The role of phenotypic plasticity in shaping ecological networks.

Plasticity-mediated changes in interaction dynamics and structure may scale up and affect the ecological network in which the plastic species are embedded. Despite their potential relevance for understanding the effects of plasticity on ecological communities, these effects have seldom been analysed. We argue here that, by boosting the magnitude of intra-individual phenotypic variation, plasticity may have three possible direct effects on the interactions that the plastic species maintains with other species in the community: may expand the interaction niche, may cause a shift from one interaction niche to another or may even cause the colonization of a new niche. The combined action of these three factors can scale to the community level and eventually expresses itself as a modification in the topology and functionality of the entire ecological network. We propose that this causal pathway can be more widespread than previously thought and may explain how interaction niches evolve quickly in response to rapid changes in environmental conditions. The implication of this idea is not solely eco-evolutionary but may also help to understand how ecological interactions rewire and evolve in response to global change.

Phenotypic plasticity guides Moricandia arvensis divergence and convergence across the Brassicaceae floral morphospace.

Many flowers exhibit phenotypic plasticity. By inducing the production of several phenotypes, plasticity may favour the rapid exploration of different regions of the floral morphospace. We investigated how plasticity drives Moricandia arvensis, a species displaying within-individual floral polyphenism, across the floral morphospace of the entire Brassicaceae family. We compiled the multidimensional floral phenotype, the phylogenetic relationships, and the pollination niche of over 3000 species to construct a family-wide floral morphospace. We assessed the disparity between the two M. arvensis floral morphs (as the distance between the phenotypic spaces occupied by each morph) and compared it with the family-wide disparity. We measured floral divergence by comparing disparity with the most common ancestor, and estimated the convergence of each floral morph with other species belonging to the same pollination niches. Moricandia arvensis exhibits a plasticity-mediated floral disparity greater than that found between species, genera and tribes. The novel phenotype of M. arvensis moves outside the region occupied by its ancestors and relatives, crosses into a new region where it encounters a different pollination niche, and converges with distant Brassicaceae lineages. Our study suggests that phenotypic plasticity favours floral divergence and rapid appearance of convergent flowers, a process which facilitates the evolution of generalist pollination systems.

Transgenerational Plasticity in Flower Color Induced by Caterpillars.

Variation in flower color due to transgenerational plasticity could stem directly from abiotic or biotic environmental conditions. Finding a link between biotic ecological interactions across generations and plasticity in flower color would indicate that transgenerational effects of ecological interactions, such as herbivory, might be involved in flower color evolution. We conducted controlled experiments across four generations of wild radish (Raphanus sativus, Brassicaceae) plants to explore whether flower color is influenced by herbivory, and to determine whether flower color is associated with transgenerational chromatin modifications. We found transgenerational effects of herbivory on flower color, partly related to chromatin modifications. Given the presence of herbivory in plant populations worldwide, our results are of broad significance and contribute to our understanding of flower color evolution.

Changes at a Critical Branchpoint in the Anthocyanin Biosynthetic Pathway Underlie the Blue to Orange Flower Color Transition in Lysimachia arvensis.

Anthocyanins are the primary pigments contributing to the variety of flower colors among angiosperms and are considered essential for survival and reproduction. Anthocyanins are members of the flavonoids, a broader class of secondary metabolites, of which there are numerous structural genes and regulators thereof. In western European populations of Lysimachia arvensis, there are blue- and orange-petaled individuals. The proportion of blue-flowered plants increases with temperature and daylength yet decreases with precipitation. Here, we performed a transcriptome analysis to characterize the coding sequences of a large group of flavonoid biosynthetic genes, examine their expression and compare our results to flavonoid biochemical analysis for blue and orange petals. Among a set of 140 structural and regulatory genes broadly representing the flavonoid biosynthetic pathway, we found 39 genes with significant differential expression including some that have previously been reported to be involved in similar flower color transitions. In particular, F3'5'H and DFR, two genes at a critical branchpoint in the ABP for determining flower color, showed differential expression. The expression results were complemented by careful examination of the SNPs that differentiate the two color types for these two critical genes. The decreased expression of F3'5'H in orange petals and differential expression of two distinct copies of DFR, which also exhibit amino acid changes in the color-determining substrate specificity region, strongly correlate with the blue to orange transition. Our biochemical analysis was consistent with the transcriptome data indicating that the shift from blue to orange petals is caused by a change from primarily malvidin to largely pelargonidin forms of anthocyanins. Overall, we have identified several flavonoid biosynthetic pathway loci likely involved in the shift in flower color in L. arvensis and even more loci that may represent the complex network of genetic and physiological consequences of this flower color polymorphism.

