scholarly journals Morphological and molecular differentiation between Culicoides oxystoma and Culicoides kingi (Diptera: Ceratopogonidae) in Tunisia

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Darine Slama ◽  
Rihab Baraket ◽  
Latifa Remadi ◽  
Emna Chaker ◽  
Hamouda Babba

Abstract Background Culicoides kingi and Culicoides oxystoma belong to the Schultzei group of biting midges. These two species are vectors of disease in livestock of economic importance. As described in the literature, morphological identification for discrimination between them is still unclear. However, species-specific identification is necessary to solve taxonomic challenges between species and to understand their roles in disease transmission and epidemiology. This study aims to develop accurate tools to discriminate C. oxystoma from C. kingi using traditional morphometry and polymerase chain reaction-restriction fragment length polymorphism (PCR RFLP) assays for use in developing countries. Methods Specimens were collected from the region of Kairouan in central Tunisia. A total of 446 C. oxystoma/C. kingi individuals were identified using traditional morphometric analyses combined with PCR–RFLP of the cytochrome c oxidase subunit I gene. Thirteen morphometric measurements were performed from the head, wings, and abdomen of slide-mounted specimens, and six ratios were calculated between these measurements. Multivariate analyses of the morphometric measurements were explored to identify which variables could lead to accurate species identification. Results Four variables, namely antennae, wings, spermathecae, and palpus length, were suitable morphometric characteristics to differentiate between the species. Digestion with the SspI restriction enzyme of the PCR product led to good discriminative ability. Molecular procedures and phylogenetic analysis confirmed the efficiency of this simple and rapid PCR–RFLP method. Conclusions This study highlights for the first time in Tunisia the presence of C. oxystoma and its discrimination from C. kingi using abdominal measurements and the PCR–RFLP method. This approach could be applied in future epidemiological studies at the national and international levels. Graphical Abstract

2010 ◽  
Vol 100 (5) ◽  
pp. 551-558 ◽  
Author(s):  
S. Bertin ◽  
L. Picciau ◽  
Z. Ács ◽  
A. Alma ◽  
D. Bosco

AbstractThe cixiid species Reptalus quinquecostatus, R. cuspidatus, R. panzeri and R. melanochaetus are widely distributed in Europe and are receiving growing attention because of their potential role as phytoplasma vectors. Identifying the Reptalus species is restricted to a few specialist entomologists and relies on the morphology of the male genitalia, hampering the identification of juveniles and females. This study provides the tools for species discrimination by integrating the morphological description, which is primarily for the genus identification, with new molecular assays, based on both ribosomal and mitochondrial DNA. PCR-RFLP assays carried out on the mitochondrial cytochrome oxidase I gene (COI) with AluI provided species-specific profiles for the four Reptalus species. Amplification of a ribosomal internal transcribed spacer (ITS2) region produced species-specific fragments of different sizes for R. quinquecostatus, R. melanochaetus, R. cuspidatus and R. panzeri. The digestion of the ITS2 PCR product with TaqI allowed the discrimination of these latter two species. This molecular identification key ensures reliable results and can be successfully applied not only to adults, but also to the nymphs feeding on the roots. The identification of the nymphs (i) extends the collection period of these monovoltine species to the whole year (adults are present for a short summer period) and (ii) allows the unambiguous identification of their actual host plants because nymphs are steady on the root system while adults tend to disperse onto other plants. Fast and reliable identification of the Reptalus species provides useful help in monitoring activities and, therefore, in designing rational control strategies to protect crops from phytoplasma infection.


1999 ◽  
Vol 77 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Ursula Eberhardt ◽  
Lutz Walter ◽  
Ingrid Kottke

Among the mycorrhizal types of spruce, Tylospora-type mycorrhizae are the most constant and abundant. Two species of the genus Tylospora occur in Europe, Tylospora fibrillosa and Tylospora asterophora. Mycorrhizae of T. asterophora are described in detail for the first time. Sequences of the internal transcribed spacer (ITS) of the ribosomal genes were obtained from T. fibrillosa and T. asterophora mycorrhizae, sporocarps, and cultured mycelium. Discrimination and identification of the two species by ITS polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) are discussed in the light of inter- and intra-specific variability. Species-specific PCR primers were designed to distinguish both species. Molecular screening of Tylospora-type mycorrhizae from field material led to unambiguous results, whereas morphological identification is likely to fail because of great similarity even at the microscopic level.Key words: Tylospora asterophora, Tylospora fibrillosa, ectomycorrhizae, taxon specific primers (TSOPs), ITS sequences.


