Molecular and morphological characterization ofEchinococcusin cervids from North America

Parasitology ◽  
2005 ◽  
Vol 132 (3) ◽  
pp. 439-447 ◽  
Author(s):  
R. C. A. THOMPSON ◽  
A. C. BOXELL ◽  
B. J. RALSTON ◽  
C. C. CONSTANTINE ◽  
R. P. HOBBS ◽  
...  
Keyword(s):  
North America ◽  
Molecular Genetic ◽  
Taxonomic Status ◽  
Morphological Characterization ◽  
Final Decision ◽  
Molecular Tools ◽  
Intermediate Hosts ◽  
The Status ◽  
Genetic Techniques

Many issues concerning the taxonomy ofEchinococcushave been resolved in recent years with the application of molecular tools. However, the status ofEchinococcusmaintained in transmission cycles involving cervid intermediate hosts remains to be determined. The recent characterization of the parasite from cervids in Finland has highlighted the paucity of data available, particularly that from North America. In this study, we have characterized a large number ofEchinococcusisolates from cervids from Western Canada on the basis of morphology and molecular genetic techniques. Our results support earlier studies suggesting thatEchinococcusof cervid origin is phenotypically and genetically distinct toEchinococcusmaintained in domestic host assemblages, and also confirms thatEchinococcusof cervid origin does not constitute a genetically homogeneous group. However, our data do not support the existence of 2 distinct genotypes (strains/subspecies) with separate geographical distributions. Our data appear to support the existence of only 1 species in cervids, but additional isolates from cervids and wolves in other endemic regions should be characterized before a final decision is made on the taxonomic status ofEchinococcusin cervids.

scholarly journals New finding of green algae with potential for algal biotechnology, Chlorococcum oleofaciens and its molecular investigation

2017 ◽  
Vol 8 (4) ◽  
pp. 532-539 ◽  
Author(s):  
Y. I. Maltsev ◽  
T. V. Konovalenko
Keyword(s):  
Light Microscopy ◽  
Molecular Genetic ◽  
Taxonomic Status ◽  
Forest Litter ◽  
Base Change ◽  
Compensatory Base Change ◽  
Algal Biotechnology ◽  
The Status ◽  
Biochemical Research ◽  
Different Strains

The practice of soil algology shows that algae from the order Chlamydomonadales are among the most poorly studied and difficult to identify due to the high heterogeneity of their morphology and ultrastructure. Only the involvement of molecular genetic methods usually makes it possible to determine their taxonomic status with high accuracy. At the same time, in the algae flora of Ukraine there are more than 250 species from the order Chlamydomonadales, the status of which in most cases is established exclusively on the basis of light microscopy. This work is devoted to the study of the biotechnologically promising green alga Chlorococcum oleofaciens, taking into account the modern understanding of its taxonomic status. Two new strains of this species, separated from samples of forest litter and oak forest soil (the Samara Forest, Dnipropetrovsk region), are described. The strains were studied at the morphological level by using light microscopy methods, as well as using molecular genetic methods based on the studies of the nucleotide genes sequences of the 18S ribosomal DNA (rDNA) and chloroplast rbcL genes, the topology of secondary structures of internal transcribed spacer 2 (ITS2). The obtained results helped to confirm the presence of C. oleofaciens in the algae flora of Ukraine. Also, the authors of the article discuss the differences in the secondary structure of ITS2 in different strains of C. oleofaciens associated with the presence of compensatory base change (CBC), hemi-CBC in helices I and II, as well as deletions in helix IV and providing a basis for the hypothesis of the existence of cryptic species within C. oleofaciens. The obtained data can be used at the stage of preliminary selection of biochemical research objects. 

Middle and Lower Pleistocene: the Homo radiation

2017 ◽  
Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde
Keyword(s):  
Morphological Characterization ◽  
Homo Erectus ◽  
Human Presence ◽  
Genus Homo ◽  
Lower Pleistocene ◽  
The Status

This chapter deals with the radiation of the genus Homo after its exit from Africa. It deals with population dispersals and the meaning of the taxon Homo erectus with respect to the African and Asian fossils. The morphological characterization of H. erectus is complemented with other sorts of evidence, such as fossil footprints. The comparison between the Asian and African specimens suggests the possible existence of the taxon Homo ergaster. The next issue is the colonization of Europe, with a distinction between “long chronology” and “short chronology,” according to a sporadic or permanent human presence. The hominins’ possible ways of entry in Europe are discussed, and the oldest exemplars, such as Homo antecessor, are described. Finally, the climatic (glaciations) and cultural alternatives are examined in order to determine the status of H. erectus considered as a whole.

scholarly journals Molecular Characterization of Haemaphysalis Species and a Molecular Genetic Key for the Identification of Haemaphysalis of North America

2020 ◽  
Vol 7 ◽  
Author(s):  
Alec T. Thompson ◽  
Kristen Dominguez ◽  
Christopher A. Cleveland ◽  
Shaun J. Dergousoff ◽  
Kandai Doi ◽  
...  
Keyword(s):  
North America ◽  
Molecular Characterization ◽  
Molecular Genetic

