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21.
ERNESTO PÉREZ-COLLAZOS PILAR CATALÁN 《Biological journal of the Linnean Society. Linnean Society of London》2007,92(3):419-429
Krascheninnikovia ceratoides (L.) Gueldenst. (Chenopodiaceae) is an irano‐turanian steppe plant with a striking geographical vicariance between the western Mediterranean and the central Asian regions. Its westernmost populations are located in the north‐east part of the Iberian Peninsula, in the narrow middle Ebro and Alfambra valleys, where they are threatened and have been catalogued as ‘vulnerable’. Genetic diversity and structure was studied in 150 individuals from five populations of these two valleys using inter‐simple sequence repeats (ISSR). A total of 121 informative bands allowed the identification of 150 genotypes. Nei's genetic diversity found in all natural populations (h = 0.448) was higher than that of other geographical restricted species. Analysis of molecular variance and spatial correlations analyses showed a strong genetic differentiation among populations (35.88%) and among valleys (22.33%). The unweighted pair‐group method of arithmetical averages and Neighbour‐joining clusterings further demonstrated a substructure of two population cores within the Ebro valley. Our genetic data suggest that the high levels of genetic diversity and the strong genetic structure found among the northern Iberian populations and ranges of K. ceratoides might result from the summed effects of its tetraploidy, its outbreeding nature, and its success in colonizing newly altered areas. However, the ISSR data might also reflect the existence of an ancient wider distribution range of the plant in the Iberian Peninsula coupled with a more recent history of habitat fragmentation. Different management conservation guidelines are recommended for this plant after our genetic analysis: a microreserve of approximately 2 km2 is proposed for the highly threatened population of Osera (Ebro valley), whereas seed collection strategies and occasional population reinforcements are suggested for the remaining populations. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92 , 419–429. 相似文献
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PILAR DELGADO M. ROSARIO ROMERO ANTONIO TORRES 《The Journal of eukaryotic microbiology》1990,37(3):182-186
The pattern of cytospindle assembly and the modifications of the microtubular cytoplasmic network during division of Paramecium are studied by means of indirect immunofluorescence. The assembly of cytospindle starts at two independent areas placed respectively around the proter's and opisthe's buccal overture. The moment of the microtubule bundles’appearance depends on their distance from the buccal opening, with those closest appearing 1st. The existence of microtubule organizing centers that act transiently during division of Paramecium is discussed. 相似文献
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A detailed knowledge of the habitat requirements of steppe birds living in farmland habitats is necessary to identify agricultural practices compatible with their conservation. The globally threatened Great Bustard Otis tarda is a partial migrant in central Iberia, but factors affecting its winter habitat use have not been identified. We assessed habitat differences between breeding and wintering areas and winter habitat selection of radiotagged migrant female Great Bustards in central Spain. Of 68 tagged females, 35% moved to wintering areas located 64.3 ± 24.0 km south of their breeding areas, and 80% wintered in a single area of c. 236 km2. A census of the population in this area identified it as one of the most important wintering areas of this species in the world, holding c. 1500 individuals. There were significant differences between breeding and wintering habitats of individually marked migrant females. Compared with breeding areas, wintering areas of migrant females were located further from roads and urban nuclei, had lower human population densities and area of urban developments, and a higher diversity of land‐use types, with less cover of cereals and more vineyards and olive groves. Within this area, radiotracked migrant females preferred sites with more vineyards and a lower land‐use diversity. Our results highlight the importance of traditional Mediterranean dry farmland mosaics, and suggest that different conservation strategies are needed for migrant and resident populations in winter to secure the conservation of suitable wintering habitat for Great Bustards in the Iberian Peninsula. 相似文献
