[Mutant generation of the testis genes and phenotype analyses in Drosophila].

Multiple genes work together to maintain the normal functions of the reproductive system. However, for many of these genes, little is known about their specific functions and mechanisms. In the present study, eight Drosophila genes, including CG4161, CG11475, CG2921, CG10541, CG7276, CG3800, CG8117 and CG16779, were selected for detailed studies based on their testis expression, undefined functions, and having highly homologous and conserved genes in humans (Homo sapiens) and mouse (Mus musculus). We analyzed their expression levels in different tissues, and determined their probably functions in male reproduction. The results showed that the first five genes were mainly expressed in testis, while other three showed ubiquitous expression in all tissues examined. Using the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) and homology-directed repair (HDR) strategies, we have systematically generated the mutants of these genes and studied their functions in male reproduction. Loss of function of CG7276 and CG3800 resulted in partial sterility and reduction of the offspring number, while other genes showed no significant impact on fertility. CG7276 -/- and CG3800 -/- mutants were partial sterile and showed various types of abnormities, including seminal vesicle atrophy, spermatogonial stem cell reduction and cellular distribution disorders. Results of DNA and F-actin staining also indicated that CG7276 and CG3800 could play important roles in spermiogenesis. The establishments of these mutants have provided means to unravel the functions and mechanisms of these genes in animal models.

[Protecting Effects of Jian'erji on Age-related Hearing Loss of C57BL/6J Mice].

Objective To observe decreased hearing in aged C57BL/6J mice, and to study pro- tective effects of Jian' erji ( JEJ ) for age-related hearing loss (AHL) and its possible mechanism. Methods Totally 36 C57BL/6J mice were randomly divided into four groups, i.e., the normal control group (n =6) , the AHL control group (n =12) , the high dose JEJ group (n =12) , the low dose JEJ group (n =6). Mice in the normal control group drank tap water from ablactation till 2 months old. Mice in the AHL control group drank tap water from ablactation till 7 months old. Mice in high and low dose JEJ groups drank JEJ at the daily dose of 3. 65 g/kg and 0. 91 g/kg respectively from ablactation till 7 months old. Six mice were selected from each group for auditory brainstem response (ABR) using brainstem evoked potentiometer on the day of ending the test. The cochlear tissue, auditory cortex, and liver were immediately collected from 6 mice of the high dose JEJ group and 6 of the AHL control group at the same ages. Contents of malondialdehyde (MDA) , end product of lipid peroxidation were detected by UV spectrophotometer using MDA coomassie blue kit. Results ABR thresholds evoked by short-pure tone from 4 to 48 KHz were in the normal range of 2 months old mice in the normal control group. Compared with 2 months old mice in the normal control group, ABR thresholds were significantly elevated in 7 months old mice of the AHL control group (P <0. 05). Significant differences also existed in ABR thresholds from 8 to 48 KHz in the high dose JEJ group (P <0. 05). Compared with 7 months old mice of the AHL control group, MDA contents in cochlear tissue, auditory cortex, and liver were obviously reduced in the high dose JEJ group (P <0. 01). Conclusions C57BL/6J mice showed significant symptoms of AHL in high frequency range at 7 months old. Daily drinking of high dose JEJ could significantly delay the occurrence and progress of AHL. Its protection might be related to antioxidant effects JEJ contained.