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Soil microorganisms play a crucial role in cycling soil nutrients and providing organic nutrients for plant growth and development. Fertilisation balances soil fertility and quality, and affects soil microbial communities. Fertilisation is a frontier subject in agricultural and environmental sciences. Here we showed that the application of high-carbon basal fertiliser treatment could improve the tobacco yield and quality when compared to chemical fertiliser, high-carbon basal fertiliser and mixed high-carbon chemical fertiliser. The potential reason is that different fertiliser treatments influence soil fertility, such as nitrogen, phosphorus, and other contents, besides soil organic matter. Further experiments revealed that populations of bacteria, fungi and actinomycetes fluctuated during tobacco development under different fertilisation treatments. Then we performed high-throughput sequencing of the 16S rRNA gene, and the results showed that the fertilisation treatments had significant effects on the microbial community, particularly within the finer taxonomic divisions or non-dominant taxa. Moreover, proteobacteria and fungal genera had significantly different relative abundances during tobacco growth under various tobacco developmental stages and fertilisation treatments. These results indicated that mixed high-carbon chemical fertiliser could improve soil fertility by influencing the soil microorganism, and that the fertilisation treatments impacted on the structure and composition of the microbial community, and especially the diversity of non-dominant taxa. However, more studies are needed to confirm their reliability.

The T cell receptor (TCR) is a complex heterodimer that recognizes fragments of antigens as peptides and binds to major histocompatibility complex molecules. The TCR α and β chains possess three hypervariable regions termed complementarity determining regions (CDR1, 2 and 3). CDR3 is responsible for recognizing processed antigen peptides. Immunoscope spectratyping is a simple technique for analyzing CDR3 polymorphisms and sequence length diversity, in order to investigate T cell function and the pattern of TCR utilization. The present study employed this technique to analyze CDR3 polymorphisms and the sequence length diversity of TCR α and β chains in porcine CD4+ and CD8+ T cells. Polymerase chain reaction products of 19 TCR α variable regions (AV) and 20 TCR β variable regions (BV) gene families obtained from the CD4+ and CD8+ T cells revealed a clear band following separation by 1.5% agarose gel electrophoresis, and each family exhibited >8 bands following separation by 6% sequencing gel electrophoresis. CDR3 spectratyping of all identified TCR AV and BV gene families in the sorted CD4+ and CD8+ T cells by GeneScan, demonstrated a standard Gaussian distribution with >8 peaks. CDR3 in CD4+ and CD8+ T cells demonstrated different expression patterns. The majority of CDR3 recombined in frame and the results revealed that there were 10 and 14 amino acid discrepancies between the longest and shortest CDR3 lengths in specific TCR AV and TCR BV gene families, respectively. The results demonstrated that CDR3 polymorphism and length diversity demonstrated different expression and utilization patterns in CD4+ and CD8+ T cells. These results may facilitate future research investigating the porcine TCR CDR3 gene repertoire as well as the functional complexity and specificity of the TCR molecule.

The differentiation characteristics of landscape pattern affect the urban thermal environment. In this study, temperature characteristics of nine types of landscape in a national forest city, Longquan City, were analyzed by temperature inversion method and spatial analysis. The landscape pattern analysis method was used to explore the correlation of landscape metrics and the thermal environment from 1 km to 3.5 km. The results showed that the high and sub-high temperature zones of Longquan City were distributed in northeast-southwest, mainly composed of urban and rural residential areas. The low and sub-low temperature zone were mainly distributed in the northwest and southeast areas, mainly composed of public welfare forests. By calculating the mean land surface temperature of each landscape type in the area below 700 m above sea level, the temperature of coniferous forest, broadleaf forest, conifer-broadleaf forest, bamboo forest and water was relatively low, whereas that of shrub land, other forest land, cultivated land and construction land was relatively high. Through the analysis of landscape pattern and thermal environment, it was found that the class pattern index was more practical than the landscape pattern index. The correlation between thermal environment effect and construction land distribution reached 0.835, coniferous forest land, broadleaf forest land, coniferous-broadleaf forest land and water were the second, up to -0.5 to -0.4. The cooling effects of different forest types vaied across different spatial scales. Broadleaved forests and coniferous-broadleaved forests were more conducive to cooling at large scales. The larger the area and volume stock of forest land, the more likely it had the lowest land surface temperature.景观格局分异特征在相当程度上影响着城市热环境.本研究以国家森林城市龙泉市为对象,通过地温反演和空间分析反映9类景观温度特征,运用景观格局分析方法从1～3.5 km 6个尺度探索格局指数与热环境的相关性.结果表明: 龙泉市高温区及次高温区主要分布于东北至西南一带,以城乡居民地为主,低温区和次低温区主要分布于西北、东南区域,以公益林为主;对海拔700 m以下区域各景观类型地表温度的统计发现,针叶林地、阔叶林地、针阔混交林地、竹林地、水域的地温均值相对较低,灌木林地、其他林地、耕地、建设用地的地温均值相对较高;对景观格局与热环境的分析发现,类型水平格局指数较景观水平格局指数更具实际意义,建设用地与热环境的相关系数可达0.835,针叶林地、阔叶林地、针阔混交林地、水域次之,在-0.5～-0.4,不同林地类型的降温效果在空间尺度上的表达不同,阔叶林地、针阔混交林地更利于在大尺度上降温;林地的面积和蓄积量越大,越易出现地表温度低值.

