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Genetic variability in the federally endangered pitcher plant Sarracenia rubra ssp. alabamensis was assessed in eight Alabama populations using starch gel electrophoresis. Ten populations of the more widespread Sarracenia rubra ssp. rubra were sampled in the southeastern United States for comparison. Fifteen allozyme loci representing 13 enzyme systems were scored for each species. In contrast to S. oreophila and S. jonesii, two previously analyzed endangered pitcher plants, genetic diversity was high for both S. rubra subspecies. Within ssp. alabamensis the percentage polymorphic loci (Ps) was 80.0, the mean number of alleles per polymorphic locus was (APs) = 2.58, and expected heterozygosity (Hes) was 0.209. Genetic diversity was slightly lower for ssp. rubra (Ps = 73.3, APs = 2.91, and Hes = 0.177). The proportion of total genetic diversity found among populations was fairly low for both species (GST = 0.09 for ssp. alabamensis and 0.14 for ssp. rubra). Little genetic divergence has occurred between the two subspecies as indicated by the lack of diagnostic alleles, the proportion of total genetic diversity between taxa (GST = 0.09), and the genetic identity estimate (I = 0.90). The relatively high genetic diversity found for ssp. alabamensis indicates that the maintenance of its evolutionary potential is possible if population sizes are maintained or increased. Low levels of genetic diversity found within small Georgia ssp. rubra populations indicate that genetic erosion may increase extinction risks for these populations.  相似文献   

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New prodigiosin-like pigment from Alteromonas rubra.   总被引:2,自引:1,他引:1       下载免费PDF全文
The red prodigiosin-like pigment from Alteromonas rubra was shown to be a mixture of prodigiosin (pigment 1) and a new cyclic isomer (pigment 2). The new structure was elucidated by mass and nuclear magnetic resonance spectra. Careful examinations of the prodigiosins produced by Serratia marcescens, Vibrio psychoerythrus, and an unidentified red bacterium (LL-100-6) failed to disclose any of the new pigment, pigment 2.  相似文献   

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The red prodigiosin-like pigment from Alteromonas rubra was shown to be a mixture of prodigiosin (pigment 1) and a new cyclic isomer (pigment 2). The new structure was elucidated by mass and nuclear magnetic resonance spectra. Careful examinations of the prodigiosins produced by Serratia marcescens, Vibrio psychoerythrus, and an unidentified red bacterium (LL-100-6) failed to disclose any of the new pigment, pigment 2.  相似文献   

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红枝鳃海牛是一种珍稀贝类,非洲东岸、红海、桑给巴尔、马达加斯加、塞舌尔群岛、印度、斯里兰卡、新加坡、泰国、马来西亚、越南、日本、澳大利亚、所罗门群岛等海域有分布,在我国目前仅见于香港、福建东山和浙江的鱼山、洞头和南麂等岛屿,但是数量很少,出现的季节很短。  相似文献   

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Polycythemia rubra vera (PV) is one of four diseases collectively called the myeloproliferative disorders (MPDs). Each disorder leads to an increased production of one or several hematopoietic cell lineages. MPDs arise from acquired mutations in a pluripotent hematopoietic stem cell. However, the molecular mechanisms leading to the development of these diseases are poorly understood. This review will summarize and evaluate recent advances in our understanding of one particular MPD, PV.  相似文献   

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Summary Large queen-potential third instar larvae after winter have been cultured with sugar and water, but no protein, for various times at various stages.When presumptive queens are treated permanently in the pre-segmenttation period they die: but if treated in the segmentation period they yield either intercastes, if they were of 2-segment leg stage of maturity or less at the time dieting started, or queens if more mature.When treated before post-winter growth they show a small increase in maturity (size-independent as far as one can tell) and an incommensurate gain in weight, but a more than commensurate gain in leg area (both greater in large larvae) and no gain in wing area. In male larvae the adult system also gains at the expense of the larval but the wing grows with the leg. Subsequent growth under normal conditions is often sporadic, with higher mortality and smaller adults than usual; only in some females from large larvae is there an acceleration of development in the segmentation period.Details of the ontogenies of queens, intercastes (which are not abnormally frequent) and workers derived from large larvae pre-treated for a period covering that known to be critical for the destruction of queenpotentiality are given in the usual way. The main features are: some queens show a short delay in development just after determination; the intercastes result from growth failures; the workers results from growth failure late in the A period and varying degrees of development acceleration in the segmentation period.A comparison of these ontogenies with those given in earlier papers is made, and the results of all contributions to date summarised.
Resumen Durante varios tiempos y etapas después del invierno la larva en estado final reina-potencial grande se ha tratado con azúcar y agua pero no con proteina.Cuando las reinas presuntas se tratan permanentemente en el periodo de pre-segmentación, ellas mueren. Si se tratan en el período de segmentación producen cruzadas, si hubiesen llegado a desarrollar patas hasta 2-segmentos/o menos al comenzar la dieta, o reinas si fuesen más avanzadas.Cuando se tratan antes del crecimiento post-invernal, demuestran un pequeño aumento de madurez (tanto se puede apreciar, el tamaño no depende de ello_ y un desproporcionado aumento de peso. Pero más que proporcionado en las patas (estos aumentos mayores en la larva grande) y ningun aumento en las alas.Asimismo, en los machos, el sistema adulto crece a expensa del larval pero las alas crecen con las patas. Subsecuente crecimiento bajo condiciones normales, es frecuentemente irregular, con mayor mortalidad y adultos mas pequenos que de costumbre. Solo en algunas hembras de lava grande se encuentra un desarrollo acelerado durante el periodo de segmentación.Detalles de la ontongene de reinas, cruzadas (cuya frecuencia no es anormal) y trabajadoras derivadas de larva grande tratadas anteriormente por un período cubriendo aquel conocido como crítico para la destruccion de potencialidad de reina, se dan en la manera de costumbre. Puntos principales son: Algunas reinas demuestran una pequeña demora en su desarrollo siguiendo su determinación. Las cruzadas resultan por falta de desarrollo. Las trabajadoras son resultado de esta falta en la ultima parte del período A y distintos grados de aceleración de desarrollo en el periodo de segmentación.Se ha efectuado una comparación de estas ontogenes con aquellas anteriormente producidas asicomo tambien un resumen de toda contribución recibida a la fecha.
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