2006 ◽  
Vol 64 (2) ◽  
pp. 328-331 ◽  
Author(s):  
Shiro Itoi ◽  
Takashi Saito ◽  
Mai Shimojo ◽  
Sayaka Washio ◽  
Haruo Sugita

Abstract Itoi, S., Saito, T., Shimojo, M., Washio, S., and Sugita, H. 2007. Identification of Girella punctata and G. leonina by PCR-RFLP analysis. – ICES Journal of Marine Science, 64: 328–331. Two Girella species, Girella punctata and G. leonina, are sympatric sister species with an extensive overlap in their respective distributions on shallow rocky reefs from Hong Kong to the south of the Japanese Islands. Juveniles of the two species cannot be discriminated easily on the basis of external characters. In this study, after morphological identification of the species, sequencing analysis was carried out for the partial 16S ribosomal RNA gene and for the D-loop region in mitochondrial DNA. A total of 109 specimens was examined. Restriction site mapping of the sequences suggested that the electrophoretic patterns of polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) analysis of the gene products would produce a species-specific banding pattern. Subsequently, the PCR-RFLP analysis showed that the method was as effective for separating the two morphologically similar species of the genus Girella as the sequencing analysis.


2015 ◽  
Vol 31 (1) ◽  
pp. 101-108 ◽  
Author(s):  
S.M. Abdel-Rahman ◽  
A.M. Elmaghraby ◽  
A.S. Haggag

PCR-RFLP technique was developed for identification and differentiation among chicken?s, duck?s, quail?s, rabbit?s and turkey's meat. DNA from small amount of muscles (0.05 g) was extracted and a region of mitochondrial DNA (cytochrome-b gene) in chicken, duck, quail, rabbit and turkey was amplified by PCR. Fragment length of the PCR product was 371 bp in chicken, 374 bp in duck and rabbit and 377 bp in both quail and turkey. Six nucleotides different makes it difficult to differentiate among these five species-specific meat. For differentiation, three different restriction enzymes (DdeI, MspI and TaqI) were used to digest the PCR products. Restriction analysis showed difference among chicken?s, duck?s, quail?s, rabbit?s and turkey's meat. Where, DdeI yielded two fragments (291 and 83 bp) only in rabbit?s meat. MspI yielded three fragments (221, 85 and 65 bp) in chicken?s meat and two fragments (290 and 87 bp) in both quail?s and turkey's meat. TaqI yielded three fragments (146, 134 and 94 bp) in duck?s meat and two fragments (226 and 151 bp) in quail?s meat. The use of Cytb- PCR-RFLP assay allowed a direct and fast authentication and differentiation among chicken?s, duck?s, quail?s, rabbit?s and turkey's meat.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1358
Author(s):  
Brigitte Sigrist ◽  
Jessica Geers ◽  
Sarah Albini ◽  
Dennis Rubbenstroth ◽  
Nina Wolfrum

Avian bornaviruses were first described in 2008 as the causative agents of proventricular dilatation disease (PDD) in parrots and their relatives (Psittaciformes). To date, 15 genetically highly diverse avian bornaviruses covering at least five viral species have been discovered in different bird orders. Currently, the primary diagnostic tool is the detection of viral RNA by conventional or real-time RT-PCR (rRT-PCR). One of the drawbacks of this is the usage of either specific assays, allowing the detection of one particular virus, or of assays with a broad detection spectrum, which, however, do not allow for the simultaneous specification of the detected virus. To facilitate the simultaneous detection and specification of avian bornaviruses, a multiplex real-time RT-PCR assay was developed. Whole-genome sequences of various bornaviruses were aligned. Primers were designed to recognize conserved regions within the overlapping X/P gene and probes were selected to detect virus species-specific regions within the target region. The optimization of the assay resulted in the sensitive and specific detection of bornaviruses of Psittaciformes, Passeriformes, and aquatic birds. Finally, the new rRT-PCR was successfully employed to detect avian bornaviruses in field samples from various avian species. This assay will serve as powerful tool in epidemiological studies and will improve avian bornavirus detection.


2018 ◽  
Vol 57 (5) ◽  
pp. 643-648
Author(s):  
Milena Kordalewska ◽  
Joanna Kalita ◽  
Zofia Bakuła ◽  
Anna Brillowska-Dąbrowska ◽  
Tomasz Jagielski

2017 ◽  
Vol 107 (0) ◽  
Author(s):  
Andrea A. F. Mourão ◽  
Diogo Freitas-Souza ◽  
Diogo T. Hashimoto ◽  
Daniela C. Ferreira ◽  
Fernanda D. do Prado ◽  
...  