The current research of kinetostatic characteristics in flexure mechanisms mainly focus on the improvement of accuracy. To reduce or eliminate the parasitic motion is considered as an approach by using the common knowledge of symmetry. However, there is no study on designing the flexure mechanisms with symmetrical features as many as possible for better kinetostatic performance, when considering the resulting cost by the symmetry. In this paper, the concept of degree of symmetry (DoS) is proposed for the first time, which is committed to symmetry design in the phase of conceptual design. A class of flexure mechanisms with 0-DoS, 1-DoS, 2-DoS and 3-DoS are synthesized respectively based on the Freedom and Constraint Topology method. Their overall compliance matrices in an analytical form formulated within the framework of the screw theory are used to analyze and compare the effect of different number of DoS on the kinetostatic characteristics for flexure mechanisms. The finite element analysis (FEA) simulations are implemented to verify the analytical results. These results show that the higher the DoS is, the smaller the parasitic motion error will be. The flexure model with 3-DoS is optimized according to the overall compliance matrix and then tested by using the FEA simulation. The testing result shows that with the best combination parameters, the parasitic motion error for 3-DoS mechanism is almost eliminated. This research introduces a design principle which can alleviate the unwanted parasitic motion for better accuracy.

The workability, strength and permeability of self-consolidating concrete (SCC), reinforced with polypropylene monofilament fibre, collated fibrillated polypropylene network fibre and a hybrid of these two, are investigated. Combined impacts of polypropylene fibres on SCC are then analysed using the theory of Bingham plastic flow, the principle of fracture mechanics and the composition of microstructure based on scanning electron microscopy. Results show that: (a) in the case of identical fibre volume fraction, the workability of fresh SCC reinforced with polypropylene monofilament fibre is better than that with fibrillated polypropylene network fibre; (b) when the fibre volume fraction is less than 0·10%, strength properties and water impermeability of hardened SCC increase with the fibre addition, and the charge passed increases slightly, but when the fibre volume fraction is higher than 0·15%, the charge increases dramatically; (c) SCC with polypropylene monofilament fibre has better impermeability, but lower static strength than that with fibrillated polypropylene network fibre; (d) compared with ordinary SCC, SCC with the hybrid of 0·05% volume fraction of polypropylene monofilament fibre and 0·05% collated fibrillated polypropylene network fibre has a 22% increase in flexural tensile strength, a 21% increase in splitting strength and a 56% decrease in water penetration depth, and the Coulomb value of chloride ion penetrability is low, about 1013 C at 56 d.

Phosphorus is the key restraining factor for algal growth and water eutrophication, which is a global problem of environmental pollution. Using a sequential phosphorus extraction method, the phosphorus forms in sediment and their distribution from different trophic area of Taihu Lake (China) and their temporal changes were studied. Results showed that, concentration of Fe-P in sediment was the highest and successively Al-P, which was much higher than that of Ca2-P, Ca10-P, Ca8-P and O-P. All the phosphorus forms were more abundant in sediment 16# of eutrophic lake area, higher than that of moderate eutrophic and the lower-grade trophic area, with the last as relatively the lowest. Phosphorus concentration in June and September was much higher than that of March. Phosphorus in sediment of Taihu Lake had great releasing potential to the overlying water.

