Molecular characterization of the ribosomal RNA gene region of Perkinsus atlanticus: its use in phylogenetic analysis and as a target for a molecular diagnosis

Parasitology ◽  
2000 ◽  
Vol 120 (4) ◽  
pp. 345-353 ◽  
Author(s):  
R. de la HERRÁN ◽  
M. A. GARRIDO-RAMOS ◽  
J. I. NAVAS ◽  
C. RUIZ REJÓN ◽  
M. RUIZ REJÓN
2020 ◽  
Vol 141 ◽  
pp. 39-46
Author(s):  
MD Dorjievna Batueva ◽  
X Pan ◽  
J Zhang ◽  
X Liu ◽  
W Wei ◽  
...  

In the present study, we provide supplementary data for Myxidium cf. rhodei Léger, 1905 based on morphological, histological and molecular characterization. M. cf. rhodei was observed in the kidneys of 918 out of 942 (97%) roach Rutilus rutilus (Linnaeus, 1758). Myxospores of M. cf. rhodei were fusiform with pointed ends, measuring 12.7 ± 0.1 SD (11.8-13.4) µm in length and 4.6 ± 0.1 (3.8-5.4) µm in width. Two similar pear-shaped polar capsules were positioned at either ends of the longitudinal axis of the myxospore: each of these capsules measured 4.0 ± 0.1 (3.1-4.7) µm in length and 2.8 ± 0.1 (2.0-4.0) µm in width. Polar filaments were coiled into 4 to 5 turns. Approximately 18-20 longitudinal straight ridges were observed on the myxospore surface. The suture line was straight and distinctive, running near the middle of the valves. Histologically, the plasmodia of the present species were found in the Bowman’s capsules, and rarely in the interstitium of the host. Phylogenetic analysis revealed that M. cf. rhodei was sister to M. anatidum in the Myxidium clade including most Myxidium species from freshwater hosts.


Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 617-624 ◽  
Author(s):  
S M Williams ◽  
J A Kennison ◽  
L G Robbins ◽  
C Strobeck

Abstract The role of reciprocal recombination in the coevolution of the ribosomal RNA gene family on the X and Y chromosomes of Drosophila melanogaster was assessed by determining the frequency and nature of such exchange. In order to detect exchange events within the ribosomal RNA gene family, both flanking markers and restriction fragment length polymorphisms within the tandemly repeated gene family were used. The vast majority of crossovers between flanking markers were within the ribosomal RNA gene region, indicating that this region is a hotspot for heterochromatic recombination. The frequency of crossovers within the ribosomal RNA gene region was approximately 10(-4) in both X/X and X/Y individuals. In conjunction with published X chromosome-specific and Y chromosome-specific sequences and restriction patterns, the data indicate that reciprocal recombination alone cannot be responsible for the observed variation in natural populations.


1991 ◽  
Vol 45 (2) ◽  
pp. 275-280 ◽  
Author(s):  
John B. Dame ◽  
Charles A. Yowell ◽  
Charles H. Courtney ◽  
W.Gary Lindgren

Plant Disease ◽  
2018 ◽  
Vol 102 (3) ◽  
pp. 576-588 ◽  
Author(s):  
Ali M. Al-Subhi ◽  
Saskia A. Hogenhout ◽  
Rashid A. Al-Yahyai ◽  
Abdullah M. Al-Sadi

Typical symptoms of phytoplasma infection were observed on 11 important crops in Oman that included alfalfa, sesame, chickpea, eggplant, tomato, spinach, rocket, carrot, squash, field pea, and faba bean. To identify the phytoplasmas in these crops, samples from infected and asymptomatic plants were collected, followed by amplifying and sequencing of the 16S ribosomal RNA, secA, tuf, imp, and SAP11 genes. We found that these sequences share >99% similarity with the peanut witches’ broom subgroup (16SrII-D). Whereas some sequence variation was found in the five genes among 11 phytoplasma isolates of different crops, all sequences grouped into one clade along with those of other phytoplasmas belonging to the 16SrII-D group. Thus, 16SrII-D phytoplasmas infect a diverse range of crops in Oman. Phytoplasmas in this group have not been reported to occur in carrot, spinach, rocket, and field pea previously. Within Oman, this is the first report of the presence of 16SrII-D phytoplasmas in tomato, spinach, rocket, carrot, squash, field pea, and faba bean. Sequences of the five genes enabled for better distinction of the 16SrII-D phytoplasmas that occur in Oman.


