Redescription of Cyprinion muscatense (Teleostei: Cyprinidae) with the first phylogenetic analysis of the genus.

Members of the genus Cyprinion (Cypriniformes: Cyprinidae) are found in the Indus River basin west to the Arabian Peninsula and the Tigris-Euphrates River drainages (Persian Gulf basin). The taxonomic status of Cyprinion including Cyprinion muscatense is poorly understood when compared to other cyprinid genera. C. muscatense has been considered as a member of the Cyprinion watsoni-microphthalmum group and a valid species endemic to the Arabian Peninsula. Here, we redescribe C. muscatense based on an integrative morphological and molecular approach and freshly sampled material from several localities in the Oman Mountains ecoregion. The results showed that C. muscatense is distinguished from the other Cyprinion species in the Arabian Peninsula by having a short, thin, and slightly serrated last unbranched dorsal fin ray; the lower number of circumpeduncular scales; lateral line scales; and also scales between the lateral line and the dorsal-fin origin. Subterminal mouth, presence of one pair of small barbels at the mouth corner, 3-4 unbranched and 9½-10½ dorsal-fin branched rays, 12-14 pectoral-fin rays, 7-8 pelvic-fin rays, 2-3 unbranched and 6½-7½ branched anal-fin rays, and 37-40 lateral line scales are other morphological characteristics of C. muscatense. C. muscatense is also well distinguished by molecular characters among its congeners. The first molecular phylogenetic analysis of the genus, covering all currently recognized Cyprinion species except for C. watsoni, is also presented. C. muscatense is resolved as the sister species to another endemic fish of the Arabian Peninsula Cyprinion mhalense, with a Kimura-2-Parameter model distance of 5.3%.

Genome-Wide Characterization of Arabian Peninsula Populations: Shedding Light on the History of a Fundamental Bridge between Continents.

The Arabian Peninsula (AP) was an important crossroad between Africa, Asia, and Europe, being the cradle of the structure defining these main human population groups, and a continuing path for their admixture. The screening of 741,000 variants in 420 Arabians and 80 Iranians allowed us to quantify the dominant sub-Saharan African admixture in the west of the peninsula, whereas South Asian and Levantine/European influence was stronger in the east, leading to a rift between western and eastern sides of the Peninsula. Dating of the admixture events indicated that Indian Ocean slave trade and Islamization periods were important moments in the genetic makeup of the region. The western-eastern axis was also observable in terms of positive selection of diversity conferring lactose tolerance, with the West AP developing local adaptation and the East AP acquiring the derived allele selected in European populations and existing in South Asia. African selected malaria resistance through the DARC gene was enriched in all Arabian genomes, especially in the western part. Clear European influences associated with skin and eye color were equally frequent across the Peninsula.

Coronavirus nCOVID-19: A pandemic disease and the Saudi precautions.

Now nCOVID-19 has a foothold in many countries, and the threat of a pandemic situation has risen. Recently a novel coronavirus (nCOVID-19) has first emerged in China, causing multiple symptoms in humans and closely related to those caused by SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome). The nCOVID-19 has reported in Wuhan city of China has recently infected over six million people and at least 0.4 million confirmed deaths all over the world, while 2.8 million people has recovered from this deadly virus. Many instances of this respiratory syndrome coronavirus infection have already reported in more than 216 countries and territories. In contrast, the majority of cases reported in the USA, Brazil, Russia, Spain, UK, Italy, France and many more countries. In today's context, the coronavirus is one of the significant issues faced by the world with plenty of cases. In these circumstances, rapid reviews which recommended by WHO (World Health Organization), and these recommendations are very significant, helpful and cover current data with different preventive measures developed by the Saudi CDC (Saudi Centre for Disease Prevention and Control). This review article describes the possible modes of transmission so that proper preventive actions should be taking. Importantly, this work mentioned the animal reservoir through which may infect humans, and it must be identified to break the transmission chain. In additions, this review paper briefly discussed the spread of the coronavirus in the Arabian Peninsula and what precaution measures are in place by each country to limit the spreading of this virus. Finally, since the number of infected people specifically those with close contact with nCOVID-19 patients is increasing daily and appears unstoppable, we used the preventive measures by pharmacists as part of health care professions.