A polyphasic study was carried out to clarify the taxonomic position of a novel strain R-30(T) isolated from the surficial layer of sediment from Taihu Lake of China. The strain formed pink colored colonies comprising coccodial cells on R2A agar. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain R-30(T) clustered with the strains of genus Roseococcus and strain Rubritepida flocculans, with Roseococcus suduntuyensis SHET(T) as the closest relative, sharing 95.6% similarity. The major fatty acids (＞5%) were 18：1ω7c (66.7%), 16： 1ω7c/16：1ω6c (10.2%) and 16：0 (8.0%). The major polar lipids were diphosphatidyl glycerol (DPG), phosphatidyl methylethanolamine (PME), phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC). The genomic DNA G+C content was 73.9 mol%. On the basis of the phylogenetic analysis and physiological and biochemical characteristics, we conclude that strain R-30(T) represents a novel genus and species of the family Acetobacteraceae, for which we propose the name Sediminicoccus rosea gen nov. sp. nov. with R-30(T) (= CGMCC 1.12302(T) = NBRC 109675(T)) as the type species and type strain.

The mechanical property of polymer modified porous concrete (PMPC) largely depends on the mechanical property of bonding material. The experimental workloads can be decreased and the PMPC mix can be optimized through studying the effect of the performance and thickness of bonding material on PMPC by finite element method. The inner pore of PMPC was taken into account in the micromechanical model according to the configuration feature of PMPC (elastic binding material + aggregate + void). Meanwhile because of the slim thickness of bonding material, the microscopic meshes were used in the model and the adopted mechanical property values of material were based on experimental representative values. It shows that (1) the calculation result coincides with the experimental result, which indicates that the micromechanical model of PMPC is exactitude; (2) the bonding material with large thickness is beneficial property of PMPC.

Aiming at the frequent occurrence of cement concrete pavement failure, the authors have for the first time raised queries about the three idealized prerequisites for the related traditional theoretical model of cement concrete pavement and carried out research. Mechanism analysis exposes: interaction between the pavement slab and base course will lead to three basic inter-layer failure types whose development and evolution subvert the three prerequisites and cause sharp inconsistency between the actual situation and the theoretical model, thus causing considerable pavement deterioration. Lab tests show that the actual carrying capacity of pavement is less than half of the theoretical one after the three basic failure types emerge, while field investigation indicates that the actual inter- layer failure is more serious. To eliminate the said inconsistency, the authors have put forward a solution, namely, a waterproof separation membrane placed between the slab and base, which will prevent the occu...

From the perspective of Fracture Mechanics, concrete/rebar bonding failure process in reinforced concrete (RC) structures means the decreasing of the crack closure force imposed by rebar in RC beams, which will result in crack propagation, and eventually structural damage. In this paper the crack-arresting mechanism of the concrete/rebar bonding stress in RC beams was analyzed, which was employed to reveal the degradation mechanism of RC beams induced by concrete/rebar bonding failure; and bending tests of RC beams were presented where effects of concrete/rebar bonding failure on bending performance of RC beams had been investigated. The concrete/rebar bonding failure was obtained by wrapping the rebar with different length of plastic film during casting. The results shows effective concrete/rebar bonding is the key to provide crack closure force, which can prevent functional degradation of RC beams.

An elastic-plastic analysis of the mode III crack surface vicinity was performed in an infinitely wide elastic-perfectly plastic plate, in which a pair of anti-plane forces applied at an arbitrary point on the crack surface. The crack line analysis method was used without the traditional small-scale yield condition. The plastic zone length, the plastic zone shape, and the elastic-plastic stress field in the vicinity of the crack surface were obtained analytically. Moreover, the plastic zone lengths in the vicinity of the crack surface and crack line were compared, and it was found that under a pair of anti-plane forces applied at an arbitrary point on the crack surface, the plastic zone length in the vicinity of the crack surface reached its maximum faster than that in the vicinity of the crack line under the same conditions, which indicates the stress state near the crack surface region is more detrimental than that near the crack line region. The variation of plastic zone length with the load position was also studied, and it was shown that when the point forces were closer to the crack tip, the plastic zone length was smaller and the stress state of the crack was more disadvantageous.

