Apoptosis is increased and cell proliferation is decreased in out-of-phase endometria from infertile and recurrent abortion patients

Background  

Various endometrial abnormalities have been associated with luteal phase deficiency: a significant dyssynchrony in the maturation of the glandular epithelium and the stroma and a prevalence of out-of-phase endometrial biopsy specimens. Out-of phase endometrium is a controversial disorder related to failed implantation, infertility and early pregnancy loss. Given that the regulation of the apoptotic process in endometrium of luteal phase deficiency is still unknown, the aim of this study was to evaluate cell proliferation, apoptosis and the levels of the main effector caspase, caspase-3 in the luteal in-phase and out-of-phase endometrium.     

Total Iron and Heme Iron Content and their Distribution in Beef Meat and Viscera

To determine the content of total iron (TFe) and heme iron (HeFe) in major cuts of meat and principal viscera of bovine origin. ⁵⁵Fe (30 mCi) was injected into two 4-month-old calves. Triplicate samples of the 12 basic American cuts of meat and major viscera were obtained from each specimen. Samples were acid digested and their iron content was read by atomic absorption spectrophotometry. Duplicate samples of the basic cuts of meat and major viscera were analyzed to determine the concentration of ⁵⁵Fe using a double isotopic technique. The mean and standard deviation of TFe for all cuts was 1.4?±?0.3 mg/100 g of meat. The mean TFe for organs was (per mg/100 g): 0.9?±?0.1 brain, 3.0?±?0.05 kidney, 3.2?±?0.04 heart, 5.7?±?0.2 lung, 6.0?±?0.1 liver, and 31.2?±?0.4 spleen. HeFe was 64% of TFe in meat and 72.8% in spleen, 53.8% in lung, 35.7% in brain, 35.0% in kidney, 27.3% in heart, and only 13.6% in liver. Blood contained 85.5% of the radioisotope and only 1.4% was found in muscle and 1.6% was found in viscera. Results suggest that bovine cuts of meat have a low variation in TFe and that HeFe comprises more than 60% of TFe.     

Characterization of Strains unlike Mesorhizobium loti That Nodulate Lotus spp. in Saline Soils of Granada,Spain

Lotus species are forage legumes with potential as pastures in low-fertility and environmentally constrained soils, owing to their high persistence and yield under those conditions. The aim of this work was the characterization of phenetic and genetic diversity of salt-tolerant bacteria able to establish efficient symbiosis with Lotus spp. A total of 180 isolates able to nodulate Lotus corniculatus and Lotus tenuis from two locations in Granada, Spain, were characterized. Molecular identification of the isolates was performed by repetitive extragenic palindromic PCR (REP-PCR) and 16S rRNA, atpD, and recA gene sequence analyses, showing the presence of bacteria related to different species of the genus Mesorhizobium: Mesorhizobium tarimense/Mesorhizobium tianshanense, Mesorhizobium chacoense/Mesorhizobium albiziae, and the recently described species, Mesorhizobium alhagi. No Mesorhizobium loti-like bacteria were found, although most isolates carried nodC and nifH symbiotic genes closely related to those of M. loti, considered the type species of bacteria nodulating Lotus, and other Lotus rhizobia. A significant portion of the isolates showed both high salt tolerance and good symbiotic performance with L. corniculatus, and many behaved like salt-dependent bacteria, showing faster growth and better symbiotic performance when media were supplemented with Na or Ca salts.Legumes can establish nitrogen-fixing associations with Gram-negative soil bacteria collectively known as rhizobia. Although the symbiotic relationships among rhizobia and many legume species of agricultural importance have been intensively studied, relatively little is known about the symbiotic bacteria of certain plant genera. Lotus is a genus of legumes that includes 125 to 130 species of herbs and small shrubs, mainly distributed in the Northern Hemisphere. Several Lotus species, particularly Lotus corniculatus, Lotus uliginosus, and Lotus tenuis, are used as pasture forage worldwide and are included by phylogenetic studies in the same clade as the model legume Lotus japonicus (4). Until recently, bacteria nodulating Lotus included both intermediate-growing (mesorhizobia) and slow-growing bacteria (12, 16). The mesorhizobia can form effective symbioses with certain Lotus spp. (group I, e.g., L. corniculatus, L. tenuis, or L. japonicus) but form tumor-like structures that do not contain bacteria on L. uliginosus, Lotus subbiflorus, and Lotus angustissimus (group II Lotus spp.) (21, 24). On the other hand, slow-growing strains are usually efficient with Lotus group II species but form no nodules or form inefficient nodules in group I species (12). However, there are rare exceptions to this rule, like strain NZP2037, that can form effective symbioses with both groups of Lotus spp. (23, 25, 28). Furthermore, fast-growing Ensifer meliloti bv. lancerottense strains have been shown to be the symbionts of Lotus lancerottensis but are unable to fix nitrogen with either group I or group II Lotus spp. (19).No apparent relationship exists between the phylogenetic position of Lotus spp. and the type of rhizobia associated. For instance, L. uliginosus and L. angustissimus, which are efficiently nodulated by the bradyrhizobia, are clustered in the same clade as L. corniculatus, L. tenuis, and L. japonicus (clade B) (4), species associated with mesorhizobia. In contrast L. subbiflorus, usually associated with the same rhizobia as L. uliginosus, is clustered in a different clade.The narrow-host-range rhizobia associated with L. corniculatus and other Lotus species were initially classified as Rhizobium loti (13). Later, when the genus Mesorhizobium was created, R. loti was reclassified as Mesorhizobium loti (14), which is considered the type species. Besides the expected differences between the moderate- and the slow-growing Lotus rhizobia, large variabilities in nitrogen-fixing effectiveness (23) as well as in total DNA-DNA hybridization (3, 6) and phylogeny (5, 40) have been shown among the “meso-growing” rhizobia strains classified as M. loti, indicating that they do not form a homogeneous group. Indeed, one of the best-characterized strains of M. loti, strain MAFF303099, has been reclassified as Mesorhizobium huakuii biovar loti (35). In fact, diverse rhizobia have recently been reported to establish symbiosis with Lotus group I species. For instance, bacteria belonging to the newly described species Mesorhizobium gobiense and Mesorhizobium tarimense, were isolated from Lotus frondosus and L. tenuis in China (10). Also, rhizobia assigned to different genera (Rhizobium, Mesorhizobium, Agrobacterium, and Aminobacter) have recently been reported as symbionts of L. tenuis in the Salado River Basin in Argentina (7). While these recent reports indicate that bacteria nodulating Lotus spp. are diverse, their symbiotic genes are rather homogeneous. In fact, most isolates from Argentina and China, regardless their taxonomic assignment, had symbiotic genes closely related to M. loti (7, 10).Soil salinity is a serious and expanding threat to agricultural productivity. Improving crop productivity in saline soils requires selection of well-adapted plant genotypes and, in the case of legumes, highly efficient rhizobial partners adapted to soil conditions. As part of the Euro-South American cooperation project LOTASSA (http://www.lotassa.com/), and aiming to isolate and select for salt-tolerant bacteria able to establish efficient symbiosis with forage Lotus spp., we explored the diversity of Lotus rhizobia in two different locations of Granada province, Spain, where the presence of native Lotus spp. had previously been reported (30).     

