Evidence of balancing selection in multiple indigenous chicken populations.

Microsatellite DNA markers, which are assumed to drift, have been widely used to assess genetic diversity in all major domestic animal species. These markers provide insight into the arrival and dispersion history of a species, with regard to their content or management history. However, no direct evidence supports current standard microsatellite markers falling under this assumption. Therefore, the objective of this study was to investigate the effect and divergence of microsatellites under different types of selection on genetic patterns and population diversity. A total of 192 birds (Gallus gallus) from eight different geographic locations were investigated using 20 microsatellites that are classified into different groups by their selective effect (neutral, positive selection, and balancing selection) by the FDIST2 outlier test. The results showed that most polymorphisms were in the balancing selection marker group, the expected heterozygosity was 0.70, the observed heterozygosity was 0.65, and the mean number of alleles was 6.91. AMOVA revealed that the balancing group contributed the lowest amount of variance among groups, which was -0.60%, the highest variance contributed within the population being 92.28% in comparison with that of other groups. A similar pattern of population genetics was revealed following Slatkin linearized FST, principal component factor analysis, and population structure by Bayesian clustering. In conclusion, balancing selective markers offer high polymorphism for estimating genetic diversity but reduced genetic divergence between populations.

Isolation and characterization of a novel acidic matrix protein hic22 from the nacreous layer of the freshwater mussel, Hyriopsis cumingii.

Matrix proteins that either weakly acidic or unusually highly acidic have important roles in shell biomineralization. In this study, we have identified and characterized hic22, a weakly acidic matrix protein, from the nacreous layer of Hyriopsis cumingii. Total protein was extracted from the nacre using 5 M EDTA and hic22 was purified using a DEAE-sepharose column. The N-terminal amino acid sequence of hic22 was determined and the complete cDNA encoding hic22 was cloned and sequenced by rapid amplification of cDNA ends-polymerase chain reaction. Finally, the localization and distribution of hic22 was determined by in situ hybridization. Our results revealed that hic22 encodes a 22-kDa protein composed of 185 amino acids. Tissue expression analysis and in situ hybridization indicated that hic22 is expressed in the dorsal epithelial cells of the mantle pallial; moreover, significant expression levels of hic22 were observed after the early formation of the pearl sac (days 19-77), implying that hic22 may play an important role in biomineralization of the nacreous layer.

Clinical analysis of cases of neonatal Streptococcus agalactiae sepsis.

With the advent of antibiotic resistance, pathogenic bacteria have become a major threat in cases of neonatal sepsis; however, guidelines for treatment have not yet been standardized. In this study, 15 cases of neonatal Streptococcus agalactiae sepsis from our hospital were retrospectively analyzed. Of these, nine cases showed early-onset and six cases showed late-onset sepsis. Pathogens were characterized by genotyping and antibiotic sensitivity tests on blood cultures. Results demonstrated that in cases with early-onset sepsis, clinical manifestations affected mainly the respiratory tract, while late-onset sepsis was accompanied by intracranial infection. Therefore, we suggest including a cerebrospinal fluid examination when diagnosing neonatal sepsis. Bacterial genotyping indicated the bacteria were mainly type Ib, Ia, and III S. agalactiae. We recommend treatment with penicillin or ampicillin, since bacteria were resistant to clindamycin and tetracycline. In conclusion, our results provide valuable information for the clinical treatment of S. agalactiae sepsis in neonatal infants.

The expression and function of Frizzled-7 in human renal cell carcinoma.