Biogeography of Mesalina (Reptilia: Lacertidae), with special emphasis on the Mesalina adramitana group from Arabia and the Socotra Archipelago.

The lacertid lizards of the genus Mesalina inhabit the arid regions of the Old World, from North Africa to NW India. Of the 19 recognized species within the genus, eleven occur in Arabia. In this study, we explore the genetic variability and phylogeographic patterns of the less studied M. adramitana group from southern Arabia and the Socotra Archipelago within the phylogenetic and biogeographic context of the entire genus. Our unprecedented sampling extends the distribution ranges of most Mesalina species and, for the first time, sequences of M. ayunensis are included in a phylogenetic analysis. We perform analyses of concatenated multilocus datasets and species trees, conduct species delimitation analyses, and estimate divergence times within a biogeographic framework. Additionally, we inferred the environmental suitability and identified dispersal corridors through which gene flow is enabled within M. adramitana. Our results show that the Socotra Archipelago was colonized approximately 7 Mya by a single oversea colonization from mainland Arabia. Then, an intra-archipelago dispersal event that occurred approximately 5 Mya resulted in the speciation between M. balfouri, endemic to Socotra, Samha and Darsa Islands, and M. kuri, endemic to Abd al Kuri Island. Similar to previous studies, we uncovered high levels of genetic diversity within the M. adramitana species-group, with two highly divergent lineages of M. adramitana living in allopatry and adapted to locally specific climatic conditions that necessitate further investigation.

Islands in the desert: environmental distribution modelling of endemic flora reveals the extent of Pleistocene tropical relict vegetation in southern Arabia.

BACKGROUND AND AIMS: Southern Arabia is a global biodiversity hotspot with a high proportion of endemic desert-adapted plants. Here we examine evidence for a Pleistocene climate refugium in the southern Central Desert of Oman, and its role in driving biogeographical patterns of endemism. METHODS: Distribution data for seven narrow-range endemic plants were collected systematically across 195 quadrats, together with incidental and historic records. Important environmental variables relevant to arid coastal areas, including night-time fog and cloud cover, were developed for the study area. Environmental niche models using presence/absence data were built and tuned for each species, and spatial overlap was examined. KEY RESULTS: A region of the Jiddat Al Arkad reported independent high model suitability for all species. Examination of environmental data across southern Oman indicates that the Jiddat Al Arkad displays a regionally unique climate with higher intra-annual stability, due in part to the influence of the southern monsoon. Despite this, the relative importance of environmental variables was highly differentiated among species, suggesting that characteristic variables such as coastal fog are not major cross-species predictors at this scale. CONCLUSIONS: The co-occurrence of a high number of endemic study species within a narrow monsoon-influenced region is indicative of a refugium with low climate change velocity. Combined with climate analysis, our findings provide strong evidence for a southern Arabian Pleistocene refugium in Oman's Central Desert. We suggest that this refugium has acted as an isolated temperate and mesic island in the desert, resulting in the evolution of these narrow-range endemic flora. Based on the composition of species, this system may represent the northernmost remnant of a continuous belt of mesic vegetation formerly ranging from Africa to Asia, with close links to the flora of East Africa. This has significant implications for future conservation of endemic plants in an arid biodiversity hotspot.

Arabian Peninsula ethnicity is associated with lower ovarian reserve and ovarian response in women undergoing fresh ICSI cycles.

