59 research outputs found
Copy Number Variation in Intron 1 of SOX5 Causes the Pea-comb Phenotype in Chickens
Pea-comb is a dominant mutation in chickens that drastically reduces the size of the comb and wattles. It is an adaptive trait in cold climates as it reduces heat loss and makes the chicken less susceptible to frost lesions. Here we report that Pea-comb is caused by a massive amplification of a duplicated sequence located near evolutionary conserved non-coding sequences in intron 1 of the gene encoding the SOX5 transcription factor. This must be the causative mutation since all other polymorphisms associated with the Pea-comb allele were excluded by genetic analysis. SOX5 controls cell fate and differentiation and is essential for skeletal development, chondrocyte differentiation, and extracellular matrix production. Immunostaining in early embryos demonstrated that Pea-comb is associated with ectopic expression of SOX5 in mesenchymal cells located just beneath the surface ectoderm where the comb and wattles will subsequently develop. The results imply that the duplication expansion interferes with the regulation of SOX5 expression during the differentiation of cells crucial for the development of comb and wattles. The study provides novel insight into the nature of mutations that contribute to phenotypic evolution and is the first description of a spontaneous and fully viable mutation in this developmentally important gene
The role of the muscarinic system in regulating estradiol secretion varies during the estrous cycle: the hemiovariectomized rat model
There is evidence that one gonad has functional predominance. The present study analyzed the acute effects of unilateral ovariectomy (ULO) and blocking the cholinergic system, by injecting atropine sulfate (ATR), on estradiol (E(2)) serum concentrations during the estrous cycle. The results indicate that ULO effects on E(2 )concentrations are asymmetric, vary during the estrous cycle, and partially depend on the cholinergic innervation. Perforation of the left peritoneum resulted in lower E(2 )serum concentrations in the three stages of the estrous cycle. At proestrus, unilateral or bilateral perforation of the peritoneum resulted in lower E(2 )serum concentrations. ULO of the right ovary (left ovary in situ) resulted in significantly higher E(2 )concentrations than animals with ULO of the left ovary (right ovary in situ). ATR treatment to ULO rats on D1 resulted in a significant drop of E(2 )serum concentrations. ULO rats treated with ATR on D2 or P, resulted in an asymmetrical E(2) secretion response; when the right ovary remained in situ an increase in E(2) was observed, and a decrease when the left ovary remained in situ. The results obtained in the present study suggest that each ovary's ability to compensate the secretion of E(2 )from the missing ovary is different and varies during the estrous cycle. The results also suggest that the cholinergic system participates in regulating ovarian E(2 )secretion. Such participation varies according to the ovary remaining in situ and the stage of the estrous cycle of the animal. The results agree with previously stated hypothesis of a neural pathway arising from the peritoneum that participates in regulating E(2 )secretion, and also supports the idea of cross-talk between the ovaries, via a neural communication, that modulates E(2 )secretion
Draft genome sequence and genetic transformation of the oleaginous alga Nannochloropis gaditana
The potential use of algae in biofuels applications is receiving significant attention. However, none of the current algal model species are competitive production strains. Here we present a draft genome sequence and a genetic transformation method for the marine microalga Nannochloropsis gaditana CCMP526. We show that N. gaditana has highly favourable lipid yields, and is a promising production organism. The genome assembly includes nuclear (~29 Mb) and organellar genomes, and contains 9,052 gene models. We define the genes required for glycerolipid biogenesis and detail the differential regulation of genes during nitrogen-limited lipid biosynthesis. Phylogenomic analysis identifies genetic attributes of this organism, including unique stramenopile photosynthesis genes and gene expansions that may explain the distinguishing photoautotrophic phenotypes observed. The availability of a genome sequence and transformation methods will facilitate investigations into N. gaditana lipid biosynthesis and permit genetic engineering strategies to further improve this naturally productive alga
The celiac ganglion modulates LH-induced inhibition of androstenedione release in late pregnant rat ovaries
