Expression of the aspartate/glutamate mitochondrial carriers aralar1 and citrin during development and in adult rat tissues.

Aralar1 and citrin are members of the subfamily of calcium-binding mitochondrial carriers and correspond to two isoforms of the mitochondrial aspartate/glutamate carrier (AGC). These proteins are activated by Ca2+ acting on the external side of the inner mitochondrial membrane. Although it is known that aralar1 is expressed mainly in skeletal muscle, heart and brain, whereas citrin is present in liver, kidney and heart, the precise tissue distribution of the two proteins in embryonic and adult tissues is largely unknown. We investigated the pattern of expression of aralar1 and citrin in murine embryonic and adult tissues at the mRNA and protein levels. In situ hybridization analysis indicates that both isoforms are expressed strongly in the branchial arches, dermomyotome, limb and tail buds at early embryonic stages. However, citrin was more abundant in the ectodermal components of these structures whereas aralarl had a predominantly mesenchymal localization. The strong expression of citrin in the liver was acquired postnatally, whereas the characteristic expression of aralar1 in skeletal muscle was detected at E18 and that in the heart began early in development (E11) and was preferentially localized to auricular myocardium in late embryonic stages. Aralar1 was also expressed in bone marrow, T-lymphocytes and macrophages, including Kupffer cells in the liver, indicating that this is the major AGC isoform present in the hematopoietic system. Both aralar1 and citrin were expressed in fetal gut and adult stomach, ovary, testis, and pancreas, but only aralar1 is enriched in lung and insulin-secreting beta cells. These results show that aralar1 is expressed in many more tissues than originally believed and is absent from hepatocytes, where citrin is the only AGC isoform present. This explains why citrin deficiency in humans (type II citrullinemia) only affects the liver and suggests that aralar1 may compensate for the lack of citrin in other tissues.     

Using vegetation indices derived from conventional digital cameras as selection criteria for wheat breeding in water-limited environments

The ability to assess green biomass is of particular interest in a number of wheat breeding environments. However, the measurement of this and similar traits is either tedious and time-consuming or requires the use of expensive, sophisticated equipment, such as field-based spectroradiometers to measure vegetation indices (VIs). Here, conventional digital cameras are proposed as affordable and easy-to-use tools for gathering field data in wheat breeding programmes. Using appropriate software, a large set of images can be automatically processed to calculate a number of VIs, based on the performance of simple colour operations on each picture. The purpose of this study was to identify a set of picture-derived vegetation indices (picVIs) and to evaluate their performance in durum wheat trials growing under rainfed and supplementary irrigation conditions. Here, zenithal pictures of each plot were obtained roughly 2 weeks after anthesis, and the picVIs that were calculated were compared with the normalised difference vegetation index (NDVI), an index derived from spectroradiometrical measurements, and with the grain yield (GY) from the same plots. The picVIs that performed best were the Hue, CIE-Lab a* and CIE-Luv u* components of the average colour of each picture, the relative green area (GA) and the 'greener area', similar to GA but excluding the more yellowish-green pixels. Our results showed a high correlation between all these picVIs and the NDVI. Moreover, in rainfed conditions, each picVI provided an estimation of GY similar to or slightly better than that provided by the NDVI. However, in irrigated conditions during anthesis, neither these picVIs nor the NDVI provided a good estimation of GY, apparently because of the saturation of the VI response in conditions of complete soil cover and high plant density.     

A survey of ontogeny pericarp features as contribution to the infratribal characterization of Myrteae (Myrtaceae)

With the aim of correlating the pericarp structure with current phylogenies of Myrteae, this study describes the ontogeny in five species included in five out of the six South American clades of the tribe. In these taxa, the outer and inner ovarian epidermis gives rise to the exocarp and the endocarp, respectively, both with 1 layer. In the mesocarp, derived from the ovarian mesophyll, secretory cavities are arranged into a circle just below the exocarp and near the endocarp in Campomanesia adamantium; only below the exocarp in Eugenia pitanga and Myrcia multiflora; more internally in Myrciaria cuspidata, and below the exocarp and throughout the mesophyll in Myrceugenia alpigena. The promising traits for phylogenetic studies in the group include: direction of elongation of pericarp layers, regions that develop most in relation to the circle of larger vascular bundles, differentiation of spongy and sclerenchymatous tissues and position of secretory cavities.     