PURPOSE: Recent studies have demonstrated that ethnicity can be an independent determinant of assisted reproductive technology (ART) outcomes. In this context, we investigate whether ART outcomes differ between Arabian Peninsula and Caucasian women. METHODS: This is a retrospective cohort study of women undergoing fresh intracytoplasmic sperm injection (ICSI)-embryo transfer (ET) cycles for male factor infertility. The study cohort was divided into 2 groups based on ethnicity-Arabian Peninsula or Caucasian. Ovarian reserve, ovarian response, and pregnancy outcomes were compared between the groups. A sub-analysis was performed between individual Arabian Peninsula nationalities for the same outcomes. A multiple linear regression model was used to assess the independent effect of ethnicity on ovarian response. RESULTS: Seven hundred sixty-three patients were included-217 (28.4%) Arabian Peninsula and 546 (71.6%) Caucasian. There was no difference in the mean age of the two groups; however, the former had a higher body mass index (28.5 ± 7.5 vs. 23.3 ± 5.7; P < 0.001). Although follicle stimulating hormone (FSH) levels and antral follicle counts (AFC) were within the normal range in both groups, Arabian Peninsula women had higher FSH levels (5.7 ± 2.5 vs. 4.9 ± 2.8; P = 0.001) and lower AFC (13.9 ± 4.7 vs. 16.5 ± 4.3; P < 0.001) when compared to Caucasian women. Women from the Arabian Peninsula also had a statistically lower number of mature oocytes retrieved (15.6 ± 6.8 vs. 14.1 ± 8.4; P = 0.01), despite requiring higher gonadotropin doses. Multiple linear regression reveled that Arabian Peninsula women had 2.5 (95% CI 2.1-3.9) less mature oocytes, even after controlling for confounders. A sub-analysis within the Arab cohort demonstrated that Qatari women had a higher yield of mature oocytes when compared to Emirati, Kuwaiti, and Saudi women. There was no difference in the rates of implantation, clinical pregnancy, or live birth when comparing individual Arabian Peninsula nationalities with each other or to Caucasians. CONCLUSIONS: Arabian Peninsula ethnicity is associated with lower ovarian reserve and ovarian response parameters in women undergoing their first ICSI-ET cycle.

A Systematic Review of the Prevalence of Atopic Diseases in Children on the Arabian Peninsula.

OBJECTIVES: To study the available data on the prevalence of atopic diseases and food allergy in children living on the Arabian Peninsula. METHODS: A PubMed search for relevant published articles was conducted using the following search terms singly or in combination: "atopy," "atopic disease," "atopic disorder," "International Study of Asthma and Allergies in Childhood," "ISAAC," "asthma," "allergic rhinitis," "eczema," and "food allergy" in combination with the names of countries of the Arabian Peninsula (Kuwait, United Arab Emirates, Bahrain, Qatar, Oman, Kingdom of Saudi Arabia, and Yemen). The search captured studies published up to December 2017. RESULTS: A total of 8 publications reporting prevalence rates of any type of atopic disease in children in 7 countries of the Arabian Peninsula were retrieved. The prevalence of all atopic disorders was comparable between countries of the Arabian Peninsula. The overall prevalence of asthma ranged from 8 to 23%, while the reported prevalence of eczema ranged from 7.5 to 22.5%. There was great variation in the prevalence rates of rhinoconjunctivitis, which ranged from 6.3 to 30.5%. The prevalence of food allergy (8.1%) was reported for 1 country only, the United Arab Emirates. CONCLUSIONS: The reported overall rates of atopic disease in countries of the Arabian Peninsula are comparable to those reported in other industrialized countries. This is probably related to the good economic status in the region, which is reflected in the living standards and lifestyle. Further, genetic factors, such as factors related to gene polymorphism, and the high rate of consanguinity in the region may contribute to the higher prevalence of atopic diseases.

Comprehensive view of the population history of Arabia as inferred by mtDNA variation.

OBJECTIVES: Genetic and archaeological research supports the theory that Arabia was the first region traversed by modern humans as they left Africa and dispersed throughout Eurasia. However, the role of Arabia from the initial migration out of Africa until more recent times is still unclear. MATERIALS AND METHODS: We have generated 379 new hypervariable segment 1 (HVS-1) sequences from a range of geographic locations throughout Yemen. We compare these data to published HVS-1 sequences representing Arabia and neighboring regions to build a unique dataset of 186 populations and 14,290 sequences. RESULTS: We identify 4,563 haplotypes unevenly distributed across Arabia and neighboring regions. Arabia contains higher proportions of shared haplotypes than the regions with which it shares these haplotypes, suggesting high levels of migration through the region. Populations in Arabia show higher levels of population expansion than those in East Africa, but lower levels than the Near East, Middle East or India. Arabian populations also show very high levels of genetic variation that overlaps with variation from most other regions. CONCLUSION: We take a population genetics approach to provide a comprehensive view of the relationships of Arabian and neighboring populations. We show that Arabian populations share closest links to the Near East and North Africa, but have a more ancient origin with slower demographic growth and/or lower migration rates. Our conclusions are supported by phylogenetic studies but also suggest that recent migrations have erased signals of earlier events.

