The dynamic information of 331 animal genetic resources in 17 important animal genetic resource provinces (regions) was analyzed. According to the population inbreeding coefficient, combining with the information of p...The dynamic information of 331 animal genetic resources in 17 important animal genetic resource provinces (regions) was analyzed. According to the population inbreeding coefficient, combining with the information of population dynamic change trend and cross degree, these genetic resources for threatened degrees were classified. The results indicated that the population size of 138 breeds had increased, 147 breeds had decreased, 3 breeds were constant, 7 breeds (or varieties) were extinct, 9 breeds (or varieties) were critically endangered and needed urgently conserve, 50 breeds (or varieties) were endangered and should be conserved. We put forward a conservation and utilization plan for animal genetic resources.展开更多
Advances in molecular biotechnology have introduced new generations of molecular markers for use in the genetic improvement of farm animals. Consequently, more accurate genetic information can be obtained to better un...Advances in molecular biotechnology have introduced new generations of molecular markers for use in the genetic improvement of farm animals. Consequently, more accurate genetic information can be obtained to better understand existing animal genetic resources. This review gives a brief summary on the development of genetic markers including both the classical genetic markers and more advanced DNA-based molecular markers. This review will help us better understand the characteristics of different genetic markers and the genetic diversity of animal genetic resources.展开更多
Background Chronic otitis media(COM) is a significant clinical problem.Understanding the mechanisms of COM is critical for its control and treatment.However,little is known of the processes leading to COM as a result ...Background Chronic otitis media(COM) is a significant clinical problem.Understanding the mechanisms of COM is critical for its control and treatment.However,little is known of the processes leading to COM as a result of lack of animal models of N-ethyl-N-nitrosourea(ENU) induced mutations in otitis media with effusion(OME).Methods Otoscopy and auditory brain response(ABR) evaluation were carried out under sedation in Nmf391nmf/nmf mice of 2,4,6 and 8 months of age.The mice were killed for study of middle and inner ear pathology.Results Tympanic membrane visualization and ABR thresholds in 1-to 8-month-old Nmf391nmf/nmf mice showed spontaneous OME and inner ear diseases in approximately 100% of the animals.The significant elevation of ABR thresholds suggested a sensorineural component in hearing loss in addition to the conductive loss.Middle and inner ear histology showed various degrees of outer hair cells loss and middle ear inflammation in all the mice,but no inflammation cells in the inner ear.The ABR threshold at 32 kHz was significantly elevated.Conclusions This study shows histopathologic changes in the Nmf391nmf/nmf mouse model of COM with effusion that have not been reported in human COM.This ENU induced mutation model of COM will be valuable for the characterization of middle ear inflammation and inner ear disease processes that are induced by middle ear infections.We propose that COM with effusion in this ENU induced mutation model is the cause of the cochlea hair cells damage.展开更多
文摘The dynamic information of 331 animal genetic resources in 17 important animal genetic resource provinces (regions) was analyzed. According to the population inbreeding coefficient, combining with the information of population dynamic change trend and cross degree, these genetic resources for threatened degrees were classified. The results indicated that the population size of 138 breeds had increased, 147 breeds had decreased, 3 breeds were constant, 7 breeds (or varieties) were extinct, 9 breeds (or varieties) were critically endangered and needed urgently conserve, 50 breeds (or varieties) were endangered and should be conserved. We put forward a conservation and utilization plan for animal genetic resources.
基金supported by National High Technology and Science Development Plan of China(No.2011AA100302)Program for New Century Excellent Talents in University(No.NCET-11-0480)Program for Changjiang Scholar and Innovation Research Team in University(IRT1191)and project(CARS-41-K01)
文摘Advances in molecular biotechnology have introduced new generations of molecular markers for use in the genetic improvement of farm animals. Consequently, more accurate genetic information can be obtained to better understand existing animal genetic resources. This review gives a brief summary on the development of genetic markers including both the classical genetic markers and more advanced DNA-based molecular markers. This review will help us better understand the characteristics of different genetic markers and the genetic diversity of animal genetic resources.
基金supported by National Natural Science Foundation of China(grant no.39970785)International Collaborate Research Foundation of National Natural Science of China(grant no.322200462)National Institutes of Health (grant no.ROIDC007392)
文摘Background Chronic otitis media(COM) is a significant clinical problem.Understanding the mechanisms of COM is critical for its control and treatment.However,little is known of the processes leading to COM as a result of lack of animal models of N-ethyl-N-nitrosourea(ENU) induced mutations in otitis media with effusion(OME).Methods Otoscopy and auditory brain response(ABR) evaluation were carried out under sedation in Nmf391nmf/nmf mice of 2,4,6 and 8 months of age.The mice were killed for study of middle and inner ear pathology.Results Tympanic membrane visualization and ABR thresholds in 1-to 8-month-old Nmf391nmf/nmf mice showed spontaneous OME and inner ear diseases in approximately 100% of the animals.The significant elevation of ABR thresholds suggested a sensorineural component in hearing loss in addition to the conductive loss.Middle and inner ear histology showed various degrees of outer hair cells loss and middle ear inflammation in all the mice,but no inflammation cells in the inner ear.The ABR threshold at 32 kHz was significantly elevated.Conclusions This study shows histopathologic changes in the Nmf391nmf/nmf mouse model of COM with effusion that have not been reported in human COM.This ENU induced mutation model of COM will be valuable for the characterization of middle ear inflammation and inner ear disease processes that are induced by middle ear infections.We propose that COM with effusion in this ENU induced mutation model is the cause of the cochlea hair cells damage.
