In this work, we analyse the blistered function in wing vein development by studying genetic mosaics of mutant cells, genetic interactions with other genes affecting vein development and blistered ...expression in several mutant backgrounds. blistered encodes for a nuclear protein homologous to the mammalian Serum Response Factor and is expressed in presumptive intervein cells of third larval instar and pupal wing discs. Clones of blistered mutant cells proliferate normally but tend to grow along veins and always differentiate as vein tissue. These observations indicate that vein-determined wing cells show a particular behaviour that is responsible for their allocation to vein regions. We observe strong genetic interactions between blistered, veinlet and genes of the Ras signaling cascade. During disc proliferation, blistered expression is under the control of the Ras signal transduction pathway, but its expression is independent of veinlet. During the pupal period, blistered and veinlet expression become interdependent and mutually exclusive. These results link the activity of the Ras pathway to the process of early determination of intervein cells, by the transcriptional control of the blistered nuclear factor.
The cells along the dorsoventral boundary of the Drosophila wing imaginal disc have distinctive properties and their specification requires Notch activity. Later in development, these cells will form ...the wing margin, where sensory organs and specialised trichomes appear in a characteristic pattern. We find that Notch is locally activated in these cells, as demonstrated by the restricted expression of the Enhancer of split proteins in dorsal and ventral cells abutting the D/V boundary throughout the third larval instar. Furthermore other genes identified by their involvement in Notch signaling during neurogenesis, such as Delta and Suppressor of Hairless, also participate in Notch function at the dorsoventral boundary. In addition, Serrate, a similar transmembrane protein to Delta, behaves as a ligand required in dorsal cells to activate Notch at the boundary. Notch gain-of-function alleles in which Notch activity is not restricted to the dorsoventral boundary cause miss-expression of cut and wingless and overgrowth of the disc, illustrating the importance of localised Notch activation for wing development.
Heritable mutations in the germ line lead to genetically heterogeneous, or mosaic, gonads. Many of the genes used in germ-line development also play roles in somatic development Saffman, E. E. & ...Lasko, P. (1999) Cell. Mol. Life Sci. 55, 1141-1163. Mutations in these genes may have cellular phenotypes throughout germ-line development leading to their differential elimination or survival, as has been observed in somatic cells Morata, G. & Ripoll, P. (1975) Dev. Biol. 42, 211-221. We investigate whether mutations in heterozygosis are subject to pregametic selection in the germ line. We initiated clones of wild-type homozygous cells at different stages of development in gonads heterozygous for eight different recessive chromosome deficiencies. Here we show that cell selection takes place in mosaic germ-line populations. This phenomenon represents a level of selection that precedes and conditions subsequent zygotic selection by affecting the genes available in the gametic population.
Mutations in the nubbin (nub) gene have a phenotype consisting of a severe wing size reduction and pattern alterations, such as transformations of distal elements into proximal ones. nub expression ...is restricted to the wing pouch cells in wing discs since early larval development. These effects are also observed in genetic mosaics where cell proliferation is reduced in all wing blade regions autonomously, and transformation into proximal elements is observed in distal clones. Clones located in the proximal region of the wing blade cause in addition nonautonomous reduction of the whole wing. Cell lineage experiments in a nub mutant background show that clones respect neither the anterior-posterior nor the dorsal-ventral boundary but that the selector genes have been correctly expressed since early larval development. The phenotypes of nub el and nub dpp genetic combinations are synergistic and the overexpression of dpp in clones in nub wings does not result in overproliferation of the surrounding wild-type cells. We discuss the role of nub in the wing's proximo-distal axis and in the formation of compartment boundaries
In this paper we present an application of the Support Vector Regression algorithm (SVMr) to the prediction of hourly ozone values in Madrid urban area. In order to improve the training capacity of ...SVMrs, we have used a recently proposed approach, based on reductions of the SVMr hyper-parameters search space. Using the modified SVMr, we study different influences which may modify the ozone prediction, such as previous ozone measurements in a given station, measurements in neighbors stations, and the influence of meteorologic variables. We use statistical tests to verify the significance of incorporating different variables into the SVMr. A comparison with the results obtained using a neural network (multi-layer perceptron) is also carried out. This study has been carried out in 5 different stations of the air pollution monitoring network of Madrid, so the conclusions raised are backed by real data. The final result of the work is a robust and powerful software for tropospheric ozone prediction in Madrid. Also, the prediction tool based on SVMr is flexible enough to incorporate any other prediction variable, such as city models, or traffic patters, which may improve the prediction obtained with the SVMr.
