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As the major somatic cell type, Sertoli cells undergo active proliferation and play essential roles to establish testis cord at fetal stage. They also function to maintain germ cell development throughout the life of testicular development. However, the significance of Sertoli cell number for testis cord development and gonocyte fate is still unclear. Nuclear protein ataxia-telangiectasia (NPAT, also known as p220), a substrate of cyclin E/cyclin-dependent kinase 2, is well known as a regulator of cell proliferation through regulating histone expression. To study the role of NPAT during Sertoli cell development, we generated a mouse strain carrying conditional floxed Npat alleles, when crossing with anti-Mullerian hormone-cre, leading to the specific deletion of Npat in Sertoli cells. Npat disruption in Sertoli cells inhibited the programmed proliferation of fetal Sertoli cells resulting in disruption of developing testis cords, and subsequent postnatal mutant testes were severely hypoplastic. Germ cells, which are presumed to be in quiescent status during perinatal stage, exited G0 phase arrest and re-enter mitotic cell cycle prematurely. Of particular note, some germ cells possessed the meiotic signal in Npat-deficient testes. Our data thus indicates that the function of Npat-dependent Sertoli cells is essential at multiple steps in testis development, and this study also identifies Sertoli cells as a major regulator of germ cell development, which are required to maintain a local growth niche to repress premature mitosis and meiosis of gonocytes.-Jiang, X., Yin, S., Fan, S., Bao, J., Jiao, Y., Ali, A., Iqbal, F., Xu, J., Zhang, Y., Shi, Q. Npat-dependent programmed Sertoli cell proliferation is indispensable for testis cord development and germ cell mitotic arrest.

S-adenosyl-L-methionine (SAM) synthetase is the key enzyme involved in the biosynthesis of SAM, which serves as a common precursor for polyamines (PAs) and ethylene. A SAM synthetase cDNA (SlSAMS1) was introduced into the tomato genome using the Agrobacterium tumefaciens transformation method. Transgenic plants overexpressing SlSAMS1 exhibited a significant increase in tolerance to alkali stress and maintained nutrient balance, higher photosynthetic capacity and lower oxidative stress compared with WT lines. Both in vivo and in vitro experiments indicated that the function of SlSAMS1 mainly depended on the accumulation of Spd and Spm in the transgenic lines. A grafting experiment showed that rootstocks from SlSAMS1-overexpressing plants provided a stronger root system, increased PAs accumulation, essential elements absorption, and decreased Na(+) absorption in the scions under alkali stress. As a result, fruit set and yield were significantly enhanced. To our knowledge, this is the first report to provide evidence that SlSAMS1 positively regulates tomato tolerance to alkali stress and plays a major role in modulating polyamine metabolism, resulting in maintainability of nutrient and ROS balance.

Diethylhexyl phthalate (DEHP) is an estrogen-like compound widely used as a commercial plasticizer and present in medical devices, tubing, food containers and packaging. It is considered an endocrine disruptor and studies on experimental animals showed that exposure to DEHP can alter the function of several organs including liver, kidneys, lungs and reproductive system, particularly the developing testes of prenatal and neonatal males. Exposure to DEHP has been proposed as a potential human health hazard. This study assessed the effects of DEHP on folliculogenesis and oocyte maturation using the mouse as the experimental model. Newborn female mice were hypodermically injected with DEHP at doses of 20 and 40 μg/kg per body weight following different exposure regimens during the weaning period. We found that DEHP altered both folliculogenesis and oocyte development. In particular, DEHP exposure significantly decreased the number of the primordial follicles at pubertal and adult age by possibly accelerating the rate of follicle recruitment dynamics, reduced and/or delayed the level of imprinted gene methylation in the oocytes and increased metaphase II spindle abnormalities in oocytes matured in vitro. Furthermore, the weight of pups and litter size of mothers exposed to DEHP were significantly lower than controls. Finally, the number of primordial follicles appeared significantly reduced also in the F1 offspring at the adult age. These results show that DEHP may have a number of adverse effects on oogenesis, especially when exposure occurs during early postnatal age, arising concerns about the exposure of human female infants and children to this compound.