The elastic-plastic stress distribution and the elastic-plastic boundary configuration near a crack surface region are significant but hard to obtain by means of the conventional analysis. A crack line analysis method is developed in this paper by considering the crack surface as an extension of the crack line. The stresses in the plastic zone, the length, and the unit normal vector of the elastic-plastic boundary near a crack surface region are obtained for an antiplane crack in an elastic-perfectly plastic solid. The usual small scale yielding assumptions are not needed in the analysis.

Enterprise Digitalization depends to a large extent on models of enterprise process built for design and analysis. From the perspectives of product life cycle and enterprise informationization lifecycle, the paper outlined a modeling scheme with IDEF suite which guided multi-view modeling of Enterprise Digitalization and its process, and provided a total solution for Enterprise Digitalization, which would facilitate internal informationization systems of enterprise integrated with networked systems outside the enterprise to support business operations, and make enterprise manufacturing sectors integrated with external networked manufacturing systems and production equipments seamlessly.

China’s manufacturing industry has obvious regional characteristics. With the regional economic development, how to improve the overall competitiveness of the regional manufacturing industry has become an important research subject for regional development. This paper analyzed the possibility of constructing Regional Manufacturing System (RMS) from the aspect of regional industrial association degree, puts forward the theoretical architecture of RMS which provides a reference model for the optimizing operation of the Manufacturing System and the business cooperation among the manufacturing enterprises in the region.

Background & aims: Loss of genomic imprinting (LOI) of insulin-like growth factor II gene ( IGF2 ) involves abnormal activation of the normally silent maternally inherited allele. LOI of IGF2 has been associated with personal and family history of colorectal neoplasia (CRN), supporting a role for LOI in colorectal carcinogenesis. Whether LOI of IGF2 is associated with known environmental risk factors for CRN is unknown. Methods: We performed quantitative hot-stop PCR for imprinting analysis of IGF2 on normal peripheral blood lymphocytes (PBL) of individuals. Environmental exposures including tobacco, alcohol, NSAIDs, and nutrient consumption (calcium, folate, selenium, fiber, and fat) were correlated with LOI expression in PBL. Odds ratios (OR) and 95% CI were calculated. Results: The prevalence of LOI of IGF2 was examined in 172 individuals. Persons with CRN (adenomas/cancer) had 5.1-fold (95% CI: 1.92–13.6) increased risk of having LOI of IGF2 in PBL compared with those without CRN. In contrast, tobacco smoking (OR = 0.96, 95% CI: 0.36–2.55), alcohol consumption (OR = 1.22, 95% CI: 0.45–3.3), and NSAIDs use (OR = 1.21, 95% CI: 0.38–3.94) were not significantly associated with LOI of IGF2 . Nutrient ingestion including calcium ( P = 0.61), folate ( P = 0.23), selenium ( P = 0.19), fiber ( P = 0.63), and fat ( P = 0.14) was not statistically correlated with LOI of IGF2 . Conclusions: Abnormal imprinting of IGF2 gene was strongly associated with CRN but not with any of the environmental exposures examined. LOI of IGF2 does not appear to be an environmentally acquired phenomenon but rather a hereditary risk factor for CRN.

GABA triggers mammalian sperm acrosome reaction (AR). Here, evidence is presented, showing that rat spermatozoa contain GABAA receptors, composed of α5, β1 and β3 subunits. The effects of GABAA receptor agonist and antagonist on the induction of AR in rat spermatozoa were assessed using the chlortetracycline assay. Muscimol, a GABAA receptor agonist, triggered AR; whereas bicuculline, a GABAA receptor antagonist and picrotoxin, a GABAA receptor/Cl− channel blocker, inhibited the ability of GABA or progesterone to induce AR. In conclusion, GABAA receptors appear to mediate the action of progesterone in inducing AR in rat spermatozoa.

Poxvirus is one of the most serious zoonosis pathogens, which has largest genome and broadest host spectrum. With the development of molecular biology, functional genomics, and immunology-related technology, the interactions between pathogen and the host, particularly a large array of host range factors and their functions have been increasingly discovered. These findings provide references for the molecular basis of poxvirus tissue tropism and host specificity. This review focus on the introduction of host range factors in major members of Chordopoxvirinae to highlight the understanding of the mechanisms of molecular genetic evolution, the host tropism, and cross-species infection of poxviruses.

