The Differences Of Hearing Threshold Of The Inducible Conditional Connexin26(Cx26) Null Of Transgenic Mouse In The SPF Environment And The Common Environment

Objective: The aim of our study was to explore the common environmental factors affectthe hearing of inducible conditional connexin26（Cx26）null transgenic mouse.Method: Generation of inducible conditional connexin26（Cx26）null transgenic mousemodels.Cx26null mice were generated by one dose injection of tamoxifen (0.3mg/gofbodyweight,6.P.).Mice were divided into four groups, Group A（Cx26loxP/loxP）and GroupB（Cx26loxP/loxP;Rosa26CreER）were placed in the SPF environment. Group C（Cx26loxP/loxP）and Group D（Cx26loxP/loxP;Rosa26CreER）were bred in the common environment.Auditorybrainstem response (ABR) was used to detect the hearing threshold of mice(30.P.).Electro-otoscopy was used to detect the incidence of otitis media. Drinking water and airquality data were detected according the national standard methods.Results: The data showed that the difference in ABR between A and C was not significant(P>0.05). The data of B and D were significantly higher than A and C, the difference wasstatistically significant(P <0.01), The difference in ABR between B and D was significant(P <0.01). The incidence of otitis media was not significant (P>0.05). For air quality,noise,PM10,ammonia, the total number of bacteria,formaldehyde, temperature, and relativehumidity have statistical differences significant (P <0.01), other differences were notsignificant(P>0.05). For drinking water quality,total number of colonies, oxygenconsumption, color and turbidity have statistical difference (P<0.01),other differences werenot significant(P>0.05).Conclusions: The hearing threshold of Cx26null mice bred in common environment wassignificantly higher than that in the SPF environment, the control mice did not change inboth environments, which indicates that environmental factors such as noise,PM10,formaldehyde,high temperature and relative humidity played role in the hearing lossof inducible conditional Cx26null transgenic mouse models.