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Prolific sheep have proven to be a valuable model to identify genes and mutations implicated in female fertility. In the Lacaune sheep breed, large variation in litter size is genetically determined by the segregation of a fecundity major gene influencing ovulation rate, named FecL and its prolific allele FecLL. Our previous work localized FecL on sheep chromosome 11 within a locus of 1.1 Mb encompassing 20 genes. With the aim to identify the FecL gene, we developed a high throughput sequencing strategy of long-range PCR fragments spanning the locus of FecLL carrier and non-carrier ewes. Resulting informative markers defined a new 194.6 kb minimal interval. The reduced FecL locus contained only two genes, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) and beta-1,4-N-acetyl-galactosaminyl transferase 2 (B4GALNT2), and we identified two SNP in complete linkage disequilibrium with FecLL. B4GALNT2 appeared as the best positional and expressional candidate for FecL, since it showed an ectopic expression in the ovarian follicles of FecLL/FecLL ewes at mRNA and protein levels. In FecLL carrier ewes only, B4GALNT2 transferase activity was localized in granulosa cells and specifically glycosylated proteins were detected in granulosa cell extracts and follicular fluids. The identification of these glycoproteins by mass spectrometry revealed at least 10 proteins, including inhibin alpha and betaA subunits, as potential targets of B4GALNT2 activity. Specific ovarian protein glycosylation by B4GALNT2 is proposed as a new mechanism of ovulation rate regulation in sheep, and could contribute to open new fields of investigation to understand female infertility pathogenesis.  相似文献   

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Expression of Human Growth Hormone by the Eukaryotic Alga, Chlorella   总被引:5,自引:0,他引:5  
A method to use Chlorella to express a recombinant heterologous protein that can be recovered from the extracellular medium has been developed. Plasmids are constructed with an extracellular secretion signal sequence inserted between a promoter region and a gene for human growth hormone (hGH). The plasmids also contain a Kanr region which confers resistance to the antibiotic G418. Protoplasts are prepared by enzymatic treatment, and the plasmid is introduced by incubation of the protoplasts with polyethylene glycol and dimethyl sulfoxide. Cells are then grown in the presence of G418, and the medium is collected from 6 days after transfection. hGH is measured by immunoassay, and values for expressed hGH of about 200–600 ng/ml are obtained. Received: 5 November 1998 / Accepted: 25 January 1999  相似文献   

5.
The snapdragon (Antirrhinum majus) centroradialis mutant (cen) is characterized by the development of a terminal flower, thereby replacing the normally open inflorescence by a closed inflorescence. In contrast to its Arabidopsis counterpart, terminal flower1, the cen-null mutant displays an almost constant number of lateral flowers below the terminal flower. Some partial revertants of an X-radiation-induced cen mutant showed a delayed formation of the terminal flower, resulting in a variable number of lateral flowers. The number of lateral flowers formed was shown to be environmentally controlled, with the fewer flowers formed under the stronger flower-inducing conditions. Plants displaying this "Delayed terminal flower" phenotype were found to be heterozygous for a mutant allele carrying a transposon in the coding region and an allele from which the transposon excised, leaving behind a 3-bp duplication as footprint. As a consequence, an iso-leucine is inserted between Asp148 and Gly149 in the CENTRORADIALIS protein. It is proposed that this mutation results in a low level of functional CEN activity, generating a phenotype that is more similar to the Arabidopsis Terminal flower phenotype.  相似文献   