Some recent studies indicated that GABAergic system is involved in mammalian sperm acrosome reaction (AR), but direct evidence pertaining to the expression of gat1 in mammalian sperm is not yet demonstrated. In this study, we evaluated the presence of 67kDa GAT1 protein and mRNA in rat testis by Western blotting and reverse transcription-polymerase chain reaction. Meanwhile, immunohistochemical and immunofluorescent analyses also identified GAT1 protein on the elongated spermatid and sperm. These results indicated that rat testis is a novel site of gat1 expression. Further studies should be taken to explore the role of GAT1 protein on sperm acrosome reaction.

Loss of imprinting (LOI), an epigenetic alteration affecting the insulin-like growth factor II gene ( IGF2 ), is found in normal colonic mucosa of about 30% of colorectal cancer (CRC) patients, but it is found in only 10% of healthy individuals. In a pilot study to investigate the utility of LOI as a marker of CRC risk, we evaluated 172 patients at a colonoscopy clinic. The adjusted odds ratio for LOI in lymphocytes was 5.15 for patients with a positive family history [95% confidence interval (95% CI), 1.70 to 16.96; probability P = 0.002], 3.46 for patients with adenomas (95% CI, 1.14 to 11.37; P = 0.026), and 21.7 for patients with CRC (95% CI, 3.48 to 153.6; P = 0.0005). LOI can be assayed with a DNA-based blood test, and it may be a valuable predictive marker of an individual's risk for CRC.

Toll-like receptors (TLRs) are germline-encoded pattern recognition receptors (PRRs) that play a central role in host cell recognition and responses to virus infection, leading to the production of interferons (IFNs) and proinflammatory cytokines. In parallel, in order to establish an infection, viruses have to develop exclusively strategies to interfere with TLRs signaling, particularly some important adaptors activation such as MyD88, NF-kappaB, TRIF and IRFs, and suppress or escape host's antiviral immune response. In this paper, we review the latest findings on the various strategies used by viruses to modulate TLRs-mediated innate immune response, with special emphasis on immune evasion mechanism of VACV, HCV and HIV. By highlighting recent progress in these areas, we hope to convey a greater understanding of how viruses hamper TLRs signaling and how to overcome viral infection.

Mouse sp56 is considered as one of the candidates for mouse zona pellucida 3 (mZP3) receptor. Up to date, its homologue has only been cloned from guinea pig, namely AM67. Based on the cDNA sequence of mouse sp56, we designed a pair of primer to amplify its homologue from rat testis cDNA. Using RT-PCR, two fragments of 743 bp and 938 bp were amplified. The PCR products show very high homology to mouse sp56. However, the 743 bp product completely lacks one of the seven Sushi domains of mouse sp56. Using the 743 bp product as the probe to detect the expression profile of sp56 in rat tissues, Northern blot shows that a approximately 2.0 kb mRNA expresses specifically in testis. Employed the RACE method, two full cDNA sequences of rat sp56 were obtained. A Mr approximately 42 KD band was detected in denatured and non-reducing protein sample of rat testis and sperm with anti-mouse sp56 monoclonal antibody by Western blot method. Rat sp56 was localized on rat sperm head by the indirect immunofluorescence method. Rat sp56 immunoreactivity was detected from the early pachytene spermatocytes and throughout the spermatogenesis. Its cloning will further our understanding of the mechanism of the sperm-egg recognition and binding.

To study the imprinting status and expression level of insulin-like growth factor 2 (IGF2) gene in colorectal cancer and to provide a clue for the mechanism of carcinogenesis of colorectal cancer.The expression levels of IGF2 in the paired colorectal cancer and adjacent normal tissue were examined and compared by use of semi-quantitative reverse transcription-polymerase chain reaction. The imprinting status of IGF2 was detected by restriction fragment length polymorphism. The relationships between the expression level of IGF2, its imprinting status, and the carcinogenesis of colorectal cancer were analyzed.IGF2 was overexpressed in 82.4% (28/34) of colorectal cancer tissues which was significantly higher than those of the matched normal tissues (P0.01, t=3.01). 87.5% (14/16) of colorectal cancer showed loss of imprinting(LOI), while 71.4%(10/14) of normal tissues also displayed LOI of IGF2.Overexpression of IGF2 was found to play an important role in carcinogenesis of colorectal cancer. LOI of IGF2 may be a prophase manifestation of colorectal cancer.