ABSTRACT The hybridization is a widely-discussed issue in several studies with fish species. For some authors, hybridization may be related with diversification and speciation of several groups, or also with the extinction of populations or species. Difficulties to differentiate species and hybrids may be a problem to correctly apply a management of wild species, because hybrid lineages, especially the advanced ones, may resemble the parental species. The genus Cichla Bloch & Schneider, 1801 constitutes an interesting experimental model, considering that hybridization and taxonomic uncertainties hinder a correct identification. Considering these problems, in this study, we developed genetic methodologies and applied meristic and morphometric approaches in wild samples in order to identify species and for test a possible hybridization between Cichla kelberi Kullander & Ferreira, 2006 and Cichla piquiti Kullander & Ferreira, 2006. For this, C. kelberi, C. piquiti and potential hybrid ( carijó) individuals were collected in Paraná and Tietê rivers (SP, Brazil). For meristic and morphometric methods, the individuals were analyzed using the statistical software Pcord 5:31, while for molecular methods, primers for PCR-multiplex were designed and enzyme for PCR-RFLP were selected, under the species-specific nucleotide. All results indicated that the carijó is not an interspecific hybrid, because it presented identical genetic pattern and morphology closed to C. piquiti. Thus, we propose that carijó is a C. piquiti morphotype. In addition, this study promotes a new molecular tool that could be used in future research, monitoring and management programs of the genus Cichla.


2021 ◽  
Vol 23 (11) ◽  
pp. 330-343
Author(s):  
Yogendra Shrestha ◽  
◽  
Jeet Bahadur Moktan ◽  
Renukaradhya Chitti ◽  
Shiv Kumar Yadav ◽  
...  

Background: Many variants detected after Wuhan-Hu-1 reference which were able to develop the resistance against the neutralizing antibodies induced by vaccine and may cause false negative results in diagnostic test. Novel variant B1.617 was detected in India and the Covid-19 cases hiked to its maximum; forcing the government towards approving a new vaccine for restricted use in emergency situation to cover a maximum population. Aims: This review looks at the efficacy, safety, and economical aspects of vaccines that have been authorized in India. Materials and methods: Wide-ranging assessment and analysis of accessible resources on online database. Results: The rAd26-s & rAd5-s demonstrate high efficacy as well as safety, followed by BBV152 and AZD1222. Various combinations of the vaccines with different platforms or vectors may induce wide range of immunity than a specific one. As per economical aspect, AZD1222 is more economical than the other two currently approved in India. Conclusion: There is a lack of clear end point to measure efficacy of the vaccine so the epidemiological studies with huge number of populations is required which may predict the perfect endpoint for efficacy measurement. Until then, inoculation with locally accessible vaccines and self-awareness about disease transmission prevention are the main options for reducing fatalities, protecting the health-care system, and eventually disease control.


2018 ◽  
Vol 11 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Emily R. Vana ◽  
Elizabeth R. Wrobel ◽  
Travis E. Wilcoxen

Congregation of individuals at high densities is known to increase disease transmission and bird-feeding activities are specifically aimed at attracting many birds to a single location. We surveyed nine potential host species for evidence of infection by each Mycoplasma gallisepticum (MG) and Avipoxvirus, or avian pox. We also examined differences in pathogen exposure at sites with bird feeders and sites without bird feeders. Finally, we compared prevalence of birds with antibodies against MG and avian pox to those that showed physical signs of infection. To test for pathogen exposure, we used indirect enzyme-linked immunosorbent assays. We found species-specific disease dynamics, as House Finches Haemorhous mexicanus had a significantly greater likelihood of having antibodies against MG than any other species. Birds at sites with feeders were more likely to have antibodies against MG. Birds at sites with feeders were no more likely to have antibodies against avian pox, but seroprevalence of avian pox did differ significantly among species. Overall, our findings suggest differential exposure and immune responses to each pathogen among species and that feeders increase the exposure of individuals to MG but not to avian pox, offering valuable new insights into the role of bird feeding activities in disease transmission among birds.


1998 ◽  
Vol 49 (5) ◽  
pp. 383 ◽  
Author(s):  
B. H. Innes ◽  
P. M. Grewe ◽  
R. D. Ward

A genetic test was developed for the identification of the six species of billfish found in Australian waters (black marlin, Indo–Pacific blue marlin, striped marlin, Indo–Pacific sailfish, shortbill spearfish and broadbill swordfish). The test was based on the PCR–RFLP analysis of a 1400 bp region of the mitochondrial DNA molecule, the d-loop, using four restriction enzymes (Hinf I, Rsa I and Sau3A I andTaq I). A total of 33 composite haplotypes were observed among 160 fish; all were species-specific. Three of the species—black marlin, striped marlin and broadbill swordfish—showed sufficient intra-specific variation to be useful in population structure analyses.


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