MERS and the dromedary camel trade between Africa and the Middle East.

Dromedary camels are the most likely source for the coronavirus that sporadically causes Middle East respiratory syndrome (MERS) in humans. Serological results from archived camel sera provide evidence for circulation of MERS coronavirus (MERS-CoV) among dromedary camels in the Greater Horn of Africa as far back as 1983 and in Saudi Arabia as far back as 1992. High seroprevalences of MERS-CoV antibodies and the high virus prevalence in Saudi Arabian dromedary camels indicate an endemicity of the virus in the Arabian Peninsula, which predates the 2012 human MERS index case. Saudi Arabian dromedary camels show significantly higher MERS-CoV carrier rates than dromedary camels imported from Africa. Two MERS-CoV lineages identified in Nigerian camels were found to be genetically distinct from those found in camels and humans in the Middle East. This supports the hypothesis that camel imports from Africa are not of significance for circulation of the virus in camel populations of the Arabian Peninsula.

Geographic distribution of MERS coronavirus among dromedary camels, Africa.

We found serologic evidence for the circulation of Middle East respiratory syndrome coronavirus among dromedary camels in Nigeria, Tunisia, and Ethiopia. Circulation of the virus among dromedaries across broad areas of Africa may indicate that this disease is currently underdiagnosed in humans outside the Arabian Peninsula.

Replicative Capacity of MERS Coronavirus in Livestock Cell Lines.

Replicative capacity of Middle East respiratory syndrome coronavirus (MERS-CoV) was assessed in cell lines derived from livestock and peridomestic small mammals on the Arabian Peninsula. Only cell lines originating from goats and camels showed efficient replication of MERS-CoV. These results provide direction in the search for the intermediate host of MERS-CoV.

Evolution of the stapeliads (Apocynaceae-Asclepiadoideae) - repeated major radiation across Africa in an Old World group.

The stapeliads of the Ceropegieae (Apocynaceae-Asclepiadoideae), are approximately 340 species of stem-succulents placed in around 30 genera, found in semi-arid parts of the Old World. Here we sampled 192 species (i.e. nearly two thirds of the total) from across the full geographic range of the group and analysed data from the two nuclear regions (nuclear ribosomal ITS and ncpGS) and five plastid regions (psbA-trnH intergenic spacer, rps16 intron, trnL-trnF intergenic spacer, trnS-trnG intergenic region and the non-coding rpl32-trnL region). We find that the stapeliads radiated first in the northern hemisphere from Africa to southern Europe and Myanmar. This radiation subtends a grade of minor clades in the south-western corner of the African continent. These were followed by a single clade containing major radiation back across Africa from South Africa to tropical Arabia (but no further east than Dhofar, Oman), which includes also a single early spread into Madagascar. We establish the monophyly of many of the genera, such as Echidnopsis Hook.f., Hoodia Hook., Huernia R. Br., Piaranthus R. Br., Rhytidocaulon P.R.O. Bally and Tridentea Haw., but find that Duvalia Haw., Orbea Haw., Stapelia L. and Tromotriche Haw. are polyphyletic. We show that in certain vegetative features, there is broad cohesion across clades. Florally, on the other hand, the stapeliads exhibit considerable plasticity and we are able to show that very differently shaped flowers as well as large and small flowers evolved repeatedly among closely related species.

Three new species of arbuscular mycorrhizal fungi discovered at one location in a desert of Oman: Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus.

