scholarly journals Genetic Diversity and Molecular Characterization of Mosquitoes (Diptera: Culicidae) In North-Central Nigeria Using Ribosomal DNA ITS2 and Mitochondrial 16S-DNA Sequences

2020 ◽  
Vol 44 (2) ◽  
pp. 78-91
Author(s):  
Oluyinka A. Iyiola

Mosquitoes are vectors of various life-threatening diseases like malaria, yellow fever, dengue fever etc. Their close proximity to human habitations allows ease for disease transmission. They have been identified by key morphological tools like their wings, legs, bristles etc. but closely related species are difficult to identify based on morphology. Molecular tools have, therefore, been employed to help with the more accurate identification. This study was aimed at identifying and characterizing different mosquito species in five different states in North-Central Nigeria using internal transcribed spacer 2 (ITS2) and mitochondrial 16S rDNA regions. Mosquito larvae were collected from stagnant water in breeding places at each collection site in North-central Nigeria. Morphological identification was carried out using standard keys. DNA extraction was performed using EZNA extraction kit. PCR amplification of ribosomal ITS2 and mitochondrial 16S-rDNA gene regions were carried out. The PCR amplicons were sequenced using primers initially used for the PCR. Sequence data were aligned in MEGA 6.0 using ClustalW multiple alignment feature and then compared with GenBank databases for similarity.  Phylogenetic analysis of DNA sequences from the ITS2 region was able to distinguish two mosquito subfamilies; Anophelinae and Culicinae as well as differentiate between and amongst Culex and Aedes species. However, it was unable to effectively distinguish between the two different species of Anopheles sequenced. Mitochondrial 16S rRNA marker was also able to distinguish the two mosquito subfamilies. It efficiently identified and differentiated Culex, Aedes and Anopheles mosquito species sequenced in this study. This study concludes that heterogeneity among Nigerian populations of Anopheles mosquitoes of may likely impact malaria vector control programs. We recommend the combination of nuclear and mitochondrial markers for effective and reliable phylogenetic study and determination of evolutionary relationship among mosquito species.

2016 ◽  
Vol 6 (2) ◽  
pp. 882-889
Author(s):  
Ernieenor Faraliana Che Lah

A reliable and rapid taxonomic identification of a mite is the basis for a correct diagnosis of important mite associated allergies as they produce species-specific allergens. A double approach (molecular and morphological) to the taxonomic identification of Aleuroglyphus ovatus was presented. Molecular identification was performed with amplification of the internal transcribed spacer region (ITS2), whilst morphological characters were examined under light microscope. The BLAST results obtained from molecular analysis of A. ovatus was shown to be in concordance with the morphological identification with 97% genetic similarity. Thus, the molecular identification based on the ITS2 region can be applied as a reliable and efficient tool for species identification of Aleuroglyphus and probably any other astigmatid mites. Our findings suggest the need for a broad taxonomic sampling especially from closely related species for an accurate identification of local mites using both DNA sequences and morphology.


Author(s):  
Paulyn Cartwright ◽  
Nathaniel M. Evans ◽  
Casey W. Dunn ◽  
Antonio C. Marques ◽  
Maria Pia Miglietta ◽  
...  

Hydroidolina is a group of hydrozoans that includes Anthoathecata, Leptothecata and Siphonophorae. Previous phylogenetic analyses show strong support for Hydroidolina monophyly, but the relationships between and within its subgroups remain uncertain. In an effort to further clarify hydroidolinan relationships, we performed phylogenetic analyses on 97 hydroidolinan taxa, using DNA sequences from partial mitochondrial 16S rDNA, nearly complete nuclear 18S rDNA and nearly complete nuclear 28S rDNA. Our findings are consistent with previous analyses that support monophyly of Siphonophorae and Leptothecata and do not support monophyly of Anthoathecata nor its component subgroups, Filifera and Capitata. Instead, within Anthoathecata, we find support for four separate filiferan clades and two separate capitate clades (Aplanulata and Capitatasensu stricto). Our data however, lack any substantive support for discerning relationships between these eight distinct hydroidolinan clades.


2019 ◽  
Vol 7 (4.14) ◽  
pp. 82
Author(s):  
N N Roseman ◽  
R Rasol ◽  
A Ismail ◽  
H R Singh ◽  
F Z M Yusof

Barnacles are marine sessile crustacean inhabiting intertidal areas of the Selangor coastline. They are seen attaching themselves to rocks and artificial structures such as jetty, piers, boats and sea walls. Being the most successful biofoulers, barnacles cause economic losses to some extent. Most of barnacles study focused on morphological identification only. Since molecular method gave more accurate results by sequence comparison, species identification was done on samples of obviously different species inhabiting artificial substrata by using mitochondrial 16S rDNA identification. In Kuala Selangor, there was only one species found on artificial substrata in Bagan Pasir and Pasir Penambang which was identified as Amphibalanus cirratus. Two species that differed in their morphological characteristics found on Morib sea walls were identified as Amphibalanus cirratus and Chthamalus malayensis. Phylogenetic tree based on the 16S rDNA showed that all the samples were in the same cluster reflecting that they are in the same clade.  


