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Spatio-temporal genetic variability in sea trout (Salmo trutta) populations from north-western Spain
1. Genetic variation at five microsatellite loci was investigated in six sea trout ( Salmo trutta ) populations to describe their spatio-temporal genetic variation in north-western Spain. We observed significant genetic variation between river basins, and isolation by distance with restricted gene flow between neighbouring rivers, which suggests an important homing behaviour.
2. Despite these populations suffering a serious demographic decline during 1998, we did not detect any reduction in their genetic variation, suggesting a reasonably high effective population size and temporal stability.
3. Genetic differences among rivers should be taken into account in future management activities. Given the high genetic variability and the temporal stability observed, we believe that no supportive breeding programmes are presently needed in these populations. 相似文献
2. Despite these populations suffering a serious demographic decline during 1998, we did not detect any reduction in their genetic variation, suggesting a reasonably high effective population size and temporal stability.
3. Genetic differences among rivers should be taken into account in future management activities. Given the high genetic variability and the temporal stability observed, we believe that no supportive breeding programmes are presently needed in these populations. 相似文献
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LUIS GARCÍA ESTEBAN PALOMA DE PALACIOS 《Botanical journal of the Linnean Society. Linnean Society of London》2009,160(2):184-196
This study, which includes 51 species and six genera of subfamily Abietoideae (Pinaceae), assesses the systematic significance of the wood structure in this group. In particular, the presence of normal and traumatic resin canals, the ray structure and the axial parenchyma constitute phylogenetically informative features. Comparative wood anatomy of Abietoideae clearly supports the monophyly of the genera Abies–Cedrus–Keteleeria–Nothotsuga–Pseudolarix–Tsuga, all of which have axial parenchyma with nodular transverse end walls in the regions of growth ring boundaries, crystals in the ray parenchyma and pitted horizontal and nodular end walls of ray parenchyma cells. Axial resin canals support a subdivision of the subfamily into two groups: Abies, Cedrus, Pseudolarix and Tsuga, without axial resin canals, and Keteleeria and Nothotsuga, with axial resin canals and a specific arrangement of traumatic axial resin canals. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 184–196. 相似文献
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This study analyses the temporal and spatial changes in abundance and distribution of the warm water species round sardinella (Sardinella aurita) in the western Mediterranean over the last decades in relation to sea water temperature. In the western Mediterranean basin (1950–2003), a significant positive relationship was found between round sardinella landings and temperature anomalies. Along a latitudinal gradient off the Mediterranean Iberian coast (1989–2004), a gradual increase in species abundance was observed from south to north, with a certain time lag going northwards, associated with the increase in sea water temperature. The abundance of round sardinella in the two warmest and southernmost areas was positively and significantly correlated with sea surface temperature registered during the start of gonad maturation the previous year. In addition, the positive relationship established between water temperature and abundance of round sardinella in the coldest and northernmost study area demonstrates that there is a temperature limit for the distribution of this species in the western Mediterranean. In addition, this study analyses round sardinella larvae distribution and abundance in the summers of 2003 and 2004, and conducts a comparison with the situation 20 years ago (summer 1983). Results show a marked increase in larval abundance during the last decades and the present appearance of larvae in the northernmost study areas, where they did not occur 20 years ago. This indicates the successful reproduction of round sardinella in the northern part of the Mediterranean, where the species has expanded, confirming its establishment in the area. 相似文献
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Plantlets were successfully regenerated from shoot segmentsof Betula celtiberica excised from young seedlings. Initiationand elongation of multiple shoot-buds were obtained after 20d culture in MS-modified medium plus BAP 0.6 mg l1 followedby 20 d culture in the same medium in the presence of a reducedBAP concentration (0.1 mg l1). Rooting was achieved 7d after having transplanted the isolated shoots to fresh medium,supplemented with IBA (0.2 mg l1). Betula celtiberica, birch, micropropagation, organogenesis 相似文献
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CELIA JIMENEZ-CERVANTES PALOMA VALVERDE JOS C. GARCÍA-BORR
N FRANCISCO SOLANO JOS A. LOZANO 《Pigment cell & melanoma research》1993,6(6):394-399
Mammalian tyrosinase exists in a variety of subcellular locations and maturation states that result from a complex post-translational processing with possible regulatory implications. So far, SDS-PAGE has proven to be the method of choice for the resolution of tyrosinase isoforms. However, the relatively poor sensitivity of the currently available specific activity stain based on incubation of the gels with L-dopa until the formation of melanin has severely limited the use of electrophoresis in regulation studies. Two alternative staining procedures are presented and discussed. The first one involves the fluoro-graphic detection of radioactive melanin after incubation of the gels in the presence of L-[3-14C]-dopa. A similar method has already been used by others (Tsukamoto et al., 1992, Pigment Cell Res. [Suppl.] 2:84–89), but its performance has not yet been compared to the one of the dopa procedure. The sensitivity of this method can be varied by adjusting the isotopic dilution of the tracer and/or the time of exposure of the gel, but it is at least ten times higher than the one of the colorimetric stain. Moreover, the intensity of the bands is proportional to the initial tyrosinase activity over a wide range. Using this procedure, the activity present in the different subcellular fractions of melanocytes in culture can be easily detected. The second procedure involves the formation of a colored adduct between dopaquinone and MBTH. Its sensitivity is also more than one order of magnitude higher than the one obtained with L-dopa alone, and comparable to the one of the fluorographic method, but, as opposed to this latter, the complete staining can be performed in less than 1 hr. 相似文献