Three new species of arbuscular mycorrhizal (AM) fungi (Glomeromycota) were isolated from soil samples collected from a hyperarid sandy plain of South Arabia. Morphological characteristics of the spores clearly differentiated them from closely related AM species. Molecular analyses were performed on rDNA sequences obtained from single spores including a ~1700 bp region comprising partial SSU, ITS, partial LSU and the ~600 bp ITS region only. The phylogenetic trees based on these regions showed that the three species belong to well described genera but are clearly distinct from known species. Consequently, we describe them here as Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus spp. nov. D. omaniana and R. arabicus were isolated from the native, arid habitat, while S. nakheelum was isolated from a nearby irrigated date palm plantation. The discovery of three new species of AM fungi from this location suggests that a number of additional undescribed AM taxa may be present in such desert ecosystems. Further work to understand the diversity and functional significance of these new AM taxa may offer new opportunities for conservation, re-vegetation, and sustainable agriculture in extremely arid environments.

Predicting climate change impacts on the distribution of endemic fish Cyprinion muscatense in the Arabian Peninsula.

Freshwater fishes are facing considerable threats in the Arabian Peninsula which is considered as a highly stressed region in the Middle East. It is predicted that northern Oman is likely to face decreasing rainfall and increasing temperature in coming decades. In this study, we focused on an endemic cyprinid fish Cyprinion muscatense, as a model to investigate impacts of climate change on the mountain fishes inhibiting in this arid region. This species is expected to be strongly affected by climate change because of its limited distribution range in a montane area surrounded by lowlands and sea, limiting the species in shift to other areas. We used an ensemble approach by considering two regressions-based species distribution modeling (SDM) algorithms: generalized linear models (GLM), and generalized additive models (GAM) to model the species habitat suitability and predict the impacts of climate change on the species habitat suitability. Based on the distribution models, the montane area located in northeastern Oman was identified as the most suitable habitat for this species. Our results indicate that, even under the minimum greenhouse gas emissions scenario (RCP 2.6), climate change will produce a high reduction in its potential future habitats. According to the results of percent contribution, elevation and annual minimum temperature were the most important variables in predicting the species suitable habitats. Results also showed that only a small percentage of suitable habitats for the species within boundaries of protected areas. Therefore, the impact of climate change on the species appears particularly alarming. Although our study was restricted to a single cyprinid freshwater species, decreases in potential habitats are likely predicted for other cyprinid fish species restricted to the mountains of this region, suggesting severe consideration is needed for aquatic systems in future conservation planning, especially for endemic freshwater fishes.

Diversity, Distribution, and applications of arbuscular mycorrhizal fungi in the Arabian Peninsula.

Investigations of arbuscular mycorrhizal fungi (AMF) received extreme interests among scientist including agronomists and environmental scientists. This interest is linked to advantages provided by AMF in enhancing the nutrients of their hosts via improving photosynthetic pigments and antioxidant production. Further, it also positively alters the production of plant hormones. AMF through its associations with plants obtain carbon while in exchange, provide nutrients. AMF have been reported to improve the growth of Tageteserecta, Zea mays, Panicum turgidum, Arachis hypogaea, Triticum aestivum and others. This review further documented the occurrence, diversity, distribution, and agricultural applications of AMF species reported in the Arabian Peninsula. Overall, we documented 20 genera and 61 species of Glomeromycota in the Arabian Peninsula representing 46.51 % of genera and 17.88 % of species of AMF known so far. Funneliformis mosseae has found to be the most widely distributed species followed by Claroideoglomus etuicatum. There are 35 research articles focused on Arabian Peninsula where the stress conditions like drought, salinity and pollutants are prevailed. Only one group studied the influence of AMF on disease resistance, while salinity, drought, and cadmium stresses were investigated in 18, 6, and 4 investigations, respectively. The genus Glomus was the focus of most studies. The conducted research in the Arabian Peninsula is not enough to understand AMF taxonomy and their functional role in plant growth. Expanding the scope of detection of AMF, especially in coastal areas is essential. Future studies on biodiversity of AMF are essential.