Within-individual phenotypic plasticity in flowers fosters pollination niche shift.

Phenotypic plasticity, the ability of a genotype of producing different phenotypes when exposed to different environments, may impact ecological interactions. We study here how within-individual plasticity in Moricandia arvensis flowers modifies its pollination niche. During spring, this plant produces large, cross-shaped, UV-reflecting lilac flowers attracting mostly long-tongued large bees. However, unlike most co-occurring species, M. arvensis keeps flowering during the hot, dry summer due to its plasticity in key vegetative traits. Changes in temperature and photoperiod in summer trigger changes in gene expression and the production of small, rounded, UV-absorbing white flowers that attract a different assemblage of generalist pollinators. This shift in pollination niche potentially allows successful reproduction in harsh conditions, facilitating M. arvensis to face anthropogenic perturbations and climate change.

UV radiation increases phenolic compound protection but decreases reproduction in Silene littorea.

Plants respond to changes in ultraviolet (UV) radiation both morphologically and physiologically. Among the variety of plant UV-responses, the synthesis of UV-absorbing flavonoids constitutes an effective non-enzymatic mechanism to mitigate photoinhibitory and photooxidative damage caused by UV stress, either reducing the penetration of incident UV radiation or acting as quenchers of reactive oxygen species (ROS). In this study, we designed a UV-exclusion experiment to investigate the effects of UV radiation in Silene littorea. We spectrophotometrically quantified concentrations of both anthocyanins and UV-absorbing phenolic compounds in petals, calyces, leaves and stems. Furthermore, we analyzed the UV effect on the photosynthetic activity in hours of maximum solar radiation and we tested the impact of UV radiation on male and female reproductive performance. We found that anthocyanin concentrations showed a significant decrease of about 20% with UV-exclusion in petals and stems, and a 30% decrease in calyces. The concentrations of UV-absorbing compounds under UV-exclusion decreased by approximately 25% in calyces and stems, and 12% in leaves. Photochemical efficiency of plants grown under UV decreased at maximum light stress, reaching an inhibition of 58% of photosynthetic activity, but their ability to recover after light-stress was not affected. In addition, exposure to UV radiation did not affect ovule production or seed set per flower, but decreased pollen production and total seed production per plant by 31% and 69%, respectively. Our results demonstrate that UV exposure produced opposing effects on the accumulation of plant phenolic compounds and reproduction. UV radiation increased the concentration of phenolic compounds, suggesting a photoprotective role of plant phenolics against UV light, yet overall reproduction was compromised.

Indirect Selection on Flower Color in Silene littorea.

Flower color, as other floral traits, may suffer conflicting selective pressures mediated by both mutualists and antagonists. The maintenance of intraspecific flower color variability has been usually explained as a result of direct selection by biotic agents. However, flower color might also be under indirect selection through correlated traits, since correlations among flower traits are frequent. In this study, we aimed to find out how flower color variability is maintained in two nearby populations of Silene littorea that consistently differ in the proportions of white-flowered plants. To do that, we assessed natural selection on floral color and correlated traits by means of phenotypic selection analysis and path analysis. Strong directional selection on floral display and flower production was found in both populations through either male or female fitness. Flower color had a negative indirect effect on the total male and female fitness in Melide population, as plants with lighter corollas produced more flowers. In contrast, in Barra population, plants with darker corollas produced more flowers and have darker calices, which in turn were selected. Our results suggest that the prevalence of white-flowered plants in Melide and pink-flowered plants in Barra is a result of indirect selection through correlated flower traits and not a result of direct selection of either pollinators or herbivores on color.

Whole Plastome Sequencing Within Silene Section Psammophilae Reveals Mainland Hybridization and Divergence With the Balearic Island Populations.

