Bioinformatics Study on Mechanism of Postnatal Development of Craniofacial Bone.

OBJECTIVE: The postnatal development of craniofacial bone plays a crucial role in shaping the overall structure and functionality of the skull and face. Understanding the underlying mechanisms of this intricate process is essential for both clinical and research purposes. In this study, the authors conducted a bioinformatics analysis using the Gene Expression Omnibus database to investigate the molecular pathways and regulatory networks involved in the postnatal development of craniofacial bone. METHODS: In this study, the online Gene Expression Omnibus microarray expression profiling data set GSE27976 was used to identify differentially expressed genes (DEGs) in different age groups. Protein-Protein Interaction network analyses, functional enrichment, and hub genes analysis were performed. The differences in immune infiltration and microenvironment among different types of cells were also analyzed. RESULTS: In total, 523 DEGs, including 287 upregulated and 236 downregulated genes, were identified. GO and KEGG analysis showed that the DEGs were significantly enriched in multiple signaling pathways, such as skeletal system morphogenesis, osteoblast differentiation, and stem cell differentiation. Immune infiltration and microenvironment characteristics analysis showed that there were significant differences in fibroblasts, mesenchymal stem cell, osteoblast, stroma score, and microenvironment score between the two groups. Five hub genes, including IGF1, IL1B, ICAM1, MMP2 , and brain-derived neurotrophic factor, were filled out. CONCLUSION: The findings of this study showed a significant shift in gene expression towards osteogenesis during the first 12 months after birth. These findings emphasize the critical role of the postnatal period in craniofacial bone development and provide valuable insights into the molecular mechanisms underlying this process.

Dimension-variable invariant imbedding (DVIIM) T-matrix computational method for the light scattering simulation of atmospheric nonspherical particles.

The invariant imbedding (IIM) T-matrix method has shown great potential in light scattering field. However, the T-matrix need to be calculated through the matrix recurrence formula derived from the Helmholtz equation, thus its computational efficiency is much lower than Extended Boundary Condition Method (EBCM). To alleviate this problem, the Dimension-Variable Invariant Imbedding (DVIIM) T-matrix method is presented in this paper. Compared with the traditional IIM T-matrix model, the dimensions of the T-matrix and relevant matrices are gradually increasing as the iteration performed step by step, thus the unnecessary operations of large matrices can be avoided in early iterations. To optimally determine the dimension of these matrices in each iterative calculation, the spheroid-equivalent scheme (SES) is also proposed. The effectiveness of the DVIIM T-matrix method is validated from the modeling accuracy and calculation efficiency. The simulation results show that compared with traditional T-matrix method, its modeling efficiency can be improved notably, especially for the particles with large size and aspect ratio, where for the spheroid with a aspect ratio of 0.5, the computational time is cut down by 25%. Though the dimension of the T matrix is cut down in the early iterations, the computational precision of DVIIM T-matrix model is not decreased notably, and a good agreement is achieved between the calculation results of DVIIM T-matrix method, IIM T-matrix method and other well-validated models (like EBCM and DDACSAT), where the relative errors of the integral scattering parameters (e.g., extinction, absorption, scattering cross sections) are generally less than 1%.

Grid-adaptive Fourier pseudospectral time domain model for the light scattering simulation of atmospheric nonspherical particles.

PSTD (pseudospectral time domain) is recognized as one of the powerful models to accurately calculate the scattering properties of nonspherical particles. But it is only good at the computation in coarse spatial resolution, and large "staircase approximation error" will occur in the actual computation. To solve this problem, the variable dimension scheme is introduced to improve the PSTD computation, in which, the finer grid cells are set near the particle's surface. In order to ensure that the PSTD algorithm can be performed on non-uniform grids, we have improved the PSTD with the space mapping technique so that the FFT algorithm can be implemented. The performance of the improved PSTD (called "IPSTD" in this paper) is investigated from two aspects: for the calculation accuracy, the phase matrices calculated by IPSTD are compared with those well tested scattering models like Lorenz-Mie theory, T-matrix method and DDSCAT; for computational efficiency, the computational time of PSTD and IPSTD are compared for the spheres with different sizes. From the results, it can be found that, the IPSTD scheme can improve the simulation accuracy of phase matrix elements notably, especially in the large scattering angles; though the computational burden of IPSTD is larger than that of PSTD, its computational burden does not increase substantially.