Chemical composition of indoor and outdoor PM2.5 in the eastern Arabian Peninsula.

Water-soluble and trace metal species in fine particulate matter (PM2.5) were determined for indoor and outdoor environments in Doha, Qatar. During the study period, PM2.5 concentrations showed significant variability across several indoor locations ranging from 7.1 to 75.8 µg m-3, while the outdoor mass concentration range was 34.7-154.4 µg m-3. The indoor and outdoor PM2.5 levels did not exhibit statistically significant correlation, suggesting efficient building envelope protection against outdoor PM2.5 pollution. Rather than outdoor sources, human activities such as cooking, cleaning, and smoking were the most significant influence on chemical composition of indoor PM2.5. NH4+ concentration was insufficient to neutralize SO42- indoors and outdoors, indicating the predominant presence of NH4HSO4. The enrichment factors indicated that outdoor Fe, Mn, Co, Cr, and Ni in PM2.5 mostly originated from crustal sources. In contrast, the remaining outdoor trace metals (Cu, Zn, As, Cd, Pb, and V) were mainly derived from anthropogenic sources. The indoor/outdoor concentration ratios revealed significant indoor sources for NH4+ and Cu. The crustal matter, water-soluble ions, and sea salt explained 42%, 21%, and 1% of the indoor PM2.5 mass, respectively. The same groups sequentially constituted 41%, 16%, and 1% of the outdoor PM2.5 mass.

Amplification of temperature extremes in Arabian Peninsula under warmer worlds.

The Paris Agreement and the Special Report on Global Warming of 1.5 °C from the Intergovernmental Panel on Climate Change (IPCC) highlighted the potential risks of climate change across different global warming levels (GWLs). The increasing occurrence of extreme high-temperature events is linked to a warmer climate that is particularly prevalent in the Arabian Peninsula (AP). This study investigates future changes in temperatures and related extremes over AP, under four GWLs, such as 1.5 °C, 2.0 °C, 3.0 °C, and 4.0 °C, with three different Shared Socioeconomic Pathways (SSPs: SSP1-2.6, SSP2-4.5, and SSP5-8.5). The study uses high-resolution datasets of 27 models from the NASA Earth Exchange Global Daily Downscaled Projections of the Coupled Model Intercomparison Project Phase 6 (NEX-GDDP-CMIP6). The results showed that the NEX-GDDP-CMIP6 individual models and their multi-model means reasonably captured the extreme temperature events. The summer maximum and winter minimum temperatures are projected to increase by 0.11-0.67 °C and 0.09-0.70 °C per decade under the selected SSPs. Likewise, the projected temperature extremes exhibit significant warming with varying degrees across the GWLs under the selected SSPs. The warm temperature extremes are projected to increase, while the cold extremes are projected to decrease under all GWLs and the selected SSPs. Overall, the findings provide a comprehensive assessment of temperature changes over AP in response to global warming, which can be helpful in the development of climate adaptation and mitigation strategies.

Biogeography and Conservation in the Arabian Peninsula: A Present Perspective.

The Arabian Peninsula, with its rugged mountains, wadis, alluvial plains, sand dune deserts, and diverse coastlines, spans over 3 million km2. The Peninsula is situated at the crossroads of Africa and Asia and is a meeting point for diverse biogeographic realms, including the Palearctic, Afrotropical, and Indomalayan regions. This convergence of biogeographic zones has resulted in a remarkably diverse flora and fauna, which is adapted to the harsh and varied climates found throughout the Peninsula. Each of the countries of the Arabian Peninsula are biologically diverse and unique in their own right, but Yemen, Saudi Arabia, and Oman are the most diverse in terms of their landforms and biological diversity. The mountainous regions support a cooler and more moderate climate compared to the surrounding lowlands, thus forming unique ecosystems that function as refugia for plant and animal species, and have a high endemism of plant species. The desert ecosystems support a variety of lifeforms that are specially adapted to an extreme arid climate. Due to its long history of human habitation and subsistence agriculture, particularly in the mountainous areas, the Arabian Peninsula possesses unique crop varieties adapted to extreme arid climates, making them important genetic resources for the future in the face of climate change. The Arabian Peninsula, though rich and diverse in its biological diversity, has been greatly affected by human activities, especially in the last 50 years, including urbanization, habitat destruction, overgrazing, and climate change, which pose significant threats to the biodiversity of the region. This review presents the biogeography and background of conservation efforts made in the countries in the Arabian Peninsula and gives the progress made in botanical research and conservation practices throughout the Peninsula.

