Correlation analysis of mandarin fish (Siniperca chuatsi) growth hormone gene polymorphisms and growth traits

Screening of trait-associated molecular markers can be used to enhance the efficiency of selective breeding. Previously, we produced the first high-density genetic linkage map for the mandarin fish (Siniperca chuatsi) and identified 11 quantitative-trait loci significantly associated with growth, of which one is located within the growth hormone (GH) gene. To investigate the GH gene polymorphisms and their correlation with growth, the complete sequence was cloned and 32 single-nucleotide polymorphisms (SNPs) and one simple-sequence repeat (SSR)were identified. Of which, eight SNPs (G1–G8) and the SSR (GH-AG)were selected for genotyping and correlation analysis with growth traits in a random population. The results showed that the four novel polymorphicloci (G1, G2, G3 and GH-AG) were significantly correlated with growth traits of mandarin fish (P < 0.05). Of these, G1, G3 and GH-AG showed highly significant correlations with multiple growth traits (P < 0.01) and the combined SNP analysis showed that G1–G3 formed four effective diplotypes (D1–D4), among which D1 was highly significantly greater than D4 (P < 0.01) for some important growth traits. In conclusion, our results show that the four polymorphic loci G1–G3 and GH-AG within the mandarin fish GH gene are significantly correlated with growth traits and could be used as candidate molecular markers for selective breedingof superior varieties of mandarin fish.

Change of nitric oxide in local muscle of crush injury hind-limbs in rats / 法医学杂志

OBJECTIVE@#To investigate the change of nitric oxide (NO) level in local muscles induced by crushing hind-limbs in rats.@*METHODS@#The rat experimental model of hind-limb crushing injury was established by crushing the hind limbs of rats with standard weight for 5 hours, thereafter releving the standard weight for another 5 hours. The rats were randomly divided into sham group, crushing group, crushing and injecting aminoguanidine (AG) group, crushing and injecting L-arginine (L-Arg) group. The NOS activity and NO level in local muscles and serum were spectrophotometrically measured, and iNOS and eNOS protein expressions in local muscles were examined by immunohistochemistry. The weight ratio of wet to dry (W/D) of local muscles was measured and the pathologic changes were observed.@*RESULTS@#The crushing hind-limbs induced serious primary and secondary injuries of local muscles such as rupture and rhadomyolysis of skeletal muscular fibers, interstitial vascular congestion and edema, and marked increase in W/D. The expressions of eNOS and iNOS were upregulated in local muscle in crush group compared with sham group. The NOS activity and NO level in local muscles and serum significantly increased. There was positive relationship between NO level and W/D in local muscles. With the usage of AG and L-arg, the hind-limb injuries seemed alleviated and aggravated, respectively.@*CONCLUSION@#The crushing hind-limbs of rats elicited the upregulation of eNOS and iNOS protein expression, the enhancement of NOS activity and the excess production of NO, the latter of which was involved in the mediation of secondary pathological changes in local muscles.

Mechanism of acute liver injury induced by crushing hindlimbs in rabbits / 法医学杂志

OBJECTIVE@#To investigate the role of oxidative stress in acute liver injury during crushing hindlimbs in rabbit.@*METHODS@#The crushing injury model in rabbit was established by intermittent crushing the hind limbs of rabbit with standard weight. The ALT and AST activities were spectrophotometrically measured. The weight ratio (wet/dry,W/D) of livers was measured with scale, and the pathologic changes were observed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and total anti-oxidant capacity (T-AOC) as well as malondialdehyde (MDA) level were spectrophotometrically measured.@*RESULTS@#As compared with control rabbits, crushing hindlimbs of rabbits induced acute liver injury with the increase in ALT and AST activities in serum,which were 4.31 (P < 0.01) and 10.54 times (P < 0.01) of control group respectively, there were cellular swellings and slight congestion of hepatic sinuses. In addition,crushing hind-limbs elicited significant decrease in SOD,CAT,GSH-Px activity and T-AOC to 17%, 29%, 24% and 21% (P < 0.01) compared with control group respectively, whereas MDA level markedly enhanced.@*CONCLUSION@#Crushing hindlimbs of rabbits induced acute liver injury and significant decrease in anti-oxidant capacity, the latter maybe play an important role in crushing hind-limbs of rabbits-elicited the acute liver injury.