6.
Insulin controls growth hormone (GH) production at multiple levels, including via a direct effect on pituitary somatotrophs. There are no data, however, on the regulation of the intact human (h) GH gene (hGH1) by insulin in non-tumor pituitary cells, but the proximal promoter region (nucleotides −496/+1) responds negatively to insulin in transfected pituitary tumor cells. A DNA-protein interaction was also induced by insulin at nucleotides −308/−235. Here, we confirmed the presence of a hypoxia-inducible factor 1 (HIF-1) binding site within these sequences (−264/−259) and investigated whether HIF-1 is associated with insulin regulation of “endogenous” hGH1. In the absence of primary human pituitary cells, transgenic mice expressing the intact hGH locus in a somatotroph-specific manner were generated. A significant and dose-dependent decrease in hGH and mouse GH RNA levels was detected in primary pituitary cell cultures from these mice with insulin treatment. Increasing HIF-1α availability with a hypoxia mimetic significantly decreased hGH RNA levels and was accompanied by recruitment of HIF-1α to the hGH1 promoter in situ as seen with insulin. Both inhibition of HIF-1 DNA binding by echinomycin and RNA interference of HIF-1α synthesis blunted the negative effect of insulin on hGH1 but not mGH. The insulin response is also sensitive to histone deacetylase inhibition/trichostatin A and associated with a decrease in H3/H4 hyperacetylation in the proximal hGH1 promoter region. These data are consistent with HIF-1-dependent down-regulation of hGH1 by insulin via chromatin remodeling specifically in the proximal promoter region.  相似文献   

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Cat eye syndrome (CES) is a developmental disorder with multiple organ involvement, associated with the duplication of a 2-Mb region of 22q11.2. Using exon trapping and genomic sequence analysis, we have isolated and characterized a gene, CECR1, that maps to this critical region. The protein encoded by CECR1 is similar to previously identified novel growth factors: IDGF from Sarcophaga peregrina (flesh fly) and MDGF from Aplysia californica (sea hare). The CECR1 gene is alternatively spliced and expressed in numerous tissues, with most abundant expression in human adult heart, lung, lymphoblasts, and placenta as well as fetal lung, liver, and kidney. In situ hybridization of a human embryo shows specific expression in the outflow tract and atrium of the developing heart, the VII/VIII cranial nerve ganglion, and the notochord. The location of this gene in the CES critical region and its embryonic expression suggest that the overexpression of CECR1 may be responsible for at least some features of CES, particularly the heart defects.  相似文献   

9.
Abstract

A gene coding for hGHRH was constructed from chemically synthesized oligonucleotides in two fragments; After subcloning and joining the total gene was expressed in E. coli as a fusion protein with β-galactosidase. Chemical cleavage thereof with cyanogen bromide, purification of Leu27 GHRH-Gly45 by chromatography followed by enzymatic conversion yielded Leu27 GHRHNH2.  相似文献   

10.
International Journal of Peptide Research and Therapeutics - The 22 kDa of human growth hormone (hGH) is naturally produced and secreted by somatotrophic cells in the anterior part of the...  相似文献   

11.
Autosomal-dominant striatal degeneration (ADSD) is an autosomal-dominant movement disorder affecting the striatal part of the basal ganglia. ADSD is characterized by bradykinesia, dysarthria, and muscle rigidity. These symptoms resemble idiopathic Parkinson disease, but tremor is not present. Using genetic linkage analysis, we have mapped the causative genetic defect to a 3.25 megabase candidate region on chromosome 5q13.3-q14.1. A maximum LOD score of 4.1 (Θ = 0) was obtained at marker D5S1962. Here we show that ADSD is caused by a complex frameshift mutation (c.94G>C+c.95delT) in the phosphodiesterase 8B (PDE8B) gene, which results in a loss of enzymatic phosphodiesterase activity. We found that PDE8B is highly expressed in the brain, especially in the putamen, which is affected by ADSD. PDE8B degrades cyclic AMP, a second messenger implied in dopamine signaling. Dopamine is one of the main neurotransmitters involved in movement control and is deficient in Parkinson disease. We believe that the functional analysis of PDE8B will help to further elucidate the pathomechanism of ADSD as well as contribute to a better understanding of movement disorders.  相似文献   

12.
应用RT-PCR方法从人淋巴细胞中扩增出亲环素B(cyclophilinB,CyPB)基因,克隆入pET-28a载体中表达.表达产物以包涵体形式存在,占细菌可溶性蛋白的15%.经Ni-NTA树脂金属螯合亲和层析和SephadexG-50柱层析纯化,SDS-PAGE检测呈单一条带,毛细管电泳为单一色谱峰,纯度达95%.经复性处理,表达产物显示肽基脯氨基顺反异构酶活性  相似文献   

