المؤلفون: MacDiarmid, Robin Marion, Khalifa, Mahmoud E.

مصطلحات موضوعية: totiviruses, Geotrichum candidum

الوصف: Supplementary Table/Figure

العلاقة: https://zenodo.org/record/8340027Test; https://doi.org/10.5281/zenodo.8340027Test; oai:zenodo.org:8340027

الإتاحة: https://doi.org/10.5281/zenodo.8340027Test
https://doi.org/10.5281/zenodo.8340026Test
https://zenodo.org/record/8340027Test

المؤلفون: Rodriguez Coy, Lorena, Plummer, Kim M., Khalifa, Mahmoud E., MacDiarmid, Robin M.

المساهمون: La Trobe University, Australian Research Council

المصدر: Frontiers in Fungal Biology ; volume 3 ; ISSN 2673-6128

مصطلحات موضوعية: General Medicine

الوصف: Plants, fungi, and many other eukaryotes have evolved an RNA interference (RNAi) mechanism that is key for regulating gene expression and the control of pathogens. RNAi inhibits gene expression, in a sequence-specific manner, by recognizing and deploying cognate double-stranded RNA (dsRNA) either from endogenous sources (e.g. pre-micro RNAs) or exogenous origin (e.g. viruses, dsRNA, or small interfering RNAs, siRNAs). Recent studies have demonstrated that fungal pathogens can transfer siRNAs into plant cells to suppress host immunity and aid infection, in a mechanism termed cross-kingdom RNAi. New technologies, based on RNAi are being developed for crop protection against insect pests, viruses, and more recently against fungal pathogens. One example, is host-induced gene silencing (HIGS), which is a mechanism whereby transgenic plants are modified to produce siRNAs or dsRNAs targeting key transcripts of plants, or their pathogens or pests. An alternative gene regulation strategy that also co-opts the silencing machinery is spray-induced gene silencing (SIGS), in which dsRNAs or single-stranded RNAs (ssRNAs) are applied to target genes within a pathogen or pest. Fungi also use their RNA silencing machinery against mycoviruses (fungal viruses) and mycoviruses can deploy virus-encoded suppressors of RNAi (myco-VSRs) as a counter-defence. We propose that myco-VSRs may impact new dsRNA-based management methods, resulting in unintended outcomes, including suppression of management by HIGS or SIGS. Despite a large diversity of mycoviruses being discovered using high throughput sequencing, their biology is poorly understood. In particular, the prevalence of mycoviruses and the cellular effect of their encoded VSRs are under-appreciated when considering the deployment of HIGS and SIGS strategies. This review focuses on mycoviruses, their VSR activities in fungi, and the implications for control of pathogenic fungi using RNAi.

الإتاحة: https://doi.org/10.3389/ffunb.2022.965781Test

المؤلفون: Khalifa, Mahmoud E.¹ (AUTHOR) mahmoud.khalifa@du.edu.eg, MacDiarmid, Robin M.^2,3 (AUTHOR) robin.macdiarmid@plantandfood.co.nz

المصدر: Viruses (1999-4915). Nov2023, Vol. 15 Issue 11, p2150. 14p.

مصطلحات موضوعية: *FUNGAL viruses, *RNA replicase, *RNA interference, *SMALL interfering RNA, *YEAST fungi, *CHIMERIC proteins