Characterization of the structure of the prokaryotic complex of Antarctic permafrost by molecular genetic techniques

Microbiology ◽  
2016 ◽  
Vol 85 (1) ◽  
pp. 102-108 ◽  
Author(s):  
N. A. Manucharova ◽  
E. V. Trosheva ◽  
E. M. Kol’tsova ◽  
E. V. Demkina ◽  
E. V. Karaevskaya ◽  
...  
Keyword(s):  
Molecular Genetic ◽  
Genetic Techniques

scholarly journals Identification and Characterization of DM1 Patients by a New Diagnostic Certified Assay: Neuromuscular and Cardiac Assessments

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Rea Valaperta ◽  
Valeria Sansone ◽  
Fortunata Lombardi ◽  
Chiara Verdelli ◽  
Alessio Colombo ◽  
...  
Keyword(s):  
Molecular Genetic ◽  
Clinical Manifestations ◽  
Molecular Method ◽  
High Reproducibility ◽  
Pathological Mechanism ◽  
Genetic Techniques ◽  
Identification And Characterization ◽  
Very High ◽  
Unambiguous Interpretation

The expansion of the specific trinucleotide sequence, [CTG], is the molecular pathological mechanism responsible for the clinical manifestations of DM1. Many studies have described different molecular genetic techniques to detect DM1, but as yet there is no data on the analytical performances of techniques used so far in this disease. We therefore developed and validated a molecular method, “Myotonic Dystrophy SB kit,” to better characterize our DM1 population. 113 patients were examined: 20 DM1-positive, 11 DM1/DM2-negative, and13 DM1-negative/DM2-positive, who had a previous molecular diagnosis, while 69 were new cases. This assay correctly identified 113/113 patients, and all were confirmed by different homemade assays. Comparative analysis revealed that the sensitivity and the specificity of the new kit were very high (>99%). Same results were obtained using several extraction procedures and different concentrations of DNA. The distribution of pathologic alleles showed a prevalence of the “classical” form, while of the 96 nonexpanded alleles 19 different allelic types were observed. Cardiac and neuromuscular parameters were used to clinically characterize our patients and support the new genetic analysis. Our findings suggest that this assay appears to be a very robust and reliable molecular test, showing high reproducibility and giving an unambiguous interpretation of results.

Cytogenetic and Molecular Characterization of Three Mimetic Species of the Genus Alagoasa Bechyné 1955 (Coleoptera: Alticinae) from the Neotropical Region

2020 ◽  
Vol 160 (4) ◽  
pp. 214-223
Author(s):  
Matheus Azambuja ◽  
Lucas A.M. Rosolen ◽  
Roberto F. Artoni ◽  
Mateus H. Santos ◽  
Mara C. Almeida
Keyword(s):  
Molecular Genetic ◽  
5S Rdna ◽  
Distinct Species ◽  
Neotropical Region ◽  
Coi Gene ◽  
Similar Species ◽  
Determination System ◽  
Genetic Techniques ◽  
Sex Determination System

Coleoptera is a mega-diverse order, but only about 1% of its species have been analyzed cytogenetically. In this order, the subfamily Alticinae presents many identification problems, mainly due to the occurrence of mimicry. The objective of this work was to cytogenetically characterize 3 very similar species of the genus Alagoasa (A. pantina, A.areata, and A.scissa). We used classical and molecular cytogenetic as well as molecular genetic techniques. All 3 species showed a diploid chromosome number of 2n = 22 (20+X+y), but differences in the morphology of the chromosomes. All had a meiotic formula of 2n = 10II+X+y and an X+y sex determination system with giant, fully asynaptic sex chromosomes, concordant characteristics observed in the subtribe Oedionychina. FISH demonstrated the presence of 18S and 5S rDNA clusters in 1 pair of autosomes, syntenic and colocalizing in the 3 analyzed species. However, in A. areata, heteromorphism between the cistrons was observed. The telomeric (TTAGG)n probe showed signals in all 3 species, with proximal signals in the X and dispersed signals in the y chromosome of A. areata, and 2 proximal signals in the X chromosome of A. scissa. Molecular analysis of the COI gene indicated that they are 3 distinct species, corroborating the observed cytogenetic characteristics.

scholarly journals Breeding of the Gull-billed Tern in the Sahara and an update on its distribution in Algeria

2020 ◽  
pp. 106-112
Author(s):  
Oussama Bouarakia ◽  
Christiane Denys ◽  
Violaine Nicolas ◽  
Touria Benazzou ◽  
Abdelaziz Benhoussa
Keyword(s):  
Mitochondrial Dna ◽  
Cytochrome B ◽  
Genetic Characterization ◽  
Taxonomic Status ◽  
The Body ◽  
Gene Analysis ◽  
Molecular Tools ◽  
Skull Measurements ◽  
Species Being

