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China is the largest producer of pearls, accounted for over 90% of world’s total pearl production. The triangle sail mussel (Hyriopsis cumingii), the most important species for freshwater pearl culture in China, is a well-known mussel recognized for pearl production with high yield and quality. Here, we reported a high-quality chromosome-level genome assembly of H. cumingii. The size of assembled genome was as large as 3.38 Gb with a scaffold N50 length of 3.19 Mb, and 2.04 Gb genome sequences were anchored onto 19 linkage groups. A total of 37,681 protein-coding genes and 50.86% of repeat elements were predicted and annotated. The expansive of 752 gene families compared to the most closely related Dreissena rostriformis, with a divergence time of 18.5 million years, might reveal an extensive set of genes associated to biomineralization, of which 237 genes were under strong positive selection in H. cumingii genome. Notably, the fibrillin gene family exhibited expansion and positive selection simultaneously, and multiple high expression after mantle implantation, suggesting the reason for outstanding biomineralization ability of H. cumingii. Furthermore, one fibrillin gene was confirmed as involving in deposition of calcium carbonate and formation of amorphous crystal during initial biomineralization based on RNA silencing and In vitro carbonate calcium crystallization assay. Fibrillin genes also diverse our attention from calcium deposition guided by matrix protein to interlamellar membrane configuration for understanding pearl formation. These findings provide a valuable genomic resource for carbonate biomineralization studies and fill the gap on freshwater mussel genome for evolutionary studies.

A breeding selection program for improving inner shell color and growth was developed for Hyriopsis cumingii, to enhance purple pearl production. In freshwater pearl culture, adjusting culture water depth and mud substrate supply are routinely carried out to improve pearl quality. To improve selection decisions in different conditions, we estimated heritabilities and genotype by environment (G × E) interactions on inner shell color and growth traits in 1571 17-month-old animals from 8 half sib family of purple selective strain of H. cumingii reared in different water depths (WD1, 32 cm; WD2, 48 cm) and mud substrates (MS, mussel pond mud substrate; SS, shrimp pond mud substrate) were analyzed. With the same mud substrate, H. cumingii reared at WD1 showed increased performance in shell color and growth. Heritability estimates for growth traits (shell length, shell height, shell width, body weight and shell weight) were higher at WD1 and higher at WD2 for inner shell color parameters (L, a, band dE⁎) when rearing in MS, while showed opposite pattern in SS. At the same water depth, H. cumingii reared with MS showed better performance in shell color and growth traits. Heritability estimates for growth traits were higher in SS and higher in MS for inner shell color parameters when rearing at WD1, while showed opposite pattern at WD2. Heritability estimates for L, a and all growth traits were moderate and high (h2 > 0.15), while were low for b and dE⁎ (h2

Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-polymers was studied. The emission intensity of the co-polymers at different RE3+ concentrations was tested. The results showed that the co-polymers of Eu-PSt and Eu-PMMA both had wide absorption peak at 200–400 nm and the strongest peak appeared at 235 nm. The fluorescent intensity of Eu3+ doped polystyrene copolymer was stronger than that of Eu3+ doped PMMA copolymer. The characteristic emission of europium ions was observed in the co-polymers. The copolymer doped with rare earth elements showed the “sensitization effect” for the central ions. The bonded-type rare earth copolymer not only enhanced the energy transfer efficiency, but also improved the fluorescence intensity by increasing the rigidity of main and side chain.