مستخلص: Mycoviruses can infect many of the major taxa of fungi including yeasts. Mycoviruses in the yeast fungus Geotrichum candidum are not well studied with only three G. candidum-associated viral species characterized to date, all of which belong to the Totiviridae genus Totivirus. In this study, we report the molecular characteristics of another two totiviruses co-infecting isolate Gc6 of G. candidum. The two totiviruses were tentatively named Geotrichum candidum totivirus 2 isolate Gc6 (GcTV2-Gc6) and Geotrichum candidum totivirus 4 isolate Gc6 (GcTV4-Gc6). Both viruses have the typical genome organization of totiviruses comprising two ORFs encoding capsid protein (CP) and RNA-dependent RNA polymerase (RdRp) at the N and C termini, respectively. The genomes of GcTV2-Gc6 and GcTV4-Gc6 are 4592 and 4530 bp long, respectively. Both viruses contain the—frameshifting elements and their proteins could be expressed as a single fusion protein. GcTV2-Gc6 is closely related to a totivirus isolated from the same host whereas GcTV4-Gc6 is related to insect-associated totiviruses. The phylogenetic analysis indicated that GcTV2-Gc6 and GcTV4-Gc6 belong to two different sister clades, I-A and I-B, respectively. It is interesting that all viruses identified from G. candidum belong to the genus Totivirus; however, this might be due to the lack of research reporting the characterization of mycoviruses from this fungal host. It is possible that the RNA interference (RNAi) mechanism cannot actively suppress totivirus accumulation in G. candidum Gc6. [ABSTRACT FROM AUTHOR]

المؤلفون: Selim, Ahmed N. A., Khalifa, Mahmoud E., Ibrahim, Marwa T., Serag, Shimaa M.

المصدر: Tanta Dental Journal ; volume 20, issue 4, page 357-364 ; ISSN 1687-8574 2536-9644

مصطلحات موضوعية: General Earth and Planetary Sciences, Water Science and Technology, Geography, Planning and Development

الوصف: Background Palatal fistula after palatal surgery in cleft patients is an annoying problem for both patients and maxillofacial surgeons. The occurrence of fistula is determined by the severity of the underlying defect, the repair technique utilized and the stress applied to the wound. Fistula recurrence rates range from 0% to 58%. Depending on the size, recurrence rate, and surgeon skill, various procedures for palatal fistula closure are documented, ranging from local mucoperiosteal flaps to free flaps. Colla-D is a pure collagen membrane developed to facilitate directed tissue regeneration and aid in the closure of palatal fistulas. Patients and methods A prospective randomized noncontrolled clinical research was conducted on 12 patients with palatal fistulas in the hard palate of cleft patients aged 6 to 20 years. Collagen membrane (Colla-D type BS) is utilized as an interposition material between the oral and nasal layers in cleft patients to aid in the closure of palatal fistulas. Results Collagen membrane was integrated with successful fistula closure in nine (75%) individuals, but palatal closure failure was detected early postoperatively in three (25%) patients. In seven patients, the oral mucosal layer dehisced, exposing the membrane, which was gradually covered by creeping oral mucosa in 4 of 7 patients over a period of 2 to 4 weeks postoperatively. All patients improved in nasalance and even failed cases improved slightly due to a decrease in fistula size, with a mean progress of 33.92% and a standard deviation of 7.28. Conclusions Colla-D collagen membrane is a safe and effective adjunct for the closure of palatal fistulas located in hard palate.

الإتاحة: https://doi.org/10.4103/tdj.tdj_58_23Test

المؤلفون: Khalifa, Mahmoud E., MacDiarmid, Robin M.

المصدر: Frontiers in Microbiology ; volume 10 ; ISSN 1664-302X

مصطلحات موضوعية: Microbiology (medical), Microbiology

الإتاحة: https://doi.org/10.3389/fmicb.2019.02318Test

المؤلفون: Rodriguez Coy, Lorena Lizeth, Plummer, Kim, Khalifa, Mahmoud E, MacDiarmid, Robin M

