首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
The maximum rise in blood glucose after 50 g lactose by mouth was determined in 40 adult Arabs. Out of 30 Bedouin, urban Saudi, and Yemeni and 9 of mixed ancestry (usually partly African), 25 (83%) and 2 (22%) respectively showed an increase of over 1-1 mmol/1 (20 mg/100 ml). In common with most northern Europeans and Hamitic people of northern Africa, Arabs in Saudi Arabia usually have high intestinal lactase concentrations in adult life. This persistence of high levels probably originated in the Arabian peninsula. Its selective advantage may have been associated with the fluid and calorie content of camels'' milk, which is important for survival in desert nomads.  相似文献   

2.
Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (∼75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids – this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region.  相似文献   

3.
Background: Apolipoprotein E (apoE) with three major alleles E2, E3 and E4 is one of the critical genes in lipid metabolism. Common apoE alleles are in association with an increase in risk for central nervous and cardiovascular diseases such as Alzheimer’s disease, dementia, multiple sclerosis, atherosclerosis, coronary heart disease, hyperlipoproteinemia and stroke. ApoE3 is known as the most frequent allele in all populations, while association of apoE gene polymorphism with reported diseases have mostly been related to other two major alleles especially apoE4. Objective: To determine of apoE alleles frequencies in Southern Iran and comparison of those frequencies with other populations. Methods: DNA was extracted from the whole blood of 198 healthy unrelated candidates from population of Fars Province, Southern Iran, for apoE genotyping who were checked up by a physician. The frequencies of apoE alleles were compared with other populations by χ2 test. Results: The frequencies of E2, E3 and E4 were 0.063, 0.886 and 0.051 respectively. These values were similar to those reported from populations of Kuwait, Oman, Lebanon, India, Turkey, Greece, Spain, Sardinia Islands of Italy and two Iranian populations but were different from South of Italy and Caucasians in other Europe regions, American, American-Indian, African, East Asian and Saudi populations (P < 0.05). Conclusion: The frequency of E4 allele as a genetic risk factor for some multifactorial diseases in the population of Southern Iran is in the lowest reported amounts in the world. Iranian population has Caucasoid origin but differs from some Caucasian populations in Europe and America. The results of present study are in agreement with the historical evidences which show admixture of Iranian population with other populations and some studies based on genetic polymorphisms in the population of Southern Iran.  相似文献   

4.

Background  

Genetic studies of the Arabian Peninsula are scarce even though the region was the center of ancient trade routes and empires and may have been the southern corridor for the earliest human migration from Africa to Asia. A total of 120 mtDNA Saudi Arab lineages were analyzed for HVSI/II sequences and for haplogroup confirmatory coding diagnostic positions. A phylogeny of the most abundant haplogroup (preHV)1 (R0a) was constructed based on 13 whole mtDNA genomes.  相似文献   

5.
Ocean circulation, geological history, geographic distance, and seascape heterogeneity play an important role in phylogeography of coral‐dependent fishes. Here, we investigate potential genetic population structure within the yellowbar angelfish (Pomacanthus maculosus) across the Northwestern Indian Ocean (NIO). We then discuss our results with respect to the above abiotic features in order to understand the contemporary distribution of genetic diversity of the species. To do so, restriction site‐associated DNA sequencing (RAD‐seq) was utilized to carry out population genetic analyses on P. maculosus sampled throughout the species’ distributional range. First, genetic data were correlated to geographic and environmental distances, and tested for isolation‐by‐distance and isolation‐by‐environment, respectively, by applying the Mantel test. Secondly, we used distance‐based and model‐based methods for clustering genetic data. Our results suggest the presence of two putative barriers to dispersal; one off the southern coast of the Arabian Peninsula and the other off northern Somalia, which together create three genetic subdivisions of P. maculosus within the NIO. Around the Arabian Peninsula, one genetic cluster was associated with the Red Sea and the adjacent Gulf of Aden in the west, and another cluster was associated with the Arabian Gulf and the Sea of Oman in the east. Individuals sampled in Kenya represented a third genetic cluster. The geographic locations of genetic discontinuities observed between genetic subdivisions coincide with the presence of substantial upwelling systems, as well as habitat discontinuity. Our findings shed light on the origin and maintenance of genetic patterns in a common coral reef fish inhabiting the NIO, and reinforce the hypothesis that the evolution of marine fish species in this region has likely been shaped by multiple vicariance events.  相似文献   