Reconstructing the phylogenetic relationships within Caryophyllaceae tribe Sileneae has been obscured by hybridization and incomplete lineage sorting. Silene is the largest genus in the Caryophyllaceae, and unraveling its evolutionary history has been particularly challenging. In order to infer the phylogenetic relationships among the five species in Silene section Psammophilae, we have performed a genome skimming approach to acquire the complete plastid genome (cpDNA), nuclear ribosomal cistron (nrDNA), and partial mitochondrial genome (mtDNA). We have included 26 populations, representing the range of each species' distribution. This section includes five morphologically similar species endemic to the Iberian Peninsula and Balearic Islands (Ibiza and Formentera), yet some of them occupy distinct edaphic habitats (e.g. maritime sands, calcareous sandstones). In addition to phylogeographic analyses, genetic structuring using the chloroplast data set was inferred with Discriminant Analysis of Principal Components (DAPC), analyses of molecular variance (AMOVA), and a partial Mantel test. Reference-guided assembly of 50 bp single-end and 250 bp paired-end Illumina reads produced the nearly complete cpDNA genome (154 kbp), partial mtDNA genome (from 81 to 114 kbp), and the nrDNA cistron (6.4 kbp). Selected variable regions of the cpDNA and mtDNA assemblies were confirmed by Sanger sequencing. Phylogenetic analyses of the mainland populations reveal incongruence among the three genomes. None of the three data sets produced relationships consistent with taxonomy or geography. In contrast, Silene cambessedesii, present in the Balearic Islands, is the only species that forms a strongly supported monophyletic clade in the cpDNA genome and is strongly differentiated with respect to the remaining taxa of the Iberian Peninsula. These results contrast with those obtained for mainland populations. Across the entire analysis, only one well-supported mainland clade of Silene littorea and Silene stockenii emerges from the southern region of the Iberian Peninsula. DAPC and AMOVA results suggest the absence of genetic structure among mainland populations of Silene section Psammophilae, whereas partial Mantel test discarded spatial correlation of genetic differentiation. The widespread incongruence between morphology-based taxonomic boundaries and phylogeography suggests a history of interspecific hybridization, in which only a substantial geographic barrier, like isolation by the Mediterranean Sea, was sufficient to create and maintain species boundaries in Silene section Psammophilae.

Stability of petal color polymorphism: the significance of anthocyanin accumulation in photosynthetic tissues.

BACKGROUND: Anthocyanins are the primary source of colour in flowers and also accumulate in vegetative tissues, where they have multiple protective roles traditionally attributed to early compounds of the metabolic pathway (flavonols, flavones, etc.). Petal-specific loss of anthocyanins in petals allows plants to escape from the negative pleiotropic effects of flavonoid and anthocyanins loss in vegetative organs, where they perform a plethora of essential functions. Herein, we investigate the degree of pleiotropy at the biochemical scale in a pink-white flower colour polymorphism in the shore campion, Silene littorea. We report the frequencies of pink and white individuals across 21 populations and underlying biochemical profiles of three flower colour variants: anthocyanins present in all tissues (pink petals), petal-specific loss of anthocyanins (white petals), and loss of anthocyanins in all tissues (white petals). RESULTS: Individuals lacking anthocyanins only in petals represent a stable polymorphism in two populations at the northern edge of the species range (mean frequency 8-21%). Whereas, individuals lacking anthocyanins in the whole plant were found across the species range, yet always at very low frequencies (< 1%). Biochemically, the flavonoids detected were anthocyanins and flavones; in pigmented individuals, concentrations of flavones were 14-56× higher than anthocyanins across tissues with differences of > 100× detected in leaves. Loss of anthocyanin pigmentation, either in petals or in the whole plant, does not influence the ability of these phenotypes to synthesize flavones, and this pattern was congruent among all sampled populations. CONCLUSIONS: We found that all colour variants showed similar flavone profiles, either in petals or in the whole plant, and only the flower colour variant with anthocyanins in photosynthetic tissues persists as a stable flower colour polymorphism. These findings suggest that anthocyanins in photosynthetic tissues, not flavonoid intermediates, are the targets of non-pollinator mediated selection.

Digital photography provides a fast, reliable, and noninvasive method to estimate anthocyanin pigment concentration in reproductive and vegetative plant tissues.

