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211.
Victoire Cardot‐Ruffino Vronique Chauvet Cassandre Caligaris Adrien Bertrand‐Chapel Nicolas Chuvin Roxane M. Pommier Ulrich Valcourt David Vincent Sylvie Martel Sophie Aires Bastien Kaniewski Pierre Dubus Philippe Cassier Stphanie Sentis Laurent Bartholin 《Genesis (New York, N.Y. : 2000)》2020,58(5)
Recombination systems represent a major breakthrough in the field of genetic model engineering. The Flp recombinases (Flp, Flpe, and Flpo) bind and cleave DNA Frt sites. We created a transgenic mouse strain ([Fsp1‐Flpo]) expressing the Flpo recombinase in fibroblasts. This strain was obtained by random insertion inside mouse zygotes after pronuclear injection. Flpo expression was placed under the control of the promoter of Fsp1 (fibroblast‐specific protein 1) gene, whose expression starts after gastrulation at Day 8.5 in cells of mesenchymal origin. We verified the correct expression and function of the Flpo enzyme by several ex vivo and in vivo approaches. The [Fsp1‐Flpo] strain represents a genuine tool to further target the recombination of transgenes with Frt sites specifically in cells of mesenchymal origin or with a fibroblastic phenotype. 相似文献
212.
Johanna Marin‐Carbonne Vincent Busigny Jennyfer Miot Claire Rollion‐Bard Elodie Muller Nadja Drabon Damien Jacob Sylvain Pont Martin Robyr Tomaso R. R. Bontognali Camille Franois Stephanie Reynaud Mark Van Zuilen Pascal Philippot 《Geobiology》2020,18(3):306-325
On the basis of phylogenetic studies and laboratory cultures, it has been proposed that the ability of microbes to metabolize iron has emerged prior to the Archaea/Bacteria split. However, no unambiguous geochemical data supporting this claim have been put forward in rocks older than 2.7–2.5 giga years (Gyr). In the present work, we report in situ Fe and S isotope composition of pyrite from 3.28‐ to 3.26‐Gyr‐old cherts from the upper Mendon Formation, South Africa. We identified three populations of microscopic pyrites showing a wide range of Fe isotope compositions, which cluster around two δ56Fe values of ?1.8‰ and +1‰. These three pyrite groups can also be distinguished based on the pyrite crystallinity and the S isotope mass‐independent signatures. One pyrite group displays poorly crystallized pyrite minerals with positive Δ33S values > +3‰, while the other groups display more variable and closer to 0‰ Δ33S values with recrystallized pyrite rims. It is worth to note that all the pyrite groups display positive Δ33S values in the pyrite core and similar trace element compositions. We therefore suggest that two of the pyrite groups have experienced late fluid circulations that have led to partial recrystallization and dilution of S isotope mass‐independent signature but not modification of the Fe isotope record. Considering the mineralogy and geochemistry of the pyrites and associated organic material, we conclude that this iron isotope systematic derives from microbial respiration of iron oxides during early diagenesis. Our data extend the geological record of dissimilatory iron reduction (DIR) back more than 560 million years (Myr) and confirm that micro‐organisms closely related to the last common ancestor had the ability to reduce Fe(III). 相似文献
213.
214.
Vincent Roubeix 《Phycological Research》2020,68(3):249-253
Little is known about direct interactions between diatoms. In this study, small diatoms attaching onto larger benthic and motile diatoms were considered. This phenomenon is commonly considered as epiphytism (with diatom epiphytes) although the exact nature of this interaction has not been investigated yet. The question that was addressed here is the specificity of the interaction, simply by observing species associations in their natural environment. A comparison of this special form of epiphytism was carried out between two sites, on a Mediterranean river and one of its tributaries. The results showed both host and epiphyte selection, but with some variability in species associations. This excludes the two alternative hypotheses that (i) large diatoms are a neutral substrate for smaller diatoms and that (ii) the interactions are strictly specific between two species. 相似文献
215.
Muriel Cario Catherine Pain Priscilla Kaulanjan‐Checkmodine Daniela Masia Gabriele Delia Vincent Casoli Pierre Costet Jean‐Franois Goussot Vronique Guyonnet‐Duperat Alice Bibeyran Khaled Ezzedine Corinne Reymermier Valrie Andre‐Frei Alain Taieb 《Pigment cell & melanoma research》2020,33(3):435-445
Human skin melanin pigmentation is regulated by systemic and local factors. According to the type of melanin produced by melanocytes, the transfer and degradation of melanosomes differ, thus accounting for most variations between ethnicities. We made the surprising observation that in a drastically changed environment, white and black phenotypes are reversible since Caucasian skin grafted onto nude mice can become black with all black phenotypic characteristics. Black xenografts differed essentially from other grafts by the levels of epidermal FGF‐2 and keratin 5. In vitro analysis confirmed that FGF‐2 directly regulates keratin 5. Interestingly, this phenomenon may be involved in human pathology. Keratin 5 mutations in Dowling–Degos Disease (DDD) have already been associated with the pheomelanosome–eumelanosome transition. In a DDD patient, keratin 5 was expressed in the basal and spinous layers, as observed in black xenografts. Furthermore, in a common age‐related hyperpigmentation disorder like senile lentigo (SL), keratin 5 distribution is also altered. In conclusion, modulation of keratin 5 expression and distribution either due to mutations or factors may account for the development of pigmentary disorders. 相似文献
216.