Genotype-phenotype characteristics and baseline natural history of Chinese myelin protein zero gene related neuropathy patients.

BACKGROUND AND PURPOSE: The aim was to characterize the phenotypic and genotypic features of myelin protein zero (MPZ) related neuropathy and provide baseline data for longitudinal natural history studies or drug clinical trials. METHOD: Clinical, neurophysiological and genetic data of 37 neuropathy patients with MPZ mutations were retrospectively collected. RESULTS: Nineteen different MPZ mutations in 23 unrelated neuropathy families were detected, and the frequency of MPZ mutations was 5.84% in total. Mutations c.103_104InsTGGTTTACACCG, c.513dupG, c.521_557del and c.696_699delCAGT had not been reported previously. Hot spot mutation p.Thr124Met was detected in four unrelated families, and seven patients carried de novo mutations. The onset age indicated a bimodal distribution: prominent clustering in the first and fourth decades. The infantile-onset group included 12 families, the childhood-onset group consisted of two families and the adult-onset group included nine families. The Charcot-Marie-Tooth Disease Neuropathy Score ranged from 3 to 25 with a mean value of 15.85 ± 5.88. Mutations that changed the cysteine residue (p.Arg98Cys, p.Cys127Trp, p.Ser140Cys and p.Cys127Arg) in the extracellular region were more likely to cause severe early-onset Charcot-Marie-Tooth disease type 1B (CMT1B) or Dejerine-Sottas syndrome. Nonsense-mediated mRNA decay mutations p.Asp35delInsVVYTD, p.Leu174Argfs*66 and p.Leu172Alafs*63 were related to severe infantile-onset CMT1B or Dejerine-Sottas syndrome; however, mutation p.Val232Valfs*19 was associated with a relatively milder childhood-onset CMT1 phenotype. CONCLUSION: Four novel MPZ mutations are reported that expand the genetic spectrum. De novo mutations accounted for 30.4% and were most related to a severe infantile-onset phenotype. Genetic and clinical data from this cohort will provide the baseline data necessary for clinical trials and natural history studies.

Application of Cherenkov radiation in tumor imaging and treatment.

Cherenkov radiation (CR) is the characteristic blue glow that is generated during radiotherapy or radioisotope decay. Its distribution and intensity naturally reflect the actual dose and field of radiotherapy and the location of radioisotope imaging agents in vivo. Therefore, CR can represent a potential in situ light source for radiotherapy monitoring and radioisotope-based tumor imaging. When used in combination with new imaging techniques, molecular probes or nanomedicine, CR imaging exhibits unique advantages (accuracy, low cost, convenience and fast) in tumor radiotherapy monitoring and imaging. Furthermore, photosensitive nanomaterials can be used for CR photodynamic therapy, providing new approaches for integrating tumor imaging and treatment. Here the authors review the latest developments in the use of CR in tumor research and discuss current challenges and new directions for future studies.

Cherenkov radiation (CR) is the characteristic blue glow that is generated during radiotherapy (a common treatment that uses radiation to kill cancer cells) or radioisotope decay (the process that emits radiation from radioisotopes). CR can be used for monitoring the dose and dose distribution of radiotherapy to prevent radiotherapy-related adverse events. In addition, radioisotope-induced CR can be used as a light source for locating the tumor region for tumor imaging. With a combination of imaging techniques, molecular probes and nanomedicine, CR exhibits huge potential and unique advantages (accuracy, low cost, convenience and fast) in tumor radiotherapy monitoring and imaging. Furthermore, some photosensitive nanomaterials have been developed to absorb CR to generate reactive oxygen species, which can result in cell death. This therapeutic strategy is known as CR photodynamic therapy. CR photodynamic therapy is available to integrate with radiotherapy or tumor imaging, providing new approaches for tumor diagnosis and treatment. Here the authors review the latest developments in the use of CR in tumor research and discuss current challenges and new directions for future studies.