Anthocyanin pigments have become a model trait for evolutionary ecology as they often provide adaptive benefits for plants. Anthocyanins have been traditionally quantified biochemically or more recently using spectral reflectance. However, both methods require destructive sampling and can be labor intensive and challenging with small samples. Recent advances in digital photography and image processing make it the method of choice for measuring color in the wild. Here, we use digital images as a quick, noninvasive method to estimate relative anthocyanin concentrations in species exhibiting color variation. Using a consumer-level digital camera and a free image processing toolbox, we extracted RGB values from digital images to generate color indices. We tested petals, stems, pedicels, and calyces of six species, which contain different types of anthocyanin pigments and exhibit different pigmentation patterns. Color indices were assessed by their correlation to biochemically determined anthocyanin concentrations. For comparison, we also calculated color indices from spectral reflectance and tested the correlation with anthocyanin concentration. Indices perform differently depending on the nature of the color variation. For both digital images and spectral reflectance, the most accurate estimates of anthocyanin concentration emerge from anthocyanin content-chroma ratio, anthocyanin content-chroma basic, and strength of green indices. Color indices derived from both digital images and spectral reflectance strongly correlate with biochemically determined anthocyanin concentration; however, the estimates from digital images performed better than spectral reflectance in terms of r2 and normalized root-mean-square error. This was particularly noticeable in a species with striped petals, but in the case of striped calyces, both methods showed a comparable relationship with anthocyanin concentration. Using digital images brings new opportunities to accurately quantify the anthocyanin concentrations in both floral and vegetative tissues. This method is efficient, completely noninvasive, applicable to both uniform and patterned color, and works with samples of any size.

Nutritional practices in very low birth weight infants: a national survey.

BACKGROUND: Significant efforts have been made to improve the nutritional support of very preterm infants. Large surveys may help to know the nutritional practices for preterm infants in neonatal units and identify if they are in line with the current guidelines. METHODS: A multicentre nationwide web-based survey on clinical feeding practices in very low birth weight (VLBW) infants was conducted in tertiary neonatal hospitals that admit infants with a birth weight < 1,500 g and/or a gestational age of < 32 weeks. RESULTS: The questionnaire was completed by 53 units (response rate, 59%). Over 90% of the units surveyed start amino-acid administration immediately after birth and more than half use novel intravenous fish oil-based lipid emulsions. Enteral nutrition is started within 24 hours of birth in 65% of units and 86% of these are medium-sized or large. Feeding volumes are increased at a rate of 10-30 ml/kg/day in > 90% of units. Monitoring of serum phosphorus was measured more frequently than albumin (p = 0.009) or triglycerides (p = 0.037), but only 28% of centres regularly measure pre-albumin as a nutritional biomarker. Human milk fortification and iron supplementation, starting at four weeks of age, are almost universal. However, only 30% of units administer 800 IU/day of vitamin D. Nearly 50% of the units discharge infants on preterm formula. CONCLUSION: Most Spanish neonatology units use early amino-acid supplementation and over half use novel fish oil-based lipid emulsions. Post-discharge nutrition practices and vitamin administration vary greatly.

Nutritional practices in very low birth weight infants: a national survey / ¿Cuál es la nutrición que administramos a nuestros recién nacidos de muy bajo peso en las unidades neonatales?: una encuesta nacional

Background: Significant efforts have been made to improve the nutritional support of very preterm infants. Large surveys may help to know the nutritional practices for preterm infants in neonatal units and identify if they are in line with the current guidelines. Methods: A multicentre nationwide web-based survey on clinical feeding practices in very low birth weight (VLBW) infants was conducted in tertiary neonatal hospitals that admit infants with a birth weight < 1,500 g and/or a gestational age of < 32 weeks. Results: The questionnaire was completed by 53 units (response rate, 59%). Over 90% of the units surveyed start amino-acid administration immediately after birth and more than half use novel intravenous fish oil-based lipid emulsions. Enteral nutrition is started within 24 hours of birth in 65% of units and 86% of these are medium-sized or large. Feeding volumes are increased at a rate of 10-30 ml/kg/day in > 90% of units. Monitoring of serum phosphorus was measured more frequently than albumin (p = 0.009) or triglycerides (p = 0.037), but only 28% of centres regularly measure pre-albumin as a nutritional biomarker. Human milk fortification and iron supplementation, starting at four weeks of age, are almost universal. However, only 30% of units administer 800 IU/day of vitamin D. Nearly 50% of the units discharge infants on preterm formula. Conclusion: Most Spanish neonatology units use early amino-acid supplementation and over half use novel fish oil-based lipid emulsions. Post-discharge nutrition practices and vitamin administration vary greatly (AU)