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Parisa Soltan-Alinejad ◽  
Javad Rafinejad ◽  
Farrokh Dabiri ◽  
Piero Onorati ◽  
Olle Terenius ◽  
...  

Abstract Objectives Annually, 1.2 million humans are stung by scorpions and severely affected by their venom. Some of the scorpion species of medical importance have a similar morphology to species with low toxicity. To establish diagnostic tools for surveying scorpions, the current study was conducted to generate three mitochondrial markers, Cytochrome Oxidase I (COI gene), 12S rDNA and 16S rDNA for six species of medically important Iranian scorpions: Androctonus crassicauda, Hottentotta saulcyi, Mesobuthus caucasicus, M. eupeus, Odontobuthus doriae, and Scorpio maurus. Results Phylogenetic analyses of the obtained sequences corroborated the morphological identification. For the first time, 12S rDNA sequences are reported from Androctonus crassicauda, Hottentotta saulcyi, Mesobuthus caucasicus and M. eupeus and also the 16S rDNA sequence from Hottentotta saulcyi. We conclude that the mitochondrial markers are useful for species determination among these medically important species of scorpions.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Henry Ddumba Mawejje ◽  
Maxwell Kilama ◽  
Simon P. Kigozi ◽  
Alex K. Musiime ◽  
Moses Kamya ◽  
...  

Abstract Background Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the malaria control interventions primarily responsible for reductions in transmission intensity across sub-Saharan Africa. These interventions, however, may have differential impact on Anopheles species composition and density. This study examined the changing pattern of Anopheles species in three areas of Uganda with markedly different transmission intensities and different levels of vector control. Methods From October 2011 to June 2016 mosquitoes were collected monthly using CDC light traps from 100 randomly selected households in three areas: Walukuba (low transmission), Kihihi (moderate transmission) and Nagongera (high transmission). LLINs were distributed in November 2013 in Walukuba and Nagongera and in June 2014 in Kihihi. IRS was implemented only in Nagongera, with three rounds of bendiocarb delivered between December 2014 and June 2015. Mosquito species were identified morphologically and by PCR (Polymerase Chain Reaction). Results In Walukuba, LLIN distribution was associated with a decline in Anopheles funestus vector density (0.07 vs 0.02 mosquitoes per house per night, density ratio [DR] 0.34, 95% CI: 0.18–0.65, p = 0.001), but not Anopheles gambiae sensu stricto (s.s.) nor Anopheles arabiensis. In Kihihi, over 98% of mosquitoes were An. gambiae s.s. and LLIN distribution was associated with a decline in An. gambiae s.s. vector density (4.00 vs 2.46, DR 0.68, 95% CI: 0.49–0.94, p = 0.02). In Nagongera, the combination of LLINs and multiple rounds of IRS was associated with almost complete elimination of An. gambiae s.s. (28.0 vs 0.17, DR 0.004, 95% CI: 0.002–0.009, p < 0.001), and An. funestus sensu lato (s.l.) (3.90 vs 0.006, DR 0.001, 95% CI: 0.0005–0.004, p < 0.001), with a less pronounced decline in An. arabiensis (9.18 vs 2.00, DR 0.15 95% CI: 0.07–0.33, p < 0.001). Conclusions LLIN distribution was associated with reductions in An. funestus s.l. in the lowest transmission site and An. gambiae s.s. in the moderate transmission site. In the highest transmission site, a combination of LLINs and multiple rounds of IRS was associated with the near collapse of An. gambiae s.s. and An. funestus s.l. Following IRS, An. arabiensis, a behaviourally resilient vector, became the predominant species, which may have implications for malaria vector control activities. Development of interventions targeted at outdoor biting remains a priority.


2010 ◽  
Vol 76 (4) ◽  
pp. 621-629 ◽  
Author(s):  
AKIRA KOMARU ◽  
HISAKO HORI ◽  
YASUHIRO YANASE ◽  
KENJI ONOUCHI ◽  
TAKESHI KATO ◽  
...  

Author(s):  
Bo-Yang Shi ◽  
Xiao-Yong Chen ◽  
Hong-Ying Sun

Abstract We describe two new species of the freshwater-crab genus Demanietta  Bott, 1966 from Tanintharyi (Tenasserim) division, southern Myanmar (Burma), Demanietta liui  sp. nov. and Demanietta lenya  sp. nov.  Demanietta liui  sp. nov. is morphologically most similar to D. thagatensis  Rathbun, 1904 and D. khirikhan  Yeo, Naiyanetr & Ng, 1999; D. lenya  sp. nov. appears close to D. manii  Rathbun, 1904, D. merguensis  Bott, 1966, and D. nakhonsi  Yeo, Naiyanetr & Ng, 1999. The two new species are easily distinguished from their most similar congeners in the shape of the external orbital tooth, epibranchial tooth, and male first gonopod. Molecular analysis based on partial mitochondrial 16S rDNA also supports the systematic position of the new taxa.


2016 ◽  
Vol 7 ◽  
Author(s):  
Shangguo Feng ◽  
Mengying Jiang ◽  
Yujun Shi ◽  
Kaili Jiao ◽  
Chenjia Shen ◽  
...  

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