Uncovering the Pathogenesis of Orofacial Clefts Using Bioinformatics Analysis.

OBJECTIVE: Many genes have been found to be associated with the occurrence of the orofacial clefts (OFC). The links between these pathogenic genes are rarely studied. In this study, bioinformatics analysis were performed in order to find associations between OFC- related genes and provide new ideas for etiology study of OFCs. METHODS: Orofacial clefts-related genes were searched and identified from the Online Mendelian Inheritance of Man (OMIM.org). These genes were then analyzed by bioinformatics methods, including protein-protein interaction network, functional enrichment analysis, module analysis, and hub genes analysis. RESULTS: After searching the database of OMIM.org and removing duplicate results, 279 genes were finally obtained. These genes were involved to 369 pathways in biological process, 56 in cell component, 64 in molecular function, and 45 in the Kyoto Encyclopedia of Genes and Genomes. Most identified genes were significantly enriched in embryonic appendage morphogenesis (29.17%), embryonic limb morphogenesis (6.06%), and limb development (4.33%) for biological process ( Fig. 5A ); ciliary tip (42.86%), MKS complex (28.57%), ciliary basal body (14.29%), and ciliary membrane (14.29%) for cell component. The top 10 hub genes were identified, including SHH, GLI2, PTCH1, SMAD4, FGFR1, BMP4, SOX9, SOX2, RUNX2 , and CDH1. CONCLUSIONS: Bioinformatics methods were used to analyze OFC- related genes in this study, including hub gene identifying and analysis, protein - protein interaction network construction, and functional enrichment analysis. Several potential mechanisms related to occurrence of OFCs were also discussed. These results may be helpful for further studies of the etiology of OFC.

Propranolol Reduces the Development of Lesions and Rescues Barrier Function in Cerebral Cavernous Malformations: A Preclinical Study.

[Figure: see text].

The Effect of TCM-Induced HAMP on Key Enzymes in the Hydrolysis of AD Model Cells.

Alzheimer's disease (AD) process is characterized classically by two hallmark pathologies: ß-amyloid (Aß) plaque deposition and neurofibrillary tangles of hyperphosphorylated tau. Aß peptides play an important role in AD, but despite much effort the molecular mechanisms of how Aß contributes to AD remain unclear. The present study evaluated the effects of the active components of Epimedium, Astragalus and Radix Puerariae induced HAMP on key enzymes in the hydrolysis of APP in HT22 cells. The active components of Epimedium, Astragalus and Radix Puerariae could effectively up-regulate the expression of HAMP, alleviate the iron overload in the brain tissues of mice, significantly improve the learning and memory ability of AD, down-regulate the expression of Aß and reduce the deposition of SP in an APPswe/PS1ΔE9 transgenic mouse model of AD. HAMP and Aß25-35 induced HT22 cells are used as AD cell models in this study to investigate the effect of the compound consisting of the effective components of Epimedium, Astragalus and Pueraria on the key enzymes in the hydrolysis of APP. After the administration of traditional Chinese medicine (TCM), the expression levels of ADAM10 and ADAM17 were increased while the expression level of BACE1 decreased. This indicates that TCM can promote the expression level of ADAM10 and ADAM17, inhibit the expression level of BACE1, thus further inhibiting the production of amyloid protein and reducing the production of Aß and SP. Compared with RNAi group, the expression level of ADAM10 and ADAM17 in Aß + RNAi group was decreased while the expression level of BACE1 increased. Compared with the Aß + RNAi group the expression level of ADAM10 and ADAM17 in the Aß + RNAi + TCM group was increased while the expression level of BACE1 was decreased. The present study indicated the effects of the active components of Epimedium, Astragalus and Radix Puerariae may alleviate AD by up-regulating the expression of HAMP, thus reducing brain iron overload, promoting the expression of ADAM10 and ADAM17, inhibiting the expression of BACE1, and reducing the deposition of Aß.