A new p-phenylenevinylene-linked perylene diimide has been synthesized and self-assembled for the formation of zero-dimensional molecular aggregate structures of nanospheres and vesicles through solvent tuning. The solid-state optical properties induced by a special wavelength laser were studied and the results indicated excellent fluorescent enhancement properties. The emission intensity of these aggregates increased with elongation of the laser irradiation time. Based on the analysis of variable-temperature (1)H NMR spectra, DFT calculations, and the single-crystal structure of the linkage group, a conformation-dependent fluorescent enhancement mechanism could be demonstrated. The mechanism is different from the fluorescent bleaching of normal solid-state fluorescent materials and offers potential applications in optical devices.

The relationship between agricultural taxation and production efficiency has been thoroughly explored for many countries. Recently, China has taken various measures including the rural taxation reform (RTR) to promote grain production and to increase farmer incomes. In this study, we investigate whether the Chinese policy of abolishing rural taxation has improved farm households’ incomes and affected their production decisions. Using household survey data obtained from three regions in China, we estimate the effect of the RTR on farmers’ income. Results show that the RTR has significantly improved farmers’ post-tax net income by 9.2% in Shandong, 16.9% in Shanxi and 16.8% in Zhejiang. These increments, mostly from farm income rather than from off-farm income, are much higher than the direct income increase from the tax savings. In addition, we examine the dynamic impact of farmers’ net income, and find that the RTR has a sustained positive income effect in Shandong and Shanxi, whereas its positive effect in Zhejiang appears temporary. We also examine farmers’ production responses to the RTR. Results show that farmers in the three regions respond in different ways: farmers in Shandong significantly increase their labour input, farmers in Zhejiang increase intermediate inputs, whereas Shanxi farmers augment their intermediate inputs and enlarge their crop acreage. It appears that the farmers’ responses to the taxation reform vary due to the agronomic and economic factors in these three regions, suggesting that diverse post-RTR supplemental policies should be implemented in different regions.

Although the relationship between meiotic recombination frequency and synaptonemal complex (SC) length has been of interest for a long time, how recombination frequency is related to SC length has not been carefully explored. To address this question, we have measured the meiotic recombination frequency as represented by MLH1 foci in 889 pachytene spermatocytes and measured the length of 19,558 autosomal SCs from 10 human males. A complex relationship between the number of MLH1 foci and total autosomal SC length per cell was observed. A positive correlation with significant correlation coefficients between the two variables was found in eight of the ten donors examined, with three donors showing weak correlation, and five showing moderate correlation. Two donors who did not show any correlation between the two variables were identified for the first time. Moreover, most cells with similar total autosomal SC length showed very different numbers of MLH1 foci both between individuals and even within an individual, and vice versa. Our data provide the first evidence for a complex relationship between the recombination frequency and total length of autosomal SCs per cell in human males. � 2012 Wiley Periodicals, Inc.

Automatic modulation classification (MC) is beneficial to digital radio receivers. Conventional MC schemes usually assume that perfect synchronization has been accomplished and then rely on certain statistical characteristics to distinguish different modulation formats. In practice, however, this perfect synchronization assumption is not reasonable since modulation classifiers operate in a non-cooperative manner and therefore, the receiver has little prior knowledge about a transmitted signal and no training is available. In this paper, we first address asynchronous MC for high-order QAMs through blind time synchronization. A characteristic function (CF) based approach is proposed to improve the performance of the conventional cumulant method. We then move on to consider asynchronous MC in the presence of frequency offset. We propose a hybrid MC scheme based on blind time synchronization, differential processing, and cumulants to solve this difficult problem. Copyright © 2010 John Wiley & Sons, Ltd.

Much recent attention has been focused on Aurora C, the third member of the mammalian Aurora kinases family that plays significant roles in mitosis. We report here that using sensitive RT-PCR to amplify the C-terminal, we found that Aurora C is not only expressed highly in testis, but also among 16 other human tissues in a broad-spectrum way. Aurora C, as a chromosomal passenger protein, is co-localized with Aurora B and Survivin in mitotic cells. Aurora C can also be associated with Aurora B and Survivin in vivo and directly binds to Survivin but not Aurora B in vitro. Over-expression of a catalytically inactive mutant of Aurora C impaired the localization of Aurora C to the spindle midzone and severely disturbed the cytokinesis, resulting in multinucleation, all of which are consistent with the results induced by the mutant of Aurora B. Furthermore, we provide evidence that Aurora C could rescue the multinucleate phenotype produced by Aurora B mutant, and vice versa. Overall, these findings demonstrate that Aurora C, a member of the chromosomal passenger complex, is required for cytokinesis.