13.
卵泡刺激素(FSH)对有腔卵泡和排卵前卵泡的促生长作用已被普遍接受,但关于其对腔前卵泡发育的作用报道结果不尽相同。关于表皮生长因子(EGF)对腔前卵泡的作用尚不确切。本研究目的在于探讨人重组卵泡刺激素(rechFSH)和EGF对早期卵泡发育的作用。利用胶原酶消化法从12日龄的小鼠卵巢中分离得到卵母细胞-颗粒细胞复合体(OGCs)(Fig.1)。体外每孔30~40个培养物并分别添加胎牛血清(FBS)、rechFSH和EGF。培养物每4天测量卵母细胞和OGCs直径,并每天照相。结果显示rechFSH显著促进小鼠OGCs及其卵母细胞的体外发育,这一作用可被EGF进一步增强(p<0.05)(Fig.2)。但到第八天培养结束时,培养后的OGCs卵母细胞要显著小于体内同期生长对照组(p<0.05)(Fig.3)。说明FSH和EGF在卵泡早期发育中起重要作用。  相似文献   

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The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface.Numerous studies have illustrated the relevant role of dissolved organic matter (DOM) present in soil solution and aquatic reservoirs (lakes, rivers, etc.) in the biological and chemical evolution of both natural and anthropogenic ecosystems (Stevenson, 1994; Tipping, 2002; Chen et al., 2004; Trevisan et al., 2011; Berbara and García, 2014; Canellas and Olivares, 2014; Mora et al., 2014a, 2014b). In many studies, DOM fractionation is made by using the methodology proposed by the International Humic Substances Society. Fractions obtained are operationally named humic acid (HA), fulvic acid, humin, and nonhumic fraction, which includes more hydrophilic compounds (polycarboxylic acids, aminoacids, sugars, etc.; Swift, 1996). Many studies have reported that HAs obtained from either organic materials (soils, soil sediments, composted wastes, etc.) or water reservoirs (rivers, lakes, etc.), extracted with alkaline water solutions, or isolated by resin fixation, reverse osmosis, or ultrafiltration (Alberts and Takács, 2004) affected the development of diverse plant species (for instance, cucumber [Cucumis sativus], tomato [Solanum lycopersicum], maize [Zea mays], wheat [Triticum aestivum], Arabidopsis [Arabidopsis thaliana], and rapeseed [Brassica Napus]) through common signaling pathways, which involved key phytoregulators, such as indole acetic acid (IAA)-nitric oxide (NO; Zandonadi et al., 2010; Canellas et al., 2011; Trevisan et al., 2011; Mora et al., 2012, 2014a), ethylene, and abscisic acid (ABA) in roots (Mora et al., 2012, 2014a) as well as cytokinins in shoots (Mora et al., 2010, 2014b). Recently, Mora et al., 2014a showed that the HA ability to enhance both shoot growth and ABA root concentration in cucumber was regulated by IAA and NO root signaling pathways. However, despite all of this information, the nature of a possible primary, common action on plant roots of HAs with diverse origin and structure remains elusive.Recently, Asli and Neumann (2010) described a new mechanism by which high concentrations of HAs extracted from diverse organic sources decreased shoot plant growth. This mechanism involved the reduction of root hydraulic conductivity (Lpr) resulting from the fouling of root cell wall pores because of the accumulation and aggregation of HA molecules at root surface. Although the concentration of HAs used by Asli and Neumann (2010) (1 g L−1) is much higher than that related to HA plant growth promotion ability (50–250 mg L−1; Rose et al., 2014), the results do raise the hypothesis that the primary, still unknown event emerging from the interaction of humic substances with root surface cells might involve an unspecific, physical action on root permeability and water uptake. This event might trigger a chain of secondary events in the root that, in turn, would affect specific hormone signaling pathways, which may regulate shoot and root growth. This HA action on plant development would be positive (increasing) or negative (decreasing) depending on HAs concentration in the rhizosphere.To explore the suitability of this hypothesis, we have tested the potential role of Lpr in the main mechanism by which HAs promote shoot growth in cucumber. To this end, we used a well-characterized and modeled sedimentary humic acid (SHA) at a concentration (100 mg of SHA organic carbon [C] L−1) that was associated with plant shoot growth promotion in previous studies (Mora, 2009; Mora et al., 2014a, 2014b). We also investigated the functional relationships between these effects of SHA on Lpr and shoot growth as well as in some shoot water-related parameters (leaf stomatal conductance [Gs] and ABA) and those caused by SHA on IAA-NO and ABA root signaling pathways. Finally, taking into account that root plasma membrane aquaporins (plasma membrane intrinsic proteins [PIPs]) are involved in the ABA regulation of Lpr in other plant systems, we also studied the role of PIPs in SHA effects on plant shoot growth.The results obtained here show that SHA enhances shoot growth in cucumber through ABA-dependent increases in both Lpr and root PIPs (CsPIPs) gene up-regulation.  相似文献   