Fine-Tuning of Sox17 and Canonical Wnt Coordinates the Permeability Properties of the Blood-Brain Barrier.

RATIONALE: The microvasculature of the central nervous system includes the blood-brain barrier (BBB), which regulates the permeability to nutrients and restricts the passage of toxic agents and inflammatory cells. Canonical Wnt/ß-catenin signaling is responsible for the early phases of brain vascularization and BBB differentiation. However, this signal declines after birth, and other signaling pathways able to maintain barrier integrity at postnatal stage are still unknown. OBJECTIVE: Sox17 (SRY [sex-determining region Y]-box 17) constitutes a major downstream target of Wnt/ß-catenin in endothelial cells and regulates arterial differentiation. In the present article, we asked whether Sox17 may act downstream of Wnt/ß-catenin in inducing BBB differentiation and maintenance. METHODS AND RESULTS: Using reporter mice and nuclear staining of Sox17 and ß-catenin, we report that although ß-catenin signaling declines after birth, Sox17 activation increases and remains high in the adult. Endothelial-specific inactivation of Sox17 leads to increase of permeability of the brain microcirculation. The severity of this effect depends on the degree of BBB maturation: it is strong in the embryo and progressively declines after birth. In search of Sox17 mechanism of action, RNA sequencing analysis of gene expression of brain endothelial cells has identified members of the Wnt/ß-catenin signaling pathway as downstream targets of Sox17. Consistently, we found that Sox17 is a positive inducer of Wnt/ß-catenin signaling, and it acts in concert with this pathway to induce and maintain BBB properties. In vivo, inhibition of the ß-catenin destruction complex or expression of a degradation-resistant ß-catenin mutant, prevent the increase in permeability and retina vascular malformations observed in the absence of Sox17. CONCLUSIONS: Our data highlight a novel role for Sox17 in the induction and maintenance of the BBB, and they underline the strict reciprocal tuning of this transcription factor and Wnt/ß-catenin pathway. Modulation of Sox17 activity may be relevant to control BBB permeability in pathological conditions.

Computational and robotic modeling reveal parsimonious combinations of interactions between individuals in schooling fish.

Coordinated motion and collective decision-making in fish schools result from complex interactions by which individuals integrate information about the behavior of their neighbors. However, little is known about how individuals integrate this information to take decisions and control their motion. Here, we combine experiments with computational and robotic approaches to investigate the impact of different strategies for a fish to interact with its neighbors on collective swimming in groups of rummy-nose tetra (Hemigrammus rhodostomus). By means of a data-based agent model describing the interactions between pairs of H. rhodostomus (Calovi et al., 2018), we show that the simple addition of the pairwise interactions with two neighbors quantitatively reproduces the collective behavior observed in groups of five fish. Increasing the number of interacting neighbors does not significantly improve the simulation results. Remarkably, and even without confinement, we find that groups remain cohesive and polarized when each agent interacts with only one of its neighbors: the one that has the strongest contribution to the heading variation of the focal agent, dubbed as the "most influential neighbor". However, group cohesion is lost when each agent only interacts with its nearest neighbor. We then investigate by means of a robotic platform the collective motion in groups of five robots. Our platform combines the implementation of the fish behavioral model and a control system to deal with real-world physical constraints. A better agreement with experimental results for fish is obtained for groups of robots only interacting with their most influential neighbor, than for robots interacting with one or even two nearest neighbors. Finally, we discuss the biological and cognitive relevance of the notion of "most influential neighbors". Overall, our results suggest that fish have to acquire only a minimal amount of information about their environment to coordinate their movements when swimming in groups.

Dendrimicelles with pH-controlled aggregation number of core-dendrimers and stability.

