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851.
Khaled K Abu-Amero José M Larruga Vicente M Cabrera Ana M González 《BMC evolutionary biology》2008,8(1):45
Background
Two potential migratory routes followed by modern humans to colonize Eurasia from Africa have been proposed. These are the two natural passageways that connect both continents: the northern route through the Sinai Peninsula and the southern route across the Bab al Mandab strait. Recent archaeological and genetic evidence have favored a unique southern coastal route. Under this scenario, the study of the population genetic structure of the Arabian Peninsula, the first step out of Africa, to search for primary genetic links between Africa and Eurasia, is crucial. The haploid and maternally inherited mitochondrial DNA (mtDNA) molecule has been the most used genetic marker to identify and to relate lineages with clear geographic origins, as the African Ls and the Eurasian M and N that have a common root with the Africans L3. 相似文献852.
Khaled E. Al-Nassar P. Michael Conneally Catherine G. Palmer Pao-lo Yu 《Human genetics》1981,57(2):192-198
Summary Frequency estimates were determined on seventeen blood group, serum protein, and red-cell enzyme markers on random samples of 193 individuals from two Bedouin tribes in addition to the general population in Kuwait. Genetic heterogeneity between the three communities is evident from the significant differences in allelic distribution of the polymorphic markers.Genetic distance measurements were used to compare the results with the oral history of descent of the two tribal communities. Results were in agreement with tribal history. 相似文献
853.
854.
Temim Deli Souad Guizeni Lotfi Ben Abdallah Khaled Said Noureddine Chatti 《Marine Biology Research》2020,16(4):280-298
ABSTRACT This investigation aims at assessing patterns of spatial genetic structure of the teleost fish Sardina pilchardus across the Siculo-Tunisian Strait (a well-known discontinuous biogeographic area) and delineating putative genetic stocks within the species. For this purpose, a total of 180 specimens, collected from 11 locations stretching across the western and eastern Mediterranean coasts of Tunisia, were analysed genetically by means of 18 nuclear allozyme loci. The outcome of this study revealed strong genetic differentiation among populations, with the marked genetic distinctiveness of the central Tunisian population at Mahdia. Despite the delineation of seven well-defined genetic groups, no significant correlation was found between genetic and geographic distances. Besides, the recorded population subdivision did not align with biogeographic boundaries, suggesting the presence of chaotic genetic patchiness. Recent genetic bottlenecks were evidenced in S. pilchardus populations. Patchy migration patterns were recorded among the examined pairs of sardine populations. Among the recorded 16 polymorphic loci, GPI-2 and SOD appeared to be subject to natural selection. Patterns of population genetic differentiation and structuring were not found to be driven by outlier loci that appeared to be under selection. Furthermore, the detected neutral GPI-1 locus was found to be responsible for most of the genetic variation among identified genetic clusters. Hence, natural selection cannot cause the detected genetic heterogeneity among sardine samples. Different explanations to the origin of chaotic genetic patterns, observed within S. pilchardus, were discussed. 相似文献
855.
Jiamei Jiang Jie Huang Jiqiu Li Khaled A.S. Al-Rasheid Saleh A. Al-Farraj Xiaofeng Lin Xiaozhong Hu 《European journal of protistology》2013,49(4):634-643
We investigate the living morphology, infraciliature, and small subunit rRNA gene sequences of two poorly known marine euplotids, Aspidisca fusca Kahl, 1928 and A. hexeris Quennerstedt, 1869, isolated from intertidal sewage outfall, northern China and sandy sediments, southern China, respectively. Improved diagnoses and morphometric data are provided for both species. Aspidisca fusca is characterized by having a peristomial spur, seven frontoventral cirri in a “polystyla-arrangement”, and two oval macronuclear nodules. Aspidisca hexeris can be recognized by having an elliptical body shape, a peristomial spur, seven membranelles in the anterior portion of adoral zone and 11–13 in the posterior part, as well as seven frontoventral cirri arranged in two oblique rows. In addition, the presence and degree of projections along the left margin of A. hexeris are highly variable among populations. Phylogenetic analyses based on small subunit rRNA gene sequence data support the validity of both A. hexeris and A. fusca as distinct species, and indicate that A. fusca is most closely related to A. aculeata and A. steini, whereas A. hexeris shows a close relationship with A. magna. 相似文献
856.
Lea Eisenbach Ofer Mandelboim Erez Bar-Haim Lior Carmon Hernan Copcow Khaled El-Shami Adrian Paz Dan Popovic Ezra Vadai Esther Tzehoval Michael Feldman Mati Fridkin 《Letters in Peptide Science》1998,5(5-6):323-328
Cytotoxic T-lymphocytes (CTLs) kill abnormal cells. CTLs recognize major histocompatibility complex class I molecules in complex with peptides derived from relevant antigens. The identification of tumor associated antigen peptides enabled the design of anti-tumor and anti-metastatic vaccines in a murine lung carcinoma. 相似文献