16.
In this study, we investigated the effects of p63 modulation in epithelial plasticity in human keratinocytes. The p63 isoforms ΔNp63α, ΔNp63β, and ΔNp63γ were ectopically expressed in normal human epidermal keratinocytes (NHEKs). The epithelial or mesenchymal state was determined by morphological changes and altered expression of various markers, e.g. fibronectin, E-Cadherin, and keratin 14. Overexpression of ΔNp63α and ΔNp63β but not ΔNp63γ isoforms led to morphological changes consistent with epithelial-mesenchymal transition (EMT). However, only ΔNp63α overexpression was able to maintain the morphological changes and molecular phenotype consistent with EMT. Interestingly, knockdown of all p63 isoforms by transfection of p63 siRNA also led to the EMT phenotype, further confirming the role of p63 in regulating the epithelial phenotype in NHEKs. EMT in NHKs accompanied loss of Grainyhead-Like 2 (GHRL2) and miR-200 family gene expression, both of which play crucial roles in determining the epithelial phenotype. Modulation of GRHL2 in NHKs also led to congruent changes in p63 expression. ChIP revealed direct GRHL2 binding to the p63 promoter. GRHL2 knockdown in NHK led to impaired binding of GRHL2 and changes in the histone marks consistent with p63 gene silencing. These data indicate the presence of a reciprocal feedback regulation between p63 and GRHL2 in NHEKs to regulate epithelial plasticity.  相似文献   

17.
Late term fetuses from genetically obese dams have slightly larger fat cells, greater adipose tissue lipoprotein lipase (LPL) activities, elevated levels of thyroid hormones, and depressed growth hormone (GH) levels when compared to fetuses from lean dams. We have investigated the influence of thyroid hormone and GH status per se on these and other adipose tissue traits by chronically treating hypophysectomized (hypox) fetuses (day 70) between day 90 and 105 of gestation with either thyroxine (T4) or human GH. Treatment with T4 decreased body weights (P<.05), increased serum T4 levels (P<.05), and enhanced skin and hair development (P<.05). Quantitative analysis of sections of perirenal and subcutaneous adipose tissue indicated that T4 increased LPL activity (P<.05), slightly increased fat cell size, and more than doubled (P<.05) lipid accretion. A hypox induced deficit in fat cell cluster number in the outer layer of subcutaneous tissue was normalized by T4 (P<.05). Conversely, human GH (hGH) treatment had no influence on body weight, increased serum hGH levels, decreased fat cell size (P<.05) and LPL activity (P<.05) but had no influence on lipid accretion. Quantitative analysis of adipose tissue sections provided direct and indirect evidence of a “critical” or “sensitive” period between 90 and 105 days, since fetal hypox at day 70 severely impeded preadipocyte recruitmentheplication during this period. Furthermore, T4 but not GH effectively normalized this hypox-induced deficiency in preadipocyte development. Therefore, T4 may have a major role in preadipocyte recruitmentheplication during late fetal life.  相似文献   

