Genome-wide comparative analysis of transposable elements in Palmae genomes

Background: Transposable elements (TEs) are the largest component of the genetic material of most eukaryotes and can play roles in shaping genome architecture and regulating phenotypic variation; thus, understanding genome evolution is only possible if we comprehend the contributions of TEs. However, the quantitative and qualitative contributions of TEs can vary, even between closely related lineages. For palm species, in particular, the dynamics of the process through which TEs have differently shaped their genomes remains poorly understood because of a lack of comparative studies. Materials and methods: We conducted a genome-wide comparative analysis of palm TEs, focusing on identifying and classifying TEs using the draft assemblies of four palm species: Phoenix dactylifera, Cocos nucifera, Calamus simplicifolius, and Elaeis oleifera. Our TE library was generated using both de novo structure-based and homology-based methodologies. Results: The generated libraries revealed the TE component of each assembly, which varied from 41-81%. Class I retrotransposons covered 36-75% of these species' draft genome sequences and primarily consisted of LTR retroelements, while non-LTR elements covered about 0.56-2.31% of each assembly, mainly as LINEs. The least represented were Class DNA transposons, comprising 1.87-3.37%. Conclusion: The current study contributes to a detailed identification and characterization of transposable elements in Palmae draft genome assemblies.

Voltage-sensitive sodium channel (Vssc) mutations associated with pyrethroid insecticide resistance in Aedes aegypti (L.) from two districts of Jeddah, Kingdom of Saudi Arabia: baseline information for a Wolbachia release program

Background

Dengue suppression often relies on control of the mosquito vector, Aedes aegypti, through applications of insecticides of which the pyrethroid group has played a dominant role. Insecticide resistance is prevalent in Ae. aegypti around the world, and the resulting reduction of insecticide efficacy is likely to exacerbate the impact of dengue. Dengue has been a public health problem in Saudi Arabia, particularly in Jeddah, since its discovery there in the 1990s, and insecticide use for vector control is widespread throughout the city. An alternative approach to insecticide use, based on blocking dengue transmission in mosquitoes by the endosymbiont Wolbachia, is being trialed in Jeddah following the success of this approach in Australia and Malaysia. Knowledge of insecticide resistance status of mosquito populations in Jeddah is a prerequisite for establishing a Wolbachia-based dengue control program as releases of Wolbachia mosquitoes succeed when resistance status of the release population is similar to that of the wild population.

Methods

WHO resistance bioassays of mosquitoes with deltamethrin, permethrin and DDT were used in conjunction with TaqMan^® SNP Genotyping Assays to characterize mutation profiles of Ae. aegypti.

Results

Screening of the voltage-sensitive sodium channel (Vssc), the pyrethroid target site, revealed mutations at codons 989, 1016 and 1534 in Ae. aegypti from two districts of Jeddah. The triple mutant homozygote (1016G/1534C/989P) was confirmed from Al Safa and Al Rawabi. Bioassays with pyrethroids (Type I and II) and DDT showed that mosquitoes were resistant to each of these compounds based on WHO definitions. An association between Vssc mutations and resistance was established for the Type II pyrethroid, deltamethrin, with one genotype (989P/1016G/1534F) conferring a survival advantage over two others (989S/1016V/1534C and the triple heterozygote). An indication of synergism of Type I pyrethroid activity with piperonyl butoxide suggests that detoxification by cytochrome P450s accounts for some of the pyrethroid resistance response in Ae. aegypti populations from Jeddah.

Conclusions

The results provide a baseline for monitoring and management of resistance as well as knowledge of Vssc genotype frequencies required in Wolbachia release populations to ensure homogeneity with the target field population. Vssc mutation haplotypes observed show some similarity with those from Ae. aegypti in southeast Asia and the Indo-Pacific, but the presence of the triple mutant haplotype in three genotypes indicates that the species in this region may have a unique population history.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04867-3.

