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1.
The electrophoretical polymorphisms of some blood proteins were studied in the Talysh population of Pirasora situated in South-East Azerbaidjan. We calculated the gene frequencies of these polymorphisms and determined the genetic distances between the Talyshes and some Iranian populations of North, Central and South Iran, Afghans, and three populations of Azerbaijan. The Talyshes are very close to Iranians of Shiraz, whereas they are distant from the Azerbaijanians. Anthropological investigations showed that the Caucasoids and Mongoloids lived in the Aragvi Basin since the Eneolithic period. This was stated by Alexeev (1974), who emphasized the mixture of the Caucasus populations from ancient times on. We calculated the genetic distances between the Caucasus populations and numerous populations of other geographic regions, considering 28 alleles of 12 loci of blood group, serum protein and red cell enzyme polymorphisms and constructed the dendrogram of these populations. The position of the Caucasus populations in the dendrogram corresponds on principle to the earlier anthropological observations. The clustering of the Caucasoid populations corresponds completely with anthropological and historical data, and supports our earlier hypothesis (Nazarova 1999) concerning the differentiation of Caucasoids, Northern Mongoloids and Amerinds from the populations, which inhabitated Asia in palaeolithic times.  相似文献   

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The genetic code has been analysed by a method similar to that used by Gregor Mendel. The current codon catalogue is shown to be symmetrically subdivisible into two discrete subcatalogues of eight quartets each by classifying the quartets asmonocoding (for one amino acid only) vsheterocoding (for two amino acids or for amino acid plus nonsense). The internal symmetries of the two subcatalogues are identical, and are governed by two common parity rules. These rules, together with one governing the subdivision itself, can be explained by the hypothesis that two primaeval sets of polynucleotide-borne anticodons, corresponding closely but not exactly with the subcatalogues originated independently and separately (were not originally together within any replicating pre-or proto-biont). The discorrespondence between the primaeval sets and the subcatalogues is itself symmetrical, involving quartets sharing identical locations in the two subcatalogues. The primaeval sets correspond exactly with the subdivisions of the catalogue proposed by Skoog and co-workers on the basis of the presence vs the absence of cytokinins or “cytokininlike bases” adjacent to the anticodons. A molecular model for the origin of the primaeval anticodon sets is described, and the relationship of the hypothesis with the origin of life, together with some possibilities for testing it, are discussed.  相似文献   

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A number of embryological features of the Pogonophora suggest that they could not derive from the Polychaeta and are closely related to Deuterostomia. These are: (1) traces of spiral cleavage that sharply differ the from cleavage of polychaetes in the prospective value of blastomeres; (2) enterocoelic formation of mesoderm; (3) the larva most closely resembles Balanoglossus that has just completed metamorphosis; proto-, meso-, and metasoma of pogonophoran larva correspond (or are homologous) to the proboscis, collar, and trunk of Balanoglossus respectively; while the telosoma can be regarded as an organ appearing late in phylogenesis that serves to burrow into the bottom; (4) larvae of Siboglinum have a transitory mouth located, as it is the case in Enteropneusta, between proto-and mesosoma, very far from the posterior end, where there is closed blastopore; therefore, the former can be considered as a secondary mouth; (5) the asymmetrical development of the anterior pair of coeloms in Pogonophora, Echinodermata, and Amphioxus allows finding homologies between organs developing from these coeloms.  相似文献   