We present a simple way to build up well-controlled coacervate-core dendrimicelles by assembly of anionic PAMAM dendrimers with a cationic-neutral diblock copolymer. Upon increasing pH, the formation of micellar structures shows constant size but the number of dendrimer molecules incorporated in one micelle decreases, following the charge stoichiometry formation rules; concomitantly, the salt stability increases. This study shows the straightforward tuning of macromolecular core-units and related micelle properties.

Synovial and pulmonary dysfunctions are induced by crosstalk of Smad and Erk pathways in an arthritis model.

In the current experiment, the effects of transforming growth factor (TGF)-ß1/Smad and ERK pathway crosstalk on synovial and pulmonary systems during rheumatoid arthritis have been investigated. For this purpose, rats were divided into normal control (NC) and model control (MC) groups. In the MC group, 0.1 ml Freund's complete adjuvant was injected intradermally into the right hind paw, and the resulting inflammation represented a rheumatoid arthritis model. Joint swelling and changes in lung functions were observed in arthritic rats. Synovial and lung were observed by light and electron microscopies. Enzyme-linked immunosorbent assays were used to detect TGF-ß1, interleukin (IL)-1ß, IL-4, IL-10, interferon-γ (IFN-γ), connective tissue growth factor (CTGF), and fibroblast growth factor (FGF). PCR, immunohistochemistry, and immunoblotting were used to detect changes in Smad and ERK pathways of synovial and lung tissues. Compared with the NC group, toe swelling was elevated in the MC group. Pulmonary functions FEV1, FEF50, FEF75, MMF, and PEF were decreased (P< 0.01). Serum cytokines IL-1ß, IL-4, TGF-ß1, and CTGF were increased, while IFN-γ, IL-10, Th1/Th2 cell ratio, and FGF were decreased (P< 0.01 or P< 0.05). Expression of TGF-ß1 and Smad2/3/4 mRNAs and TGF-ß1, TßRI, TßRII, Smad2/3, p-Smad2/3, and Smad4 proteins in the synovial membrane and lung tissue were increased, and expression of Smad7 mRNA and protein was decreased (P<0.01) or P<0.05). Expression of ERK2 mRNA and p-ERK1/2 protein was increased in the synovial membrane and lung tissue, and expression of ERK1/2 mRNAs and ERK1/2 and p-ERK1/2 proteins was increased in lung tissue (P< 0.01 or P< 0.05). Correlation analysis showed that FEV1 was negatively correlated with TGF-ß1 mRNA and protein in arthritic rats, FEF25 was negatively correlated with Smad4 protein, and FEF50 was negatively correlated with the TßRII protein, and FEF75, TGF-ß1 and Smad3 mRNAs. There was a negative correlation between Smad2/3 protein and a negative correlation between PEF and TGF-ß1 protein (P< 0.05). FEF50 and MMF were positively correlated with Smad7 mRNA (P< 0.05). FEV1 was negatively correlated with ERK2 mRNA, and FEF25 was negatively correlated with p-ERK1/2 protein. FEF75 and MMF were negatively correlated with ERK1/2 and p-ERK1/2, respectively (P< 0.05). ERK1 mRNA was positively correlated with Smad3 mRNA and TßRII protein, ERK2 mRNA was positively correlated with p-Smad2/3, and ERK1/2 protein was positively correlated with Smad2 mRNA, Smad4 protein, p-ERK1/2 protein, Smad4 mRNA, and p-Smad2/3 protein (P< 0.05). p-ERK1/2 protein was negatively correlated with Smad7 protein (P< 0.05). It is concluded that arthritic rats have synovial and systemic pulmonary damage. Smad and ERK pathway crosstalk leads to systemic lesions. Smad and ERK pathways are gradually activated by phosphorylation under the induction of the TGF-ß1 promoter, and then participate in transcriptional activities, leading to the increase in synovial inflammation of arthritis, pulmonary lesions, and decreases in lung functions.