2002 ◽  
Vol 23 (2) ◽  
pp. 288-292 ◽  
Author(s):  
Martı́n Garcı́a-Varela ◽  
Michael P Cummings ◽  
Gerardo Pérez-Ponce de León ◽  
Scott L Gardner ◽  
Juan P Laclette

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258318
Author(s):  
Marta Antas ◽  
Monika Olech ◽  
Anna Szczotka-Bochniarz

Porcine epidemic diarrhoea (PED) is a highly contagious enteric viral disease of pigs with a high morbidity and mortality rate, which ultimately results in huge economic losses in the pig production sector. The etiological agent of this disease is the porcine epidemic diarrhoea virus (PEDV) which is an enveloped, positive single-stranded RNA virus. The aim of this study was to perform molecular characterization of PEDV to identify the strains circulating in Poland. In this study, 662 faecal samples from 2015 to 2021 were tested with reverse transcription quantitative real-time PCR (RT-qPCR) and the results showed that 3.8% of the tested samples revealed a positive result for PEDV. A phylogenetic analysis of the complete genome and complete S gene sequences showed that Polish PEDV strains belonged to the G1b (S-INDEL) subgroup and were closely related to the European PEDV strains isolated from 2014 to 2019. Furthermore, RDP4 analysis revealed that the Polish PEDV strains harboured a recombinant fragment of ~400 nt in the 5’ end of S gene with PEDV and swine enteric coronavirus (SeCoV) being the major and minor parents, respectively. Antigenic analysis showed that the aa sequences of neutralizing epitopes were conserved among the Polish PEDV strains. Only one strain, #0100/5P, had a unique substitution in the COE epitope. However, Polish PEDV strains showed several substitutions, especially in the COE antigen, as compared to the classical strain CV777. To the best of our knowledge, this is the first report concerning the molecular characterization of porcine epidemic diarrhoea virus strains, as well as the first phylogenetic analysis for PEDV in Poland.


2021 ◽  
Vol 102 (4) ◽  
Author(s):  
Takeshi Tsugawa ◽  
Yoshiki Fujii ◽  
Yusuke Akane ◽  
Saho Honjo ◽  
Kenji Kondo ◽  
...  

Group A rotaviruses (RVAs) infect a wide variety of mammalian and avian species. Animals act as a potential reservoir to RVA human infections by direct virion transmission or by contributing genes to reassortants. Here, we report the molecular characterization of a rare human RVA strain Ni17-46 with a genotype G15P[14], isolated in Japan in 2017 during rotavirus surveillance in a paediatric outpatient clinic. The genome constellation of this strain was G15-P[14]-I2-R2-C2-M2-A13-N2-T9-E2-H3. This is the first report of an RVA with G15 genotype in humans, and sequencing and phylogenetic analysis results suggest that human infection with this strain has zoonotic origin from the bovine species. Given the fact that this strain was isolated from a patient with gastroenteritis and dehydration symptoms, we must take into account the virulence of this strain in humans.


2020 ◽  
Vol 15 (4) ◽  
pp. 247-254
Author(s):  
Murat Karamese ◽  
Erkan Ozmen ◽  
Hakan Aydin ◽  
Mehmet Ozkan Timurkan ◽  
Mesud Fakirullahoglu

Aim: The objective was to investigate the genotypic relationship of S and M segments in Crimean-Congo hemorrhagic fever virus (CCHFV) by phylogenetic analysis in 25 patients from seven endemic cities in Turkey. Materials & methods: A total of 25 samples from patients with CCHF were included between 2012 and 2015. Phylogenetic tree analyses were inferred using MEGA version-6.0 and distances were calculated by Kimura’s 2-parameter. Results: Phylogenetic analysis showed that all isolated viruses (n = 25) were in the predicted clades such as clade V- Europe-1 regarding both S and M segments of the CCHFV. Conclusion: Further epidemiological, molecular and phylogenic studies should be performed in both reservoir animals/vectors and humans to determine the incidence of tick-borne infectious disease and to help to develop vaccines for prevention of the disease.


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