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111.
F. BAGNOLI G. G. VENDRAMIN† A. BUONAMICI† A. G. DOULIS‡ S. C. GONZÁLEZ-MARTÍNEZ§ N. LA PORTA¶ D. MAGRI P. RADDI F. SEBASTIANI†† S. FINESCHI 《Molecular ecology》2009,18(10):2276-2286
This study represents the first large-scale analysis using nuclear molecular markers to assess genetic diversity and structure of Cupressus sempervirens L.. Genetic and fossil data were combined to infer the possible role of human activity and evolutionary history in shaping the diversity of cypress populations. We analysed 30 populations with six polymorphic nuclear microsatellite markers. Dramatic reductions in heterozygosity and allelic richness were observed from east to west across the species range. Structure analysis assigned individuals to two main groups separating central Mediterranean and eastern populations. The two main groups could be further divided into five subgroups which showed the following geographical distributions: Turkey with the Greek islands Rhodes and Samos, Greece (Crete), Southern Italy, Northern Italy, Tunisia with Central Italy. This pattern of genetic structure is also supported by samova and Barrier analyses. Palaeobotanical data indicated that Cupressus was present in Italy in the Pliocene, Pleistocene and Holocene. Furthermore, our molecular survey showed that Italian cypress populations experienced bottlenecks that resulted in reduced genetic diversity and allelic richness and greater genetic differentiation. Recent colonization or introduction may also have influenced levels of diversity detected in the Italian populations, as most individuals found in this range today have multilocus genotypes that are also present in the eastern range of the species. The data reveal a new interpretation of the history of cypress distribution characterized by ancient eastern populations (Turkey and Greek islands) and a mosaic of recently introduced trees and remnants of ancient, depauperate populations in the central Mediterranean range. 相似文献
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Katie T. Burke Perry L. Colvin Leslie Myatt Gregory A. Graf Friedhelm Schroeder Laura A. Woollett 《Journal of lipid research》2009,50(6):1146-1155
The fetus has a high requirement for cholesterol and synthesizes cholesterol at elevated rates. Recent studies suggest that fetal cholesterol also can be obtained from exogenous sources. The purpose of the current study was to examine the transport of maternal cholesterol to the fetus and determine the mechanism responsible for any cholesterol-driven changes in transport. Studies were completed in pregnant hamsters with normal and elevated plasma cholesterol concentrations. Cholesterol feeding resulted in a 3.1-fold increase in the amount of LDL-cholesterol taken up by the fetus and a 2.4-fold increase in the amount of HDL-cholesterol taken up. LDL-cholesterol was transported to the fetus primarily by the placenta, and HDL-cholesterol was transported by the yolk sac and placenta. Several proteins associated with sterol transport and efflux, including those induced by activated liver X receptor, were expressed in hamster and human placentas: NPC1, NPC1L1, ABCA2, SCP-x, and ABCG1, but not ABCG8. NPC1L1 was the only protein increased in hypercholesterolemic placentas. Thus, increasing maternal lipoprotein-cholesterol concentrations can enhance transport of maternal cholesterol to the fetus, leading to 1) increased movement of cholesterol down a concentration gradient in the placenta, 2) increased lipoprotein secretion from the yolk sac (shown previously), and possibly 3) increased placental NPC1L1 expression. 相似文献
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Mark J. Statham Deborah A. Woollett Susan Fresquez Jerene Pfeiffer Jonathan Richmond Alice Whitelaw Ngaio L. Richards Michael F. Westphal Benjamin N. Sacks 《The Journal of wildlife management》2020,84(1):66-74
Noninvasive fecal sampling combined with genetic analysis is a technique allowing the study of elusive or otherwise difficult to monitor species without the need for direct contact. Although this method is widely used in birds and mammals, it has never been successfully applied on a large scale in reptiles. The blunt-nosed leopard lizard (Gambelia sila) is an endangered species endemic to the San Joaquin Desert, California, USA. Presently, acquiring data on the species for research and management involves more traditional methods such as live capture or visual surveys, the latter of which are required for regulatory monitoring in accordance with wildlife agency protocols. We used an approach for gathering additional information that combines conservation detection dogs trained to locate blunt-nosed leopard lizard scat samples with genetic analysis for identifying and distinguishing among sympatric lizard species. We developed 2 polymerase chain reaction assays that produce fluorescently labelled amplicons of species-specific fragment length for 6 lizard species in the study area. Using these assays, we genetically identified to species 78% (255 of 327) of samples collected by dog-handler teams across 4 years. The majority of the genetically identified samples (82.4%; 210 of 255) were confirmed as originating from blunt-nosed leopard lizards. Although an assessment of the viability of detection dogs in regulatory monitoring efforts is required, our ability to recover usable DNA and to differentiate among a diverse group of lizards highlights the broad potential of our methodology for noninvasive sampling in reptiles. © 2019 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society. 相似文献
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MANUEL B. CRESPO ANTONIO DE LA TORRE JOSE L. SOLANAS 《Botanical journal of the Linnean Society. Linnean Society of London》1994,116(2):135-144
Linaria arabiniana sp. nov. is described from coastal sand dunes of a very reduced area in Alicante Province (south-eastern part of the Iberian Peninsula). It is a perennial herb characterized by its 3–4-verticillate leaves, glabrous stems, large violet or rarely yellow flowers, and bicoloured usually flat seeds. Morphological characteristics and taxonomic affinities of this taxon are discussed, as are data on its ecology, phytosociology, and eventual conservation features. 相似文献
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