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51.
Thibaut Capblancq Jesús Mavrez Delphine Rioux Laurence Desprs 《Ecology and evolution》2019,9(11):6444-6457
Until complete reproductive isolation is achieved, the extent of differentiation between two diverging lineages is the result of a dynamic equilibrium between genetic isolation and mixing. This is especially true for hybrid taxa, for which the degree of isolation in regard to their parental species is decisive in their capacity to rise as a new and stable entity. In this work, we explored the past and current patterns of hybridization and divergence within a complex of closely related butterflies in the genus Coenonympha in which two alpine species, C. darwiniana and C. macromma, have been shown to result from hybridization between the also alpine C. gardetta and the lowland C. arcania. By testing alternative scenarios of divergence among species, we show that gene flow has been uninterrupted throughout the speciation process, although leading to different degrees of current genetic isolation between species in contact zones depending on the pair considered. Nonetheless, at broader geographic scale, analyses reveal a clear genetic differentiation between hybrid lineages and their parental species, pointing out to an advanced stage of the hybrid speciation process. Finally, the positive correlation observed between ecological divergence and genetic isolation among these butterflies suggests a potential role for ecological drivers during their speciation processes. 相似文献
52.
Distribution dynamics of the Tnt1 retrotransposon in tobacco 总被引:1,自引:0,他引:1
Le QH Melayah D Bonnivard E Petit M Grandbastien MA 《Molecular genetics and genomics : MGG》2007,278(6):639-651
Retrotransposons contribute significantly to the size, organization and genetic diversity of plant genomes. Although many
retrotransposon families have been reported in plants, to this day, the tobacco Tnt1 retrotransposon remains one of the few
elements for which active transposition has been shown. Demonstration that Tnt1 activation can be induced by stress has lent
support to the hypothesis that, under adverse conditions, transposition can be an important source of genetic variability.
Here, we compared the insertion site preference of a collection of newly transposed and pre-existing Tnt1 copies identified
in plants regenerated from protoplasts or tissue culture. We find that newly transposed Tnt1 copies are targeted within or
close to host gene coding sequences and that the distribution of pre-existing insertions does not vary significantly from
this trend. Therefore, in spite of their potential to disrupt neighboring genes, insertions within or near CDS are not preferentially
removed with age. Elimination of Tnt1 insertions within or near coding sequences may be relaxed due to the polyploid nature
of the tobacco genome. Tnt1 insertions within or near CDS are thus better tolerated and can putatively contribute to the diversification
of tobacco gene function.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
53.
54.
Katherine L. Helbig Robert J. Lauerer Jacqueline C. Bahr Ivana A. Souza Candace T. Myers Betül Uysal Niklas Schwarz Maria A. Gandini Sun Huang Boris Keren Cyril Mignot Alexandra Afenjar Thierry Billette de Villemeur Delphine Héron Caroline Nava Stéphanie Valence Julien Buratti Christina R. Fagerberg Heather C. Mefford 《American journal of human genetics》2019,104(3):562
55.
56.
Bouguerche Chahinez Tazerouti Fadila Gey Delphine Justine Jean-Lou 《Systematic parasitology》2019,96(8):681-694
Systematic Parasitology - Allogastrocotyle bivaginalis Nasir & Fuentes Zambrano, 1983, the sole species of Allogastrocotyle Nasir & Fuentes Zambrano, 1983, was described from... 相似文献
57.
Delphine Durette‐Morin Kimberley T. A. Davies Hansen D. Johnson Moira W. Brown Hilary Moors‐Murphy Bruce Martin Christopher T. Taggart 《Marine Mammal Science》2019,35(4):1280-1303
North Atlantic right whale monitoring in Roseway Basin, Canada, is primarily based on short‐term (<14 d) visual surveys conducted during August–September. Variability in survey effort has been the biggest limiting factor to studying changes in the population's occurrence and habitat use. Such efforts could be enhanced considerably using passive acoustic monitoring (PAM). We sought to determine if variation in whale presence, relative abundance, demography, and/or behavior (estimated through visual surveys) could be explained by variation in three right whale call types in this habitat. A generalized linear model was fit to 23 d of concurrent PAM and visual monitoring during four summers within the Roseway Basin Right Whale Critical Habitat boundaries. The model revealed significant positive relationships between relative abundance, call counts and presence of surface‐active group behavior. PAM can refine daily right whale presence estimates. While visual observations (n = 23 d) implied a 40% decline in right whale presence during 2014–2015 relative to 2004–2005, PAM data (n = 211 d) showed right whales were present between 71%–85% of survey days throughout all years analyzed. We demonstrate that PAM is a useful tool to extend periods of right whale monitoring, especially in areas where visual monitoring efforts may be limited. 相似文献
58.
59.
Limnological and ecophysiological aspects of Aphanizomenon ovalisporum bloom in Lake Kinneret, Israel 总被引:3,自引:0,他引:3
Hadas O; Pinkas R; Delphine E; Vardi A; Kaplan A; Sukenik A 《Journal of plankton research》1999,21(8):1439-1453
The first appearance of Aphanizomenon ovalisporum in
Lake Kinneret in August 1994 was apparently boosted by relatively high
concentrations of total dissolved phosphorus (12 g P l-1 as compared to an
average of 8 g P l-1). The increasing
Aphanizomenon biomass in a lake in which phytoplankton
are generally phosphate limited in summer and autumn was accompanied by
high enzymatic activity of alkaline phosphatase, reaching values of 2830
nmol MU l-1 h-1, suggesting a
great demand for phosphorus. In addition, the nitrogen requirement of the
developing population of Aphanizomenon was partly
provided by nitrogen fixation, as indicated by a high percentage of
heterocysts. Laboratory experiments demonstrated that filtrate from an old
Peridinium gatunense culture enhanced
Aphanizomenon growth. Thus, it is postulated that the
degradation of the massive Peridinium bloom in spring
and early summer supported the development of
A.ovalisporum. The high pH and alkalinity during the
bloom of Aphanizomenon indicate that
A.ovalisporum is probably a
HCO3- user. After 1994, akinetes of
A.ovalisporum were left in sediments and the water
column, and could be a source for the next year's bloom. This possibility
was demonstrated by inoculation of lake water and sediments into
nitrogen-depleted BG-11 medium, resulting in the dominance of
A.ovalisporum.
相似文献
60.
A reduced exopolysaccharide phenotype is associated with inability to synthesize polyhydroxyalkanaote (PHA) stores in Sinorhizobium meliloti strain Rm1021. Loss of function mutations in phbB and phbC result in non-mucoid colony morphology on Yeast Mannitol Agar, compared to the mucoid phenotype exhibited by the parental strain. This phenotype is attributed to reduction in succinoglycan synthesis. We have used complementation of this phenotype and the previously described D-3-hydroxybutyrate/acetoacetate utilization phenotype to isolate a heterologous clone containing a Bradyrhizobium japonicum phbC gene. Sequence analysis confirmed that this clone contains one of the five predicted phbC genes in the B. japonicum genome. The described phenotypic complementation strategy should be useful for isolation of novel PHA synthesis genes of diverse origin. 相似文献