Systematics and evolutionary significance of the small Abrocomidae from the early Miocene of southern South America

Octodontoidea is the most species-rich clade among hystricomorph rodents, and has a fossil record going back to at least the late Oligocene. Affinities of fossils previous to the late Miocene differentiation of the extant families Abrocomidae, Echimyidae and Octodontidae are controversial, essentially because these fossils may share few apomorphies with modern species. In fact, pre-late Miocene representatives of Abrocomidae had not been recognised until very recently. Here we revise the early Miocene genus Acarechimys, originally assigned to Echimyidae, and alternatively to stem Octodontoidea or to Octodontidae. A systematic and parsimony-based phylogenetic analysis of the species traditionally included in Acarechimys showed that this genus is part of stem Abrocomidae. These results are primarily supported by morphology of the mandible and lower molars. Acarechimys is here restricted to three species, A. minutus, A. pulchellus and Acarechimys pascuali sp. nov., while another species, A. constans, is here transferred to a new abrocomid genus. The remaining species were nested within Octodontidae. According to these results, Abrocomidae might have been as diverse as its sister clade Octodontidae-Echimyidae during the late Oligocene–early Miocene. Extinction of this diversity would have resulted in marked loss of evolutionary history, with extant abrocomids being currently restricted to late-diverged euhypsodont representatives.     

Molecular phylogeny of Geoplaninae (Platyhelminthes) challenges current classification: proposal of taxonomic actions

Despite likely being the most diverse group within the Tricladida, the systematics of land planarians (Geoplanidae) has received minor attention. The most species‐rich ingroup, the subfamily Geoplaninae, is restricted to the Neotropics. The systematics of Geoplaninae remains uncertain. Unique features supporting the genera are scanty; moreover, parts of the known species have been poorly described, making comparative studies difficult. Likewise the evolutionary relationships among land planarians remain insufficiently understood. In the present study, a phylogenetic hypothesis for selected taxa of Geoplaninae based on the molecular data is presented and discussed in the light of morphological features. Our phylogenetic inference is based on the fragments of three nuclear regions (18S, 28S rDNA and EF‐1α) and a mitochondrial marker (cytochrome oxidase I) for which we considered three optimality criteria (parsimony, maximum likelihood and Bayesian inference). Although our data provide little support for most basal nodes, our phylogenetic trees show a number of well‐supported clades, unveiling morphologically homogeneous groups. According to these results, we propose to separate Geoplana into Barreirana (formerly considered a subgenus), Cratera gen. n., Imbira gen. n., Matuxia gen. n., Obama gen. n. and Paraba gen. n., emend the diagnoses of Barreirana, Geoplana, Notogynaphallia, Pasipha and Xerapoa and review the classification of the species within these genera. For Geoplana goetschi sensu Marcus, (1951), a new name is proposed.     