18.
Replicated artificial selection for high levels of voluntary wheel running in an outbred strain of mice favored an autosomal recessive allele whose primary phenotypic effect is a 50% reduction in hind-limb muscle mass. Within the High Runner (HR) lines of mice, the numerous pleiotropic effects (e.g., larger hearts, reduced total body mass and fat mass, longer hind-limb bones) of this hypothesized adaptive allele include functional characteristics that facilitate high levels of voluntary wheel running (e.g., doubling of mass-specific muscle aerobic capacity, increased fatigue resistance of isolated muscles, longer hind-limb bones). Previously, we created a backcross population suitable for mapping the responsible locus. We phenotypically characterized the population and mapped the Minimsc locus to a 2.6-Mb interval on MMU11, a region containing ∼100 known or predicted genes. Here, we present a novel strategy to identify the genetic variant causing the mini-muscle phenotype. Using high-density genotyping and whole-genome sequencing of key backcross individuals and HR mice with and without the mini-muscle mutation, from both recent and historical generations of the HR lines, we show that a SNP representing a C-to-T transition located in a 709-bp intron between exons 11 and 12 of the Myosin heavy polypeptide 4 (Myh4) skeletal muscle gene (position 67,244,850 on MMU11; assembly, December 2011, GRCm38/mm10; ENSMUSG00000057003) is responsible for the mini-muscle phenotype, Myh4Minimsc. Using next-generation sequencing, our approach can be extended to identify causative mutations arising in mouse inbred lines and thus offers a great avenue to overcome one of the most challenging steps in quantitative genetics.  相似文献   

19.

Background

Recombinant human growth hormone (rhGH) reduces visceral adipose tissue (VAT) volume in HIV-infected patients but can worsen glucose homeostasis and lipoatrophy. We aimed to determine if adding rosiglitazone to rhGH would abrogate the adverse effects of rhGH on insulin sensitivity (SI) and subcutaneous adipose tissue (SAT) volume.

Methodology/Principal Findings

Randomized, double-blind, placebo-controlled, multicenter trial using a 2×2 factorial design in which HIV-infected subjects with abdominal obesity and insulin resistance were randomized to rhGH 3 mg daily, rosiglitazone 4 mg twice daily, combination rhGH + rosiglitazone, or double placebo (control) for 12 weeks. The primary endpoint was change in SI by frequently sampled intravenous glucose tolerance test from entry to week 12. Body composition was assessed by whole body magnetic resonance imaging (MRI) and dual Xray absorptiometry (DEXA).Seventy-seven subjects were randomized of whom 72 initiated study drugs. Change in SI from entry to week 12 differed across the 4 arms by 1-way ANCOVA (P = 0.02); by pair-wise comparisons, only rhGH (decreasing SI; P = 0.03) differed significantly from control. Changes from entry to week 12 in fasting glucose and glucose area under the curve on 2-hour oral glucose tolerance test differed across arms (1-way ANCOVA P = 0.004), increasing in the rhGH arm relative to control. VAT decreased significantly in the rhGH arms (−17.5% in rhGH/rosiglitazone and −22.7% in rhGH) but not in the rosiglitazone alone (−2.5%) or control arms (−1.9%). SAT did not change significantly in any arm. DEXA results were consistent with the MRI data. There was no significant rhGH x rosiglitazone interaction for any body composition parameter.

Conclusions/Significance

The addition of rosiglitazone abrogated the adverse effects of rhGH on insulin sensitivity and glucose tolerance while not significantly modifying the lowering effect of rhGH on VAT.

Trial Registration

Clinicaltrials.gov NCT00130286  相似文献   

20.
OSM是一种对黑色素瘤细胞显示抑制作用的细胞因子.为进行OSM针对黑色素瘤的基因-放射治疗研究,构建了小鼠Egr-1基因调控序列引导入OSMcDNA真核表达质粒(pEO),pEO质粒转染小鼠B-16黑色素瘤细胞,经G418和抗人OSM抗体的筛选,获得了稳定表达OSM的克隆细胞(pEO-1细胞),OSM表达量可达5.97ng每105细胞天,分子量为32kD.pEO-1细胞用一定浓度H2O2处理后OSM表达量可提高62%,表明pEO重组质粒可在氧自由基的刺激作用下增强OSM表达  相似文献   

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