6.
Ceratomyxa hamour n. sp. was found to infect the gallbladder of the orange‐spotted grouper, Epinephelus coioides located off the Saudi Arabian coast of the Arabian Gulf. The infection was reported as a free‐floating spore in the bile, and pseudoplasmodia were not observed. Mature spores were crescent‐shaped and measured on average 7 μm in length and 16 μm in thickness. The polar capsule, meanwhile, had length to width measurements of 4 μm and 3 μm on average. A periodical survey was conducted throughout a sampling period between December 2012 and December 2013, with the results showing that the parasite was present throughout the year with a mean prevalence of 32.6%. The objective of this study was to characterize this new species based on its morphological and molecular differences from previously described species. Molecular analysis based on the partial sequence of the SSU rDNA gene, showed the highest similarity (97.8%) to Ceratomyxa buri, reported in the cultured yellow tail Seriola quinqueradiata in Japan. Indeed, C. buri and the new species described here formed an individual cluster with a high degree of bootstrap support. This is the first reported species of genus Ceratomyxa from the Arabian Gulf fishes off Saudi Arabia.  相似文献   

7.
Plant hotspot areas are the areas that are very rich in plant species diversity. These areas have a priority for conservation. To highlight the plant diversity for nature conservation purposes a case study in Al Baha region, Saudi Arabia is presented, in which the importance of the natural vegetation and flora of one of the hotspot areas of Saudi Arabia is evaluated through the explanation of its natural plant species. A survey study has been conducted in an area of 167.6 km2, a 97 sample each with 20X20 m were laid out covering the whole ecological zones of the study site. Data of flora, vegetation cover and topography were gathered from each sample site. The study revealed about 319 plant species belonging to 228 genera and 75 families. Two species were found endemic to Saudi Arabia, 14 were endemics to Arabian Peninsula, and five were regional endemics that are only found in East Africa and Arabian Peninsula, while 39 species are rare and endangered.  相似文献   

8.
As multiple sclerosis (MS) has long been known to be associated with Leber, hereditary optic neuropathy (LHON), a disease caused by mitochondrial (mtDNA) mutations, in this study we assessed possible involvement of mtDNA point mutation in MS patients. Fifty-two MS patients whose disease was confirmed with revised McDonald criteria and referred to Iranian Center of Neurological Research of Imam Khomeini hospital during 2006–2007 entered the study. Secondary mtDNA mutations, age, gender, clinical disability according to expanded disability status scale (EDSS), course of the disease, and presenting symptoms were the variables investigated in this study. DNA purification was performed by Diatom DNA Extraction Kit. Analysis of data was done by SPSS V11.5. The prevalent mutations with frequency of 19.2% were J, L, and T haplogroups. Haplotype A was more prevalent in patients with younger age of onset (P-value = 0.012) and high proportion of haplogroup H was associated with optic nerve involvement (P-value = 0.015). No motor symptoms were seen in haplogroup H patients. There is no significant relationship between duration of the disease and EDSS in different mutation of mtDNA.  相似文献   

9.
Sickle-cell disease with raised fetal hemoglobin is found relatively frequently in the eastern part of the Arabian Peninsula. In contrast to the severe and sometimes life-threatening complications of sickle-cell disease in the black population, Saudi Arabs homozygotes for HbS gene exhibit a mild course for this disease. Here we present a Saudi sickle-cell patient with an unusually low fetal hemoglobin level. Moreover, this individual has beta 0-thalassemia and a deficiency in the enzyme glucose-6-phosphate dehydrogenase. Clinical and hematological examinations revealed a remarkably benign condition. This observation is potentially important since most of the mild clinical symptoms of sickle-cell disease have been attributed to high fetal hemoglobin. Clearly in this case, other factors are operating and may be also operating in those patients with high fetal hemoglobin.  相似文献   

