Identification of 15 novel polymorphic microsatellite loci in pearl oyster (Pinctada fucata).

The pearl oyster Pinctada fucata is a commercially important marine shellfish. As a result, genetic improvement and selective-breeding program have been conducted for this species. Polymorphic microsatellites are effective molecular markers to investigate molecular marker-assisted selection and genetic variance. In this study, microsatellite DNAs were screened and characterized based on the partial genome sequence of P. fucata. We identified 111 microsatellite DNA motifs through mining the published draft genome sequence of P. fucata. Forty-two loci were screened with 8 P. fucata individuals, and 15 were found to be polymorphic and were therefore further evaluated using 40 wild individuals from the Daya Bay, Shenzhen City, Guangdong Province, China. The number of alleles per locus ranged from 3 to 8, with an average of 5.2667 for the 15 polymorphic loci. Observed and expected heterozygosities ranged from 0.1154 to 0.6216 (0.3321 on average) and 0.4950 to 0.8491 (0.6768 on average), respectively. Of the 15 polymorphic loci, 12 loci deviated from Hardy-Weinberg equilibrium after Bonferroni correction (P < 0.0033). Polymorphism information content ranged from 0.44 to 0.83 with a mean value of 0.63. The results suggest that the markers isolated in this study can be used for research on molecular marker-assisted selection and genetic variance of P. fucata.

Genetic diversity and structure of the threatened species Sinopodophyllum hexandrum (Royle) Ying.

Sinopodophyllum hexandrum is an important medicinal plant that has been listed as an endangered species, making the conservation of its genetic diversity a priority. Therefore, the genetic diversity and population structure of S. hexandrum was investigated through inter-simple sequence repeat analysis of eight natural populations. Eleven selected primers generated 141 discernible fragments. The percentage of polymorphic bands was 37.59% at the species level, and 7.66-24.32% at the population level. Genetic diversity of S. hexandrum was low within populations (average HE = 0.0366), but higher at the species level (HE = 0.0963). Clear structure and high genetic differentiation were detected between populations using unweighted pair groups mean arithmetic and principle coordinate analysis. Clustering approaches clustered the eight sampled populations into three major groups, and AMOVA confirmed there to be significant variation between populations (63.27%). Genetic differentiation may have arisen through limited gene flow (Nm = 0.3317) in this species. Isolation by distance among populations was determined by comparing genetic distance versus geographical distance using the Mantel test. The results revealed no correlation between spatial pattern and geographic location. Given the low within-population genetic diversity, high differentiation among populations, and the increasing anthropogenic pressure on this species, in situ conservation measures, in addition to sampling and ex situ preservation, are recommended to preserve S. hexandrum populations and to retain their genetic diversity.

Transcriptional profiles of emasculated flowers of black locust (Robinia pseudoacacia) determined using the cDNA-AFLP technique.

Black locust (Robinia pseudoacacia) is a tree in the subfamily Faboideae, native to North America, that has been naturalized and widely planted in temperate Europe and Asia. Black locust has important ecological and economic value, but its quality needs improvement. Hybridization programs are important for black locust breeding, but the low rate of fruit set after controlled pollination limits both its breeding and that of other monoclinous plant species that share this problem. In this study, we investigated gene expression in emasculated black locust flowers using the cDNA-amplified fragment length polymorphism technique to determine why the rate of fruit set is low after controlled pollination. Flowers that were emasculated after being frozen in liquid nitrogen were used as controls. Changes in the flower transcriptome were more dramatic at 5 h after emasculation than at 48 h. Injury caused by emasculation decreased the expression levels of genes associated with metabolism, growth regulation, signal transduction, and photosynthesis, and it increased the expression of genes related to stress-response metabolism, signal transduction, and promotion of senescence. The changes in the expression levels of these genes had negative effects on sugar metabolism, protein metabolism, lipid metabolism, energy metabolism, matter transport, signal transduction, osmotic regulation, pH regulation, and photosynthesis. Thus, emasculation accelerated flower senescence, resulting in low fruit set.

Diagnostic values of microRNA-31 in peripheral blood mononuclear cells for pediatric pulmonary tuberculosis in Chinese patients.

We investigated the diagnostic values of microRNA-31 in peripheral blood mononuclear cells (PBMCs) for pediatric pulmonary tuberculosis in Chinese patients. Sixty-five children with TB were selected for this study, which was conducted at the Department of Infectious Diseases People's Hospital of Laiwu City between December 2013 and December 2014. Sixty healthy children, selected in parallel, served as the control group. Real-time PCR was used to detect miR-31 expression in PBMCs. Serum levels of IL-6, TNF-α, NF-κB, and IFN-γ was detected by ELISA. ROC curve was employed to evaluate the diagnostic value of miR-31 in pediatric TB. Results show that expression of miRNA-31 in pediatric TB patients was significantly lower than that in normal children (0.48 ± 0.15 vs 1.23 ± 0.36, P < 0.05). By contrast, serum levels of the innate immune response cytokines, IL-6, TNF-α, NF-κB, and IFN-γ, were significantly higher in pediatric TB patients compared with normal children (P < 0.05). Furthermore, miRNA-31 expression was negatively correlated with serum levels of IL-6 (t = 69.91, P < 0.001), TNF-α (t = 10.96, P < 0.001), NF-κB (t = 39.94, P < 0.001), and IFN -γ (t = 37.94, P < 0.001). The cut-off threshold of miR-31 for pediatric TB diagnosis is 0.835 with a sensitivity of 98.5% and a specificity of 86.7%. Therefore, miR-31 has the potential to be a diagnostic marker in pediatric TB patients.