Antecedentes: se han realizado esfuerzos significativos para mejorar la nutrición en los recién nacidos muy prematuros. Las grandes encuestas pueden ayudar a conocer cuál es la nutrición que reciben los recién nacidos prematuros en las unidades neonatales e identificar si están en línea con las directrices actuales. Métodos: se llevó a cabo una encuesta multicéntrica a nivel nacional sobre las prácticas clínicas empleadas en la alimentación en los recién nacidos de muy bajo peso en hospitales de nivel III que ingresan recién nacidos con un peso al nacer < 1.500 g y/o una edad gestacional < 32 semanas. Resultados: el cuestionario fue completado por 53 unidades neonatales (tasa de respuesta del 59%). Más del 90% de las unidades estudiadas inician la administración de aminoácidos inmediatamente después del nacimiento y más de la mitad utilizan nuevas emulsiones lipídicas intravenosas que contienen aceite de pescado. La nutrición enteral se inicia en las primeras 24 horas de nacimiento en el 65% de las unidades y el 86% de ellas son medianas o grandes. El volumen de alimentación aumenta a una velocidad de 10-30 ml/kg/día en > 90% de las unidades. El fósforo sérico se monitoriza con mayor frecuencia que la albúmina (p = 0,009) o los triglicéridos (p = 0,037), pero solo el 28% de los centros miden regularmente la prealbúmina como biomarcador nutricional. La fortificación de la leche humana y la suplementación con hierro, a partir de las cuatro semanas de edad, es casi universal. Sin embargo, solo el 30% de las unidades administran 800 UI/día de vitamina D. Casi el 50% de las unidades utilizan leche de fórmula del prematuro al alta de las unidades. Conclusión: la mayoría de las unidades neonatales españolas administran precozmente los suplementos de aminoácidos y más de la mitad emplean emulsiones de lípidos a base de aceite. Hay una importante variación en las prácticas nutricionales posteriores al alta y en la administración de vitaminas (AU)

[Does corticosteroid treatment during the pre and postnatal periods affect the neurodevelopmental outcome of premature newborns?]

INTRODUCTION: Glucocorticoids, widely used in the perinatal period, may be associated with adverse neurodevelopmental effects. OBJECTIVES: To analyze neurodevelopmental outcomes in a cohort of very low birth weight newborns treated with antenatal and/or postnatal corticosteroids. MATERIALS AND METHODS: This was a prospective cohort study in which we included all very low birth weight babies admitted to the neonatal intensive care unit of a tertiary hospital between 2008 and 2013. We compared the neurodevelopment among very low birth-weight newborns who did not receive prenatal corticosteroid therapy and those who received a complete course (two doses of 12 mg betamethasone) and an incomplete course (one dose), and between those who did not receive postnatal corticosteroid therapy and those who received it (systemic dexamethasone after the first week of life). Motor, neurosensory and cognitive functions, as well as behavior disorders during the first two years of age were evaluated. RESULTS: A total of 225 very low birth weight newborns were analyzed; 83.6% received prenatal corticosteroid therapy (24% incomplete treatment schedule and 59.6% complete schedule). Only 13.3% received systemic dexamethasone during the postnatal period. Neurological monitoring was performed corticosteroid therapy and more neurological disorders, and no significant differences were found among those who received complete and incomplete courses of prenatal corticosteroid therapy. CONCLUSION: These results did not demonstrate an association between perinatal corticosteroid therapy and worse neurodevelopmental outcomes in very low birth weight newborns.

¿Afecta el tratamiento con corticoides en los periodos prenatal y posnatal el neurodesarrollo del recién nacido prematuro? / Does corticosteroid treatment during the pre and postnatal periods affect the neurodevelopmental outcome of premature newborns?

Resumen Introducción. Los glucocorticoides, ampliamente utilizados en el periodo perinatal, pueden asociarse con efectos adversos en el neurodesarrollo. Objetivo. Analizar los resultados del tratamiento con corticoides en el periodo prenatal y en el posnatal en el neurodesarrollo de una cohorte de recién nacidos de muy bajo peso. Materiales y métodos. Se hizo un estudio prospectivo de cohortes en los recién nacidos de muy bajo peso hospitalizados en la unidad de cuidados intensivos neonatales de un hospital de tercer nivel entre el 2008 y el 2013. Se comparó el neurodesarrollo entre aquellos que no recibieron tratamiento prenatal con corticoides y quienes recibieron el esquema completo (dos dosis de 12 mg de betametasona) o el incompleto (una dosis). También, se compararon los resultados en el neurodesarrollo de los recién nacidos que no recibieron tratamiento posnatal y aquellos que sí (dexametasona sistémica a partir de la primera semana de vida). Se evaluó la función motora, la neurosensorial y la cognitiva, así como los trastornos de conducta durante los dos primeros años de vida. Resultados. Se analizaron 225 recién nacidos de muy bajo peso; 83,6 % de las madres había recibido tratamiento prenatal con corticoides (esquema incompleto: 24 %; esquema completo: 59,6 %). Durante el periodo posnatal solamente el 13,3 % había recibido dexametasona sistémica. El seguimiento neurológico se llevó a cabo en 194 neonatos. En el análisis de regresión logística no se detectó que el tratamiento prenatal no el posnatal se asociara con más trastornos neurológicos, ni hubo diferencias significativas entre quienes recibieron el esquema completo y los que recibieron el incompleto durante el periodo prenatal. Conclusión. Los resultados de este estudio no pudieron demostrar que el tratamiento perinatal con corticoides se asociara con peores resultados en el neurodesarrollo en recién nacidos de muy bajo peso.