10.
Apolipoproteins (lipid-free) are lipid-binding proteins that circulate in the plasma of human blood and are responsible for the clearance of lipoproteins. Apolipoprotein E (ApoE) is one of the several classes of this protein family. It acts as a ligand for the low-density lipid (LDL) receptors and is important for the clearance of very low-density lipid (VLDL) and chylomicron remnants. The APOE gene locus is polymorphic, with three major known alleles, APOE*3, *4, and *2. We investigated the distribution of the allele frequency of the APOE gene locus and describe here the genetic variation in four Kuwaiti subpopulations: Arab origin (Arabian peninsula), Arab Bedouin tribes, Iranian origin, and the heterogeneous population. We also describe the use of Spreadex gels in resolving the amplified and digested products of the APOE gene locus. DNA was extracted from whole blood and subjected to PCR and then to RFLP analysis. Allele and genotype frequencies were estimated for the total population and for each subpopulation. Statistical analysis showed no difference in the allele frequencies between the four groups. The frequency of APOE*3 in the Kuwaiti population was highest (88.4%) followed by the frequency of APOE*4 (6.5%) and APOE*2 (5.1%). The genotype and allele frequencies obtained for the Kuwaiti population fell within the reported worldwide distribution for the APOE gene locus. Moreover, the results obtained in this study showed no statistical difference (p > 0.05) between the APOE allele and genotype frequencies between the subgroups for all six genotypes and three alleles, supporting the assumption of admixture in the Kuwaiti population and that the obtained frequencies were in Hardy-Weinberg equilibrium. Finally, we found that the distribution of the APOE alleles in Kuwait differs somewhat from those reported in other Arab populations, suggesting that the Arabs originating from the Arabian peninsula are different from those of Lebanon, Morocco, and Sudan.  相似文献   

11.
Camera trapping can detect and monitor rare species in landscapes spanning thousands of square kilometres but placement of cameras in areas where the animals most likely occur will increase detection success. This vital information is lacking for the critically endangered Arabian leopard (Panthera pardus nimr) that has undergone a 90% decline across its range in Saudi Arabia. We aimed to identify suitable Arabian leopard habitat and potential population capacity in Saudi Arabia using data from leopards living in ecologically analogous habitat in South Africa and Oman. We developed a resource selection function (RSF) from 14 leopards’ GPS data in the Cederberg, South Africa, and validated the model using three leopards in the Little Karoo, and two Arabian leopards in Oman. We then projected the model to the historical range of Arabian leopards in Saudi Arabia to estimate likely leopard locations and potential population sizes based on home range metrics. The RSF successfully discriminated between used and available locations (specificity = 96.7%) and had high predictive ability (Rho > 0.9). Leopards selectively used areas away from human settlements and roads, with high enhanced vegetation index, and intermediate slopes and elevations. Saudi Arabia could theoretically host 4 distinct populations totalling 162–362 Arabian leopard females, depending on home range size. Camera traps deployed in the south-western mountains of Saudi Arabia may be most likely to detect remnant populations of Arabian leopards. Further research is needed into the local abundance of prey species and human activity to ensure the persistence of suitable leopard ranges and inform conservation actions.  相似文献   

12.
The Arabian Honeybee Apis mellifera jemenitica is endemic to the Arabian Peninsula. It is highly adapted to temperature extremes and drought dominating the region. In this study, the mitochondrial Cytochrome Oxidase I (COI) was analyzed in 133 specimens of A. m. jemenitica from eight localities along the Red Sea cost of Saudi Arabia. Results revealed 33 synonymous, and 6 non-synonymous mutations within the COI sequences, resulting in change of 4 amino acids. Phylogenetic analysis based on either type of mutations revealed two main haplogroups accounting for 94% of the samples. In total Eighteen new haplotypes were identified and uploaded in the genebank, Fourteen of them are restricted to one/both haplogroups. All haplotypes identified in this study clustered with reference COI sequences of the sub-lineag Z (African Lineage). However one Haplotype (MW428270) represents high COI variability compared to other haplotypes and may resemble different evolutionary sub-lineage. Tajima's Neutrality Test (Ps = 0.025; D = -1.5) indicated population size expansion that took place after selective sweep and/or purifying selection.  相似文献   

13.
Summary Among a small group of Saudi Arabs the Duffy blood group (Fy(a-b-)) was found to be associated with the sickle cell trait more often than could be explained by random gene combination thus supporting the concept that African gene flow brought the sickle cell trait to the Arabian peninsula. Based on recent observations concerning the possible role of Fy(a-b-) as a resistance factor againstvivax malaria, it is proposed that the gene combination AS FyFy is likely to be selected in areas wherefalciparum andvivax infections are endemic and mixed infections occur frequently.  相似文献   

