scholarly journals Variasi Genetik Rice tungro bacilliform virus (RTBV) dari Daerah Istimewa Yogyakarta, Nusa Tenggara Barat, dan Sulawesi Tengah

2018 ◽  
Vol 13 (2) ◽  
pp. 75
Author(s):  
R. Heru Praptana ◽  
Y. B. Sumardiyono ◽  
Sedyo Hartono ◽  
Y. Andi Trisyono
Keyword(s):  
Open Reading Frame ◽  
Rice Tungro Bacilliform Virus ◽  
Rice Tungro Spherical Virus ◽  
Nephotettix Virescens ◽  
Reading Frame ◽  
Open Reading Frame 2

<p>Tungro merupakan salah satu penyakit penting pada padi yang menjadi kendala dalam peningkatan produksi padi di Indonesia. Penyakit ini disebabkan oleh infeksi dua virus yang berbeda secara serologis, yaitu Rice tungro bacilliform virus (RTBV) dan Rice tungro spherical virus (RTSV) yang hanya dapat ditularkan oleh wereng hijau, terutama Nephotettix virescens (Distant) secara semipersisten. Informasi keragaman genetik virus tungro diperlukan sebagai pertimbangan dalam pengendalian penyakit tungro menggunakan varietas tahan. Penelitian ini bertujuan mengidentifikasi keragaman genetik RTBV dari tiga daerah endemis virus tungro di Indonesia berdasarkan sekuen basa nukleotida dan asam amino pada open reading frame 2 (ORF2). Isolat RTBV dikoleksi di Daerah Istimewa Yogyakarta, Nusa Tenggara Barat, dan Sulawesi Tengah dengan cara penularan virus tungro secara buatan pada bibit padi varietas TN1 menggunakan wereng hijau hasil tangkapan dari lapangan. Analisis homologi sebagian sekuen DNA ORF2 RTBV menunjukkan bahwa ketiga isolat memiliki variasi kesamaan basa nukleotida dan asam amino, berturut-turut 94-98% dan 97-100%. Ketiga isolat berbeda jauh dengan isolat dari negara lain dengan tingkat kesamaan genetik 77-95% berdasarkan sekuen basa nukleotida dan 82-98% berdasarkan sekuen asam amino. Keragaman dan hubungan kekerabatan genetik ketiga isolat RTBV tidak berkorelasi dengan perbedaan geografis asal isolat. Adanya keragaman genetik antarisolat RTBV mengindikasikan bahwa berbagai strategi penggunaan varietas tahan perlu dilaksanakan untuk menjaga durabilitas ketahanan padi.</p>

scholarly journals Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1385
Author(s):  
Giulia Pezzoni ◽  
Lidia Stercoli ◽  
Eleonora Pegoiani ◽  
Emiliana Brocchi
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Recombinant Antigen ◽  
Open Reading Frame ◽  
Reading Frame ◽  
E Coli ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

scholarly journals Hepatitis E Virus (HEV) Open Reading Frame 2 Antigen Kinetics in Human-Liver Chimeric Mice and Its Impact on HEV Diagnosis

2019 ◽  
Vol 220 (5) ◽  
pp. 811-819 ◽  
Author(s):  
Ibrahim M Sayed ◽  
Lieven Verhoye ◽  
Claire Montpellier ◽  
Florence Abravanel ◽  
Jacques Izopet ◽  
...  
Keyword(s):  
Density Gradient ◽  
Hepatitis E Virus ◽  
Gradient Analysis ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Viral Rna ◽  
Humanized Mice ◽  
Molecular Diagnostic ◽  
Reading Frame ◽  
Open Reading Frame 2

Abstract Background Hepatitis E virus infection (HEV) is an emerging problem in developed countries. Diagnosis of HEV infection is based on the detection of HEV-specific antibodies, viral RNA, and/or antigen (Ag). Humanized mice were previously reported as a model for the study of HEV infection, but published data were focused on the quantification of viral RNA. However, the kinetics of HEV Ag expression during infection remains poorly understood. Methods Plasma specimens and suspensions of fecal specimens from HEV-infected and ribavirin-treated humanized mice were analyzed using HEV antigen–specific enzyme-linked immunosorbent assay, reverse transcription–quantitative polymerase chain reaction analysis, density gradient analysis, and Western blotting. Result Open reading frame 2 (ORF2) Ag was detected in both plasma and stool from HEV-infected mice, and levels increased over time. Contrary to HEV RNA, ORF2 Ag levels were higher in mouse plasma than in stool. Interestingly, ORF2 was detected in plasma from mice that tested negative for HEV RNA in plasma but positive for HEV RNA in stool and was detected after viral clearance in mice that were treated with ribavirin. Plasma density gradient analysis revealed the presence of the noninfectious glycosylated form of ORF2. Conclusion ORF2 Ag can be used as a marker of active HEV infection and for assessment of the effect of antiviral therapy, especially when fecal samples are not available or molecular diagnostic tests are not accessible.

Primary structure of open reading frame 2 and 3 of the hepatitis E virus isolated from Morocco

1999 ◽  
Vol 57 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Jihong Meng ◽  
Mian-er Cong ◽  
Xing Dai ◽  
Jacques Pillot ◽  
Michael A. Purdy ◽  
...  
Keyword(s):  
Primary Structure ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Open Reading Frame 2
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