Abstract Introduction: Glucocorticoids, widely used in the perinatal period, may be associated with adverse neurodevelopmental effects. Objectives: To analyze neurodevelopmental outcomes in a cohort of very low birth weight newborns treated with antenatal and/or postnatal corticosteroids. Materials and methods: This was a prospective cohort study in which we included all very low birth weight babies admitted to the neonatal intensive care unit of a tertiary hospital between 2008 and 2013. We compared the neurodevelopment among very low birth-weight newborns who did not receive prenatal corticosteroid therapy and those who received a complete course (two doses of 12 mg betamethasone) and an incomplete course (one dose), and between those who did not receive postnatal corticosteroid therapy and those who received it (systemic dexamethasone after the first week of life). Motor, neurosensory and cognitive functions, as well as behavior disorders during the first two years of age were evaluated. Results: A total of 225 very low birth weight newborns were analyzed; 83.6% received prenatal corticosteroid therapy (24% incomplete treatment schedule and 59.6% complete schedule). Only 13.3% received systemic dexamethasone during the postnatal period. Neurological monitoring was performed in 194 infants. Logistic regression analysis did not detect an association between prenatal and postnatal corticosteroid therapy and more neurological disorders, and no significant differences were found among those who received complete and incomplete courses of prenatal corticosteroid therapy. Conclusion: These results did not demonstrate an association between perinatal corticosteroid therapy and worse neurodevelopmental outcomes in very low birth weight newborns.

¿Afecta el tratamiento con corticoides en los periodos prenatal y posnatal el neurodesarrollo del recién nacido prematuro?

Introducción. Los glucocorticoides, ampliamente utilizados en el periodo perinatal, pueden asociarse con efectos adversos en el neurodesarrollo. Objetivo. Analizar los resultados del tratamiento con corticoides en el periodo prenatal y en el posnatal en el neurodesarrollo de una cohorte de recién nacidos de muy bajo peso. Materiales y métodos. Se hizo un estudio prospectivo de cohortes en los recién nacidos de muy bajo peso hospitalizados en la unidad de cuidados intensivos neonatales de un hospital de tercer nivel entre el 2008 y el 2013. Se comparó el neurodesarrollo entre aquellos que no recibieron tratamiento prenatal con corticoides y quienes recibieron el esquema completo (dos dosis de 12 mg de betametasona) o el incompleto (una dosis). También, se compararon los resultados en el neurodesarrollo de los recién nacidos que no recibieron tratamiento posnatal y aquellos que sí (dexametasona sistémica a partir de la primera semana de vida). Se evaluó la función motora, la neurosensorial y la cognitiva, así como los trastornos de conducta durante los dos primeros años de vida. Resultados. Se analizaron 225 recién nacidos de muy bajo peso; 83,6 % de las madres había recibido tratamiento prenatal con corticoides (esquema incompleto: 24 %; esquema completo: 59,6 %). Durante el periodo posnatal solamente el 13,3 % había recibido dexametasona sistémica. El seguimiento neurológico se llevó a cabo en 194 neonatos. En el análisis de regresión logística no se detectó que el tratamiento prenatal no el posnatal se asociara con más trastornos neurológicos, ni hubo diferencias significativas entre quienes recibieron el esquema completo y los que recibieron el incompleto durante el periodo prenatal. Conclusión. Los resultados de este estudio no pudieron demostrar que el tratamiento perinatal con corticoides se asociara con peores resultados en el neurodesarrollo en recién nacidos de muy bajo peso.

