Characterization of MRF genes and their tissue distributions and analysis of the effects of starvation and refeeding on the expression of these genes in Acipenser dabryanus muscle.

The purpose of the study was to clone the sequences of myogenic regulatory factors in Acipenser dabryanus and explore the changes in their expression during starvation and refeeding in A. dabryanus muscle. One hundred twenty fish (60.532 ± 0.284 g) were randomly assigned to four groups (fasted for 0, 3, 7 or 14 d and then refed for 14 d). Our predictions showed that the coding sequences of myod1, myf5, myog and myf6 in A. dabryanus encoded 275, 248, 248 and 243 amino acids, respectively, and the expression of the four genes was the highest in muscle. During fasting, the expression of myod1 in muscle was significantly decreased in the 14 d group. The expressions of myf5 and myf6 were increased significantly at first and then decreased with prolonged starvation time. The expression of myog in the 14 d group was significantly decreased compared with other groups (P < 0.05). During refeeding, the highest values of myod1 and myf6 expression were found in the 3 d group (P < 0.05).The expressions of myf5 and myog in 0 d and 3 d group were significantly higher than those in 7 d and 14 d group (P < 0.05). These results indicate that myogenic regulatory factors (MRFs) play important roles in muscle growth and development in A. dabryanus. The inhibition of long-term starvation (14 d) on the expression of myogenic regulatory factors is probably one of the reasons why it can not achieve full compensation for growth.

Effects of starvation and refeeding on growth performance, appetite, growth hormone-insulin-like growth factor axis levels and digestive function of Acipenser dabryanus.

The aim of this study was to explore the effects and mechanisms of different starvation treatments on the compensatory growth of Acipenser dabryanus. A total of 120 fish (60·532 (sem 0·284) g) were randomly assigned to four groups (fasting 0, 3, 7 or 14 d and then refed for 14 d). During fasting, middle body weight decreased significantly with prolonged starvation. The whole-body and muscle composition, serum biochemical indexes, visceral indexes and digestive enzyme activities had been effected with varying degrees of changes. The growth hormone (GH) level in serum was significantly increased in 14D; however, insulin-like growth factor-1 (IGF-1) showed the opposite trend. The neuropeptide Y (npy) mRNA level in brain was significantly improved in 7D; peptide YY (pyy) mRNA level in intestine was significantly decreased during fasting. After refeeding, the final body weight, percentage weight gain, specific growth rate, feed intake, feed efficiency and protein efficiency ratio showed no difference between 0D and 3D. The changes of whole-body and muscle composition, serum biochemical indexes, visceral indexes and digestive enzyme activities had taken place in varying degrees. GH levels in 3D and 7D were significantly higher than those in the 0D; the IGF-1 content decreased significantly during refeeding. There was no significant difference in npy and pyy mRNA levels. These results indicated that short-term fasting followed by refeeding resulted in full compensation and the physiological and biochemical effects on A. dabryanus were the lowest after 3 d of starvation and 14 d of refeeding. Additionally, compensation in A. dabryanus may be mediated by appetite genes and GH, and the degree of compensation is also affected by the duration of starvation.

The complete mitochondrial genome of Schizothorax prenanti (Tchang) (Teleostei, Cyprinidae, Schizothoracinae).

The ya-fish, Schizothorax prenanti, is a well-known commercial cold-water fish species with the hexaploid karyotype distributed in the upper reaches of the Yangtze River and its tributaries on the western Sichuan Plateau in China. The complete mitogenome of S. prenanti is 16,587 bp in length, containing 37 genes of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region (D-loop). The gene nucleotide composition of S. prenanti is 29.6% A, 25.4% T, 27.1% C and 17.9% G, with a slight AT bias of 55.0%. The complete mitogenome sequence of S. prenanti could provide useful data for further studies on genetic structure and diversity, as well as the artificial cultivation and breeding of S. prenanti.

[Correlation of the expressions of VEGF-C and VEGFR-3 to the pathological grade of prostate cancer].

OBJECTIVE: To investigate the correlation of the expression of VEGF-C and VEGFR-3 to the pathological grade of human prostate cancer. METHODS: Immunohistochemistry was used to detect the expression of VEGF-C and VEGFR-3 in 25 cases of prostate cancer tissues. RESULTS: The total positivity rates of VEGF-C and VEGFR-3 were 80% and 76% in these cancer tissues, respectively. The positivity rates of VEGF-C was 94.7% in the 19 cases with Gleason scores no less than 6 (group I), significantly higher than the rate (33%) in the 6 cases with Gleason scores between 4 and 6 (group II) (P<0.01). The positivity rates for VEGFR-3 also showed a significant difference between groups I and II (89.5% vs 33.3%, P<0.05). The expression level of VEGF-C was correlated to the Gleason score of prostate cancer (R=0.436, P<0.05), and the correlation between VEGFR-3 and the Gleason score was even more obvious (R=0.608, P<0.01). Their expressions, however, did not show any correlations to the patients age, PSA or the volume of the prostate. CONCLUSION: VEGF-C and VEGFR-3 may serve as new markers for evaluating the malignancy of prostate cancer with Gleason score not less than 4.

[Expression and significance of PCNA and p27 in benign prostate hypertrophy and prostate carcinoma].

OBJECTIVE: To investigate the expression of PCNA and p27 in human benign prostate hypertrophy (BPH) and prostate carcinoma (PCa) and their effect on the genesis and progression of the tumor. METHODS: The paraffin-embedded sections of 30 cases with BPH and 37 cases with PCa were collected. The expression of p27 and PCNA protein were examined by S-P immunohistochemical method. Comparative analysis for BPH and pathological grade and clinical stage of PCa was performed. RESULTS: The expression of PCNA in BPH (3.3%) was significantly lower than that in Pca (83.8%, P < 0.01). The expression of p27 in BPH (70.0%) was significantly higher than that in Pca (27.0%, P < 0.05). The expression of p27 was not correlated with histological grade and clinical stage in Pca (P > 0.05). An inverse correlation was found between p27 and PCNA expression in BPH (P < 0.01), while no correlation was found in Pca (P > 0.05). CONCLUSION: The loss or decreased expression of p27 protein may be related to the genesis of benign prostate hypertrophy, but not to the development of prostate carcinoma; the overexpression of PCNA may play an important role in the malignant behavior and progression of prostate carcinoma.