To account for the increased proportion of paternal nondisjunction in 47,XXY males as compared to other trisomies, it has been suggested that the XY bivalent, with its reduced region of homology, is particularly susceptible to nondisjunction. Molecular studies of liveborn Klinefelter syndrome (47,XXY) individuals have reported an association between the absence of recombination in the pseudoautosomal region and nondisjunction of the XY bivalent. In this study we examined single sperm from a normal 46,XY male to determine if there is any alteration in the recombination frequency of aneuploid disomic 24,XY sperm compared to unisomic sperm (23,X or Y). Two DNA markers STS/STS pseudogene and DXYS15 were typed in sperm from a heterozygous man to determine if recombination had occurred in the pseudoautosomal region. Individual unisomic sperm (23,X or Y) were isolated using a FACStar(Plus) flow cytometer into PCR tubes. To identify disomic 24,XY sperm, 3-colour FISH analysis was performed with probes for chromosomes X,Y and 1. The 24,XY cells were identified using fluorescence microscopy, each disomic sperm was scraped off the slide using a glass needle attached to a micromanipulator and then put into a PCR tube. Hemi-nested PCR analysis of the two markers was performed to determine the frequency of recombination. A total of 329 unisomic sperm and 150 disomic sperm have been typed. The frequency of recombination between the two DNA markers was 38.3% for the unisomic sperm, similar to frequencies previously reported. The 24,XY disomic sperm had an estimated recombination frequency of 25.3%, however, a highly significant decrease compared to the unisomic 23,X or 23,Y sperm (chi(2) = 10.7, P = 0.001). This direct analysis of human sperm indicates that lack of recombination in the pseudoautosomal region is a significant cause of XY nondisjunction and thus Klinefelter syndrome.

The frequencies of aneuploid and diploid sperm were determined in a 47,XYY male using multi-color fluorescence in situ hybridization (FISH) analysis, and compared with those from 10 control donors. A total of 30,078 sperm from the patient was scored, 15,044 by two-color FISH for chromosomes 13 and 21, and 15,034 by three-color FISH for the sex chromosomes using chromosome 1 as an internal autosomal control for diploidy and lack of hybridization. The frequencies of X-bearing (49.73%) and Y-bearing sperm (49.46%) in control males were not significantly different from the expected 50% (chi(2)-test for goodness of fit). The ratio of 24,X (50.60%) to 24, Y sperm (48.35%) in the patient, however, was significantly different from the controls (P = 0.0144, chi(2)-test for independence) and from the expected 1:1 ratio (P = 0.0055, chi(2)-test for goodness of fit). There was no significant increase in the frequency of diploid sperm when compared with the controls (chi(2)-test for independence). Significantly increased frequencies were found for 24,YY (0.07% vs. 0.02%, P = 0.0009) and 24,XY (0.44% vs. 0.29%, P = 0.0025), but not for 24,XX (0.05% vs. 0.05%, P > 0. 05), 24,+13 (0.07% vs. 0.07%, P > 0.05) or 24,+21 sperm (0.21% vs. 0. 18%, P > 0.05) in the 47,XYY male when compared with control donors (chi(2)-test for independence). Our results support the theory that loss of the extra Y chromosome occurs during spermatogenesis in most cells. In this XYY patient there was a significant increase in the frequency of sperm with sex chromosomal abnormalities but no suggestion of an inter-chromosomal effect on autosomes. All 3-color FISH studies in the literature demonstrate a significantly increased risk of gonosomal aneuploidy in XYY males, with the risk being on the order of 1%.

Merrifield resin-supported hydrocinchonidinium salts containing particular functional groups that can participate in hydrogen bonding were prepared and evaluated as chiral phase-transfer catalysts ...

Merrifield resin supported cinchona ammonium salts bearing 2′-fluorobenzene, 2′-cyanobenzene and 2′- N -oxypyridine groups were prepared and applied to the phase-transfer catalytic alkylation of N -(diphenylmethylene)glycine tert -butyl ester for the enantioselective synthesis of α-amino acids (76–96% ee).