N-myc Downstream-Regulated Gene 1 (NDRG1) is known as a differentiation-related gene that plays important roles in cell differentiation, organ formation, and embryonic development. NDRG1 has recently been shown to be associated with carcinogenesis and tumor progression in a wide variety of tumors. Phosphatase and tensin homolog deleted from chromosome (PTEN), a phosphatase and tensin homolog located on chromosome 10, is shown to be a tumor suppressor and is often mutated or deleted in various tumor cells, particularly in endometrial carcinoma. Using an immunohistochemical approach, we investigated the expression of NDRG1 and PTEN in normal endometrium, atypical hyperplasia, and endometrial carcinoma. All tumor tissues harvested in this study were derived from endometrioid carcinoma Type I, that were estrogen-related. Our results demonstrate that the expression of NDRG1 was up-regulated in 5/40 (12.5%), 18/34 (52.94%), and 86/103 (83.5%) normal endometrium, atypical hyperplasia, and endometrial carcinoma cases, respectively (P0.01), while in 6/40 (15%), 20/34 (58.82%), and 89/103 (86.41%) normal endometrium, atypical hyperplasia, and endometrial carcinoma cases, respectively. PTEN expression was significantly decreased (P0.01). Statistical analyzes demonstrated a positive correlation between NDRG1 up-regulation and PTEN down-regulation (P0.01). The expression of NDRG1 had no correlation with the differentiation degree of the tumor cells, lymph-node metastasis, and/or abdominal cavity implantation (P0.05). Our results indicated that development of endometrial carcinoma is associated with an overexpression of NDRG1 and the loss of PTEN expression. Identification of changes in the NDRG1 and PTEN expression may be a significant diagnostic tool for the early detection of endometrial carcinoma.

Mutation/deletion of PTEN has been known to be involved in the development of many cancers including endometrial carcinoma. NDRG1 (N-myc downstream-regulated gene 1) is reported to be associated with tumourigenesis. PTEN expression has been shown to be correlated with NDRG1 in both prostate and breast cancer. In this study, we explored the possibility that PTEN alteration may cause carcinogenesis of endometrioid carcinoma by regulating the expression of the NDRG1 gene.Tissue blocks of 103 patients with pathologically confirmed endometrioid carcinoma were included. All the carcinoma tissues were accompanied with varied degree of necrosis. Using two-step method and avidin-biotin peroxidase complex immunohistochemistry method, the correlation of the two genes expression in ischaemic area and the relationship of NDRG1 expression between ischaemic and non-ischaemic area in endometrioid carcinomas was evaluated.PTEN alteration and NDRG1 expressions were significantly increased in the ischaemic area of endometrioid carcinoma compared with their expressions in the normal endometrium respectively (P0.001, P0.001). A positive correlation was found between PTEN alteration and NDRG1 expression in the ischaemic area of endometrioid carcinoma.We suggest that NDRG1 may be an important candidate gene in facilitating endometrium carcinogenesis in the adaptation of hypoxia for survival. Alteration of PTEN may upregulate NDRG1 expression, which plays an important role in the process leading to endometrial carcinogenesis.

To evaluate the efficiency of liposome mediated gene transfer to retina, the time of gene expression in retinal cells, retinal damage caused by liposome and the possibility of using liposome mediated gene transfer to retina for treating fundus diseases.The ratio of cationic liposome to green fluorescein protein (GFP) expression plasmid for high efficacy of transfection was tested in vitro. Then optimal liposome-plasmid mixture was injected into the subretinal space of Sprague-Dawley (SD) or Royal college of surgeon (RCS) rats. The GFP expression was observed by using fluorescence microscopy, and morphological changes were examined by using paraffin embedded sections, HE staining and transmission electron microscopy.The GFP expression in retinal cells was observed lasting more than 4 weeks. However, upon 4 weeks of transfection the swelling and degeneration in outer segment of photoreceptors could be observed. The aggravated degeneration with disappearance of outer segments, only one layer of photoreceptor nucleus surviving, apoptotic inner granular layer cells and neovascularization were observed 8 weeks after transfection. But no inflammatory cells were observed. Three of 5 RCS rats that received plasmid pCNTF (ciliary neurotrophic factor) delivery at 4 weeks old showed more surviving nuclei of photoreceptors after 3 to 5 weeks of transfection.Liposome is able to deliver genes to retinal cells with efficacy, and the expression of therapeutic gene such as CNTF in retinal cells can rescue photoreceptors from degeneration. But liposome used here is to some extent harmful to photoreceptors.

We describe and analyze the problems existing on RCR network, a family of scalable interconnection network topologies proposed by Sun and Cheung, which include disconnected graph, the definition of bisection width, and network diameter. And, necessary modifications on some RCR topological parameters including bisection width and network diameter are made.