The <Emphasis Type="Italic">Drosophila</Emphasis>STIM1 orthologue,dSTIM, has roles in cell fate specification and tissue patterning

Background  

Mammalian STIM1 and STIM2 and the single Drosophila homologue dSTIM have been identified as key regulators of store-operated Ca²⁺ entry in cells. STIM proteins function both as molecular sensors of Ca²⁺concentration in the endoplasmic reticulum (ER) and the molecular triggers that activate SOC channels in the plasma membrane. Ca²⁺ is a crucial intracellular messenger utilised in many cellular processes, and regulators of Ca²⁺ homeostasis in the ER and cytosol are likely to play important roles in developmental processes. STIM protein expression is altered in several tumour types but the role of these proteins in developmental signalling pathways has not been thoroughly examined.     

Genotype frequencies and linkage disequilibrium in the CEPH human diversity panel for variants in folate pathway genes MTHFR, MTHFD, MTRR, RFC1, and GCP2

BACKGROUND

Genetic variation in enzymes involved in vitamin metabolism is a candidate for analysis in studies of how nutritional covariates may impact a disease state. The role of folate pathway genes in birth defects and cardiovascular disease in humans has been widely studied. Since incidence rates for these disorders vary by geographic origins, it is useful to know which variants are the best candidates for studies based on genotype and allele frequency, as well as linkage disequilibrium (LD) in founder populations.

METHODS

Six polymorphisms in five folate metabolism‐related genes (MTHFR, MTHFD, MTRR, GCP2, and RFC1) were genotyped on a collection of 1064 DNA samples from populations around the world, which were made available by the Centre d'Étude du Polymorphisme Humain (CEPH) consortium for analysis.

RESULTS

In this study we report the genotype frequencies for variants in the MTHFR, MTHFD, MTRR, GCP2, and RFC1 genes, and the LD for two variants (C677T and A1298C) in MTHFR.

CONCLUSIONS

The rare allele frequency for each of the five genes studied varied widely. LD is strongest in Pakistani and Brazilian populations (D′ = 1.0) and weakest in Mexican populations (D′ = 0.45). These findings will allow the selection of variants that will provide the most power in studies of folate pathway genes involving different ancestral populations, and contribute to our knowledge of the population distribution of selected nutritional gene variants. Birth Defects Research (Part A), 2003. © 2003 Wiley‐Liss, Inc.

     

Laser surgery of zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) embryos using femtosecond laser pulses: Optimal parameters for exogenous material delivery,and the laser's effect on short- and long-term development

Background  

Femtosecond (fs) laser pulses have recently received wide interest as an alternative tool for manipulating living biological systems. In various model organisms the excision of cellular components and the intracellular delivery of foreign exogenous materials have been reported. However, the effect of the applied fs laser pulses on cell viability and development has yet to be determined. Using the zebrafish (Danio rerio) as our animal model system, we address both the short- and long-term developmental changes following laser surgery on zebrafish embryonic cells.     

Pathophysiologic consequences following inhibition of a CFTR-dependent developmental cascade in the lung

Background  

Examination of late gestation developmental genes in vivo may be limited by early embryonic lethality and compensatory mechanisms. This problem is particularly apparent in evaluating the developmental role of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in the cystic fibrosis (CF) phenotype. A previously described transient in utero knockout (TIUKO) technology was used to address the developmental role of CFTR in the rat lung.     

Conservation and divergence of ADAM family proteins in the <Emphasis Type="Italic">Xenopus</Emphasis> genome

Background  

Members of the disintegrin metalloproteinase (ADAM) family play important roles in cellular and developmental processes through their functions as proteases and/or binding partners for other proteins. The amphibian Xenopus has long been used as a model for early vertebrate development, but genome-wide analyses for large gene families were not possible until the recent completion of the X. tropicalis genome sequence and the availability of large scale expression sequence tag (EST) databases. In this study we carried out a systematic analysis of the X. tropicalis genome and uncovered several interesting features of ADAM genes in this species.     

Origin and evolution of the Notch signalling pathway: an overview from eukaryotic genomes

Background  

Of the 20 or so signal transduction pathways that orchestrate cell-cell interactions in metazoans, seven are involved during development. One of these is the Notch signalling pathway which regulates cellular identity, proliferation, differentiation and apoptosis via the developmental processes of lateral inhibition and boundary induction. In light of this essential role played in metazoan development, we surveyed a wide range of eukaryotic genomes to determine the origin and evolution of the components and auxiliary factors that compose and modulate this pathway.     

Protein-protein interaction as a predictor of subcellular location

Background  

Many biological processes are mediated by dynamic interactions between and among proteins. In order to interact, two proteins must co-occur spatially and temporally. As protein-protein interactions (PPIs) and subcellular location (SCL) are discovered via separate empirical approaches, PPI and SCL annotations are independent and might complement each other in helping us to understand the role of individual proteins in cellular networks. We expect reliable PPI annotations to show that proteins interacting in vivo are co-located in the same cellular compartment. Our goal here is to evaluate the potential of using PPI annotation in determining SCL of proteins in human, mouse, fly and yeast, and to identify and quantify the factors that contribute to this complementarity.     

Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

Background  

Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted.     

Cell-specific expression of tryptophan decarboxylase and 10-hydroxygeraniol oxidoreductase,key genes involved in camptothecin biosynthesis in <Emphasis Type="Italic">Camptotheca acuminata</Emphasis> Decne (Nyssaceae)

Background  

Camptotheca acuminata is a major natural source of the terpenoid indole alkaloid camptothecin (CPT). At present, little is known about the cellular distribution of the biosynthesis of CPT, which would be useful knowledge for developing new strategies and technologies for improving alkaloid production.     