Zinc hyperaccumulation substitutes for defense failures beyond salicylate and jasmonate signaling pathways of Alternaria brassicicola attack in Noccaea caerulescens

The hypothesis of metal defense as a substitute for a defective biotic stress signaling system in metal hyperaccumulators was tested using the pathosystem Alternaria brassicicola–Noccaea caerulescens under low (2 µM), medium (12 µM) and high (102 µM) Zn supply. Regardless the Zn supply, N. caerulescens responded to fungal attack with the activation of both HMA4 coding for a Zn transporter, and biotic stress signaling pathways. Salicylate, jasmonate, abscisic acid and indoleacetic acid concentrations, as well as biotic stress marker genes (PDF1.2, CHIB, LOX2, PR1 and BGL2) were activated 24 h upon inoculation. Based on the activation of defense genes 24 h after the inoculation an incompatible fungal–plant interaction could be predicted. Nonetheless, in the longer term (7 days) no effective protection against A. brassicicola was achieved in plants exposed to low and medium Zn supply. After 1 week the biotic stress markers were even further increased in these plants, and this compatible interaction was apparently not caused by a failure in the signaling of the fungal attack, but due to the lack of specificity in the type of the activated defense mechanisms. Only plants receiving high Zn exhibited an incompatible fungal interaction. High Zn accumulation in these plants, possibly in cooperation with high glucosinolate concentrations, substituted for the ineffective defense system and the interaction turned into incompatible. In a threshold‐type response, these joint effects efficiently hampered fungal spread and, consequently decreased the biotic stress signaling.     

Influence of sex, slaughter weight and carcass weight on “non-carcass” and carcass quality in segureña lambs

The effects of sex, slaughter weight and carcass weight on carcass characteristics and meat quality traits were evaluated using 100 Segureña lambs. The management of all lambs was similar prior to slaughter at 19–25 kg. Slaughtered animals with a hot carcass weight below 20 kg were assigned to class B, and those greater than 22 kg to class C. Carcass weight had a significant influence on “non-carcass” components, dressing percentage, subjective carcass conformation, fat deposits, carcass fatness, bone and most carcass measurements. Sex had a significant effect on age at slaughter, “non-carcass” components, rib measurements, dressing percentage, fat deposits, and neck and shoulder percentage. As the weight increased, the carcass measurements also increased. Concurrently, while improving the conformation indices of the carcass, leg and dressing percentages, neither the commercial cuts of the animal nor tissue composition was significantly affected. Sex primarily affected the quantity of all types of fat deposits.     

Laboratory rearing conditions for improved growth of juvenile Helix aspersa Müller snails

A laboratory rearing system in semi-controlled conditions is proposed to facilitate the behavioural rhythms of the edible snail (Helix aspersa) and to produce a high growth rate with low variability. The growth data were used to construct a model for weight estimation based on age. The animals' live weights showed low variability (<17%) and normal distribution. The best model for estimating weight from age is the logistic model, with a high corelation coefficient (>90%), and a high level of significance for the coefficient (P < 0.0001).     

Reconstitution and organization of Escherichia coli proto-ring elements (FtsZ and FtsA) inside giant unilamellar vesicles obtained from bacterial inner membranes

We have incorporated, for the first time, FtsZ and FtsA (the soluble proto-ring proteins from Escherichia coli) into bacterial giant unilamellar inner membrane vesicles (GUIMVs). Inside the vesicles, the structural organization and spatial distribution of fluorescently labeled FtsZ and FtsA were determined by confocal microscopy. We found that, in the presence of GDP, FtsZ was homogeneously distributed in the lumen of the vesicle. In the presence of GTP analogs, FtsZ assembled inside the GUIMVs, forming a web of dense spots and fibers. Whereas isolated FtsA was found adsorbed to the inner face of GUIMVs, the addition of FtsZ together with GTP analogs resulted in its dislodgement and its association with the FtsZ fibers in the lumen, suggesting that the FtsA-membrane interaction can be modulated by FtsZ polymers. The use of this novel in vitro system to probe interactions between divisome components will help to determine the biological implications of these findings.     

Variation among vocalizations of Taraba major (Aves: Thamnophilidae) subspecies

Geographical variation of bird vocalizations may be related to factors influencing sound production and sound propagation. If birds, e.g. the Great Antshrike (Taraba major), produce vocalizations that develop normally in the absence of learning, these variations may reflect evolutionary divergence within species. In this case, vocal variation could be influenced by habitat structure, since abiotic features and vegetal cover affect sound propagation through environment. Selective pressures may be acting on populations in different ways, which could culminate in a process of speciation. Thus, we searched for structural variation of Great Antshrike vocalizations between subspecies and sought for relationships between these vocal variation and environmental structure. We found variations in frequency and time features of vocalizations among subspecies, which are correlated to latitude, elevation and climate. We also observed an increase in vocal differences along with an increase in distances between individuals, which could reflect isolation of subspecies and the vocal adaptation to different environments.