14.
Boromophus saudicus sp. n. (subfamily Pimeliinae Latreille, 1802, tribe Boromorphini Skopin, 1978) is described from the Kingdom of Saudi Arabia (Rawdhat Khorim, Riyadh Province). This finding represents the first record of the genus Boromorphus Wollaston, 1854 from the Arabian Peninsula. The species was collected from Acacia trees and from pitfall traps.  相似文献   

15.
Using non-destructive sampling we provide further genetic characterisations for spiny mice (Acomys dimidiatus/cahirinus) and gerbils (Gerbillus sp.) in three regions in Saudi Arabia. All individuals were sequenced for a fragment of the cytochrome b gene, and compared against available conspecifics and closely related taxa. We confirm the existence of a second Acomys dimidiatus/cahirinus lineage specific to the Arabian Peninsula as seen previously. The Arabian Gerbillus nanus is shown to group with Middle Eastern rather than African conspecifics. A second cryptic Gerbillus lineage was also sampled across multiple locations, which may be an uncharacterised G. dasyurus.  相似文献   

16.
Asaccus geckos are distributed in southwest Asia, mainly in Iran and Arabia. Currently, seven Asaccus species are recognized in Arabia, all endemic to the isolated Hajar Mountains in Oman and the UAE, an area regarded as a biodiversity and endemicity hotspot. Previous phylogenetic studies have shown a non‐monophyletic structure of the Arabian Asaccus species, with the Hajar endemic A. montanus diverging first from the remaining Iranian and Arabian taxa, thus suggesting a possible Arabian origin for the genus. Despite the species’ obvious phylogeographical importance, no study has yet explored its intraspecific diversity. In this study, we assessed the genetic diversity and phylogeography of A. montanus and its phylogenetic relationships with the rest of the Arabian Asaccus species and some available representatives from Iran. We used both mitochondrial and nuclear data to assess phylogenetic relationships based on haplotype networks, concatenated datasets and species trees, performed species delimitation analyses, and estimated divergence times and genetic diversity. We suggest Asaccus began diverging during the Middle Oligocene, a period of major tectonic activity in and around Arabia. Our results mainly support previous phylogenetic studies and uncover the presence of cryptic diversity within A. montanus. Asaccus montanus diverged in the Jebel Akhdar Mountain range into two deep allopatric lineages during the Late Pliocene. Our findings suggest further taxonomic research is necessary for this species, especially due to its vulnerable status and restricted range in an area of great conservation importance.  相似文献   

17.
The ant genus Carebara of the Arabian Peninsula is revised. Carebara abuhurayri Sharaf & Aldawood, 2011 is synonymized under Carebara arabica Collingwood & van Harten, 2001. Carebara arabica is redescribed and a Neotype is fixed based on a specimen collected from southwestern Kingdom of Saudi Arabia. A new species, C. fayrouzae sp. n. is described from Saudi Arabia based on queens, major and minor workers. Keys to major and minor workers of the two Arabian Carebara species are given.  相似文献   

18.
Saudi Arabian camels {Camelus dromedarius) are infected with three species of Eimeria: E. dromedarii (28.4%), E. rajasthani < 22.2%), and E. cameli (19.2%); 41.6% of the animals examined were positive. The highest prevalence of infection was reported in the western region of the country. Mixed infection with two Eimeria species is most common; E. dromedarii was most frequently and generally the most predominant species. Eimeria dromedarii and E. rajasthani are described for the first time from Saudi Arabian camels.  相似文献   

19.

Background  

The importance of diarrhoeagenic Escherichia coli (DEC) infections in the Arabian Gulf including Kuwait is not known. The prevalence of DEC (enterotoxigenic [ETEC], enteropathogenic [EPEC], enteroinvasive [EIEC], enterohemorrhagic [EHEC] and enteroaggregative [EAEC]) was studied in 537 children ≤ 5 years old hospitalised with acute diarrhoea and 113 matched controls from two hospitals during 2005–07 by PCR assays using E. coli colony pools.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号