Search results for "Morphogenesi"

Gyrification from constrained cortical expansion

2014

The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated a…

Segment polarity and DV patterning gene expression reveals segmental organization of theDrosophilabrain

2003

The insect brain is traditionally subdivided into the trito-, deuto- and protocerebrum. However, both the neuromeric status and the course of the borders between these regions are unclear. The Drosophila embryonic brain develops from the procephalic neurogenic region of the ectoderm, which gives rise to a bilaterally symmetrical array of about 100 neuronal precursor cells, called neuroblasts. Based on a detailed description of the spatiotemporal development of the entire population of embryonic brain neuroblasts, we carried out a comprehensive analysis of the expression of segment polarity genes (engrailed, wingless, hedgehog, gooseberry distal,mirror) and DV patterning genes (muscle segmen…

The 5' Untranslated Region of the

2018

Many of the virulence traits that make Candida albicans an important human fungal pathogen are regulated on a transcriptional level. Here, we report an important regulatory contribution of translation, which is exerted by the extensive 5′ untranslated regulatory sequence (5′ UTR) of the transcript for the protein Efg1, which determines growth, metabolism, and filamentation in the fungus. The presence of the 5′ UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5′ UTR sequences, it appears that the virulence of C. albicans depends on the combination of transcriptional and translational regulatory mec…

INTRODUCTION TO MORPHOGENESIS AND RELATED PROBLEMS

1973

Independence between developmental stability and canalization in the skull of the house mouse.

2000

The relationship between the two components of developmental homeostasis, that is canalization and developmental stability (DS), is currently debated. To appraise this relationship, the levels and morphological patterns of interindividual variation and fluctuating asymmetry were assessed using a geometric morphometric approach applied to the skulls of laboratory samples of the house mouse. These three samples correspond to two random-bred strains of the two European subspecies of the house mouse and their F1 hybrids. The inter- and intraindividual variation levels were found to be smaller in the hybrid group compared to the parental ones, suggesting a common heterotic effect on skull canali…

Lactate Dehydrogenase Isozymes in the Developing Rat Brain

1962

THE immaturity and the lack of differentiation of the rat brain at birth has been shown some fifty years ago by Sugita1 in a classic paper on the postnatal morphogenesis of the brain in this animal. The sequence of physiological and biochemical changes which parallel the histological maturation of the rat brain has been investigated, however, only recently.

Age-dependent changes in the transcription profile of long-lived Drosophila over-expressing glutamate cysteine ligase

2011

Abstract In our prior studies ( Orr et al., 2005 ) we achieved a 30–50% increase in the life span of Drosophila by manipulating glutathione (GSH) production in neuronal tissues, through over-expression of glutamate-cysteine ligase (GCL), a key enzyme in glutathione biosynthesis. In the present study, we identified gene response patterns from which plausible mechanisms responsible for the observed effects on life span might be inferred. Functional clustering analysis of the transcriptome data revealed that biological processes affected by GCLc in young flies (10 days) were generally related to cell morphogenesis and differentiation, while those in older flies were associated with nucleosome …

Functional Studies of Regulatory Genes in the Sea Urchin Embryo

2008

Sea urchin embryos are characterized by an extremely simple mode of development, rapid cleavage, high transparency, and well-defined cell lineage. Although they are not suitable for genetic studies, other approaches are successfully used to unravel mechanisms and molecules involved in cell fate specification and morphogenesis. Microinjection is the elective method to study gene function in sea urchin embryos. It is used to deliver precise amounts of DNA, RNA, oligonucleotides, peptides, or antibodies into the eggs or even into blastomeres. Here we describe microinjection as it is currently applied in our laboratory and show how it has been used in gene perturbation analyses and dissection o…

Induction of a disintegrin and metalloprotease 33 during embryonic lung development and the influence of IL-13 or maternal allergy.

2009

Background Asthma pathogenesis involves gene and environmental interactions. A disintegrin and metalloprotease 33 (ADAM33)/Adam33 is a susceptibility gene for asthma and bronchial hyperresponsiveness in human beings and mice. ADAM33 is almost exclusively expressed in mesenchymal cells, including mesenchymal progenitors in developing lungs. Objective Because maternal allergy is a risk factor for asthma, we hypothesized that an allergic environment affects ADAM33/Adam33 expression during human and mouse lung development. Methods Human embryonic/fetal lung (HEL) tissues were collected from first-trimester terminations of pregnancy. These were processed immediately or used for explant culture ±…

Financial Sustainability and Morphogenesis of Urban Transformation Project

2015

The urban transformation projects are very complex and have to be examined from several points of view (socio-cultural, environmental, infrastructural, administrative, and economic-financial) to determine their sustainability. This study aims to test the financial analysis as a tool for outlining the morphogenesis of the project’s characteristics and exploring the frontiers of the financial feasibility especially when the urban projects, according to Italian laws, involve Public Private Partnerships (PPPs). A financial model is applied to a case study (the transformation of an abandoned railway area) in which the absence of an adequate returns on investment, because of the crisis of the rea…