Effects Of Active Immunization Against INH-a,AMH And PRL Fusion Proteins On Egg Production And Broodiness In Zhedong White Goose

The low laying performance of goose has always been a key bottleneck restricting the development of goose industry.Some studies have shown that the broodiness greatly affects the performance of egg production.However,it is difficult that the conventional breeding improve the egg production because the heritability of broody traits and laying traits are low.Active immunization against reproductive hormone that suppresses reproductive performance induces antibodies that produce the hormone,which inhibit or attenuat the physiological function of the hormone.The active immunization has been widely used in low fertility animal and achieved remarkable effects.The inhibin-a(INH-a)inhibits animal fertility through negative feedback regulation of FSH.The prolactin(PRL)acts as direct hormone to regulate poultry broodiness.The AMH is highly expressed in the stage of broodiness,which is related to the abundant small follicles in poultry broodying stage.In this study,the Zhedong white geese with low egg production and strong broody behavior were selected and were immunized actively against INH-a,AMH and PRL fusion proteins,and the egg production and broody characteristics were explored after active immunization.The main results of this experiment were as follows:1.In order to obtain the fusion protein of goose INH-a,AMH and PRL,the CDS regions of goose INH-a,AMH and PRL genes were cloned and the prokaryotic expression vectors PET-INH?,PET-AMH and PET-PRL were constructed.The inducible expression conditions of these three vectors were optimized.The expression bacteria was induced significancely at 15?for 16 h when the OD600 was 0.6-0.8,the final concentration of IPTG was 0.2 mM.The three fusion proteins were successfully obtained by the SDS-PAGE.The molecular weights of protein expressed by INH-a,AMH and PRL was about 42 kDa,72 kDa and 30 kDa,respectively,which was equal to the theoretical values.Therefore,it was proved that the expressed proteins were the fusion protein of goose INH-?,AMH and PRL.2.In order to determine the effects of active immunization against INH-a,AMH and PRL fusion proteins on plasma antibodies and related reproductive hormones in Zhedong White Goose,the purified PET-INH?,PET-AMH and PET-PRL fusion proteins were intramuscular injected into the 300-day-old Zhedong White Geese.The INH-a,AMH and PRL fusion proteins could produce corresponding antibodies after fundamental immunity 10 days,and reduce the content of AMH and PRL in Zhedong White Geese.Meanwhile,the active immunization also increased the content of LH,and more LH was produced when the geese were immunized INH-a fusion protein 10 d and 40 d compared with control geese(P<0.05)3.In order to reveal the effects of active immunization against INH-?,AMH and PRL fusion proteins on the reproductive performance of Zhedong White Goose.The egg production and broody characteristics were changed after active immunization agaist three fusion proteins.The initial broodiness times were shortened 10 d,4 d and 1 d after immuning INH-a,AMH and PRL recombinant protein,respectively,and the broody periods were reduced 12.5 d,3.5 d and 8.5 d,respectively.The proportion of newly emerged broodiness geese was decreased obviously.In addition,the number of prehierarchical follicles increased from 76 to 195,114 and 140 compared with control geese,and the egg production was increased by 0.5 egg/goose,0.42 egg/goose and 1.34 egg/goose in the 40 d observation period.The results suggested that active immunization against INH-?,AMH and PRL fusion protein could reduced the incidence rate of goose broodiness and increase the goose egg production,specially against PRL fusion proteinTaken together,in this study,the successful construction of PET-INH?,PET-AMH and PET-PRL vectors could efficiently expresse INH-a,AMH and PRL,and the corresponding fusion proteins were obtained after dissolution,renaturation and purification.Immune PRL fusion protein could significantly reduce the broodying incidence and improve the laying performance in Zhedong White Goose;while immunizing INH-a could significantly increase the LH content in the goose,the broodying incidence was significantly reduced and the broodying time was shortened,however,only partial geese could improve the egg production performance;in addition,immune AMH could also increase the goose egg production to a certain extent.