Timed maternal melatonin treatment reverses circadian disruption of the fetal adrenal clock imposed by exposure to constant light

Surprisingly, in our modern 24/7 society, there is scant information on the impact of developmental chronodisruption like the one experienced by shift worker pregnant women on fetal and postnatal physiology. There are important differences between the maternal and fetal circadian systems; for instance, the suprachiasmatic nucleus is the master clock in the mother but not in the fetus. Despite this, several tissues/organs display circadian oscillations in the fetus. Our hypothesis is that the maternal plasma melatonin rhythm drives the fetal circadian system, which in turn relies this information to other fetal tissues through corticosterone rhythmic signaling. The present data show that suppression of the maternal plasma melatonin circadian rhythm, secondary to exposure of pregnant rats to constant light along the second half of gestation, had several effects on fetal development. First, it induced intrauterine growth retardation. Second, in the fetal adrenal in vivo it markedly affected the mRNA expression level of clock genes and clock-controlled genes as well as it lowered the content and precluded the rhythm of corticosterone. Third, an altered in vitro fetal adrenal response to ACTH of both, corticosterone production and relative expression of clock genes and steroidogenic genes was observed. All these changes were reversed when the mother received a daily dose of melatonin during the subjective night; supporting a role of melatonin on overall fetal development and pointing to it as a 'time giver' for the fetal adrenal gland. Thus, the present results collectively support that the maternal circadian rhythm of melatonin is a key signal for the generation and/or synchronization of the circadian rhythms in the fetal adrenal gland. In turn, low levels and lack of a circadian rhythm of fetal corticosterone may be responsible of fetal growth restriction; potentially inducing long term effects in the offspring, possibility that warrants further research.     

Mediterranean Species of Caulerpa Are Polyploid with Smaller Genomes in the Invasive Ones

Caulerpa species are marine green algae, which often act as invasive species with rapid clonal proliferation when growing outside their native biogeographical borders. Despite many publications on the genetics and ecology of Caulerpa species, their life history and ploidy levels are still to be resolved and are the subject of large controversy. While some authors claimed that the thallus found in nature has a haplodiplobiontic life cycle with heteromorphic alternation of generations, other authors claimed a diploid or haploid life cycle with only one generation involved. DAPI-staining with image analysis and microspectrophotometry were used to estimate relative nuclear DNA contents in three species of Caulerpa from the Mediterranean, at individual, population and species levels. Results show that ploidy levels and genome size vary in these three Caulerpa species, with a reduction in genome size for the invasive ones. Caulerpa species in the Mediterranean are polyploids in different life history phases; all sampled C. taxifolia and C. racemosa var. cylindracea were in haplophasic phase, but in C. prolifera, the native species, individuals were found in both diplophasic and haplophasic phases. Different levels of endopolyploidy were found in both C. prolifera and C. racemosa var. cylindracea. Life history is elucidated for the Mediterranean C. prolifera and it is hypothesized that haplophasic dominance in C. racemosa var. cylindracea and C. taxifolia is a beneficial trait for their invasive strategies.     

Manipulation of pre-target activity on the right frontal eye field enhances conscious visual perception in humans

The right Frontal Eye Field (FEF) is a region of the human brain, which has been consistently involved in visuo-spatial attention and access to consciousness. Nonetheless, the extent of this cortical site's ability to influence specific aspects of visual performance remains debated. We hereby manipulated pre-target activity on the right FEF and explored its influence on the detection and categorization of low-contrast near-threshold visual stimuli. Our data show that pre-target frontal neurostimulation has the potential when used alone to induce enhancements of conscious visual detection. More interestingly, when FEF stimulation was combined with visuo-spatial cues, improvements remained present only for trials in which the cue correctly predicted the location of the subsequent target. Our data provide evidence for the causal role of the right FEF pre-target activity in the modulation of human conscious vision and reveal the dependence of such neurostimulatory effects on the state of activity set up by cue validity in the dorsal attentional orienting network.     

