Study On Embryo Development And Early Antioxidant Ability Of Schizothorax Grahami

In this study,on the one hand,to comprehend the morphology of the early developmental stage,the digestion and utilization of yolk,on the other hand,the basic rules of organ phylogeny of chizothorax grahami were studied.In order to understand the changes of antioxidant capacity during early development;meanwhile so as to torecognize the characteristics of growth and the expression of growth genes in early development,next to expound their functions.1.Observation of the embryonic development characteristics of Schizothorax grahami.The results showed that the mature eggs of Schizothorax grahami were spherical,with an egg diameter of（2.78±0.20）mm,the egg weight of（14.65±0.52）mg,the water swelling（4.29±0.14）mm,and the egg weight（36.65±1.70）mg.Under the condition of water temperature（14.27±0.94）°C,the blastodisc stage was observed in 2.42h,entered the cleavage stage at 4.50h,and then the blastula stage in13.77h,and entered the gastruia stage at 40.50h.53.22h entered the stage of organ formation.The fertilized eggs were hatched in 165h,with the sum effective accumulative temperature of 2508h·°C.The total length of newly hatched larvae had was（11.52±0.51）mm.The characteristics of external morphology in different developmental stages were described in detail,and it was found that the developmental characteristics and the temperature requirements of Schizothorax grahami embryo were similar from those of other Subfamilies.This study provides technical support for the resource recovery of Schizothorax.2.In order to understand the early growth characteristics of Schizothorax grahami.The full length and body weight of Schizothorax grahami larvae and juveniles were measured,and the overall development trend was made.The result is that the most suitable growth equation is obtained through comparative analysis,and its growth characteristics are explored through the fullness and growth indicators.The results showed that the power function relationship between the full length and body weight of Schizothorax grahami 1～27days old was:L=0.00028W^4.939,R²=0.806.The correlation between the full length and the age of Schizothorax grahami in the early ydevelopment stage can be expressed by a cubic function curve,the relationship is:L=0.001D³-0.23D²+0.512D+11.129,R²=0.982.The correlation between body weight and age is closest to the cubic curve:W=-0.008D³+0.410D²-3.807D+15.144,R2=0.976.The analysis showed that Schizothorax grahami fish grew at an allometric rate at the age of 1～27days.The growth rate of the full length at the age of 11 days was greater than but greater than the body weight,and the growth rate of the body weight at the age of 11～27days was faster than that of the full length.This study found that the 17-day-old Schizothorax grahami had the largest weight gain,but its full length was indeed the smallest increase,which may be related to the growth of its organs.This requires later studies on the allometric growth of its organs.3.In order to understand the changes of antioxidant enzyme activities during the development of Schizothorax grahami embryos and juveniles,the level of antiox-idant enzyme activities during the development of Schizothorax grahami embryos and juveniles was developed using biochemical methods.The results show that:（1）All enzymes measured in mature eggs are active.The activities of superoxide dismutase,catalase and glutathione peroxidase in fertilized eggs were high-er than those in mature eggs,while the malondialdehyde content,protein carbonyl content,lactate dehydrogenase activity and total resistance,The oxidation capacity is lower than that of mature eggs.（2）Superoxide dismutase activity,catalase activity,malondialdehyde content and total antioxidant capacity during embryonic development gradually increased to the stage of organ formation,and then decreased to the pre-exudation stage,glutathione hydrogen peroxide The enzyme activity gradually decreased to the stage of organ formation,and then increased to the premembrane stage,while the changes of protein carbonyl content and lactate dehydrogenase activity fluctuated.（3）In the post-embryonic stage,the larvae are in the endogenous to mixed trophic stage.Superoxide dismutase activity,catalase activity,glutathione catalase,malondialdehyde content,lactate dehydrogenase Both activity and total antioxidant capacity increased,but protein carbonyl content decreased.The results showed that T-SOD and GSH-Px played an important role in the embryonic development of Schizothorax grahami.Moreover,the oxidative damage of Schizothorax grahami was more serious after hatching than before.4.RT-PCR and fluorescent quantitative PCR technology to study the expression of GH,GHR and IGF-IIa genes in the early development of Schizothorax grahami.The results showed that the expression levels of GH and GHR genes in the embryonic development stage of Schizothorax grahami were extremely low,and reached the maximum with the emergence period,and then the expression level continued to increase during the endogenous to exogenous vegetative period;IGF-IIa gene Schizothorax grahami has expression in all stages,but only the gastroenterate stage and the later stage of the membrane emergence stage have obvious expression,and the expression level in other periods is extremely low,and reaches the highest in the exogenous nutrition stage.The results show that the regulatory factors of different fishes are different,and the specific regulatory mechanism in the early development of Schizothorax grahami needs further study.