PRC1-mediated epigenetic programming is required to generate the ovarian reserve

10 p.-4 fig.The ovarian reserve defines the female reproductive lifespan, which in humans spans decades due to robust maintenance of meiotic arrest in oocytes residing in primordial follicles. Epigenetic reprogramming, including DNA demethylation, accompanies meiotic entry, but the chromatin changes that underpin the generation and preservation of ovarian reserves are poorly defined. We report that the Polycomb Repressive Complex 1 (PRC1) establishes repressive chromatin states in perinatal mouse oocytes that directly suppress the gene expression program of meiotic prophase-I and thereby enable the transition to dictyate arrest. PRC1 dysfuction causes depletion of the ovarian reserve and leads to premature ovarian failure. Our study demonstrates a fundamental role for PRC1-mediated gene silencing in female reproductive lifespan, and reveals a critical window of epigenetic programming required to establish ovarian reserve.Funding sources: National Institutes of Health grants R01GM122776 and R35GM141085 to S.H.N.Peer reviewe

Variants of C-C Motif Chemokine 22 (CCL22) Are Associated with Susceptibility to Atopic Dermatitis: Case-Control Studies

Atopic dermatitis (AD) is a common inflammatory skin disease caused by multiple genetic and environmental factors. AD is characterized by the local infiltration of T helper type 2 (Th2) cells. Recent clinical studies have shown important roles of the Th2 chemokines, CCL22 and CCL17 in the pathogenesis of AD. To investigate whether polymorphisms of the CCL22 gene affect the susceptibility to AD, we conducted association studies and functional studies of the related variants. We first resequenced the CCL22 gene and found a total of 39 SNPs. We selected seven tag SNPs in the CCL22 gene, and conducted association studies using two independent Japanese populations (1st population, 916 cases and 1,032 controls; 2nd population 1,034 cases and 1,004 controls). After the association results were combined by inverse variance method, we observed a significant association at rs4359426 (meta-analysis, combined P = 9.6×10−6; OR, 0.74; 95% CI, 0.65–0.85). Functional analysis revealed that the risk allele of rs4359426 contributed to higher expression levels of CCL22 mRNA. We further examined the allelic differences in the binding of nuclear proteins by electrophoretic mobility shift assay. The signal intensity of the DNA-protein complex derived from the G allele of rs223821, which was in absolute LD with rs4359426, was higher than that from the A allele. Although further functional analyses are needed, it is likely that related variants play a role in susceptibility to AD in a gain-of-function manner. Our findings provide a new insight into the etiology and pathogenesis of AD

ORAI1 Genetic Polymorphisms Associated with the Susceptibility of Atopic Dermatitis in Japanese and Taiwanese Populations

Atopic dermatitis is a chronic inflammatory skin disease. Multiple genetic and environmental factors are thought to be responsible for susceptibility to AD. In this study, we collected 2,478 DNA samples including 209 AD patients and 729 control subjects from Taiwanese population and 513 AD patients and 1027 control subject from Japanese population for sequencing and genotyping ORAI1. A total of 14 genetic variants including 3 novel single-nucleotide polymorphisms (SNPs) in the ORAI1 gene were identified. Our results indicated that a non-synonymous SNP (rs3741596, Ser218Gly) associated with the susceptibility of AD in the Japanese population but not in the Taiwanese population. However, there is another SNP of ORAI1 (rs3741595) associated with the risk of AD in the Taiwanese population but not in the Japanese population. Taken together, our results indicated that genetic polymorphisms of ORAI1 are very likely to be involved in the susceptibility of AD

Formation of Organic Rice Production Areas and Specialized Farmers Cooperatives in Northeast China : A Case Study of Wuchang City

Growing as a production area of japonica rice, Wuchang City in Northeast China has been attracting attention as a major production area of organic rice during the last decade. The formation of this region as a production area seems to be closely linked to the farmers' organizations, which have undertaken the changing role of processing and distribution companies. This role is particularly important to the way the farmers' organizations have developed in rural China. Since the Law of the People's Republic of China on Specialized Farms Cooperatives was introduced in 2007, Specialized Farmers Cooperatives have been rapidly forming, which is regarded as a supplement to the processing and distribution enterprises in the market. The first part of this paper explores the reasons for Wuchang City becoming a production area of high-quality rice. The second part examines Wuchang City's Minle Township, for a closer look at the way the organic production areas formed. The final part of this paper uses FS Organic Specialized Farmers Cooperative as a case study to investigate the role of farmers' organizations in this process. The signification of rural organizations during the formation of production area had been revealed when gradually changed from type 2, exclusive marketing cooperatives led by processing and distribution enterprises, to type 1, cooperatives promoted by administrative and technology organizations. Township officials had played a significant role in helping FS cooperative shift from farmers'cooperative of type 2 to type 1. It should be noticed that FS cooperative is managed by township officials under the conditions of market economy, other than the old bureaucratic system such as village-owned company. In addition, the operating plan of FS cooperative was discussed by village heads based on the administrative structure of the township. Until now the cooperative has covered more than 60% of the paddy fields. and its members' income has been well protected by a contract price. As the competition of rice business in Minle Township is very fierce, and the production base is in flux, it is difficult for a company to control farmers for their interests only by controlling the production materials. Different from the exclusive marketing cooperatives of type 2, farmers' cooperatives of type 1, promoted by local government. should not be regarded as a coincidence. Development of FS cooperative is a useful model to encourage further cooperation among local governments and farmers