Protein Tyrosine Phosphatase/ Protein Tyrosine Kinase Mediated Insulin-like Signalling Pathway To Regulate The Development Of Grasshopper,Oedaleus Asiaticus

Protein tyrosine phosphatase?PTPs?and protein tyrosine kinase?PTKs?are the key genes responsible for the regulation of insect insulin-like pathway?ILP?,cells growth,metabolism initiation,gene transcription and observing immune response.Signal transduction in insect cell,proliferation,differentiation and cell communication is also associated with PTPs and PTKs.In the present experiment,the grasshopper?Oedaleus asiaticus Bey-Bienko?were treated with dsRNA of protein tyrosine non-receptor type 4?PTPN4?and protein tyrosine kinase 5?PTK5?along with control?ddH₂O?to understand the developmental phases of grasshopper through ILP.Significant reduction was recorded in body dry mass,growth rate and overall performance except survival rate in 5^th instar of O.asiaticus after the injection of dsPTK5.Expression of genes in ILP 5^th instar of O.asiaticus by the application of dsPTPN4and dsPTK5 revealed that the expression of PTK,INSR?insulin receptor?,IRS?insulin receptor substrate?,PI3K?phosphoinositide 3-kinase?,PDK?3-phosphoinositide-dependent protein kinase?,Akt?protein kinase B?and FOXO?forkhead transcription factor?were significantly down regulated except PTPN4,which remained non-significant.On the other hand,about the phosphorylation levels of the four important proteins of ILP in O.asiaticus,with the injection of dsPTK5,P-IRS and P-FOXO were significantly affected,P-IRS was significantly down regulated at the 0.05 probability level,while P-FOXO was significantly up regulated.The results showed that PTK5 increased the oxidative stress of ILP pathway.This indicated that the stress response in the ILP of O.asiaticus increased.Regarding association of protective enzymatic activities,including ROS?relative oxygen species?,CAT?catalase?and PO?phenol oxidase?increased significantly with injection of dsPTK5 as compared to dsPTPN4 and control,while dsPTPN4 treatment slightly raised the CAT and PO activities and with significant contribution.Additionally,genistein?PTK inhibitor?,PTP1B-IN-1?PTP1B inhibitor?and control?dimethyl sulfoxide,DMSO?were also applied to grasshopper.The survival rates were not significantly different amongst treatments.However,growth rate,body mass,and overall biological performance reduced significantly,following genistein treatment.By comparison,no any significant difference between treatment PTP1B-IN-1 treatment and control.Gene expression and protein phosphorylation levels of the PTK5,PTP1B?FOXO cascade,indicators of stress response in the ILP reduced in response to genistein application.It is important that the phosphorylation level of P-FOXO was significantly decreased under the treatment of genistein and PTP1B-IN-1,and the reaction of FOXO to genistein and PTP1B-IN-1increased the activities of protective enzymes?POD and CAT?.Finally,I conclude that the growth,dry weight and overall expressiveness of O.asiaticus are all negatively affected by ILP pathway after PTK5 activity was inhibited,which ultimately benefited insect detoxification with high-energy cost.Conversely,when inhibiting the activity of PTP1B,it can balance and regulate the development of insects by promoting the expression of the ILP pathway and regulating the activity of protective enzymes in insects.