Objective To establish the different degrees of rat diffuse axonal injury (DAI) model by using a self‐made DAI device .Methods A total of 70 healthy adult clean SD rats were selected and randomly divided into the normal control group (n=10) and DAI group (n=60) ,then the DAI group was randomly subdivided into the group A ,B ,and C ,20 cases in each group .The rat head injury model was prepared by using the self‐made experimental device ,which made the rat head to simultaneously produce instant oversized linear and angular accelerations ,different degrees of rat DAI model ,including mild DAI(group A) ,moderate DAI (group B) and severe DAI(group C) ,were induced by different rotation back and forth ,accelerated movement times under the con‐stant air pressure .The pathological and behavior effect evaluation was performed .Results With the injury degree aggravating ,the time interval of nerve physiological reflex recovery and awakening time in the acute DAI groups were increased (P<0 .05) .The nerve function score after 7 d in the DAI groups was decreased (P<0 .05);the death rates within 14 d after injury in the group A , B and C were 5 .0% ,25 .0% and 50 .0% respectively .With the injury degree aggravating ,the DAI pathological characteristics were more significant .Conclusion This device could effectively establish different injury degrees of DAI animal model .

To determine the role of outer dense fiber (ODF) in multiple morphological abnormalities of the sperm flagella in Akap4 gene defect mice.
 Methods: Akap4 knock-out (KO) mouse model was established by using gene editing technology. Akap4-KO male mice were identified by genotype. Seven sexually mature male Akap4-KO mice served as an experimental group, and 7 sexually mature wild-type (WT) male mice served as a control group. The changes in body weight and testicular weight were measured. Computer aided sperm analysis (CASA) was used to detect sperm motility. Sperm morphology was detected by modified Periodic Acid-Schif (PAS) staining. The ultra-structure of sperm was observed under the scanning and transmission electron microscope. Sperm flagella associated protein expression and localization were detected by immunofluorescence. Spermatogenesis function of testis was evaluated by HE and PAS staining. Ultra-structure of seminiferous tubules was observed under the transmission electron microscope.
 Results: Akap4-KO mice had no natural fertility. The sperm motility of Akap4-KO male mice was lower than that of WT male mice (8.81% vs 46.02%, P<0.01). In Akap4-KO male mice the percentage of sperm, with shortened tail and coiled tail was 91.18% which was higher than that of WT male mice (P<0.01). There was no statistically significance in the testicular weight, spermatogensis function, and sperm count between the 2 groups (P>0.01). The longitudinal column of fibrous sheath in Akap4-KO male mice was absent, and the residues of transverse rib remained, which was consistent with the immunofluorescence localization of AKAP3 protein. No. 3 and No. 8 ODF in the principal piece were disordered, which was in consistent with ectopic localization of ODF2 protein.
 Conclusion: Multiple morphological abnormalities of the sperm flagella in mice are resulted from disorder of "9+2" microtubules and the abnormally expanded lumen at the proximal of the principal piece via causing dysplasia of the transverse rib due to Akap4 gene defect, and separation of the ODF of No. 3 and No. 8 via loss of longitudinal column.
A Kinase Anchor Proteins ; Animals ; Fluorescent Antibody Technique ; Infertility, Male ; Male ; Mice ; Sperm Motility ; Sperm Tail ; Spermatozoa