PURPOSE: Wnt/ß-catenin has emerged as an important signal pathway in renal cell carcinoma (RCC) pathogenesis. Frizzled 7 (Fzd7) is a member of Frizzled (Fzd) receptor family which binds with Wnt ligands and transduces canonical and non-canonical pathways. However, the expression of Fzd7 in human RCC is poorly investigated. METHODS: 53 RCC tissues and peri-tumor tissues were collected from the patients treated with radical nephrectomy. The expression of Fzd7 was investigated by immunohistochemical staining. Three RCC cells were transfected with Fzd7shRNA and GFPshRNA to investigate the function of Fzd7 in RCC cells. RESULTS: The immunohistochemical analysis showed that Fzd7 protein expression level was significantly increased in RCC tissues when compared with peri-tumor tissues, which suggested that Fzd7 might be involved in the formation of tumors. However, the Fzd7 expression was not correlated with clinicopathological parameters. Three RCC cell lines: 786-O, Caki-1, and OS-RC-2 also expressed Fzd7. With Fzd7 expression being interfered by shRNA, the RCC cell proliferation was mildly decreased. Wnt3a could stimulate the RCC cells proliferation, but the stimulation was decreased when Fzd7 expression was interfered. Restoring the Fzd7 expression led to the proliferation stimulation effect of Wnt3a being restored. CONCLUSIONS: This paper suggests that Fzd7 may act as one of the molecules that take part in the course of RCC formation. Fzd7 can be activated by Wnt3a to stimulate cell proliferation.

Identification of natural recombinants derived from PCV2a and PCV2b.

Porcine circovirus type 2 (PCV2) is considered to be the main pathogen in PC-associated diseases, and significantly affects the global pig-producing industry. PCV2 continuously evolves by point mutations and genome recombinations. In the present study, we aimed to further identify recombinant PCV2 strains. We used polymerase chain reaction to detect PCV2 in the carcasses of pigs with suspected infections from different regions of Guangdong Province in China. DNA was extracted from samples with confirmed infection and full- genome amplification, sequencing, phylogenetic tree construction, gene recombination detection, and sequence alignment were performed in gene recombination analysis. Our results show that recombination occurred between the strains SHC (DQ104421) and ZhuJi2003 (AY579893). The recombination resulted in three recombinants: GD003 (KM503044), GD005 (KM487708), and GD008 (KM487709). Further analyses revealed that these novel recombinants appeared to result from recombination between the PCV2a and PCV2b strains, with crossover regions located in ORF2. This study was a comprehensive analysis that used several different methods, which demonstrated that a cluster of PCV2 strains resulted from the same type of inter-genotypic recombination pattern, with a breakpoint in the structural protein coding region. The results of our study provide both information on the recombination mechanism and disease pathogenesis and useful data for the prevention of PCV2 in the swine industry.

Molecular cloning and expression analysis of TRAF3 in chicken.

Tumor necrosis factor receptor-associated factor 3 (TRAF3) is a crucial regulator that suppresses c-Jun N-terminal kinase and non-canonical nuclear factor-kB signaling, but facilitates type I interferon production. To determine TRAF3 function in innate immune responses among birds, particularly chicken, we cloned and characterized the chicken TRAF3 gene (chTRAF3) and detected its tissue expression profile in chicken. We also detected the differential expression of chTRAF3 and its downstream gene interferon-ß (IFN-ß) upon different stimuli in primary chicken embryo fibroblast cells. Two chTRAF3 gene products, chTRAF3-1 and chTRAF3-2, can be produced by alternative splicing. The full-length coding sequence of chTRAF3 (chTRAF3-1) was 1704 base pairs and encoded a protein of 567 amino acids with high identity to TRAF3 homologs from mammals and other birds. The deduced amino acid sequence showed typical characteristics of TRAFs, with a RING finger domain, 2 zf-TRAF motifs, and a MATH domain. Quantitative real-time polymerase chain reaction analysis revealed broad expression of chTRAF3 in all detected tissues, with abundant expression in the spleen, thymus, lung, and small intestine. Expression of chTRAF3 was significantly upregulated in a time- and concentration-dependent manner in chicken embryo fibroblast cells challenged with poly I:C or poly dA-dT. Furthermore, chTRAF3 and IFN-ß mRNA expression from chicken embryo fibroblast cells challenged with Newcastle disease virus F48E9 suffered intense suppression compared with Newcastle disease virus Mukteswar infection. Our results indicate that chTRAF3 plays important roles in defending against both RNA and DNA virus infection.