Copine A plays a role in the differentiation of stalk cells and the initiation of culmination in <Emphasis Type="Italic">Dictyostelium</Emphasis> development

Background  

Copines are calcium-dependent phospholipid-binding proteins found in diverse eukaryotic organisms. We are studying the function of copines in Dictyostelium discoideum, a single-celled amoeba that undergoes cell differentiation and morphogenesis to form multicellular fruiting bodies when placed in starvation conditions. Previously, we showed that Dictyostelium cells lacking the copine A (cpnA) gene are not able to complete the developmental cycle, arresting at the slug stage. The aim of this study is to further characterize the developmental defect of the cpnA- cells.     

MIF‐173G/C (rs755622) polymorphism as a risk factor for acute lymphoblastic leukemia development in children

Background

Macrophage inhibitory factor (MIF) is a pro‐inflammatory cytokine modulating monocyte motility and a pleiotropic regulator of different biological and cellular processes. The MIF‐173G/C (rs755622) polymorphism is found in the promoter region and affects its activity. The present study investigated the MIF polymorphism as a risk factor for the development of acute lymphoblastic leukemia (ALL) in Egyptian children.

Methods

We analyzed the MIF‐173G/C (rs755622) polymorphism in 180 ALL cases and 150 healthy control children by amplification of the gene using a polymerase chain reaction followed by restriction endonuclease digestion and running on an agarose gel for visualization of the product.

Results

We found a significant incidence of the homozygous polymorphic (CC) genotype and the combined polymorphic genotypes (GC + CC) in ALL patients compared to healthy controls (p = 0.001 and p = 0.007, respectively), whereas the wild‐type genotype (GG) was more common in healthy controls (p = 0.006). Multivariate logistic regression analysis adjustment for MIF different genotypes and other potential risk factors such as age, sex and parental smoking indicated that the CC genotype is the only significant risk factor for the test (p = 0.02). We also noted that, by increasing the C‐allele representation within the gene [GC, CC], there was an increase in total leukocytic count (p = 0.09 and p = 0.001, respectively) that may reflect the bad prognostic impact of the polymorphic allele, although further studies are needed.

Conclusions

The results of the present study indicate that the MIF‐173G/C (rs755622) polymorphism is a risk factor for childhood ALL development with respect to both homozygous and combined polymorphic genotypes. In addition, the increased leukocytic count in synchronization with the increased representation of the polymorphic C‐allele may reflect its bad prognostic impact.     

Characterization of Diaphanous-related formin FMNL2 in human tissues

Background  

Diaphanous-related formins govern actin-based processes involved in many cellular functions, such as cell movement and invasion. Possible connections to developmental processes and cellular changes associated with malignant phenotype make them interesting study targets. In spite of this, very little is known of the tissue distribution and cellular location of any mammalian formin. Here we have carried out a comprehensive analysis of the formin family member formin -like 2 (FMNL2) in human tissues.     

Characterization,phylogeny, alternative splicing and expression of <Emphasis Type="Italic">Sox30</Emphasis> gene

Background  

Members of the Sox gene family isolated from both vertebrates and invertebrates have been proved to participate in a wide variety of developmental processes, including sex determination and differentiation. Among these members, Sox30 had been considered to exist only in mammals since its discovery, and its exact function remains unclear.     

Oral infection with the Salmonella enterica serovar Gallinarum 9R attenuated live vaccine as a model to characterise immunity to fowl typhoid in the chicken

Background  

Salmonella enterica serovar Gallinarum (S. Gallinarum) is the causative agent of fowl typhoid, a severe systemic disease of chickens that results in high mortality amongst infected flocks. Due to its virulence, the immune response to S. Gallinarum is poorly characterised. In this study we have utilised infection by the live attenuated S. Gallinarum 9R vaccine strain in inbred chickens to characterise humoral, cellular and cytokine responses to systemic salmonellosis.     

Duplication,divergence and persistence in the Phytochrome photoreceptor gene family of cottons (<Emphasis Type="Italic">Gossypium</Emphasis> spp.)

Background  

Phytochromes are a family of red/far-red photoreceptors that regulate a number of important developmental traits in cotton (Gossypium spp.), including plant architecture, fiber development, and photoperiodic flowering. Little is known about the composition and evolution of the phytochrome gene family in diploid (G. herbaceum, G. raimondii) or allotetraploid (G. hirsutum, G. barbadense) cotton species. The objective of this study was to obtain a preliminary inventory and molecular-evolutionary characterization of the phytochrome gene family in cotton.     

Straw blood cell count,growth, inhibition and comparison to apoptotic bodies

Background  

Mammalian cells transform into individual tubular straw cells naturally in tissues and in response to desiccation related stress in vitro. The transformation event is characterized by a dramatic cellular deformation process which includes: condensation of certain cellular materials into a much smaller tubular structure, synthesis of a tubular wall and growth of filamentous extensions. This study continues the characterization of straw cells in blood, as well as the mechanisms of tubular transformation in response to stress; with specific emphasis placed on investigating whether tubular transformation shares the same signaling pathway as apoptosis.     

The eggshell is required for meiotic fidelity, polar-body extrusion and polarization of the C. elegans embryo

Background  

Fertilization restores the diploid state and begins the process by which the single-cell oocyte is converted into a polarized, multicellular organism. In the nematode, Caenorhabditis elegans, two of the earliest events following fertilization are secretion of the chitinous eggshell and completion of meiosis, and in this report we demonstrate that the eggshell is essential for multiple developmental events at the one-cell stage.     

Analysis of gene expression in cotton fiber initials

Background  

Cotton (Gossypium hirsutum L.) fibers are trichomes that initiate from the ovule epidermis. Little is known about the developmental pathway causing fiber to differentiate from ovular epidermal cells even though limits on the number of cells that differentiate into fiber will limit yield.