TAK-242, Toll-Like Receptor 4 Antagonist, Attenuates Brain Edema in Subarachnoid Hemorrhage Mice.

BACKGROUND: Brain edema is a common and critical pathology following subarachnoid hemorrhage (SAH). Toll-like receptor 4 (TLR4) activation may exacerbate brain edema. The purpose of this study was to clarify if TAK-242, a TLR4 antagonist, suppresses brain edema formation and neurological impairments after SAH in mice. METHODS: A total of 46 mice underwent endovascular perforation to induce SAH or sham operation and were classified as Sham+TAK-242, SAH+ phosphate-buffered saline (PBS), and SAH + TAK-242 groups. The PBS or TAK-242 was administered intracerebroventricularly to mice at 30 min from the operation. Neurobehavioral tests, SAH severity, and brain water content were evaluated at 24 h from the operation. RESULTS: The SAH + PBS group was significantly worse in neurological tests (P < 0.001) and brain water content of the cerebral hemisphere in the bleeding side (p = 0.005) compared with the Sham+PBS group, while there were no differences between the SAH + TAK-242 and Sham+PBS groups. SAH severity in the SAH + PBS group was similar to that in the SAH + TAK-242 group. CONCLUSIONS: Intracerebroventricular administration of TAK-242 possibly prevents neurological impairments at least via suppression of brain edema.

Age- and Sex-Related Development of the Normal Human Ear in a Child Population.

BACKGROUND: A large number of researches related to auricle development have been conducted in different countries, but there were few similar studies in China, especially in Chinese children. This study was designed to investigate the auricular development by measuring normal age- and sex-related dimensions of auricles in Chinese children. METHODS: A total of 900 participants were evaluated according to their age and gender. From the landmarks, the dimensions of the and tragus including length and width, the relevant indices, inclination angles were measured. The average score of each item was calculated according to age and gender. RESULTS: The dimensions of the and tragus including width and length showed certain developmental patterns respectively. No significantly difference was found for the inclination angles and relative indices between different age groups and different sides. CONCLUSIONS: The data indicated that there was a certain pattern of auricular development. There were also gender difference in the development of auricle. There were certain proportional relationships between different subunits of the auricle. These results may be useful for designing the plan of auricular reconstruction.

A Survey of Aesthetic Standards of the Ear.

BACKGROUND: The aesthetic standards of the ear are very important for evaluation of auricular surgery. Few studies have previously assessed ear aesthetics, especially in China. This study aimed to investigate aesthetic standards of the ear in a Chinese population. MATERIALS AND METHODS: A questionnaire was administered to Chinese individuals, which included assessment of the general impressions of the ear and other facial aesthetic units, the individual aesthetic subunits of the ear, the effects of different ear subunits on ear symmetry and the degree of the subunits to which the participants wanted to change. Answers were recorded on a five-point Likert-style scale. Statistical analysis was performed using SPSS ver. 17.0. RESULTS: A total of 319 responses were received, 50.3% women and 49.7% men. The external ear received the lowest degree of attention either on the front or on the lateral view of the face in both genders. Among the individual aesthetic units, the earlobe received the most attention and the fine structures the lowest. The helix had the greatest effect on the ear symmetry. The structure that participants most wanted to change was the earlobe in males and the helix in females. There were significant differences on the evaluation of the helix and crus of helix among the groups divided according to educational background (P < 0.001). CONCLUSION: The results showed that the structures that people were most concerned about were the helix and earlobe. There were gender differences in the results which were also influenced by education background.

[Clinical cases and experimental evaluation of liver injury related to anti-psoriasis Keyin Pills].