Introduction: Glucocorticoids, widely used in the perinatal period, may be associated with adverse neurodevelopmental effects. Objectives: To analyze neurodevelopmental outcomes in a cohort of very low birth weight newborns treated with antenatal and/or postnatal corticosteroids. Materials and methods: This was a prospective cohort study in which we included all very low birth weight babies admitted to the neonatal intensive care unit of a tertiary hospital between 2008 and 2013. We compared the neurodevelopment among very low birth-weight newborns who did not receive prenatal corticosteroid therapy and those who received a complete course (two doses of 12 mg betamethasone) and an incomplete course (one dose), and between those who did not receive postnatal corticosteroid therapy and those who received it (systemic dexamethasone after the first week of life). Motor, neurosensory and cognitive functions, as well as behavior disorders during the first two years of age were evaluated. Results: A total of 225 very low birth weight newborns were analyzed; 83.6% received prenatal corticosteroid therapy (24% incomplete treatment schedule and 59.6% complete schedule). Only 13.3% received systemic dexamethasone during the postnatal period. Neurological monitoring was performed in 194 infants. Logistic regression analysis did not detect an association between prenatal and postnatal corticosteroid therapy and more neurological disorders, and no significant differences were found among those who received complete and incomplete courses of prenatal corticosteroid therapy. Conclusion: These results did not demonstrate an association between perinatal corticosteroid therapy and worse neurodevelopmental outcomes in very low birth weight newborns.

Transcriptome and Biochemical Analysis of a Flower Color Polymorphism in Silene littorea (Caryophyllaceae).

Flower color polymorphisms are widely used as model traits from genetics to ecology, yet determining the biochemical and molecular basis can be challenging. Anthocyanin-based flower color variations can be caused by at least 12 structural and three regulatory genes in the anthocyanin biosynthetic pathway (ABP). We use mRNA-Seq to simultaneously sequence and estimate expression of these candidate genes in nine samples of Silene littorea representing three color morphs (dark pink, light pink and white) across three developmental stages in hopes of identifying the cause of flower color variation. We identified 29 putative paralogs for the 15 candidate genes in the ABP. We assembled complete coding sequences for 16 structural loci and nine of ten regulatory loci. Among these 29 putative paralogs, we identified 622 SNPs, yet only nine synonymous SNPs in Ans had allele frequencies that differentiated pigmented petals (dark pink and light pink) from white petals. These Ans allele frequency differences were further investigated with an expanded sequencing survey of 38 individuals, yet no SNPs consistently differentiated the color morphs. We also found one locus, F3h1, with strong differential expression between pigmented and white samples (>42x). This may be caused by decreased expression of Myb1a in white petal buds. Myb1a in S. littorea is a regulatory locus closely related to Subgroup 7 Mybs known to regulate F3h and other loci in the first half of the ABP in model species. We then compare the mRNA-Seq results with petal biochemistry which revealed cyanidin as the primary anthocyanin and five flavonoid intermediates. Concentrations of three of the flavonoid intermediates were significantly lower in white petals than in pigmented petals (rutin, quercetin and isovitexin). The biochemistry results for rutin, quercetin, luteolin and apigenin are consistent with the transcriptome results suggesting a blockage at F3h, possibly caused by downregulation of Myb1a.

On flavonoid accumulation in different plant parts: variation patterns among individuals and populations in the shore campion (Silene littorea).

The presence of anthocyanins in flowers and fruits is frequently attributed to attracting pollinators and dispersers. In vegetative organs, anthocyanins and other non-pigmented flavonoids such as flavones and flavonols may serve protective functions against UV radiation, cold, heat, drought, salinity, pathogens, and herbivores; thus, these compounds are usually produced as a plastic response to such stressors. Although, the independent accumulation of anthocyanins in reproductive and vegetative tissues is commonly postulated due to differential regulation, the accumulation of flavonoids within and among populations has never been thoroughly compared. Here, we investigated the shore campion (Silene littorea, Caryophyllaceae) which exhibits variation in anthocyanin accumulation in its floral and vegetative tissues. We examined the in-situ accumulation of flavonoids in floral (petals and calyxes) and vegetative organs (leaves) from 18 populations representing the species' geographic distribution. Each organ exhibited considerable variability in the content of anthocyanins and other flavonoids both within and among populations. In all organs, anthocyanin and other flavonoids were correlated. At the plant level, the flavonoid content in petals, calyxes, and leaves was not correlated in most of the populations. However, at the population level, the mean amount of anthocyanins in all organs was positively correlated, which suggests that the variable environmental conditions of populations may play a role in anthocyanin accumulation. These results are unexpected because the anthocyanins are usually constitutive in petals, yet contingent to environmental conditions in calyxes and leaves. Anthocyanin variation in petals may influence pollinator attraction and subsequent plant reproduction, yet the amount of anthocyanins may be a direct response to environmental factors. In populations on the west coast, a general pattern of increasing accumulation of flavonoids toward southern latitudes was observed in calyxes and leaves. This pattern corresponds to a gradual increase of UV-B radiation and temperature, and a decrease of rainfall toward the south. However, populations along the southern coast exposed to similar climatic stressors showed highly variable flavonoid contents, implying that other factors may play a role in flavonoid accumulation.