مصطلحات موضوعية: Uncategorized

الوصف: Plants, fungi, and many other eukaryotes have evolved an RNA interference (RNAi) mechanism that is key for regulating gene expression and the control of pathogens. RNAi inhibits gene expression, in a sequence-specific manner, by recognizing and deploying cognate double-stranded RNA (dsRNA) either from endogenous sources (e.g. pre-micro RNAs) or exogenous origin (e.g. viruses, dsRNA, or small interfering RNAs, siRNAs). Recent studies have demonstrated that fungal pathogens can transfer siRNAs into plant cells to suppress host immunity and aid infection, in a mechanism termed cross-kingdom RNAi. New technologies, based on RNAi are being developed for crop protection against insect pests, viruses, and more recently against fungal pathogens. One example, is host-induced gene silencing (HIGS), which is a mechanism whereby transgenic plants are modified to produce siRNAs or dsRNAs targeting key transcripts of plants, or their pathogens or pests. An alternative gene regulation strategy that also co-opts the silencing machinery is spray-induced gene silencing (SIGS), in which dsRNAs or single-stranded RNAs (ssRNAs) are applied to target genes within a pathogen or pest. Fungi also use their RNA silencing machinery against mycoviruses (fungal viruses) and mycoviruses can deploy virus-encoded suppressors of RNAi (myco-VSRs) as a counter-defence. We propose that myco-VSRs may impact new dsRNA-based management methods, resulting in unintended outcomes, including suppression of management by HIGS or SIGS. Despite a large diversity of mycoviruses being discovered using high throughput sequencing, their biology is poorly understood. In particular, the prevalence of mycoviruses and the cellular effect of their encoded VSRs are under-appreciated when considering the deployment of HIGS and SIGS strategies. This review focuses on mycoviruses, their VSR activities in fungi, and the implications for control of pathogenic fungi using RNAi.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::863e3546fbbee53629ccfba2a8195d4bTest

المؤلفون: Khalifa, Mahmoud E.¹ mahmoud.khalifa@du.edu.eg, Dessoky, Eldessoky S.², Sadik, Atef S.³

المصدر: JAPS: Journal of Animal & Plant Sciences. Aug2022, Vol. 32 Issue 4, p1101-1109. 9p.

مصطلحات موضوعية: SCLEROTINIA sclerotiorum, DOUBLE-stranded RNA, FUNGAL viruses, RNA

مستخلص: Several mycoviruses have potential to induce hypovirulence on their fungal pathogens and therefore the interest in mycoviruses has increased in recent years. In the current study, a single double-stranded RNA (dsRNA) molecule of 2531 nts was detected, sequenced and characterized from an Egyptian isolate (D7) of Sclerotinia sclerotiorum fungus. The dsRNA has one open reading frame (ORF), in its positive strand, encoding a protein with conserved motifs characteristic of viral RNA-dependent RNA-polymerases (RdRps). The RdRp encoded by the ORF shares 91.84% identity with that of isolate HC025 of sclerotinia sclerotiorum mitovirus 1 (SsMV1) and consequently it was tentatively named SsMV1-D7. As for previously described mitoviruses, the termini of the (+) strand of SsMV1-D7 RNA could potentially fold into stable secondary structures. Horizontal transmission and virulence experiments showed that SsMV1-D7 is probably responsible for the altered growth and virulence of S. sclerotiorum. [ABSTRACT FROM AUTHOR]

: Copyright of JAPS: Journal of Animal & Plant Sciences is the property of Knowledge Bylanes and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Khalifa, Mahmoud E., Pearson, Michael N.

المساهمون: Bioprotection Research Centre (Theme 3: Plant Bioprotection Systems Biology, Project 8) and The University of Auckland, New Zealand, New Zealand Institute for Plant and Food Research

المصدر: Virology ; volume 464-465, page 441-449 ; ISSN 0042-6822

مصطلحات موضوعية: Virology

الإتاحة: https://doi.org/10.1016/j.virol.2014.07.005Test
https://api.elsevier.com/content/article/PII:S0042682214003110?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S0042682214003110?httpAccept=text/plainTest

المؤلفون: Fatma S., Abdel Razek, S., El-Masry Samar, S. D., Ibrahim, T. F., El-Arabi, Khalifa, Mahmoud E., A. S., Sadik

المصدر: Egyptian Academic Journal of Biological Sciences, G, Microbiology; 2022, Vol. 14 Issue 2, p1-18, 18p

مصطلحات موضوعية: DNA analysis, SINGLE-stranded DNA, COAT proteins (Viruses), BANANAS, NUCLEAR proteins, GENOMES, PEPTIDES