The functional relationship between GABA(A) and GABA(B) receptors in regulating acrosome reaction (AR) of rat spermatozoa was demonstrated by studying the differential effects of a GABA(B) agonist and an antagonist on the process. AR rates were determined using the chlortetracycline staining assay. The induction of AR in rat sperm by GABA was found to be a biphasic phenomenon; i.e., AR rates increased with increasing GABA concentrations up to5 micro M and at higher concentrations of the neurotransmitter (5 micro M), there was a reductionin the AR rates. This biphasic phenomenon is apparently due to the differential interaction of the neurotransmitter with GABA receptor subtypes in a dose-dependent manner; i.e., GABA(A) receptors (stimulatory) are primarily activated at low concentration of GABA, while GABA(B) receptors (inhibitory) become activated at higher concentrations. This hypothesis is supported by the present findings that treatment with saclofen, a GABA(B) receptor antagonist, did not influence the AR rates effected by GABA at low concentrations; while the AR rates were maintained at the maximum level at higher concentrations of GABA, resulting in the elimination of the biphasic phenomenon. Baclofen, a GABA(B) receptor agonist, blocks the AR activating action of GABA at both low and high concentrations. It would appear that the induction of AR in rat sperm by GABA is regulated by the proportionality of activated GABA(A) and GABA(B) receptors acting as a yin-yang control.

GABA triggers mammalian sperm acrosome reaction (AR). Here, evidence is presented, showing that rat spermatozoa contain GABAA receptors, composed of alpha5, beta1 and beta3 subunits. The effects of GABAA receptor agonist and antagonist on the induction of AR in rat spermatozoa were assessed using the chlortetracycline assay. Muscimol, a GABAA receptor agonist, triggered AR; whereas bicuculline, a GABAA receptor antagonist and picrotoxin, a GABAA receptor/Cl- channel blocker, inhibited the ability of GABA or progesterone to induce AR. In conclusion, GABAA receptors appear to mediate the action of progesterone in inducing AR in rat spermatozoa.

gamma-Aminobutyric acid (GABA) can mimic and potentiate the action of progesterone in initiating the acrosome reaction (AR) of mammalian sperm, indicating that sperm contain receptors for GABA. This contention was validated by identifying the receptor (R) subtype, GABA(A)R, in mammalian sperm. In the present study a second subtype, GABA(B)R, was identified in rat testis and sperm. Total RNAs of rat testis and sperm were prepared and used as template to synthesize the respective cDNAs by the RT-PCR method. Two splice variants of the cDNA coding GABA(B)R1 (GABA(B)R1a and GABA(B)R1c) and GABA(B)R2 were identified. Extracts of rat testis, spermatogenic cells and sperm contained two proteins with estimated molecular sizes of 130 and 100 kDa, corresponding to GABA(B)R1a and GABA(B)R1c/lb, respectively, determined by Western blot using polyclonal anti-GABA(B)R1 antibody. By an indirect immunofluorescence technique, GABA(B)R1 was located on the head of rat sperm. The present finding is the first direct demonstration that mammalian sperm contain GABA(B)R.

Little is known of how the genetic background effects the phenomenon of genomic imprinting. The H19 gene belongs to a cluster of imprinted genes on human chromosome 11. Here we show that the alternative splicing of a human H19 transcript is genotype-specific. Moreover, this variant transcript, which lacks exon 4, is either not found at all, is widely expressed or is confined to extra-villous cytotrophoblasts in first trimester placenta, depending on a combination of the genotype and the sex of the transmitting parent.

The imprinted H19 gene produces a fully processed transcript that does not exhibit any conserved open reading frame between mouse and man. Although transcriptional control elements associated with the mouse H19 locus have been shown to control the neighboring Igf2 gene incis, the prevailing view is that the cytoplasmicH19 transcript does not display any function. In contrast to earlier reports, we show here that the H19 transcript is associated with polysomes in a variety of cell types, in both mouse and man. A possible trans-function of the H19 gene is suggested by a reciprocal correlation in trans between cytoplasmic H19 and IGF2 mRNA levels, as well as IGF2 mRNA translatability. We discuss these results in terms of their challenge to the prevailing dogma on the function of the enigmatic H19 gene, as well as with respect to the ontogeny of the Beckwith-Wiedemann syndrome, and propose that the human H19 gene is an antagonist of IGF2expressivity in trans.