Night life on the beach: selfing to avoid pollinator competition between two sympatric Silene species.

BACKGROUND AND AIMS: Evolution of autonomous selfing may be advantageous because it allows for reproductive assurance. In co-flowering plants competing for pollinators, the least common and/or attractive could suffer pollen limitations. Silene niceensis and S. ramosissima are taxonomically related species sharing the same habitat, although S. ramosissima is less abundant and has a more restricted distribution. They also have the same a priori nocturnal pollinator syndrome, and show an overlapping flowering phenology. The aim of this study was to investigate whether a selfing strategy in S. ramosissima allows it to avoid pollinator competition and/or interspecific pollen transfer with S. niceensis, which would thus enable both species to reach high levels of fruit and seed set. METHODS: The breeding system, petal colour, flower life span and degree of overlap between male and female phases, floral visitor abundance and visitation rates were analysed in two sympatric populations of S. niceensis and S. ramosissima in southern Spain. KEY RESULTS: Autonomous selfing in S. ramosissima produced very high fruit and seed set, which was also similar to open-pollinated plants. Silene niceensis showed minimum levels of autonomous selfing, and pollen/ovule ratios were within the range expected for the breeding system. In contrast to S. niceensis, flower life span was much shorter in S. ramosissima, and male and female organs completely overlapped in space and time. Upper surface petals of both species showed differing brightness, chroma and hue. Flowers of S. niceensis were actively visited by moths, hawkmoths and syrphids, whereas those of S. ramosissima were almost never visited. CONCLUSIONS: The findings show that different breeding strategies exist between the sympatric co-flowering S. niceensis and S. ramosissima, the former specializing in crepuscular-nocturnal pollination and the latter mainly based on autonomous selfing. These two strategies allow both species to share the restricted dune habitat in which they exist, with a high female reproductive success due to the absence of pollinator competition and/or interspecific pollen flow.

Diversity of sexual systems within different lineages of the genus Silene.

Species and populations can be categorized by their sexual systems, depending on the spatial distribution of female and male reproductive structures within and among plants. Although a high diversity of sexual systems exists in Silene, their relative frequency at the genus and infrageneric level is unknown. Here, we carried out an extensive literature search for direct or indirect descriptions of sexual systems in Silene species. We found descriptions of sexual systems for 98 Silene species, where 63 and 35 correspond to the phylogenetically supported subgenera Silene and Behenantha, respectively. Hermaphroditism was the commonest sexual system (58.2 %), followed by dioecy (14.3 %), gynodioecy (13.3 %) and gynodioecy-gynomonoecy (i.e. hermaphroditic, female and gynomonoecious plants coexisting in the same population; 12.2 %). The presence of these sexual systems in both subgenera suggests their multiple origins. In 17 species, the description of sexual systems varied, and in most cases these differences corresponded to variations within or among populations. Interestingly, the poorly studied gynodioecy-gynomonoecy sexual system showed similar frequency to dioecy and gynodioecy in both subgenera. In addition, the incidence of gynodioecy-gynomonoecy was analysed in the species of section Psammophilae (Silene littorea, S. psammitis, S. adscendens and S. cambessedesii), in a survey of 26 populations across the distribution area of the species. The four species showed gynomonoecy-gynodioecy in most populations. Hermaphrodites were the most frequent morph, with a low number of females and gynomonoecious plants in all populations. The frequency of sexual morphs varied significantly among the studied populations but not among species. Female plants generally produced smaller numbers of flowers than hermaphroditic or gynomonoecious plants, and the percentages of female flowers per population were low. All these findings suggest that the gynodioecious-gynomonoecious sexual system in section Psammophilae is closer to hermaphroditism or gynomonoecy than gynodioecy.