Multiorgan metastasis of human HER-2⁺ breast cancer in Rag2⁻/⁻;Il2rg⁻/⁻ mice and treatment with PI3K inhibitor

In vivo studies of the metastatic process are severely hampered by the fact that most human tumor cell lines derived from highly metastatic tumors fail to consistently metastasize in immunodeficient mice like nude mice. We describe a model system based on a highly immunodeficient double knockout mouse, Rag2?/?;Il2rg?/?, which lacks T, B and NK cell activity. In this model human metastatic HER-2? breast cancer cells displayed their full multiorgan metastatic potential, without the need for selections or additional manipulations of the system. Human HER-2? breast cancer cell lines MDA-MB-453 and BT-474 injected into Rag2?/?;Il2rg?/? mice faithfully reproduced human cancer dissemination, with multiple metastatic sites that included lungs, bones, brain, liver, ovaries, and others. Multiorgan metastatic spread was obtained both from local tumors, growing orthotopically or subcutaneously, and from cells injected intravenously. The problem of brain recurrencies is acutely felt in HER-2? breast cancer, because monoclonal antibodies against HER-2 penetrate poorly the blood-brain barrier. We studied whether a novel oral small molecule inhibitor of downstream PI3K, selected for its penetration of the blood-brain barrier, could affect multiorgan metastatic spread in Rag2?/?; Il2rg?/? mice. NVP-BKM120 effectively controlled metastatic growth in multiple organs, and resulted in a significant proportion of mice free from brain and bone metastases. Human HER-2? human breast cancer cells in Rag2?/?;Il2rg?/? mice faithfully reproduced the multiorgan metastatic pattern observed in patients, thus allowing the investigation of metastatic mechanisms and the preclinical study of novel antimetastatic agents.     

Breaking down Complex Saproxylic Communities: Understanding Sub-Networks Structure and Implications to Network Robustness

Saproxylic insect communities inhabiting tree hollow microhabitats correspond with large food webs which simultaneously are constituted by multiple types of plant-animal and animal-animal interactions, according to the use of trophic resources (wood- and insect-dependent sub-networks), or to trophic habits or interaction types (xylophagous, saprophagous, xylomycetophagous, predators and commensals). We quantitatively assessed which properties of specialised networks were present in a complex networks involving different interacting types such as saproxylic community, and how they can be organised in trophic food webs. The architecture, interacting patterns and food web composition were evaluated along sub-networks, analysing their implications to network robustness from random and directed extinction simulations. A structure of large and cohesive modules with weakly connected nodes was observed throughout saproxylic sub-networks, composing the main food webs constituting this community. Insect-dependent sub-networks were more modular than wood-dependent sub-networks. Wood-dependent sub-networks presented higher species degree, connectance, links, linkage density, interaction strength, and were less specialised and more aggregated than insect-dependent sub-networks. These attributes defined high network robustness in wood-dependent sub-networks. Finally, our results emphasise the relevance of modularity, differences among interacting types and interrelations among them in modelling the structure of saproxylic communities and in determining their stability.     

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

Background

American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources.

Methodology/Principal Findings

We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu.

Conclusions/Significance

Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions.     

Degradation of biogenic amines by vineyard ecosystem fungi. Potential use in winemaking

Aims: To evaluate the ability of grapevine ecosystem fungi to degrade histamine, tyramine and putrescine in synthetic medium and in wines. Methods and Results: Grapevine and vineyard soil fungi were isolated from four locations of Spain and were subsequently identified by PCR. A total of 44 fungi were evaluated for in vitro amine degradation in a microfermentation system. Amine degradation by fungi was assayed by reversed‐phase (RP)‐HPLC. All fungi were able to degrade at least two different primary amines. Species of Pencillium citrinum, Alternaria sp., Phoma sp., Ulocladium chartarum and Epicoccum nigrum were found to exhibit the highest capacity for amine degradation. In a second experiment, cell‐free supernatants of P. citrinum CIAL‐274,760 (CECT 20782) grown in yeast carbon base with histamine, tyramine or putrescine, were tested for their ability to degrade amines in three different wines (red, white and synthetic). The highest levels of biogenic amine degradation were obtained with histamine‐induced enzymatic extract. Conclusion: The study highlighted the ability of grapevine ecosystem fungi to degrade biogenic amines and their potential application for biogenic amines removal in wine. Significance and Impact of Study: The fungi extracts described in this study may be useful in winemaking to reduce the biogenic amines content of wines, thereby preventing the possible adverse effects on health in sensitive individuals and the trade and export of wine.     