Keyin Pills is a kind of traditional Chinese medicine for the treatment of psoriasis, but it has been reported that it can cause serious liver injury. In this paper, we used the integrated evidence chain method to retrieve and reevaluate the adverse drug reaction database, CNKI literature and cases of liver injury relating to Keyin Pills in specialist hepatology hospitals. We screened out 23 cases with the causal relationship of the possible grade and above. Among them, 11 cases showed the positive causal relationship only with Keyin Pills, accounting for 47.83%, suggesting that there was objective liver injury caused by Keyin Pills. The incubation period of liver injury caused by Keyin Pills is 1-90 days, and the cumulative dosage span is 20-1 800 g. There were obvious individual diffe-rences. There was no relationship between liver injury as well as dose and course of treatment, suggesting that Keyin Pills could induce immune idiosyncratic liver injury. Furthermore, based on the liver injury model induced by immunological stress, it was confirmed that Keyin Pills could induce acute liver injury in a dose-dependent manner in rats with immunological stress. The toxic dose(14 g·kg~(-1)) of a single dose was 6.7 times of the clinical equivalent dose, and had no significant effect on the biochemical index of liver function and histopathology in normal rats. Decomposition experiments showed that Dictamnus dasycarpus in Keyin Pills is the main medicinal flavor that causes special liver injury, and the other three medicines had neither liver injury nor compatibility attenuation effect. The results suggest that clinical medication shall pay attention to the risk of liver injury caused by Keyin Pills in patients with immunological stress.

Recent Sex Chromosome Divergence despite Ancient Dioecy in the Willow Salix viminalis.

Sex chromosomes can evolve when recombination is halted between a pair of chromosomes, and this can lead to degeneration of the sex-limited chromosome. In the early stages of differentiation sex chromosomes are homomorphic, and even though homomorphic sex chromosomes are very common throughout animals and plants, we know little about the evolutionary forces shaping these types of sex chromosomes. We used DNA- and RNA-Seq data from females and males to explore the sex chromosomes in the female heterogametic willow, Salix viminalis, a species with ancient dioecy but with homomorphic sex chromosomes. We detected no major sex differences in read coverage in the sex determination (SD) region, indicating that the W region has not significantly degenerated. However, single nucleotide polymorphism densities in the SD region are higher in females compared with males, indicating very recent recombination suppression, followed by the accumulation of sex-specific single nucleotide polymorphisms. Interestingly, we identified two female-specific scaffolds that likely represent W-chromosome-specific sequence. We show that genes located in the SD region display a mild excess of male-biased expression in sex-specific tissue, and we use allele-specific gene expression analysis to show that this is the result of masculinization of expression on the Z chromosome rather than degeneration of female-expression on the W chromosome. Together, our results demonstrate that insertion of small DNA fragments and accumulation of sex-biased gene expression can occur before the detectable decay of the sex-limited chromosome.

Transcriptome profiling of tobacco (Nicotiana tabacum) pollen and pollen tubes.

BACKGROUND: Pollen tube growth is essential for plant reproduction and represents a widely employed model to investigate polarized cell expansion, a process important for plant morphogenesis and development. Cellular and regulatory mechanisms underlying pollen tube elongation are under intense investigation, which stands to greatly benefit from a comprehensive understanding of global gene expression profiles in pollen and pollen tubes. Here, RNA sequencing technology was applied to de novo assemble a Nicotiana tabacum male gametophytic transcriptome and to compare transcriptome profiles at two different stages of gametophyte development: mature pollen grains (MPG) and pollen tubes grown for six hours in vitro (PT6). RESULTS: De novo assembly of data obtained by 454 sequencing of a normalized cDNA library representing tobacco pollen and pollen tube mRNA (pooled mRNA isolated from mature pollen grains [MPG] and from pollen tubes grown in vitro for 3 [PT3] or 6 [PT6] hours) resulted in the identification of 78,364 unigenes. Among these unigenes, which mapped to 24,933 entries in the Sol Genomics Network (SGN) N. tabacum unigene database, 24,672 were predicted to represent full length cDNAs. In addition, quantitative analyses of data obtained by Illumina sequencing of two separate non-normalized MPG and PT6 cDNA libraries showed that 8979 unigenes were differentially expressed (differentially expressed unigenes: DEGs) between these two developmental stages at a FDR q-value of <0.0001. Interestingly, whereas most of these DEGs were downregulated in PT6, the minor fraction of DEGs upregulated in PT6 was enriched for GO (gene ontology) functions in pollen tube growth or fertilization. CONCLUSIONS: A major output of our study is the development of two different high-quality databases representing the tobacco male gametophytic transcriptome and containing encompassing information about global changes in gene expression after pollen germination. Quantitative analyses of these databases 1) indicated that roughly 30% of all tobacco genes are expressed in the male gametophyte, and 2) support previous observations suggesting a global reduction of transcription after pollen germination. Interestingly, a small number of genes, many of which predicted to function in pollen tube growth or fertilization, were found to be upregulated in elongating pollen tubes despite globally reduced transcription.

