Effect Of Dietary Zinc On Growth And Development Of Female Macrobrachium Nipponense

Macrobrachium nipponense is commonly known as prawns and river prawns,and belongs to the Palaemonidae and Macrobrachium.Because of its delicious meat and rich nutritional value,it is one of the main fresh water breeds in China.With the expansion of the Macrobrachium nipponense culture scale and the deterioration of the breeding environment caused by high-density breeding,germplasm degradation and other problems have become increasingly serious,which has become an important factor restricting the further development of the Macrobrachium nipponense culture industry.Therefore,it is necessary to strengthen the basic biological research of Macrobrachium nipponense.In this paper,physiological and biochemical and molecular biological methods and techniques are used to comprehensively explore the effects of zinc on the growth and development of Macrobrachium nipponense,with a view to accumulating basic data for efficient artificial breeding of Macrobrachium nipponense.The main findings of this paper are as follows: 1.Effect of dietary Zinc on the growth and ovary development of female Macrobrachium nipponenseAdding an appropriate level of zinc to the feed can promote the growth and female ovarian development of Macrobrachium nipponense.The average weight of experimental female shrimp was(0.668 ± 0.157)g,and the experimental diets were five zinc gradient groups of 0,30,60,120,and 180 mg/kg.After being cultured for 10 weeks,observe the effects of different levels of zinc in the feed on the growth index and ovarian development of female shrimp.The results showed that with the increase of zinc content in feed,the survival rate of female Macrobrachium nipponense was lowest in the 180 mg/kg group,and the gonad index was highest in the 60 mg/kg group.When the zinc content was 60 mg/kg,the weight gain rate and feed coefficient have a significant promotion effect;according to a polyline analysis of the relationship between zinc level and weight gain rate in the female prawns of Macrobrachium nipponense,it can be seen that when the zinc content is 57.00 mg/kg,female shrimp have the maximum weight gain rate.When the zinc content in the feed was 60 mg/kg,the estradiol and progesterone content in the serum of female shrimp had the maximum.Observation of the ultrastructure of the female ovary can further find that the appropriate zinc group can maintain the structural integrity,the number of lipid droplets and yolk particles increased and the structure is complete,the number of rough endoplasmic reticulum is large,and the ovarian tissue structure of the high concentration group There is a certain degree of deformation and cavitation.2.Effect of dietary Zinc on antioxidant and non-specific immunity of female Macrobrachium nipponenseAdding appropriate zinc in the feed can improve the antioxidant performance and non-specific immune performance of female Macrobrachium nipponense.When the zinc content in the feed is 30-60 mg/kg,the T-SOD,Cu-Zn SOD,and CAT enzyme activities are highest in the hepatopancreas,and the MDA content is the lowest when the zinc content is 60 mg/kg;at 60-120 mg/kg,the non-specific immune enzymes AKP and PO had the highest activity in serum.When the zinc content was 60 mg/kg,the expression of non-specific immune Toll-like receptor pathway-related genes in hepatopancreas was the highest.The above results indicate that zinc has an important role in the antioxidant and non-specific immunity of female Macrobrachium nipponense.3.Cloning and expression analysis of Wee1 and OTUB genes from Macrobrachium nipponenseThe Wee1 and OTUB gene full-length sequences were amplified according to our laboratory's Macrobrachium nipponense transcriptome database.The full-length Wee1 gene cDNA sequence is 2776 bp,the open reading frame ORF is 1920 bp,and encodes 639 amino acid residues.According to the results of real-time PCR,Wee1 gene was expressed in all tissues of Macrobrachium nipponense,with the highest expression in hepatopancreas and ovary.With different levels of zinc added to the feed,Wee1 gene expression was significantly different in different treatment groups in ovarian tissue.Wee1 gene expression was the lowest when the zinc content in the feed was 60 mg/kg,and Wee1 gene expression was at 180 mg/kg.The expression level was the highest;with the increase of zinc content in feed,the content of development-related gene cdc2 gradually increased,the content of cyclinB gene first increased and then decreased,and the interaction of related genes together regulated the development of ovaries.The full-length cDNA of OTUB gene is 946 bp,and the open reading frame ORF is 804 bp,encoding 267 amino acid residues.According to the results of real-time PCR,OTUB gene was expressed in various tissues of Macrobrachium nipponense,with the highest expression in hepatopancreas and testis,followed by ovary.The expression of OTUB gene in different treatment groups in ovarian tissue was significantly different under the effect of different levels of zinc in the feed.When the zinc content in the feed was 60 mg/kg,the expression of OTUB gene was the lowest,and at 180 mg/kg,the OTUB gene was the highest expression.According to the degree of expression of the above genes,it can be seen that zinc plays an important role in ovarian development of females of Macrobrachium nipponense.In general,the addition of zinc at an appropriate level in the feed can promote the growth,ovarian development,and immune capacity of female Macrobrachium nipponense.Comprehensive consideration,the 60 mg / kg zinc content in the feed is more suitable for the growth and development of female Macrobrachium nipponense...