| Phospholipase C gamma 1 (PLC γ1) is an important signal molecular in the typical tyrosine protein kinase signal transduction pathway.When activated by tyrosine kinase ,it hydrolyzesphosphatidylinositol-4,5-bisphosphate (PIP2) generating two second messenger molecules: inositol l,4,5-trisphosphate(IP3) and diacylglycerol(DAG), which regulates intracellular levels of Ca2+ and activates protein kinase C(PKC) that can triggers a downstream kinase cascade,respectively. The mouse deficient of plcγ1 by gene targeting techniques dies at embryonic day 9(E9),which indicates PLCγ1 plays an important role during the embryo development, although the exact mechanism involved is unknown. DAG and IP3 generated by activated PLC yl is a regulator of pancreas secretion .The mobilization of calcium by IP3 is thought to be an vital factor during the process.However, the exact mechanism also remains unknown.In order to explore the exact functions of PLCγ1 during embryo development and pancreas secretion, several methods such asimmunohistochemistry, immunocytochemistry by electron microscope were adopted in our experiments to provide some experimental morphological informations.Firstly ,to observe the expression of PLC γ1 in fetal mouse tissues by immunohistochemistry.The results show that: A. PLCyl is ubiquitously distributed in fetal mouse tissues:It is expressed in most tissues regardless of the different developmental stages ,while a distinct expression is found in brain,renal,collectingduct,cartilage,skeletalmuscle,cardiac muscle,connective tissue. B. The expression of PLCyl shows the temporal and spatial differences, (a) . The expression of PLC yl shows the temporal and spatial differences in brain: PLC yl is expressed in all parts of brain .especially in cerebrum cortex. The expression of PLC yl in the layers of cerebrum cortex at different developmental stages just follows the steps of migration of neurons.ie, PLC yl shows a more distinct expression in the layers in which more neurons are distributed. In the experiment, the expression of PLC yl in the layers of cerebrum cortex at embryonic day ll(Ell),embroyonic day 14(E14),embryonic day 18(E18),and postnatal day 5(P5) is detected.The results show that: at Ell, the expression of PLCyl is more distinct in ventricular zone (neuroepithelium)which is close to ventricular of cerebrum cortex;at El4, the expression of PLC yl is more distinct in ventricular zone and intermediate zone of cerebrum cortex; at El8, with the outward migration of neurons the areas of distinct expression of PLC γ1 also transfer outward. The expression of PLC yl is most distinct in intermediate zone and cortial plate instead of in ventricular zone of cerebrum cortex.At P5, the expression of PLC yl decreases obviously,but the neurons in cortial plate still show strong positive reactions .In nerve nucleus of the brain ,the positive reactions of neurons are more distinct than those of the glia cells around, of which is weak, (b) .The expression of PLC yl in fetal mouse chondrocyte shows temporal difference.it increases with the embryonic development .The expression level of PLCγ1 in chondrocytes of E14,E16 and El8 was compared and the results are: at E14,it is low;at E16,it increase and at E18,itis the highest.(c).The expression level of PLCγ1 in fetal mouse renal collecting duct shows temporal difference: it decreases with the embryonic development .The expression leval of PLC γ1 in renal collecting duct of E14,E16 and E18 was compared and the results are: at E14,it is high;at E16, E18,it decreaseSjand there is no distinct difference between the two stages .C.The detection of the expression of PLC yl depends on the fixation time .An appropriate fixation time is from 6 to 10 hours.The antigens lose obviously when the fixation time exceeds 24 hours and little antigens could be detected then.Secondly,to evaluate the quantity of PLCγ1 antigen in brain,kidney,limbs,heart,stomach ,lung,liver,spleen and pancreas at the...
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