Oral gel loaded with penciclovir-lavender oil nanoemulsion to enhance bioavailability and alleviate pain associated with herpes labialis

Herpes labialis, caused by herpes simplex virus type 1, is usually characterized by painful skin or mucosal lesions. Penciclovir (PV) tablets are found to be effective against herpes labialis but suffer from poor oral bioavailability. This study aimed to combine the benefits of PV and lavender oil (LO), which exhibits anesthetic activity, in the form of a self-nanoemulsifying drug delivery system (SNEDDS) for the treatment of herpes labialis. Toward this purpose, LO (oil), Labrasol:Labrafil M1944 CS in the ratio of 6:4 (surfactant mixture), and Lauroglycol-FCC (co-surfactant, selected based on the solubility of PV) were evaluated as the independent factors using a distance quadratic mixture design. The formulation was optimized for the minimum globule size and maximum stability index and was determined to contain 14% LO, 40.5% Labrasol:Labrafil 1944 (6:4), and 45.5% Lauroglycol-FCC. The optimized PV-LO-SNEDDS was embedded in chitosan hydrogel and the resulting formulations coded by (O3) were prepared and evaluated. The rheological studies demonstrated a combined pseudoplastic and thixotropic behavior with the highest flux of PV permeation across sheep buccal mucosa. Compared to a marketed 1% PV cream, the O3 formulation exhibited a significantly higher and sustained PV release, nearly twice the PV permeability, and a relative bioavailability of 180%. Overall, results confirm that the O3 formulation can provide an efficient delivery system for PV to reach oral mucosa and subsequent prolonged PV release. Thus, the PV-LO-SNEDDS embedded oral gel is promising and can be further evaluated in clinical settings to establish its therapeutic use in herpes labialis.

CRISPR technology: new paradigm to target the infectious disease pathogens

OBJECTIVE

Infectious diseases are one of the prime causes of death worldwide. An innovative sequence specific editing technology "Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)" has been tested on a broad range of microorganisms to target and destroy invading foreign DNA to human cells or tissues. This study aimed to discuss the mechanism and therapeutic usage of CRISPR/Cas9 genome editing technology in the management of various infectious disease pathogens.

MATERIALS AND METHODS

We conducted a broad search of the English-language literature in "PubMed" using the search terms "CRISPR", "Cas-9", "Genome editing", "Gene therapy", "infectious disease pathogens". All the articles were reviewed and required information was recorded.

RESULTS

CRISPR technology is used to modify and modulate the gene expression in biomedical research and therapeutic development. This technology facilitates the understanding of fundamental biology and broadens the horizon of treatments of germ-laden conditions.

CONCLUSIONS

The applications of CRISPR technology are widely established in the diagnosis and treatment of various bacterial, viral, fungal and parasitic infectious diseases. CRISPR technology is a simple, efficient and tested on a broad range of microorganisms to rectify disease-associated genetic defects and destroy invading foreign DNA to human cells or tissues.

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection: epidemiology, pathogenesis and clinical characteristics

OBJECTIVE

Middle East Respiratory Syndrome Coronavirus-(MERS-CoV) infection is an evolving worldwide health crisis. The early diagnosis and management of the disease remains a major challenge. This study designed to discuss the epidemiology, pathogenesis and clinical appearances of MERS-CoV infections.

MATERIALS AND METHODS

We conducted a broad search of the English-language literature in "PubMed" "Medline" "Web of knowledge", "EMBASE" and "Google Scholar" World Health Organization-WHO" using the key words "Middle East Respiratory Syndrome", "MERS", "MERS-CoV" "Epidemiology" "Transmission" "Pathogenesis" "Clinical Characteristics". We reviewed the literature on epidemiology, pathogenesis and clinical appearances of MERS-CoV infection and the required information was documented.

RESULTS

The global prevalence of MERS-CoV infection from June 2012 to April 2018 is 2206 people. The number of cases reported from Saudi Arabia is 1831 (83%) with mortality rate of 787 (35.67%). The main clinical manifestations are fever, chills, generalized myalgia, cough, shortness of breath, nausea, vomiting and diarrhea. The age-allied prevalence of MERS-CoV was highest amongst elderly people with chronic debilitating diseases such as pulmonary diseases, end-stage renal illness, diabetes mellitus and malignancy.

CONCLUSIONS

MERS-CoV infection is an emerging global health concern, affected people in 27 countries in the various continents. MERS-CoV infection has been identified mainly in the Middle East, Europe, Africa, Asia and North America. Early detection and management of MERS-CoV infection is of critical importance to minimize the burden of the disease.

