Multisource noninvasive genetics of brown bears (Ursus arctos) in Greece reveals a highly structured population and a new matrilineal contact zone in southern Europe

In human‐dominated landscapes, connectivity is crucial for maintaining demographically stable mammalian populations. Here, we provide a comprehensive noninvasive genetic study for the brown bear population in the Hellenic Peninsula. We analyze its population structuring and connectivity, estimate its population size throughout its distribution, and describe its phylogeography in detail for the first time. Our results, based on 150 multilocus genotypes and on 244‐bp sequences of the mtDNA control region, show the population is comprised by three highly differentiated genetic clusters, consistent with geographical populations of Pindos, Peristeri, and Rhodope. By detecting two male bears with Rhodopean ancestry in the western demes, we provide strong evidence for the ongoing genetic connectivity of the geographically fragmented eastern and western distributions, which suggests connectivity of the larger East Balkan and Pindos‐Dinara populations. Total effective population size (Ne) was estimated to be 199 individuals, and total combined population size (NC) was 499, with each cluster showing a relatively high level of genetic variability, suggesting that migration has been sufficient to counteract genetic erosion. The mtNDA results were congruent with the microsatellite data, and the three genetic clusters were matched predominantly with an equal number of mtDNA haplotypes that belong to the brown bear Western mitochondrial lineage (Clade 1), with two haplotypes being globally new and endemic. The detection of a fourth haplotype that belongs to the Eastern lineage (Clade 3a1) in three bears from the western distribution places the southernmost secondary contact zone between the Eastern and Western lineages in Greece and generates new hypotheses about postglacial maxima migration routes. This work indicates that the genetic composition and diversity of Europe's low‐latitude fringe population are the outcome of ancient and historical events and highlight its importance for the connectivity and long‐term persistence of the species in the Balkans

A Dynamical Model of Oocyte Maturation Unveils Precisely Orchestrated Meiotic Decisions

Maturation of vertebrate oocytes into haploid gametes relies on two consecutive meioses without intervening DNA replication. The temporal sequence of cellular transitions driving eggs from G2 arrest to meiosis I (MI) and then to meiosis II (MII) is controlled by the interplay between cyclin-dependent and mitogen-activated protein kinases. In this paper, we propose a dynamical model of the molecular network that orchestrates maturation of Xenopus laevis oocytes. Our model reproduces the core features of maturation progression, including the characteristic non-monotonous time course of cyclin-Cdks, and unveils the network design principles underlying a precise sequence of meiotic decisions, as captured by bifurcation and sensitivity analyses. Firstly, a coherent and sharp meiotic resumption is triggered by the concerted action of positive feedback loops post-translationally activating cyclin-Cdks. Secondly, meiotic transition is driven by the dynamic antagonism between positive and negative feedback loops controlling cyclin turnover. Our findings reveal a highly modular network in which the coordination of distinct regulatory schemes ensures both reliable and flexible cell-cycle decisions

Effect of two UV-absorbing greenhouse-covering films on growth and yield of an eggplant soilless crop

The use of UV absorbing films as greenhouse cover material is spreading out in protected cultivation. Although their effects on pest and disease management have received much attention, few studies focus on their effects on the crop. This study aims at assessing the consequences of UV absorbing film on the behaviour and production of an eggplant crop by comparing two different UV absorbing films (0 and 3% UV transmittance) to a standard polyethylene film (5% UV transmittance). Results show that the eggplants grown in the greenhouse with 0% transmission to UV light are about 21% taller and have about 17% higher leaf product (leaf length x width) than the plants grown in the greenhouse with 5% transmission to UV light. Finally, given that the production was slightly increased in quantity (20%) and quality (bigger fruits) in the greenhouse with absence of UV light compared to that with 5% transmission coefficient, it can be concluded that growing soilless eggplant under UV-absorbing material can be achieved with the same or better results as under standard covering material. Any other enhancement that the UV-absorbing film will bring (lower pest and disease impact on the crop, lower pesticide load and costs) will therefore be to the benefit of the grower. (c) 2006 Elsevier B.V. All rights reserved

Absolute absorption cross-section measurements of CO2 in the ultraviolet from 200 to 206 nm at 295 and 373 K

Laboratory measurements of the absolute absorption cross-section of CO 2 at the temperatures 295 and 373 K have been made between 200 and 206 nm using cavity ring-down spectroscopy. Below 205 nm, the cross-section at 373 K is significantly larger than at 295 K, whereas beyond 205 nm measurements at both temperatures yield cross-sections approximately equal to the Rayleigh scattering cross-section, within experimental error. The present measurements should resolve a long-standing discrepancy between previously published data on this system. © 2004 Elsevier B.V. All rights reserved

Influence of dietary sesame meal, vitamin E and selenium supplementation on milk production, composition, and fatty acid profile in dairy goats

Although sesame oil meal is rich in linoleic acid, and both selenium (Se) and vitamin E (VitE) protect prone-unsaturated fatty acids (UFA) from oxidation, their influence on goats’ milk fatty acids (FAs) profile have not been studied. Thus, thirty dairy goats were divided into five groups and fed with alfalfa hay and concentrates. Two types of concentrates were used; one for the control (CON) and another for the treated groups. In the concentrate of the treated groups which contained sesame oil meal, apart from the quantities of VitE and Se included in the trace mineral-vitamin premix, either no extra VitE and Se (SOM) or extra 60 mg of VitE/Kg of concentrate (SOME), or 0.1 mg organic Se/Kg of concentrate (SOMSe) or its combination (60 mg of VitE and 0.1 mg organic Se/Kg of concentrate) (SOMESe) were incorporated. In blood plasma, the proportion of C14:0 reduced significantly in the SOME-fed goats compared with CON-fed goats while that of C16:0 reduced significantly in those goats fed the SOM, SOMSe, SOMESe diets. The proportions of medium-chain FAs (MCFA) and saturated FAs (SFA), and the atherogenicity index value reduced significantly in the milk of treated animals. Significant was also the decline in the SFA/UFA ratio in the milk of goats fed with the SOM, SOME and SOMESe diets. On the contrary, the proportions of long-chain FAs in the milk of SOM and SOMESe fed goats increased significantly. A significant increase in the proportions of UFA in the milk of SOME and SOMESe-fed goats and in the proportions of MUFA in those goats fed the SOM, SOME and SOMESe diets was found. In conclusion, the SOMESe diet can be considered as the most effective nutritional strategy to affect positively the goats’ milk FAs profile since the sharpest modifications in the aforementioned FAs were observed with this dietary treatment

Redundant pathways for Cdc2 activation in Xenopus oocyte: either cyclin B or Mos synthesis

Xenopus oocytes are arrested in meiotic prophase I. Progesterone induces the resumption of meiotic maturation, which requires continuous protein synthesis to bring about Cdc2 activation. The identification of the newly synthesized proteins has long been a goal. Two plausible candidates have received extensive study. The synthesis of cyclin B and of c-Mos, a kinase that activates the mitogen-activated protein kinase pathway in oocytes, is clearly upregulated by translational control in response to progesterone. Recent studies suggest that ablation of either c-Mos or cyclin B synthesis by antisense oligonucleotides does not block meiotic maturation. Here, however, we show that when both pathways are simultaneously inhibited, progesterone no longer triggers maturation; adding back either c-Mos or cyclin B restores meiotic maturation. We conclude that the specific synthesis of either B-type cyclins or c-Mos, induced by progesterone, is required to induce meiotic maturation. The two pathways seem to be functionally redundant