A link between LEAFY and B-gene homologues in Welwitschia mirabilis sheds light on ancestral mechanisms prefiguring floral development

- Flowering plants evolved from an unidentified gymnosperm ancestor. Comparison of the mechanisms controlling development in angiosperm flowers and gymnosperm cones may help to elucidate the mysterious origin of the flower. - We combined gene expression studies with protein behaviour characterization in Welwitschia mirabilis to test whether the known regulatory links between LEAFY and its MADS-box gene targets, central to flower development, might also contribute to gymnosperm reproductive development. - We found that WelLFY, one of two LEAFY-like genes in Welwitschia, could be an upstream regulator of the MADS-box genes APETALA3/PISTILLATA-like (B-genes). We demonstrated that, even though their DNA-binding domains are extremely similar, WelLFY and its paralogue WelNDLY exhibit distinct DNA-binding specificities, and that, unlike WelNDLY, WelLFY shares with its angiosperm orthologue the capacity to bind promoters of Welwitschia B-genes. Finally, we identified several cis-elements mediating these interactions in Welwitschia and obtained evidence that the link between LFY homologues and B-genes is also conserved in two other gymnosperms, Pinus and Picea. - Although functional approaches to investigate cone development in gymnosperms are limited, our state-of-the-art biophysical techniques, coupled with expression studies, provide evidence that crucial links, central to the control of floral development, may already have existed before the appearance of flowers.This work was supported by funding from the Centre National de la Recherche Scientifique (ATIP+ to F.P.), the ANAgence Nationale de la Recherche (ANR) (Plant-TFcode to F.P. and C.P.S.), PhD fellowships from the University J. Fourier, Grenoble (to E.M. and M.M.), Grenoble Alliance for Cell and Structural Biology (ANR-10-LABX-49-01), the SYNTHESYS Project (to E.M.), the Floral Genome Project (National Science Foundation (NSF) Plant Genome Research Program project DBI-0115684 to M.W.F.) and NSF DEB-9974374 (to M.W.F.)

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A Reflection on Economic Uncertainty and Fertility in Europe: The Narrative Framework

none5openVignoli, Daniele; Guetto, Raffaele; Bazzani, Giacomo; Pirani, Elena; Minello, AlessandraVignoli, Daniele; Guetto, Raffaele; Bazzani, Giacomo; Pirani, Elena; Minello, Alessandr

Resistance of thermally modified ash (Fraxinus excelsior L.) wood under steam pressure against rot fungi, soil-inhabiting micro-organisms and termites

Thermal modification processes have been developed to increase the biological durability and dimensional stability of wood. The aim of this paper was to study the influence of ThermoWood® treatment intensity on improvement of wood decay resistance against soil-inhabiting micro-organisms, brown/white rots and termite exposures. All of the tests were carried out in the laboratory with two different complementary research materials. The main research material consisted of ash (Fraxinus excelsior L.) wood thermally modified at temperatures of 170, 200, 215 and 228 °C. The reference materials were untreated ash and beech wood for decay resistance tests, untreated ash wood for soil bed tests and untreated ash, beech and pine wood for termite resistance tests. An agar block test was used to determine the resistance to two brown-rot and two white-rot fungi according to CEN/TS 15083-1 directives. Durability against soil-inhabiting micro-organisms was determined following the CEN/TS 15083-2 directives, by measuring the weight loss, modulus of elasticity (MOE) and modulus of rupture (MOR) after incubation periods of 24, 32 and 90 weeks. Finally, Reticulitermes santonensis species was used for determining the termite attack resistance by non-choice screening tests, with a size sample adjustment according to EN 117 standard directives on control samples and on samples which have previously been exposed to soil bed test. Thermal modification increased the biological durability of all samples. However, high thermal modification temperature above 215 °C, represented by a wood mass loss (ML%) due to thermal degradation of 20%, was needed to reach resistance against decay comparable with the durability classes of ‘‘durable’’ or ‘‘very durable’’ in the soil bed test. The brown-rot and white-rot tests gave slightly better durability classes than the soil bed test. Whatever the heat treatment conditions are, thermally modified ash wood was not efficient against termite attack neither before nor after soft rot degradation

The Effect of Gender Policies on Fertility: The Moderating Role of Education and Normative Context

In this paper, we aim to assess the extent to which individual-level completed fertility varies across contexts characterized by policies supporting different gender division of labor models. We examine key labor market and care policies that shape gender relations in households and in the public domain. We also consider the role of gender norms, which can act as both a moderator and a confounding factor for policy effects. We hypothesize that, by facilitating role compatibility and reducing the gendered costs of childrearing, policies that support gender equality lead to an increase in fertility levels and to a reduction in fertility differentials by the level of education. Using individual-level data from the European Union Survey on Income and Living Conditions for 16 countries, combined with country-level data, we analyze completed fertility through multilevel Poisson’s models. We find that the national level of childcare coverage is positively associated with fertility. Family allowances, prevalence of women’s part-time employment and length of paid leaves were also found to be positively associated with completed fertility, though the associations were not statistically significant. These variables show a significant positive pattern according to education. A high number of average working hours for men are negatively associated with completed fertility and show a strong negative pattern by educational level. The prevalence of gender-egalitarian norms is highly predictive of fertility levels, yet we found no consistent evidence of a weaker association of gender-equality policies in countries where egalitarian values are less prevalent