The meiotic regulator JASON utilizes alternative translation initiation sites to produce differentially localized forms.

The JASON (JAS) protein plays an important role in maintaining an organelle band across the equator of male meiotic cells during the second division, with its loss leading to unreduced pollen in Arabidopsis. In roots cells, JAS localizes to the Golgi, tonoplast and plasma membrane. Here we explore the mechanism underlying the localization of JAS. Overall, our data show that leaky ribosom scanning and alternative translation initiation sites (TISs) likely leads to the formation of two forms of JAS: a long version with an N-terminal Golgi localization signal and a short version with a different N-terminal signal targeting the protein to the plasma membrane. The ratio of the long and short forms of JAS is developmentally regulated, with both being produced in roots but the short form being predominant and functional during meiosis. This regulation of TISs in meiocytes ensures that the short version of JAS is formed during meiosis to ensure separation of chromosome groups and the production of reduced pollen. We hypothesize that increased occurrence of unreduced pollen under stress conditions may be a consequence of altered usage of JAS TISs during stress.

Effect of low-magnitude different-frequency whole-body vibration on subchondral trabecular bone microarchitecture, cartilage degradation, bone/cartilage turnover, and joint pain in rabbits with knee osteoarthritis.

BACKGROUD: Whole-body vibration(WBV) has been suggested for the prevention of subchondral bone loss of knee osteoarthritis (OA) . This study examined the effects of different frequency of whole-body vibration on subchondral trabecular bone microarchitecture, cartilage degradation and metabolism of the tibia and femoral condyle bone, and joint pain in an anterior cruciate ligament transection (ACLT)-induced knee osteoarthritisrabbit model. METHOD: Ninety adult rabbits were divided into six groups: all groups received unilateral ACLT; Group 1, ACLT only; Group 2, 5 Hz WBV; Group 3, 10 Hz WBV; Group 4, 20 Hz WBV; Group 5, 30 Hz WBV; and Group 6, 40 Hz WBV. Pain was tested via weight-bearing asymmetry. Subchondral trabecular bone microarchitecture was examined using in vivo micro-computed tomography. Knee joint cartilage was evaluated by gross morphology, histology, and ECM gene expression level (aggrecan and type II collagen [CTX-II]). Serum bone-specific alkaline phosphatase, N-mid OC, cartilage oligometric protein, CPII, type I collagen, PIIANP, G1/G2 aggrecan levels, and urinary CTX-II were analyzed. RESULTS: After 8 weeks of low-magnitude WBV, the lower frequency (10 Hz and 20 Hz) WBV treatment decreased joint pain and cartilage resorption, accelerated cartilage formation, delayed cartilage degradation especially at the 20 Hz regimen. However, the higher frequencies (30 Hz and 40 Hz) had worse effects, with worse limb function and cartilage volume as well as higher histological scores and cartilage resorption. In contrast, both prevented loss of trabeculae and increased bone turnover. No significant change was observed in the 5 Hz WBV group. CONCLUSION: Our data demonstrate that the lower frequencies (10 Hz and 20 Hz) of low-magnitude WBV increased bone turnover, delayed cartilage degeneration, and caused a significant functional change of the OA-affected limb in ACLT-induced OA rabbit model but did not reverse OA progression after 8 weeks of treatment.