BACKGROUND: Although the control of ovarian production of steroid hormones is mainly of endocrine nature, there is increasing evidence that the nervous system also influences ovarian steroidogenic output. The purpose of this work was to study whether the celiac ganglion modulates, via the superior ovarian nerve, the anti-steroidogenic effect of LH in the rat ovary. Using mid- and late-pregnant rats, we set up to study: 1) the influence of the noradrenergic stimulation of the celiac ganglion on the ovarian production of the luteotropic hormone androstenedione; 2) the modulatory effect of noradrenaline at the celiac ganglion on the anti-steroidogenic effect of LH in the ovary; and 3) the involvement of catecholaminergic neurotransmitters released in the ovary upon the combination of noradrenergic stimulation of the celiac ganglion and LH treatment of the ovary. METHODS: The ex vivo celiac ganglion-superior ovarian nerve-ovary integrated system was used. This model allows studying in vitro how direct neural connections from the celiac ganglion regulate ovarian steroidogenic output. The system was incubated in buffer solution with the ganglion and the ovary located in different compartments and linked by the superior ovarian nerve. Three experiments were designed with the addition of: 1) noradrenaline in the ganglion compartment; 2) LH in the ovarian compartment; and 3) noradrenaline and LH in the ganglion and ovarian compartments, respectively. Rats of 15, 19, 20 and 21 days of pregnancy were used, and, as an end point, the concentration of the luteotropic hormone androstenedione was measured in the ovarian compartment by RIA at various times of incubation. For some of the experimental paradigms the concentration of various catecholamines (dihydroxyphenylalanine, dopamine, noradrenaline and adrenaline) was also measured in the ovarian compartment by HPLC. RESULTS: The most relevant result concerning the action of noradrenaline in the celiac ganglion was found on day 21 of pregnancy resulting in the inhibition of androstenedione release from the ovarian compartment. In addition on day 15 of pregnancy, LH placed in the ovarian compartment led to an inhibition of the release of androstenedione, and this inhibitory effect was further reinforced by the joint action of noradrenaline in the celiac ganglion and LH in the ovary. The levels of catecholamines in the ovarian compartment showed differences among the experiments; of significance, the joint treatment of noradrenaline in the celiac ganglion and LH in the ovary resulted in a remarkable increase in the ovarian levels of noradrenaline and adrenaline when compared to the effect achieved by either one of the compounds added alone. CONCLUSION: Our results demonstrate that the noradrenergic stimulation of the celiac ganglion reinforces the LH-induced inhibition of androstenedione production by the ovary of late pregnant rats, and that this effect is associated with marked changes in the release of catecholamines in the ovary
Sepsis Enhances Epithelial Permeability with Stretch in an Actin Dependent Manner
Ventilation of septic patients often leads to the development of edema and impaired gas exchange. We hypothesized that septic alveolar epithelial monolayers would experience stretch-induced barrier dysfunction at a lower magnitude of stretch than healthy alveolar epithelial monolayers. Alveolar epithelial cells were isolated from rats 24 hours after cecal ligation and double puncture (2CLP) or sham surgery. Following a 5-day culture period, monolayers were cyclically stretched for 0, 10, or 60 minutes to a magnitude of 12% or 25% change in surface area (ΞSA). Barrier function, MAPk and myosin light chain (MLC) phosphorylation, tight junction (TJ) protein expression and actin cytoskeletal organization were examined after stretch. Significant increases in epithelial permeability were observed only in 2CLP monolayers at the 12% ΞSA stretch level, and in both 2CLP and sham monolayers at the 25% ΞSA stretch level. Increased permeability in 2CLP monolayers was not associated with MAPk signaling or alterations in expression of TJ proteins. 2CLP monolayers had fewer actin stress fibers before stretch, a more robust stretch-induced actin redistribution, and reduced phosphorylated MLCK than sham monolayers. Jasplakinolide stabilization of the actin cytoskeleton in 2CLP monolayers prevented significant increases in permeability following 60 minutes of stretch to 12% ΞSA. We concluded that septic alveolar epithelial monolayers are more susceptible to stretch-induced barrier dysfunction than healthy monolayers due to actin reorganization
NKX2-3 Transcriptional Regulation of Endothelin-1 and VEGF Signaling in Human Intestinal Microvascular Endothelial Cells
BACKGROUND: NKX2-3 is associated with inflammatory bowel disease (IBD). NKX2-3 is expressed in microvascular endothelial cells and the muscularis mucosa of the gastrointestinal tract. Human intestinal microvascular endothelial cells (HIMECs) are actively involved in the pathogenesis of IBD and IBD-associated microvascular dysfunction. To understand the cellular function of NKX2-3 and its potential role underlying IBD pathogenesis, we investigated the genes regulated by NKX2-3 in HIMEC using cDNA microarray. METHODOLOGY/PRINCIPAL FINDINGS: NKX2-3 expression was suppressed by shRNA in two HIMEC lines and gene expression was profiled by cDNA microarray. Pathway Analysis was used to identify gene networks according to biological functions and associated pathways. Validation of microarray and genes expression in intestinal tissues was assessed by RT-PCR. NKX2-3 regulated genes are involved in immune and inflammatory response, cell proliferation and growth, metabolic process, and angiogenesis. Several inflammation and angiogenesis related signaling pathways that play important roles in IBD were regulated by NKX2-3, including endothelin-1 and VEGF-PI3K/AKT-eNOS. Expression levels of NKX2-3, VEGFA, PI3K, AKT, and eNOS are increased in intestinal tissues from IBD patients and expression levels of EDN1 are decreased in intestinal tissues from IBD patients. These results demonstrated the important roles of NKX2-3, VEGF, PI3K, AKT, eNOS, and EDN1 in IBD pathogenesis. Correlation analysis showed a positive correlation between mRNA expression of NKX2-3 and VEGFA and a negative correlation between mRNA expression of NKX2-3 and EDN1 in intestinal tissues from IBD patients. CONCLUSION/RELEVANCE: NKX2-3 may play an important role in IBD pathogenesis by regulating endothelin-1 and VEGF signaling in HIMECs