Global seasonal occurrence of middle east respiratory syndrome coronavirus (MERS-CoV) infection

OBJECTIVE

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is an evolving global health crisis. Despite recent efforts, there are numerous notable gaps in the understanding of MERS-CoV seasonal diversity. We aimed at investigating the global seasonal occurrence of Middle East Respiratory Syndrome coronavirus (MERS-CoV) outbreaks.

MATERIALS AND METHODS

We obtained the data on the prevalence and occurrence of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection from the World Health Organization (WHO) for all the MERS cases reported from the various countries and their allied ministries. We also recorded the research documents published in various global scientific journals on the seasonal occurrence of MERS-CoV infection during the period 2012-2017.

RESULTS

Worldwide 2048 laboratory confirmed cases of MERS-CoV infection were reported from June 2012 to the Dec 2017. 1680 (82.03%) cases were from the Saudi Arabia and 368 (17.96%) cases were reported from the other countries of the world. The maximum number of cases reported in June was 474 (23.14%). 287 (14.01%) cases were reported from Saudi Arabia and remaining 187 (9.13%) cases were reported from all over the world. The number of cases reported from April to June was 396 (19.33%) while the cases encountered from October to December were 231 (11.27%).

CONCLUSIONS

The highest global seasonal occurrence of Middle East Respiratory Syndrome coronavirus-MERS-CoV outbreak cases were found in the month of June, while the lowest was found in the month of January during the period of 2012 to 2017. The pattern of MERS-CoV infections has been observed to have seasonal variations. It is suggested that the health officials should highlight the seasonal occurrence of MERS-CoV outbreak and take better preventive measures to minimize the disease burden nationally and globally.

Cellular responses of hyaluronic acid-coated chitosan nanoparticles

In recent years, nanotechnology has been proven to offer promising biomedical applications for in vivo diagnostics and drug delivery, stressing the importance of thoroughly investigating the biocompatibility of potentially translatable nanoparticles (NPs). Herein, we report the cellular responses of uncoated chitosan NPs (CS NPs) and hyaluronic acid-coated chitosan NPs (HA-CS NPs) when introduced into Chinese hamster ovary cells (CHO-K1) in a dose-dependent manner (2.5, 0.25, 0.025, 0.0025, and 0.00025 mg mL-1) at two time points (24 and 48 h). MTS assay, cell proliferation, showed a decrease in the viability of cells when treated with 0.25 and 2.5 mg mL-1 CS NPs. When exposed to high doses of CS NPs, the lactate dehydrogenase (LDH) enzyme started to leak out of the cells and the cellular levels of mitochondrial potentials were significantly reduced accompanied by a high production of intracellular reactive oxygen species (ROS). Our study provides molecular evidence of the biocompatibility offered by HA-CS NPs, through ROS scavenging capabilities rescuing cells from the oxidative stress, showing no observed cellular stress and thereby revealing the promising effect of anionic hyaluronic acid to significantly reduce the cytotoxicity of CS NPs. Our findings are important to accelerate the translation and utilization of HA-CS NPs in drug delivery, demonstrating the pronounced effect of surface modifications on modulating the biological responses.

CRISPR technology: new paradigm to target the infectious disease pathogens

OBJECTIVE

Infectious diseases are one of the prime causes of death worldwide. An innovative sequence specific editing technology "Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)" has been tested on a broad range of microorganisms to target and destroy invading foreign DNA to human cells or tissues. This study aimed to discuss the mechanism and therapeutic usage of CRISPR/Cas9 genome editing technology in the management of various infectious disease pathogens.

MATERIALS AND METHODS

We conducted a broad search of the English-language literature in "PubMed" using the search terms "CRISPR", "Cas-9", "Genome editing", "Gene therapy", "infectious disease pathogens". All the articles were reviewed and required information was recorded.

RESULTS

CRISPR technology is used to modify and modulate the gene expression in biomedical research and therapeutic development. This technology facilitates the understanding of fundamental biology and broadens the horizon of treatments of germ-laden conditions.

CONCLUSIONS

The applications of CRISPR technology are widely established in the diagnosis and treatment of various bacterial, viral, fungal and parasitic infectious diseases. CRISPR technology is a simple, efficient and tested on a broad range of microorganisms to rectify disease-associated genetic defects and destroy invading foreign DNA to human cells or tissues.