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Results of analysis of the Caucasian fauna of fleas and their association with mammal and avian hosts are reported. The Caucasian fauna of potential flea hosts comprises about 130 species of mammals and about 470 species of birds. Most of the flea species in the Caucasian fauna (88 out of 155) parasitize rodents, 51 species of which are permanent hosts of different flea species; 13 flea species occur on 11 species of insectivores; 13 flea species, on 13 species of chiropterans; 14 flea species, on 20 species of carnivores. Only 2 flea species parasitize artiodactyles. 54 species of birds are permanent hosts of 23 species of fleas from 4 genera in the Caucasus. Ten types of ranges of flea species are distinguished; host associations of the Caucasian flea species from these groups are discussed. The greatest numbers of hosts from the families Cricetidae, Muridae, and Sciuridae are associated with fleas with Euro-Asian (extra-Siberian), European, Turanian, and Iranian ranges. Soricidae are known as hosts of flea species with European and Euro-Turanian ranges. Four major groups of flea taxa are represented in the Caucasian fauna. The distribution of the first group is determined by the influence of the palaeofauna of the ancient European continent in the early Cenozoic; that of the second group, by the influence of the fauna of the ancient Asian continent during the Paleogene and part of the Neogene; the third, by the influence of the fauna of southern Europe starting with the Miocene. The fourth group comprises the species which immigrated from northern Europe and Asia in the Late Neogene (2–3 mln years ago).  相似文献   

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The distribution of genetic markers of blood groups (ABO, Rhesus, MNSs, P, Duffy, Kell-Cellano), plasma proteins (Hp, Gc, Tf, C'3) and red-cell enzymes (AcP, EstD, GLO-1), and also ABH secretion among 10 populations of Western Georgia has been studied. The common characteristic of distribution of gene frequencies for the markers studied was obtained as a whole in Georgia. The Georgians were compared for these markers with some populations of the Caucasus, Europe and West Asia. Among Caucasian populations, Georgians are most similar to Abkhasians. According to some systems, Georgians are close to European groups (ABO, Dubby, GLO-1, EstD), while they are similar to West-Asian groups, as judged by other systems (ABH secretion, AcP). According to Rhesus and MNSs systems, Georgians differ both from populations of Europe and from populations of West Asia.  相似文献   

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Distribution of the genetic markers of blood groups (AB0, Rhesus, MN, MNSs, P, Kell-Cellano); plasma proteins (Hp, C'3, Tf, Gc); red-cell enzymes (AcP, EstD, GLO-1) and also ABH-secretion was studied among 6 ethnic groups of Dagesthan. Distribution of gene frequencies in Dagesthan populations and other Caucasian ethnic groups was comparatively studied.  相似文献   

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Travelers to North Yemen nearly invariably report that Yemeni people are universally addicted to the drug qat and that the problems of the country are related to this. On the other hand, the majority of Yemenis claim that qat is not only harmless, but that it has many virtues. After describing the chemistry of the drug and the customs of use, this paper addresses the question of the concept of addiction in terms of data gathered during an extensive field study of qat use. Questions of latency, tolerance and availability are discussed, while particular attention and data are devoted to an examination of the analgesic hypothesis. It is concluded that a more complex theory is needed to deal with drug dependencies and that social and cultural perspectives must be added to concepts of the physiological and psychological effects of drugs if progress is to be made toward understanding institutional drug use such as is found with regard to qat.  相似文献   

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Distribution of the genetic markers of blood groups (ABO, Rhesus, MNSs, P, Duffy, Kell-Cellano, Lewis); serum proteins (Hp, C'3, Tf, Gc); red-cell enzymes (AcP, EstD, GLO-1, 6-PGD, PGM-1) and also ABH-secretion was studied among 6 native populations of the Karachaev-Cherkess Autonomous and Kabardin-Balkar Autonomous Republic. The results were used in analysis of the interpopulation variations and genetic relationship of the populations to their geographical neighbours.  相似文献   

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On the origin of the term "stem cell"   总被引:2,自引:0,他引:2  
Stem cells have fascinated both biologists and clinicians for over a century. Here, we discuss the origin of the term "stem cell," which can be traced back to the late 19th century. The term stem cell originated in the context of two major embryological questions of that time: the continuity of the germ-plasm and the origin of the hematopoietic system. Theodor Boveri and Valentin H?cker used the term stem cell to describe cells committed to give rise to the germline. In parallel, Artur Pappenheim, Alexander Maximow, Ernst Neumann, and others used it to describe a proposed progenitor of the blood system. The original meanings of the term stem cell, rather than being historical relics, continue to capture important aspects of the biology of stem cells as we see them today.  相似文献   

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