Characterization of ESTs from black locust for gene discovery and marker development.

Black locust (Robinia pseudoacacia L.) is an ecologically and economically important species. However, it has relatively underdeveloped genomic resources, and this limits gene discovery and marker-assisted selective breeding. In the present study, we obtained large-scale transcriptome data using a next-generation sequencing platform to compensate for the lack of black locust genomic information. Increasing the amount of transcriptome data for black locust will provide a valuable resource for multi-gene phylogenetic analyses and will facilitate research on the mechanisms whereby conserved genes and functions are maintained in the face of species divergence. We sequenced the black locust transcriptome from a cDNA library of multiple tissues and individuals on an Illumina platform, and this produced 108,229,352 clean sequence reads. The high-quality overlapping expressed sequence tags (ESTs) were assembled into 36,533 unigenes, and 4781 simple sequence repeats were characterized. A large collection of high-quality ESTs was obtained, de novo assembled, and characterized. Our results markedly expand the previous transcript catalogues of black locust and can gradually be applied to black locust breeding programs. Furthermore, our data will facilitate future research on the comparative genomics of black locust and related species.

Association of polymorphisms of the xeroderma pigmentosum complementation group F gene with increased glioma risk.

We aimed to investigate the role of 4 single nucleotide polymorphisms of the xeroderma pigmentosum complementation group F (XPF) gene (rs3136038, rs1799798, rs1800067, and rs2276466) in glioma, and the roles of gene-gene interactions in the risk of developing this type of cancer. We collected samples from 225 glioma cases and 262 controls and genotyped the rs3136038, rs1799798, rs1800067, and rs2276466 polymorphisms using a 384-well plate format with the Sequenom MassARRAY platform. Individuals carrying the rs1800067 GG genotype were more likely to have an increased risk of glioma when compared with carriers of the A/A genotype in a co-dominant model, with an odds ratio (OR) [95% confidence interval (CI)] of 2.85 (1.14-7.76). However, we did not find an association with increased risk of glioma for the polymorphisms rs3136038, rs1799798, and rs2276466 in XPF. The combination genotype of the rs1800067 G allele and the rs2276466 G allele was associated with a moderate risk of glioma (OR = 1.71, 95%CI = 1.02-2.87). Our study suggests that the rs1800067 genetic variant of XPF functions in the development of glioma.

Association of MHC class-III gene polymorphisms with ER-positive breast cancer in Chinese Han population.

Polymorphisms of the major histocompatibility complex (MHC) have been linked to many diseases, especially autoimmune disorders. Previous studies have shown that genetic variants in MHC class III are associated with breast cancer. To determine if there is an association between MHC class III and breast cancer risk in the Chinese Han population, we carried out a hospital-based case-control study in Guangdong and Jiangsu Provinces, including 216 histologically confirmed breast cancer patients and 216 healthy controls. Nine SNP markers distributed in the class III-coding region were detected using the Sequenom MassARRAY(®) iPLEX System. Deviation from Hardy-Weinberg equilibrium was observed for seven SNPs. There was no significant association between these seven SNP variants and breast cancer in these Chinese women (unconditional logistic regression analysis). However, chr6_31697494 at BAT2, one of the seven SNPs, was found to be significantly associated with both ER- and PR-positive breast cancer. In addition, both chr6_31911109 at C6orf48 and chr6_31975605 at ZBTB12, another two of the seven SNPs, show relevance with ER-positive breast cancer. In conclusion, this is the first evidence that genetic polymorphisms in the MHC class III region are significantly associated with ER-positive breast cancer in the Han Chinese population.

Characterization of nine novel microsatellite loci for the Venus clam (Cyclina sinensis).

The Venus clam, Cyclina sinensis, is one of the most important bivalves in China marine aquaculture. Using (CA)(15)-enriched genomic libraries of this species, nine novel polymorphic microsatellite loci were isolated and characterized. The mean number of observed alleles per locus was 16 (range 8-24). The observed and expected heterozygosity ranged from 0.119 to 0.872 and from 0.626 to 0.931, respectively. Three loci had significant departure from Hardy-Weinberg equilibrium and non-significant linkage disequilibrium was found among all nine loci. These highly informative microsatellite markers should be useful for population genetic analyses of C. sinensis.