title: Generation and Application of Male Mice with Specific Expression of Green Fluorescent Protein in Germ Cells.
abstract: The study aimed to generate a mouse line with green fluorescent protein (GFP) specifically expressed in male germ cells to assess testicular toxicity.
  
  
  
  The mouse line with GFP specifically expressed in male germ cells was generated by mating a germ cell-specific transgenic Cre male mouse with a double-fluorescent reporter female mouse using Cre/loxP. The mouse line was administered ethylene glycol monomethyl ether (EGME) by oral gavage. Then, the green fluorescence intensity in the testes was used as an indicator to examine the potential for testicular toxicity testing by molecular biology, histopathology, and in vivo imaging techniques.
  
  
  
  Specific testicular GFP expression was observed in mice. GFP was mainly expressed in the germ cell lineage and concentrated in secondary spermatocytes/spermatocytes and spermatozoa. After administration of EGME, at the organ level, the green fluorescent intensity of the testes was decreased by 11 days and had disappeared by 34 days. Frozen testicular sections stained with DAPI showed significantly decreased green fluorescence in secondary spermatocytes and sperm cells. These observations were consistent with the testis weight and results of testicular histopathology.
  
  
  
  With the application of in vivo imaging becoming popular, this mouse line with GFP specifically expressed in the male germ cells may have some advantages for the study of reproductive toxicity.
authors.affiliation: Laboratory Animal Center, Peking University, 5 Yiheyuan Road, Beijing, 100871, China.|School of Public Health, Jilin University, 1163 Xinmin Street, Changchun, 130021, China.
authors.forename: Zhiru
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Laboratory Animal Center, Peking University, 5 Yiheyuan Road, Beijing, 100871, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: Laboratory Animal Center, Peking University, 5 Yiheyuan Road, Beijing, 100871, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Cao
authors.affiliation: School of Public Health, Jilin University, 1163 Xinmin Street, Changchun, 130021, China. merry_h@qq.com.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Liu
authors.affiliation: Laboratory Animal Center, Peking University, 5 Yiheyuan Road, Beijing, 100871, China. deshengz@pku.edu.cn.
authors.forename: Desheng
authors.initials: D
authors.lastname: Zhu
mesh_terms: D000818:Animals; D005026:Ethylene Glycols / Q000494:pharmacology; D005260:Female; D005453:Fluorescence; D005629:Frozen Sections; D015870:Gene Expression / Q000187:drug effects; D005838:Genotype; D005854:Germ Cells / Q000187:drug effects / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D009929:Organ Size / Q000187:drug effects; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism; D013737:Testis / Q000187:drug effects / Q000473:pathology
chemical_list: D005026:Ethylene Glycols; D049452:Green Fluorescent Proteins; C005219:methyl cellosolve
keywords: Cre-loxP; Ddx4; EGME; GFP; Reproductive toxicity; Testis