frequencies can be obtained from the corresponding author on request. Thereafter, the CLUMP, 49 CHECKHET, 50 GENEPOP, 51 POWERMARKER 52 and STRUCTURE 53 software packages were used to investigate for population stratification both between as well as within the patient and the control sample.…”

Section: Genomic Controlmentioning

confidence: 99%

A neuronal nitric oxide synthase (NOS-I) haplotype associated with schizophrenia modifies prefrontal cortex function

et al. 2006

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Nitric oxide (NO) is a gaseous neurotransmitter thought to play important roles in several behavioral domains. On a neurobiological level, NO acts as the second messenger of the Nmethyl-D-aspartate receptor and interacts with both the dopaminergic as well as the serotonergic system. Thus, NO is a promising candidate molecule in the pathogenesis of endogenous psychoses and a potential target in their treatment. Furthermore, the chromosomal locus of the gene for the NO-producing enzyme NOS-I, 12q24.2, represents a major linkage hot spot for schizophrenic and bipolar disorder. To investigate whether the gene encoding NOS-I (NOS1) conveys to the genetic risk for those diseases, five NOS1 polymorphisms as well as a NOS1 mini-haplotype, consisting of two functional polymorphisms located in the transcriptional control region of NOS1, were examined in 195 chronic schizophrenic, 72 bipolar-I patients and 286 controls. Single-marker association analysis showed that the exon 1c promoter polymorphism was linked to schizophrenia (SCZ), whereas synonymous coding region polymorphisms were not associated with disease. Long promoter alleles of the repeat polymorphism were associated with less severe psychopathology. Analysis of the mini-haplotype also revealed a significant association with SCZ. Mutational screening did not detect novel exonic polymorphisms in patients, suggesting that regulatory rather than coding variants convey the genetic risk on psychosis. Finally, promoter polymorphisms impacted on prefrontal functioning as assessed by neuropsychological testing and electrophysiological parameters elicited by a Go-Nogo paradigm in 48 patients (continuous performance test). Collectively these findings suggest that regulatory polymorphisms of NOS1 contribute to the genetic risk for SCZ, and modulate prefrontal brain functioning.

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Section: Genomic Controlmentioning

confidence: 99%

A neuronal nitric oxide synthase (NOS-I) haplotype associated with schizophrenia modifies prefrontal cortex function

et al. 2006

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“…In particular, studies on wild animals (Bentousi & Cabaret, 1999; Braisher et al , 2004) identified different host specificity, local adaptation or other factors, which in turn could influence nematode spreading, interspecific transmission and management. The study of parasite population genetics (Criscione et al , 2005; Troell et al , 2006) has recently been supported by the development of a variety of molecular marker analyses.…”

Section: Introductionmentioning

confidence: 99%

Genetic variability ofHaemonchus contortus(Nematoda: Trichostrongyloidea) in alpine ruminant host species

et al. 2009

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Genetic variability of the ovine parasite Haemonchus contortus from the Alpine area was investigated using mitochondrial DNA (nd4 gene), internal transcribed spacers 1 and 2 and microsatellites, in order to assess whether cross-transmission between domestic and wild ruminants occurs. The dataset was composed of 78 individual adult male H. contortus collected from chamois (Rupicapra r. rupicapra), roe deer (Capreolus capreolus), alpine ibex (Capra ibex ibex), domestic goat (Capra hircus) and sheep (Ovis aries) from different alpine areas. The data obtained show low host specificity and high genetic variation within H. contortus populations. The analyses indicate the presence of two mitochondrial haplotype clusters among host species and the absence of cryptic parasite species, confirming H. contortus as a generalist nematode and suggesting that parasite transmission between populations of domestic and wild ruminants normally occurs.

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“…Over the years, numerous 'first-generation' molecular and biochemical methods have been developed for identifying Haemonchus species and for examining drug-resistant genotypes. Restriction enzyme digestion followed by agarose gel electrophoresis (Beh et al, 1989), Southern blotting (Roos et al, 1990;Zarlenga et al, 1994), repetitive DNA hybridization probes in conjunction with Southern blots or dot blots (Christensen et al, 1994a,b), and isoenzyme banding profiles (Bentounsi and Cabaret, 1999;Echevarria et al, 1992;Knox and Jones, 1992) were among the most popular examples of first-generation technologies. Sensitivity and specificity, however, were key issues that prompted the transition to PCR-based assays for developing more advanced tests.…”

Section: Molecular Methods For Identifying Haemonchus 31 Haemonchus mentioning

confidence: 99%

The Identification of Haemonchus Species and Diagnosis of Haemonchosis

Zarlenga

Hoberg

Tuo

2016

Haemonchus Contortus and Haemonchosis – Past, Present and Future Trends

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Diagnosis is often equated with identification or detection when discussing parasitic diseases. Unfortunately, these are not necessarily mutually exclusive activities; diseases and infections are generally diagnosed and organisms are identified. Diagnosis is commonly predicated upon some clinical signs; in an effort to determine the causative agent, identification of genera and species is subsequently performed. Both identification and diagnosis play critical roles in managing an infection, and involve the interplay of direct and indirect methods of detection, particularly in light of the complex and expanding problem of drug-resistance in parasites. Accurate and authoritative identification that is cost- and time-effective, based on structural and molecular attributes of specimens, provides a foundation for defining parasite diversity and changing patterns of geographical distribution, host association and emergence of disease. Most techniques developed thus far have been grounded in assumptions based on strict host associations between Haemonchus contortus and small ruminants, that is, sheep and goats, and between Haemonchus placei and bovids. Current research and increasing empirical evidence of natural infections in the field demonstrates that this assumption misrepresents the host associations for these species of Haemonchus. Furthermore, the capacity of H. contortus to utilize a considerably broad spectrum of ungulate hosts is reflected in our understanding of the role of anthropogenic forcing, the 'breakdown' of ecological isolation, global introduction and host switching as determinants of distribution. Nuanced insights about distribution, host association and epidemiology have emerged over the past 30years, coincidently with the development of increasingly robust means for parasite identification. In this review and for the sake of argument, we would like to delineate the diagnosis of haemonchosis from the identification of the specific pathogen. As a foundation for exploring host and parasite biology, we will examine the evolution of methods for distinguishing H. contortus from other common gastrointestinal nematodes of agriculturally significant and free-ranging wild ruminants using morphological, molecular and/or immunological methods for studies at the species and genus levels.

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Analysis of helminth genetic data: comparative examples with Haemonchus contortus isozymes using exact tests or resampling procedures

Cited by 11 publications

References 8 publications

A neuronal nitric oxide synthase (NOS-I) haplotype associated with schizophrenia modifies prefrontal cortex function

A neuronal nitric oxide synthase (NOS-I) haplotype associated with schizophrenia modifies prefrontal cortex function

Genetic variability ofHaemonchus contortus(Nematoda: Trichostrongyloidea) in alpine ruminant host species

The Identification of Haemonchus Species and Diagnosis of Haemonchosis

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