Meta-analysis of the correlation between the TNF-α308G/A polymorphism and polycystic ovary syndrome.

Previous studies have suggested that the tumor necrosis factor alpha (TNF-α) gene 308G/A polymorphism may be associated with polycystic ovary syndrome (PCOS) risk. However, this relationship is controversial. The present meta-analysis aimed to evaluate the correlation between the TNF-α308G/A polymorphism and susceptibility to PCOS. A systematic electronic search of PubMed and Embase databases was conducted using specific inclusion criteria. Summary odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated, and all statistical analyses were performed using STATA 12.0. The results of our meta-analysis showed no significant association between the TNF-α308G/A polymorphism and PCOS risk (AA vs GG: OR = 0.80, 95%CI = 0.31-2.08; AG vs GG: OR = 1.03, 95%CI = 0.59-1.81; dominant model: OR = 1.02, 95%CI = 0.60-1.71; recessive model: OR = 0.87, 95%CI = 0.35-2.16). Based on the statistical data, our meta-analysis indicates that the TNF-α308G/A sequence variation may be not related to PCOS susceptibility. Further large and well-designed studies are needed to confirm this conclusion.

Karyotype analysis and ribosomal gene localization of spotted knifejaw Oplegnathus punctatus.

The spotted knifejaw, Oplegnathus punctatus, is an important aquaculture fish species in China. To better understand the chromosomal microstructure and the karyotypic origin of this species, cytogenetic analysis was performed using Giemsa staining to identify metaphase chromosomes, C-banding to detect C-positive heterochromatin, silver staining to identify the nucleolus organizer regions (Ag-NORs), and fluorescence in situ hybridization (FISH) for physical mapping of the major (18S rDNA) and minor (5S rDNA) ribosomal genes. The species showed a karyotype of 2n = 48 for females, composed of 2 submetacentric and 46 telocentric chromosomes, with a fundamental number (FN) = 50, while the karyotype of males was 2n = 47, composed of 1 exclusive large metacentric, 2 submetacentric, and 44 telocentric chromosomes, with FN = 50. These karyotype results suggest that O. punctatus might have an X1X1X2X2/X1X2Y multiple sex chromosome system. C-positive heterochromatin was distributed in the centromeres of all chromosomal pairs and in the terminal portions of some chromosomes. A single pair of Ag-positive NORs was found to be localized at the terminal regions of the short arms of the subtelocentric chromosome pair, which was supported by FISH of 18S rDNA. After FISH, 5S rDNA were located on the interstitial regions of the smallest telocentric chromosome pair. This study was the first to identify the karyotype of this species and will facilitate further research on karyotype evolution in the order Perciformes.

Identification and analysis of a 5-bp indel of a porcine BMP7 gene promoter.

Bone morphological protein7 (BMP7), a member of the transforming growth factor-ß (TGF-ß) family, was first identified because of its ability to induce ectopic chondro-osteogenesis in vivo. It also plays a crucial role in the growth, development, and physiological functioning of the reproductive system. Among intra-ovarian growth factors, many studies have shown that BMP7 plays a pivotal role in regulating the early phases of follicular growth. We detected a 5-bp insertion-deletion at 602 bp upstream from the transcription start site of the BMP7 gene promoter among 258 pigs of 3 breeds. Along with 2 homoduplex DNAs, another 4 previously unknown bands (named A, B, C, and D) were detected by non-denaturing polyacrylamide gel electrophoresis. By DNA sequencing, we found that PCR products from heterozygotes contained 2 homoduplexes and 4 heteroduplexes. Genetic polymorphism analysis revealed 3 genotypes (AA, AB, and BB) at this site; the distribution of these genotypes followed Hardy-Weinberg equilibrium. A was the dominant allele (0.715), and AA was the dominant genotype (0.500). The polymorphism information content value was calculated to be 0.325, the expected heterozygosity was 0.407, and effective number of alleles was 1.688, indicating an intermediate degree of polymorphism and good potential for selection and breeding. Highly significant differences were found between different breeds and distributions of genotypes. Based on correlation analysis, the 5-bp indel site does not significantly affect porcine reproductive traits (total number of births, number of piglets born alive, litter birth weight, and litter weight at 21 days; P>0.05), which was consistent with the results of genetic variation analysis.

Distribution and pathogen identification of cassava brown leaf spot in China.

Cassava brown leaf spot surveys were conducted in the main cassava plantation areas of China between 2007 and 2012 in order to understand the distribution of the disease. Cassava plants were damaged by the disease to different degrees in most of the survey sites. Samples were collected and seven strains were isolated from lesions. The mycelium-breaking plus black light induction method was applied for sporulation. Microconidia were formed by means of fragmentation on artificial medium plates. When the leaf was stabbed and inoculated with conidia solution, similar symptoms were formed 14 days later. Morphological characteristics of the specimens and conidia were similar to descriptions of Passalora henningsii infection. The internal transcribed spacer (ITS) regions of rDNA were obtained with primer pair ITS1/ITS4 and deposited in GenBank, which differed by three base pairs from that of the P. henningsii isolate (AF284389). The ITS sequences of related species were downloaded from the NCBI database, and phylogenetic analysis showed that the sequences originating from our strains clustered in the same clade as the AF284389 isolate. Biological characteristics were evaluated in two strains from different sites, which indicated that the optimum conditions for mycelia growth were a temperature of 26° to 28°C, carrot agar medium, pH 6, and continuous dark; cassava leaf juice added to malt extract and cassava leaf juice added to potato dextrose agar were the best media for conidia production. The optimal and lethal temperatures for macroconidia germination were 26° to 28°C, and 60°C for 10 min, respectively.