Genetic Diversity Evaluation and Conservation of Topmouth Culter (Culter alburnus) Germplasm in Five River Basins in China.

To study the genetic diversity of Culter alburnus (C. alburnus) populations, we analyzed the genetic diversity of five C. alburnus populations from Songhua Lake (SH), Huaihe River (HH), Changjiang River (CJ), Taihu Lake (TH), and Gehu Lake (GH) based on mitochondrial COI gene sequences. The results showed that the average contents of bases T, C, A, and G in the 526 bp COI gene sequence were 25.3%, 18.1%, 28.1%, and 28.6%, respectively, which showed AT bias. A total of 115 polymorphic sites were detected in the five populations, and 11 haplotypes (Hap) were defined. The nucleotide diversity (Pi) of the five populations ranged from 0.00053 to 0.01834, and the haplotype diversity (Hd) ranged from 0.280 to 0.746, with the highest genetic diversity in the TH population, followed by the SH population, with lower genetic diversity in the HH, CJ and GH populations. The analysis of the fixation index (Fst) and the genetic distance between populations showed that there was significant genetic differentiation between the SH population and the other populations, and the genetic distances between all of them were far; the genetic diversity within populations was higher than that between populations. Neutral tests, mismatch distributions, and Bayesian skyline plot (BSP) analyses showed that the C. alburnus populations have not experienced population expansion and are relatively stable in historical dynamics.

Egg yolk IgY against RHDV capsid protein VP60 promotes rabbit defense against RHDV infection.

VP60 capsid protein is the major structural and immunogenicity protein of RHDV (Rabbit hemorrhagic disease virus, RHDV), and has been implicated as a main protein antigen in RHDV diagnosis and vaccine design. In this report, egg yolk antibody (IgY) against N-terminal of VP60 was evaluated and developed as a new strategy for RHDV therapy. Briefly, N-terminal of VP60 (∼250aa) fragment was cloned and inserted into pET28a expression vector, and then the resultant plasmid, pET28a/VP60-N, was transformed into E. coli BL21(DE3) for recombinant VP60-N protein (rVP60-N) expression. Next, the rVP60-N was purified by Ni(+)-affinity purification chromatography and identified by Western blotting with RHDV antiserum. After immunizing the chickens with rVP60-N, the anti-rVP60-N IgY was isolated, and the activity and specificity of the IgY antibody were analyzed by ELISA and Western blotting. In our results, the rVP60-N could be expressed in E. coli as soluble fraction, and the isolated anti-rVP60-N IgY demonstrated a high specificity and titer (1:22,000) against rVP60-N antigen. For further evaluation of the IgY efficacy in vivo, rabbits were grouped randomly and challenged with RHDV, and the results showed that anti-rVP60-N IgY could significantly protect rabbits from virus infection and promote the host survival after a sustained treatment with anti-rVP60-N IgY for 5 days. Taken together, our study demonstrates evidence that production of IgY against VP60 could be as a novel strategy for the RHDV therapy.

Increasing thickness and fibrosis of the cartilage in acetabular dysplasia: a rabbit model research.

BACKGROUND: The order and mechanism of pathological changes in acetabular dysplasia are still unclear. This study investigated cartilage changes in rabbit acetabular dysplasia models at different ages. METHODS: Twenty-seven 1-month-old New Zealand rabbits underwent cast immobilization of the left hind limb in knee extension. Serial acetabular dysplasia models were established by assessment of the acetabular index and Sharp's angle on radiographs. The thickness of the acetabular cartilage was measured under a microscope, and fibrosis was observed. Ultrastructural changes were investigated with scanning electron microscopy and transmission electron microscopy. The messenger RNA expression of collagen I and II, ß1 integrin, and caspase-9 were measured by real-time fluorescence quantitative polymerase chain reaction. RESULTS: In an immature group of rabbits, the acetabular index of the treated hip increased with animal growth. The cartilage on the brim of the left acetabulum was significantly thicker than that on the right side. The collagen fibrils on the surface of the cartilage became gross, and the chondrocytes in the enlargement layer underwent necrosis. In a mature group of rabbits, the left Sharp's angle increased in the rabbits with 6-week casting. The cartilage on the brim of the left acetabulum underwent fibrosis. The chondrocytes were weakly stained, and the number of lysosomes was much larger than normal. The messenger RNA expression of collagen I and II, ß1 integrin, and caspase-9 in the cartilage differed significantly at different ages. CONCLUSIONS: Increasing thickness followed by fibrosis may be the order of pathological cartilage changes in acetabular dysplasia, with changes in ultrastructure and collagen expression contributing to the process.

[Experimental study on the expression of II type collagen and MMP-7 in acetabular cartilage of developmental dysplasia of hip].

OBJECTIVE: To detect the changes of expressions of II type collagen and matrix metalloproteinases-7 (MMP-7) of acetabular cartilage in early DDH (developmental dysplasia of hip) and to investigate the relevance between II type collagen and MMP-7 and the retrogression mechanism of acetabular cartilage. METHODS: The animal model of DDH was successfully established in 8 rabbits by applying the method of knee extension in which left lower extremity as experimental group and right one as control group. And the stains of HE and toluidine blue were applied on the samples of acetabular cartilage to observe the changes of chondrocytes and extracellular matrix (ECM). The techniques of immunohistochemical staining and Western blot were employed to respectively qualify and quantitate the expression of II type collagen and MMP-7. RESULTS: Pathohistological observation indicated the signs of retrogressive changes of acetabular cartilage in experimental group, including a loss of ECM in toluidine blue stain and a cluster of chondrocytes in HE stain. The positive numbers of II type collagen and MMP-7 by immunohistochemical staining in experimental group were both higher than that of control group. The quantitative amounts of II type collagen and MMP-7 by Western blot in experimental group were both higher than that of control group. Both significant differences existed between two groups (P < 0.05). CONCLUSION: The expression of II type collagen and MMP-7 is correlated to a retrogression of acetabular cartilage and increases obviously in early DDH. The amount and intensity of II type collagen and MMP-7 are probably the rationale of differential retrogression of cartilage.