مصطلحات جغرافية: EGYPT

مستخلص: Banana bunchy top disease (BBTD) caused by Banana bunchy top virus (BBTV) was recorded in the early twentieth century in Egypt. It is considered the most economic impact on banana yield productivity. Bioinformatics analyses of the complete genome of an Egyptian isolate of BBTV compared to overseas BBTV isolates or strains and other Nanoviruses were aimed. Banana leaf samples naturally infected with BBTD were collected from the open field and the presence of BBTV was detected via PCR. Bioinformatics analyzes of the BBTV-DNA genome were also studied. The experimental results showed that BBTV isolates of this study had a genome that consists of six encapsidated single-stranded DNA components (BBTV-DNA-R (LC468138, - U3 (LC468139), -S (LC468140), -M (LC468141), - C (LC468142) and –N (LC468143)) of ~ 1.1 kb in length, each with one open reading frame (ORF) in the virion-sense Two conserved regions (Common region-stem loop (CR-SL) and common region-M (RC-M)). TATA box, i.e., non-nucleotide potential TATA and polyadenylation signals adjacent to GC-rich regions that contain the TTG sequence were found. Differences ranging from 0.55 to 4.60% were recorded when BBTV components were compared to the most similar oversea BBTV strains of seven countries. Phylogenetic trees confirmed the genetic relationships among the high percentage of similarity between the compared BBTV strains. Families of Gene domains, restriction enzyme maps and differences between BBTV components and those of nano viruses were also discussed. The six BBTV-DNA components contain ORFs encoding the genes of rolling-circle replication initiation protein (rp, DNA-R), a protein of unknown function (DNA-U3), a coat protein peptide (cp, DNA-S), movement protein (mv, DNA-M), cell cycle link protein (ccl, DNA-C) and a nuclear shuttle protein (ns, DNA-N), respectively. Further studies should be done using molecular docking tools in a trial to find a suitable control strategy for BBTV. [ABSTRACT FROM AUTHOR]

: Copyright of Egyptian Academic Journal of Biological Sciences, G, Microbiology is the property of Egyptian Academic Journal of Biological Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Elmayah, Nada M., El-Fallal, Amira A., Abou-Dobara, Mohamed I., Khalifa, Mahmoud E.

المصدر: Jordan Journal of Biological Sciences; Jun2022, Vol. 15 Issue 3, p511-522, 12p

مصطلحات موضوعية: SILVER nanoparticles, ASPERGILLUS niger, ENERGY dispersive X-ray spectroscopy, TALAROMYCES, ALTERNARIA, FOURIER transform infrared spectroscopy, SURFACE plasmon resonance

مستخلص: Central composite design (CCD) as one of response surface designs was employed to optimize the biosynthesis process of silver nanoparticles (AgNPs). In this design, fungal cell-free filtrate of Talaromyces stipitatus was applied as a biosource for the biosynthesis of AgNPs. Different variables with five levels were used to optimize AgNPs biosynthesis. Independent variables were concentration of silver nitrate (AgNO3; mmole), temperature (°C), time, pH and ratio of AgNO3 to cell free extract. While dependent variable was peak intensity of surface plasmon resonance (SPR) at wavelength 420 nm. The predicted optimal setup parameters were AgNO3 concentration of 7 mmol, temperature of 25 °C, time of 91.2 hr, pH of 8 and ratio of AgNO3 solution to cell-free extract of 2:1. The characteristics of biosynthesized AgNPs were revealed using Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, energy dispersive x-ray analysis (EDX), and transmission electron microscopy (TEM). Biosynthesized AgNPs appeared to be spherical, with mean size of 13.95 nm and zeta potential of 9.85 mV. Biosynthesized AgNPs were also examined for their antimicrobial properties against selected bacterial and fungal pathogens including Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Aspergillus flavus, A. niger, Fusarium oxysporum and Alternaria alternata. [ABSTRACT FROM AUTHOR]

: Copyright of Jordan Journal of Biological Sciences is the property of Hashemite University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)