Ming-Chih Chiu Kei Nukazawa Thaddeus Carvajal Vincent H. Resh Bin Li Kozo Watanabe 《Ecography》2020,43(12):1891-1901
Different shapes of landscape boundaries can affect the habitat networks within them and consequently the spatial genetic-patterns of a metapopulation. In this study, we used a mechanistic framework to evaluate the effects of landscape shape, through watershed elongation, on genetic divergence among populations at the metapopulation scale. Empirical genetic data from four, sympatric stream-macroinvertebrates having aerial adults were collected from streams in Japan to determine the roles of species-specific dispersal strategies on metapopulation genetics. Simulation results indicated that watershed elongation allows the formation of river networks with fewer branches and larger topographic constraints. This results in decreased interpopulation connectivity but a lower level of spatial isolation of distal populations (e.g. those found in headwaters) occurring in the landscapes examined. Distal populations had higher genetic divergence when their downstream-biased dispersal (relative to upstream- and/or overland-biased dispersal) was high. This underscores the importance of distal populations influencing genetic divergence at the metapopulation scale for species having downstream-biased dispersal. In turn, lower genetic divergence was observed under watershed elongation when the genetic isolation of distal populations was decreased in such species. This strong association between landscape shape and evolutionary processes highlights the importance of natural, spatial architecture in assessing the effectiveness of conservation and management strategies. 相似文献
217.
218.
John Soghigian Andrea Gloria‐Soria Vincent Robert Gilbert Le Goff Anna‐Bella Failloux Jeffrey R. Powell 《Molecular ecology》2020,29(19):3593-3606
Aedes aegypti is among the best‐studied mosquitoes due to its critical role as a vector of human pathogens and ease of laboratory rearing. Until now, this species was thought to have originated in continental Africa, and subsequently colonized much of the world following the establishment of global trade routes. However, populations of this mosquito on the islands in the southwestern Indian Ocean (SWIO), where the species occurs with its nearest relatives referred to as the Aegypti Group, have received little study. We re‐evaluated the evolutionary history of Ae. aegypti and these relatives, using three data sets: nucleotide sequence data, 18,489 SNPs and 12 microsatellites. We found that: (a) the Aegypti Group diverged 16 MYA (95% HPD: 7–28 MYA) from its nearest African/Asian ancestor; (b) SWIO populations of Ae. aegypti are basal to continental African populations; (c) after diverging 7 MYA (95% HPD: 4–15 MYA) from its nearest formally described relative (Ae. mascarensis), Ae. aegypti moved to continental Africa less than 85,000 years ago, where it recently (<1,000 years ago) split into two recognized subspecies Ae. aegypti formosus and a human commensal, Ae. aegypti aegypti; (d) the Madagascar samples form a clade more distant from all other Ae. aegypti than the named species Ae. mascarensis, implying that Madagascar may harbour a new cryptic species; and (e) there is evidence of introgression between Ae. mascarensis and Ae. aegypti on Réunion, and between the two subspecies elsewhere in the SWIO, a likely consequence of recent introductions of domestic Ae. aegypti aegypti from Asia. 相似文献
219.
Sara Marin Anaïs Gibert Juliette Archambeau Vincent Bonhomme Mylne Lascoste Benoit Pujol 《Molecular ecology》2020,29(16):3010-3021
Phenotypic divergence among natural populations can be explained by natural selection or by neutral processes such as drift. Many examples in the literature compare putatively neutral (FST) and quantitative genetic (QST) differentiation in multiple populations to assess their evolutionary signature and identify candidate traits involved with local adaptation. Investigating these signatures in closely related or recently diversified species has the potential to shed light on the divergence processes acting at the interspecific level. Here, we conducted this comparison in two subspecies of snapdragon plants (eight populations of Antirrhinum majus pseudomajus and five populations of A. m. striatum) in a common garden experiment. We also tested whether altitude was involved with population phenotypic divergence. Our results identified candidate phenological and morphological traits involved with local adaptation. Most of these traits were identified in one subspecies but not the other. Phenotypic divergence increased with altitude for a few biomass‐related traits, but only in A. m. striatum. These traits therefore potentially reflect A. m. striatum adaptation to altitude. Our findings imply that adaptive processes potentially differ at the scale of A. majus subspecies. 相似文献
220.
Vincent A. Viblanc Quentin Schull Antoine Stier Laureline Durand Emilie Lefol Jean‐Patrice Robin Sandrine Zahn Pierre Bize Franois Criscuolo 《Molecular ecology》2020,29(16):3154-3166
Because telomere length and dynamics relate to individual growth, reproductive investment and survival, telomeres have emerged as possible markers of individual quality. Here, we tested the hypothesis that, in species with parental care, parental telomere length can be a marker of parental quality that predicts offspring phenotype and survival. In king penguins (Aptenodytes patagonicus), we experimentally swapped the single egg of 66 breeding pairs just after egg laying to disentangle the contribution of prelaying parental quality (e.g., genetics, investment in the egg) and/or postlaying parental quality (e.g., incubation, postnatal feeding rate) on offspring growth, telomere length and survival. Parental quality was estimated through the joint effects of biological and foster parent telomere length on offspring traits, both soon after hatching (day 10) and at the end of the prewinter growth period (day 105). We expected that offspring traits would be mostly related to the telomere lengths (i.e., quality) of biological parents at day 10 and to the telomere lengths of foster parents at day 105. Results show that chick survival up to 10 days was negatively related to biological fathers’ telomere length, whereas survival up to 105 days was positively related to foster fathers’ telomere lengths. Chick growth was not related to either biological or foster parents’ telomere length. Chick telomere length was positively related to foster mothers’ telomere length at both 10 and 105 days. Overall, our study shows that, in a species with biparental care, parents’ telomere length is foremost a proxy of postlaying parental care quality, supporting the “telomere – parental quality hypothesis.” 相似文献