Characterization of the Fusarium wilt resistance Fom-2 gene in melon

The melon gene Fom-2, which confers resistance to Fusarium oxysporum f.sp. melonis (Fom) races 0 and 1, has been previously characterized by map-based cloning, and it encodes a protein with a nucleotide binding site (NBS) and leucine-rich repeats (LRRs). Here, we used the primer Fom2-LRR₁₆₃₉ to clone and sequence a partial LRR region of the Fom-2 gene in 11 melon accessions resistant to Fusarium wilt from various geographic regions. Our work revealed that the structure of the partial LRR domain is highly conserved between eight of these resistant accessions and is similar to the resistant allele in the previously characterized PI-161375 line. Conversely, PI-124111 is a unique line that presents the same resistant allele that was previously described in the MR-1 line. The accession Cum-355 presents a protein that differs from that encoded by both the resistant lines PI-161375 and MR-1. This result suggests that Cum-355 has a new resistant allele of Fom-2 that determines the same specificity. Importantly, based on the sequence of the Fom-2 LRR domain, two sequence characterized amplified region (SCAR) markers, Fom2-R₄₀₈ and Fom2-S₃₄₂, were developed for Fom-2 resistant and susceptible alleles, respectively. These allele-specific PCR markers could be used as co-dominant markers when their primer pairs were combined in a multiplex PCR reaction. The specificity of these functional markers (FM) was validated on a set of 27 genotypes representing several melon types. These FM markers are expected to enhance the reliability and cost-effectiveness of marker-assisted selection for the Fom-2 gene in melon.     

Sequence characterization,in silico mapping and cytosine methylation analysis of markers linked to apospory in Paspalum notatum

In previous studies we reported the identification of several AFLP, RAPD and RFLP molecular markers linked to apospory in Paspalum notatum. The objective of this work was to sequence these markers, obtain their flanking regions by chromosome walking and perform an in silico mapping analysis in rice and maize. The methylation status of two apospory-related sequences was also assessed using methylation-sensitive RFLP experiments. Fourteen molecular markers were analyzed and several protein-coding sequences were identified. Copy number estimates and RFLP linkage analysis showed that the sequence PnMAI3 displayed 2–4 copies per genome and linkage to apospory. Extension of this marker by chromosome walking revealed an additional protein-coding sequence mapping in silico in the apospory-syntenic regions of rice and maize. Approximately 5 kb corresponding to different markers were characterized through the global sequencing procedure. A more refined analysis based on sequence information indicated synteny with segments of chromosomes 2 and 12 of rice and chromosomes 3 and 5 of maize. Two loci associated with apomixis locus were tested in methylation-sensitive RFLP experiments using genomic DNA extracted from leaves. Although both target sequences were methylated no methylation polymorphisms associated with the mode of reproduction were detected.     

Vitamin D receptor polymorphisms in hypertensive disorders of pregnancy

Hypertension is the most common medical disorder in pregnancy, and a leading cause of maternal and neonatal morbidity and mortality. Vitamin D endocrine system has important influence on immune modulation and endothelial function, which play a role in preeclampsia (PE) and gestational hypertension (GH). Vitamin D receptor (VDR) is present in a large variety of cell types, including placental cells. We examined whether there is an association between VDR polymorphisms (FokI, ApaI and BsmI) with PE or with GH. Restriction fragment length polymorphism techniques were used to genotype 529 pregnant (154 with GH, 162 with PE, and 213 healthy pregnant—HP). VDR haplotype frequencies were inferred using the PHASE 2.1 program. We found similar genotype distributions for the three VDR polymorphisms in both PE and GH groups compared with the HP group (all P?>?0.05). In parallel with these findings, the VDR haplotype frequency distribution was similar in both PE and GH groups compared with the HP group (all P?>?0.05). Our results showing no significant association between VDR polymorphisms or haplotypes with PE or GH suggest that genetic variations in VDR do not predispose to hypertensive disorders of pregnancy.