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JUAN GALINDO MÓNICA MARTÍNEZ-FERNÁNDEZ PILAR SUÁREZ PALOMA MORÁN FUENCISLA SAN JUAN EMILIO ROLÁN-ALVAREZ 《Biological journal of the Linnean Society. Linnean Society of London》2009,98(1):225-233
Natural selection can play an important role in the maintenance of genetic polymorphisms, despite ongoing gene flow. In the present study, we use previously analysed allozymic loci and perform an F ST outlier-based analysis to detect the signatures of divergent selection between sympatric ecotypes of the marine snail Littorina saxatilis at different localities. The results obtained show that different allozyme polymorphisms are affected (directly or indirectly) by selection at distinct geographical regions. The Phosmogluco mutase-2 locus was the best candidate for adaptation and further biochemical analyses were performed. The kinetic properties of the three more common genotypes of Pgm-2 were studied. The results obtained are concordant with two alternative hypotheses: (1) natural selection is acting directly on this locus or, more probably, (2) selection is affecting a genomic region tightly linked to the enzyme locus. In both cases, the known existence of a parallel and partially independent origin of these ecotypes would explain why different candidate loci were detected in different localities. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 225–233. 相似文献
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MARÍA R. ALONSO SARA L. GOODACRE BRENT C. EMERSON MIGUEL IBÁÑEZ RAINER HUTTERER KLAUS GROH 《Biological journal of the Linnean Society. Linnean Society of London》2006,89(1):169-187
Five new species of land snail (family Enidae) are described from La Gomera (Canary Islands) of which the majority, on the basis of anatomy alone, could be incorporated within a new supraspecific taxon. In addition to the morphological study of these new species, a region of the 16S mitochondrial gene is sequenced from three of the new species and a range of species of Napaeus from within its two subgenera ( Napaeinus and Napaeus ) . There is a disparity between the morphological and preliminary molecular phylogenetic data. Possible explanations for this conflict are discussed, as well as the evolutionary relationships among these different taxa, and it is suggested that this group may be an excellent model for further studies of adaptation and diversification. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 169–187. 相似文献
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R. PANADERO C. MARTÍNEZ‐CARRASCO L. LEÓN‐VIZCAÍNO C. LÓPEZ P. DÍEZ‐BAÑOS M. P. MORRONDO F. ALONSO 《Medical and veterinary entomology》2010,24(4):418-424
During the 2003–2005 hunting seasons, a total of 120 Cervidae, including 39 red deer (Cervus elaphus hispanicus) and 81 fallow deer (Dama dama), were examined for subcutaneous myiasis. Animals were shot from January to June in southern Spain. Specific antibodies against Hypodermatinae (Diptera: Oestridae) were detected by indirect enzyme‐linked immunosorbent assay (iELISA) using a crude larval extract (CLE) and a purified antigen [hypodermin C (HC)] obtained from first instars of Hypoderma lineatum (De Villers) (Diptera: Oestridae). Hypoderma actaeon Brauer was the only species detected in this study, which represents the first confirmation of this species in fallow deer from Spain. The overall prevalence of animals presenting subcutaneous larvae (14.2%) was considerably lower than the prevalences determined by iELISA with CLE (43.3%) and HC (40.0%). Red deer showed a higher prevalence of Hypoderma than fallow deer. The concordance between larval examination during the hunting season and iELISA using both antigens was low, whereas the concordance between the CLE and HC ELISAs was good. Larval antigens obtained from H. lineatum constitute a good tool for the diagnosis of H. actaeon in Cervidae, especially when the hunting season does not coincide with the maximum presence of larvae on the back. 相似文献
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PILAR DELGADO PURIFICACION CALVO ANTONIO TORRES 《The Journal of eukaryotic microbiology》1987,34(1):104-110
The cyst wall of Paraurostyla weissei consists of four morphologically distinct layers. It shows an ultrastructure and composition similar to that of the previously described kinetosome-resorbing cysts, and its cytoplasm displays characteristics of “urostylid-type” cysts. Therefore it is possible to consider it a “transition ciliate” between Stichotrichina and Sporadotrichina. 相似文献