High-throughput sequencing reveals the structure and metabolic resilience of desert microbiome confronting climate change.

Introduction: Desert ecosystems harbor a unique microbial diversity that is crucial for ecological stability and biogeochemical cycles. An in-depth understanding of the biodiversity, compositions, and functions of these microbial communities is imperative to navigate global changes and confront potential threats and opportunities applicable to agricultural ecosystems amid climate change. Methods: This study explores microbial communities in the rhizosphere and endosphere of desert plants native to the Arabian Peninsula using next-generation sequencing of the 16S rRNA gene (V3-V4 hypervariable region). Results: Our results reveal that each microbial community has a diverse and unique microbial composition. Based on alpha and beta diversity indices, the rhizosphere microbiome is significantly diverse and richer in microbial taxa compared to the endosphere. The data reveals a shift towards fast-growing microbes with active metabolism, involvement in nutrient cycling, nitrogen fixation, and defense pathways. Our data reveals the presence of habitat-specific microbial communities in the desert, highlighting their remarkable resilience and adaptability to extreme environmental conditions. Notably, we observed the existence of radiation-resistant microbes such as Deinococcus radiotolerans, Kocuria sp., and Rubrobacter radiotolerans which can tolerate high levels of ionizing radiation. Additionally, examples of microbes exhibiting tolerance to challenging conditions include Nocardioides halotolerans, thriving in high-salinity environments, and hyperthermophilic microbes such as Quasibacillus thermotolerans. Moreover, functional analysis reveals enrichment in chaperon biosynthesis pathways associated with correct protein folding under heat stress conditions. Discussion: Our research sheds light on the unique diversity of desert microbes and underscores their potential applications to increase the resilience of agriculture ecosystems, offering a promising strategy to fortify crops against the challenges posed by climate change, ultimately supporting sustainable food production for our ever-expanding global population.

Microsatellite-based analysis reveals Aedes aegypti populations in the Kingdom of Saudi Arabia result from colonization by both the ancestral African and the global domestic forms.

The Aedes aegypti (Linnaeus, 1762) mosquito is the main vector of dengue, chikungunya and Zika and is well established today all over the world. The species comprises two forms: the ancestral form found throughout Africa and a global domestic form that spread to the rest of the tropics and subtropics. In Saudi Arabia, A. aegypti has been known in the southwest since 1956, and previous genetic studies clustered A. aegypti from Saudi Arabia with the global domestic form. The purpose of this study was to assess the genetic structure of A. aegypti in Saudi Arabia and determine their geographic origin. Genetic data for 17 microsatellites were collected for A. aegypti ranging from the southwestern highlands of Saudi Arabia on the border of Yemen to the north-west in Madinah region as well as from Thailand and Uganda populations (as representatives of the ancestral African and global domestic forms, respectively). The low but significant level of genetic structuring in Saudi Arabia was consistent with long-distance dispersal capability possibly through road connectivity and human activities, that is, passive dispersal. There are two main genetic groupings in Saudi Arabia, one of which clusters with the Ugandan population and the other with the Thailand population with many Saudi Arabian individuals having mixed ancestry. The hypothesis of genetic admixture of the ancestral African and global domestic forms in Saudi Arabia was supported by approximate Bayesian computational analyses. The extent of admixture varied across Saudi Arabia. African ancestry was highest in the highland area of the Jazan region followed by the lowland Jazan and Sahil regions. Conversely, the western (Makkah, Jeddah and Madinah) and Najran populations corresponded to the global domesticated form. Given potential differences between the forms in transmission capability, ecology and behaviour, the findings here should be taken into account in vector control efforts in Saudi Arabia.