Water stress and light intensity effects on growth and nocturnal acid accumulation in a terrestrial CAM bromeliad (Bromelia humilis Jacq.) under natural conditions

Summary Seasonal variations in CAM performance of sunexposed and partially shaded populations of Bromelia humilis were measured under natural conditions in a semi-arid region in northern Venezuela. The sun population consisted of smaller plants, with lower chlorophyll and total nitrogen contents per unit leaf area compared with plants from the partial-shade population. During the dry season CAM activity, assessed as nocturnal acid accumulation, was higher in the partial-shade population. Acid accumulation was stimulated by irrigation in both populations within 24 h after treatment. Daily changes in concentration of soluble sugars were opposite to leaf acidity indicating their role as carbon source for acid synthesis during the night. The change in nocturnal sugar concentration was always more than the amount required for acid accumulation, suggesting other carbohydrate-consuming processes such as transportation of sugars out of the leaf. CAM activity was higher during the rainy season, and differences between populations were smaller. At the end of the rainy season reduction of CAM activity caused by drought was first detected in the sun population. Measured ratios of glucan/soluble sugar show a higher proportion of readily utilizable sugars during periods of active CAM and growth. Under conditions of continuous high light intensity and air temperature leading to all year round high potential evaporation in semiarid tropical regions, fully exposed populations of B. humilis show a pronounced reduction of metabolic activity. Partial shade favours growth and CAM activity in this constitutive CAM species. It is concluded that water stress, and not light intensity, is the predominant limiting factor for growth of this species under natural conditions.     

Population structure of the black arowana (Osteoglossum ferreirai) in Brazil and Colombia: implications for its management

In regions with high biodiversity, where species are exploited as a source of income, it is essential to learn more about the species that are being commercialized. For the ornamental fish black arowana (Osteoglossum ferreirai), distributed only in Colombia and Brazil, there is currently a lack of information about population estimates in each location, genetic data and lastly, about the events that lead to the current distribution of the species. A genetic population study was conducted by sequencing the mitochondrial genes cytochrome b and ATPase 6, and genotyping of eight microsatellite loci. Mitochondrial gene results indicated the absence of variable sites, and the microsatellite results showed a significantly lower heterozygosity than expected demonstrating that currently the genetic diversity of the species is low. The fact that this species is been exploited and that it shows low genetic diversity means it can quickly become endangered. For this reason, conservation, management and use programs for the black arowana should include and consider the genetic data obtained as well as additional life history and ecological factors to promote its sustainable use.     

Genetic structure of Cydia pomonella populations in Argentina and Chile implies isolating barriers exist between populations

The codling moth (Cydia pomonella (L.)) is an invasive pest of pome fruits introduced to the Americas in the 19–20^th centuries. This pest is widespread on both sides of the Andes range separating Argentina and Chile. We performed an analysis of the population genetic variability and structure of C. pomonella in Argentina and Chile using 13 microsatellite markers and sampled C. pomonella from apple as the main host plant along its distribution area (approx. 1,800 km). A total of 22 locations (11 from Chile and 11 from Argentina) were sampled. Significant genetic differentiation was observed among samples from Argentina and Chile (F_SC = 0.045) and between all localities (F_ST = 0.085). Significant isolation by distance (IBD) was found for each country and when samples from both sides of the Andes range were pooled, although a lower correlation coefficient was observed. The Mantel test showed that the geographic distance and highest altitude of the mountains between locations were significantly associated with the pairwise F_ST when samples from both sides of the Andes range were pooled. According to a Bayesian assignment test (STRUCTURE), samples from Argentina and Chile conformed to two distinct genetic clusters. Our results also suggest that the recent invasion of C. pomonella in the southernmost localities (Aysén Region in Chile and Santa Cruz Province in Argentina) originated in populations from the respective sides of the Andes range. Our results indicate a genetic exchange of C. pomonella within each country and significant genetic differentiation between countries, which could be explained by dispersal mediated by human activities related to fruit production within each country with little exchange between them. A possible explanation is that the Andes range could be a significant barrier for dispersal by flight, and quarantine barriers could prevent the movement of plant material or infested fruit between countries.     

Nitrogen fixation (Acetylene reduction) by free-livingRhizobium meliloti

Evidence is presented thatRhizobium meliloti is able to fix nitrogen (as scored by acetylene reduction) while growing in the absence of a plant host. The highest nitrogen fixation rate was obtained when bacteria were grown in defined liquid medium under normal atmosphere in sealed tubes. The nitrogen fixation rates obtained are of the same order as those reported for other rhizobia.