The taxonomic status of the gerbil Gerbillus amoenus in relation to Gerbillus nanus and the distribution range of these two species in Africa and/or Asia have long been debated and are not yet fully clarified. In our study, we identify two specimens of small gerbils that we captured in two localities of the south of Morocco, using morphometric and/or molecular tools. The body and skull measurements were not able to unambiguously discriminate between three closely related small gerbils (Gerbillus amoenus, Gerbillus nanus and Gerbillus henleyi). However, the cytochrome b gene analysis showed that our two specimens cluster unambiguously with haplotypes of G. amoenus. This represents the first genetic characterization of G. amoenus in Morocco. It confirms, based on mitochondrial DNA, that the previously described species living in Africa is indeed G. amoenus and not G. nanus, the latter species being present strictly in Asia.

scholarly journals Morphological Characterization of Emerging Cercariae among Lymnaeid Snails from Barangay Cawongan, Padre Garcia, Batangas, Philippines

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Gregorio L. Martin I ◽  
Esperanza C. Cabrera
Keyword(s):  
Light Exposure ◽  
Statistical Tests ◽  
Morphological Characterization ◽  
Snail Host ◽  
Single Type ◽  
Intermediate Hosts ◽  
Level Of Significance ◽  
Host Parasite ◽  
Cercarial Emergence

Background and Objectives. Lymnaeid snails are the known intermediate hosts of the liver fluke Fasciola spp. and therefore play an important role in the parasite’s life cycle. The study is conducted to determine specificity of snail host-parasite interaction and to determine the snail-trematode infection rate by cercarial emergence, characterizing the emerging larvae using standardized key. Materials and Methods. A total of 750 snails were collected from a rice field in Barangay Cawongan, Padre Garcia, Batangas, from November 2016 to March 2017 (n=150/month). Preliminary snail identification was based on morphological features of the shell. Each snail was acclimatized for 24 hours in a 50-ml capacity container before being exposed to strong artificial light. The 150 snails collected per month were grouped into 5 batches (n=30/batch) with each batch receiving different number of light exposures. Emerging cercariae were described and characterized using photo-referencing and standardized keys. All statistical tests were performed at p<0.05 level of significance using SPSS ver. 20. Results. The total cercarial shedding rate of the snails studied, as a measure of the infected snails, was found to be 35.6% and was positively associated with the length of the snail shell [OR = 1.809; 95% CI: 1.471–2.225; p<0.001], but not with the weight [OR = 0.003; 95% CI: 0.00–0.275; p=0.012] and width of the shell [OR = 0.937; 95% CI: 0.672–1.305]. The rates varied from 29.3% to 38.0% based on the frequency of 6-hour light exposure. Appearance of encysted forms increased with increasing number of light exposures [OR = 10.27, 95% CI: 3.04–34.76, p<0.001]. Three distinct cercariae were identified, namely, echinostome, longifurcate-pharyngeate distome cercariae (Strigea cercariae), and the virgulate xiphidiocercaria, with 26.4%, 2.27%, and 0.67% infection monitored by cercarial emergence, respectively. Conclusion. Local lymnaeid snails were infected with a single type of trematode larvae and coinfection with multiple larvae was rare but was encountered.

scholarly journals Morphological and genomic characterization of Rhynchospora tenuis complex (Cyperaceae) and its taxonomic implications

Rodriguésia ◽  
2012 ◽  
Vol 63 (4) ◽  
pp. 775-784 ◽  
Author(s):  
Vanessa Silva Michelan ◽  
Rafael Trevisan ◽  
Carlos Roberto Maximiano da Silva ◽  
Rogério Fernandes de Souza ◽  
Modesto Luceño ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Species Complex ◽  
Issr Markers ◽  
Morphological Similarity ◽  
Molecular Tools ◽  
The Status ◽  
Genomic Characterization ◽  
Taxonomic Implications ◽  
Shape And Size

Species of Rhynchospora sect. Tenues are morphologically very similar. Rhynchospora tenuis complex is the most problematic species complex in this group and it concentrates entities of difficult delimitation, as is the case of R. tenuis, R. tenuis subsp. austro-brasiliensis and R. enmanuelis. Samples of these three taxonomic entities, besides R. junciformis and R. breviuscula (Dichromena), were analyzed in a comparative way using morphologic, cytogenetic and molecular tools. Despite of high morphological similarity between these taxa, R. tenuis was separated from R. tenuis subsp. austro-brasiliensis and R. enmanuelis according to chromosome numbers (2n = 4 and 2n = 18) and ISSR markers. The combined analysis of shape and size of achenes and stylopodium, number of spikelets, cytogenetic features and molecular markers suggest a clear proximity among Rhynchospora junciformis, R. tenuis subsp. austro-brasiliensis and R. enmanuelis, in relation to R. tenuis. These data indicate the need for a new taxonomic review of R. sect. Tenues, mainly to solve the status and nomenclatural situation of R. tenuis subsp. austro-brasiliensis and R. enmanuelis.

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