Behavioral genetics and taste
This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed. Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste
Interleukin-32 Promotes Osteoclast Differentiation but Not Osteoclast Activation
Background: Interleukin-32 (IL-32) is a newly described cytokine produced after stimulation by IL-2 or IL-18 and IFN-Ξ³. IL-32 has the typical properties of a pro-inflammatory mediator and although its role in rheumatoid arthritis has been recently reported its effect on the osteoclastogenesis process remains unclear. Methodology/principal findings: In the present study, we have shown that IL-32 was a potent modulator of osteoclastogenesis in vitro, whereby it promoted the differentiation of osteoclast precursors into TRAcP+ VNR+ multinucleated cells expressing specific osteoclast markers (up-regulation of NFATc1, OSCAR, Cathepsin K), but it was incapable of inducing the maturation of these multinucleated cells into bone-resorbing cells. The lack of bone resorption in IL-32-treated cultures could in part be explain by the lack of F-actin ring formation by the multinucleated cells generated. Moreover, when IL-32 was added to PBMC cultures maintained with soluble RANKL, although the number of newly generated osteoclast was increased, a significant decrease of the percentage of lacunar resorption was evident suggesting a possible inhibitory effect of this cytokine on osteoclast activation. To determine the mechanism by which IL-32 induces such response, we sought to determine the intracellular pathways activated and the release of soluble mediators in response to IL-32. Our results indicated that compared to RANKL, IL-32 induced a massive activation of ERK1/2 and Akt. Moreover, IL-32 was also capable of stimulating the release of IL-4 and IFN-Ξ³, two known inhibitors of osteoclast formation and activation. Conclusions/significance: This is the first in vitro report on the complex role of IL-32 on osteoclast precursors. Further clarification on the exact role of IL-32 in vivo is required prior to the development of any potential therapeutic approach
Predictions for the future of kallikrein-related peptidases in molecular diagnostics
Kallikrein-related peptidases (KLKs) form a cancer-related ensemble of serine proteases. This multigene family hosts the most widely used cancer biomarker that is PSA-KLK3, with millions of tests performed annually worldwide. The present report provides an overview of the biomarker potential of the extended KLK family (KLK1-KLK15) in various disease settings and envisages approaches that could lead to additional KLK-driven applications in future molecular diagnostics. Particular focus is given on the inclusion of KLKs into multifaceted cancer biomarker panels that provide enhanced diagnostic, prognostic and/or predictive accuracy in several human malignancies. Such panels have been described so far for prostate, ovarian, lung and colorectal cancers. The role of KLKs as biomarkers in non-malignant disease settings, such as Alzheimerβs disease and multiple sclerosis, is also commented upon. Predictions are given on the challenges and future directions regarding clinically oriented KLK research
HIV-1 Tat Co-Operates with IFN-Ξ³ and TNF-Ξ± to Increase CXCL10 in Human Astrocytes
HIV-associated neurological disorders (HAND) are estimated to affect 60% of the HIV infected population. HIV-encephalitis (HIVE), the pathological correlate of the most severe form of HAND is often characterized by glial activation, cytokine/chemokine dysregulation, and neuronal damage and loss. However, the severity of HIVE correlates better with glial activation rather than viral load. One of the characteristic features of HIVE is the increased amount of the neurotoxic chemokine, CXCL10. This chemokine can be released from astroglia activated with the pro-inflammatory cytokines IFN-Ξ³ and TNF-Ξ±, in conjunction with HIV-1 Tat, all of which are elevated in HIVE. In an effort to understand the pathogenesis of HAND, this study was aimed at exploring the regulation of CXCL10 by cellular and viral factors during astrocyte activation. Specifically, the data herein demonstrate that the combined actions of HIV-1 Tat and the pro-inflammatory cytokines, IFN-Ξ³ and TNF-Ξ±, result in the induction of CXCL10 at both the RNA and protein level. Furthermore, CXCL10 induction was found to be regulated transcriptionally by the activation of the p38, Jnk, and Akt signaling pathways and their downstream transcription factors, NF-ΞΊB and STAT-1Ξ±. Since CXCL10 levels are linked to disease severity, understanding its regulation could aid in the development of therapeutic intervention strategies for HAND
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