The function of extramacrochaetae is required during the development of the Drosophila wing in processes such as cell proliferation and vein differentiation. extramacrochaetae encodes a transcription ...factor of the HLH family, but unlike other members of this family, Extramacrochaetae lacks the basic region that is involved in interaction with DNA. Some phenotypes caused by extramacrochaetae in the wing are similar to those observed when Notch signalling is compromised. Furthermore, maximal levels of extramacrochaetae expression in the wing disc are restricted to places where Notch activity is higher, suggesting that extramacrochaetae could mediate some aspects of Notch signalling during wing development. We have studied the relationships between extramacrochaetae and Notch in wing development, with emphasis on the processes of vein formation and cell proliferation. We observe strong genetic interaction between extramacrochaetae and different components of the Notch signalling pathway, suggesting a functional relationship between them. We show that the higher level of extramacrochaetae expression coincides with the domain of expression of Notch and its downstream gene Enhancer of split-m(beta). The expression of extramacrochaetae at the dorso/ventral boundary and in boundary cells between veins and interveins depends on Notch activity. We propose that at least during vein differentiation and wing margin formation, extramacrochaetae is regulated by Notch and collaborates with other Notch-downstream genes such as Enhancer of split-m(beta).
In this letter we propose a class of neural network banks to improve the performance of average total ozone in column (TOC) prediction, using real satellite data over the Iberian Peninsula. The ...proposed neural network banks exploit the possibility of separating the average TOC series into its known components, applying different neural networks as input to different structures which form the final bank. These neural network banks have proven to be very effective in the experiments carried out, obtaining important improvements over standard networks in the prediction of average TOC data series over the Iberian Peninsula. Also, we show that this good performance of the neural network banks is maintained when different procedures of deseasonalization are applied to the ozone measure and also to the prediction variables.
The vein locus (vn) includes lethal alleles (designated also defective dorsal discs) that prevent growth of dorsal discs and in viable genetic combinations reduce the number of cells of the adult ...wing. Those effects are prominent in genetic mosaics. Cell proliferation is reduced in all regions of the wing blade in a local autonomous way. These effects are more extreme when mutant clones occupy full intervein regions bordering veins. Clones have, in addition, nonautonomous effects (accommodation) in the proliferation of wild-type cells of the same wing. These effects are more extreme in double mutant vn (ddd) and ve (rhomboid) allelic combinations. Developmental analysis shows that cell proliferation stops earlier in larval development the stronger the vn allele considered. A model is discussed of how cell proliferation is controlled by cellular interactions.
In this essay, we discuss the contribution of local cell interactions, as opposed to global cues, such as hormones and morphogens, to the determination of the size and shape of organs. This ...internalistic notion is based on the integration of physiological experiments, clonal analysis and genetic mosaics of morphogenetic mutants. Physiological experiments such as regeneration, cell dissociation and re-aggregation, and feeder layers, reveal the existence of regional specificities related to regional patterning, positional values and cell polarity. On the other hand, clonal analysis shows homogeneous and exponential growth by mitosis associated with oriented cell divisions along two axes of growth. Preferential mitotic orientations are also regional characteristic. Finally, genetic mosaics of morphogenetic mutants help to understand the genetic and eventually the molecular bases of morphogenesis, revealing the modes of cell behavior (such as positional accommodation, mitotic orientations, cell affinities and cell recognition) at work in the generation of the constant sizes and shapes of Drosophila imaginal structures. These classical and recent findings contribute to a more updated Entelechia model of morphogenesis.
This article refers to the paper “Assessment of table olive fermentation by functional data analysis” (Ruiz-Bellido et al., 2016) 1. The dataset include pH, titratable acidity, yeast count and area ...values obtained during fermentation process (380 days) of Aloreña de Málaga olives subjected to five different fermentation systems: i) control of acidified cured olives, ii) highly acidified cured olives, iii) intermediate acidified cured olives, iv) control of traditional cracked olives, and v) traditional olives cracked after 72h of exposure to air. Many of the Tables and Figures shown in this paper were deduced after application of Functional Data Analysis to raw data using a routine executed under R software for comparison among treatments by the transformation of raw data into smooth curves and the application of a new battery of statistical tools (functional pointwise estimation of the averages and standard deviations, maximum, minimum, first and second derivatives, functional regression, and functional F and t-tests).
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