Browsing by Issue Date, starting with "2018-06-08"
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- Involvement of hormones, cytokines and angiogenic factors on mare oviduct physiological function and fibrosisPublication . Bravo, Pedro Nuno d’Almeida Monteirinho Pinto; Dias, Graça Maria Leitão Ferreira; Costa, Rosário Plácido Roberto daThe oviduct is a very important organ of the female reproductive system, as it plays a crucial role in providing the ideal conditions for the final preparation of the gametes for fertilization and to support the early embryo development. This work contributed to: (i) clarify the role of ovarian steroid hormones, oxytocin (OXT) and TNFα on the modulation of oviduct prostaglandin secretion; (ii) relate the expression of angiogenic growth factors during angiogenesis, with oviductal function; (iii) evaluate the expression of OVGP1 throughout the estrous cycle in the mare; (iv) and to investigate the expression of collagen in equine oviduct and its correlation with endometrial fibrosis and possible pathways involved. Post-mortem tissues were used for experimental works, such as histological stains, immunohistochemistry (IHQ), western blot analysis, qPCR evaluation, enzyme immunoassay, oviduct epithelial cells and tissue explants in vitro culture. In equine oviduct, ESR1, ESR2, PGR, OXTR, PTGES and AKR1C3 mRNA and protein expression was estrous cycle dependent and varied with oviduct portions. Ovarian steroid hormones, OXT and TNFα stimulation of PGF2α and/or PGE2 production also depended on estrous cycle dependent and changed in the different portions of oviduct. In addition, protein and mRNA expression of FGF, VEGF and their receptors differed throughout the estrous cycle and between oviduct portions and agreed with changes in microvascular density and/or oviductal secretory function. Oviduct glycoprotein 1 (OVGP1) transcription presented differences throughout the oviduct portions, and in different phases of estrous cycle. A higher expression was observed in isthmus and during follicular phase (P < 0.05). Also in the follicular phase, OXT and TNFα upregulated OVGP1 transcription; in the early luteal phase, estradiol (E2), while in mid luteal phase, it was progesterone (P4) that stimulated its transcription. However, OVGP1 in vitro production was not dependent of E2, P4, OXT or TNF treatments in any oviduct portion. Furthermore, sperm cells also up-regulated OVGP1 production, in isthmus, in early luteal phase (P < 0.05). COL1 and COL3 transcription in isthmus was correlated with the correspondent transcription in the endometrium. Particularly in isthmus, AKR1C3 was implicated with collagen transcription (P < 0.05). Collagen transcription in isthmus was correlated with MMPs transcription in endometrium (P < 0.05). Thus, in the mare, endometrium fibrosis appears to reflect collagen deposition in the oviduct.
- Las relaciones Cuba y Unión Europea: «el comienzo de una gran amistad»Publication . Díaz Barrado, Cástor Miguel; Morán Blanco, SagrarioEn este artículo se describen y analizan los vaivenes de la relación con Cuba de la Unión Europea que han evolucionado desde el no entendimiento cultivado en los primeros años a los intentos de cooperación que quieren ahora hacerse primar. La primera parte se centra en la Posición Común de 1996, que tensó las ya difíciles relaciones entre ambas partes, mientras que la segunda analiza en profundidad el Acuerdo de Diálogo Político y de Cooperación de 2016, punto de inflexión que abriría una nueva etapa de carácter más cordial.
- Playing evolution in the laboratory: From the first major evolutionary transition to global warmingPublication . De mendonça fragata almeida, Inês; Simões, Pedro; Matos, Margarida; Szathmáry, Eörs; Santos, MauroExperimental evolution allows testing hypothesis derived from theory or from observed patterns in nature. We have designed a droplet-based microfluidic ‘evolution machine’ to test how transient compartmentalization (‘trait-groups’) of independent molecular replicators (likely a critical step in the origin of life) could have prevented the spread of parasitic mutants; that is, inactive RNAs that have been reported to spoil a system of free replicators. In remarkable agreement with the theory, we show that this simple population structure was sufficient to prevent takeover by inactive RNAs. A more complex scenario arises when we use experimental evolution to test field-derived hypothesis; for instance, the idea that temperature is driving genetic spatiotemporal patterns of climate change. In the fly Drosophila subobscura, latitudinal clines in gene arrangement frequencies occur worldwide, and more equatorial gene arrangements are becoming more frequent at higher latitudes as a correlated response to climate change. However, the evolution at different constant temperatures in the laboratory was not consistent with patterns in nature, suggesting some limitations of experimental evolution. Finally, also in D. subobscura, we show that repeatability in experimental evolution is staggeringly consistent for life history traits, making evolution quite predictable and suggesting that laboratory selection can quickly erase differences between populations. Yet, the genetic paths used to attain the same adaptive phenotypes are complex and unpredictable.