Expression of uncharacterized male germ cell-specific genes and discovery of novel sperm-tail proteins in mice

• Published in: PloS one 2017-07, Vol.12 (7), p.e0182038-e0182038
• Main Authors: Kwon, Jun Tae, Ham, Sera, Jeon, Suyeon, Kim, Youil, Oh, Seungmin, Cho, Chunghee
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Biology and Life Sciences; Blotting, Western; Cell division; Cellular proteins; Coding; Computer Simulation; Cytoskeleton; Epididymis; Fertility; Fertilization; Flagella; Fluorescent Antibody Technique; Gene expression; Gene Expression Regulation; Genes; Genes - physiology; Genetic aspects; Germ cells; Health aspects; Humans; Immunoblotting; Immunofluorescence; Immunoglobulins; In vitro methods and tests; Life sciences; Male; Medicine and Health Sciences; Mice; Motility; Properties; Proteins; Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Rodents; Sperm; Sperm Tail - metabolism; Spermatogenesis; Spermatogenesis - physiology; Spermatozoa - metabolism; Testes; Testis - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0182038

The identification and characterization of germ cell-specific genes are essential if we hope to comprehensively understand the mechanisms of spermatogenesis and fertilization. Here, we searched the mouse UniGene databases and identified 13 novel genes as being putatively testis-specific or -predominant. Our in silico and in vitro analyses revealed that the expressions of these genes are testis- and germ cell-specific, and that they are regulated in a stage-specific manner during spermatogenesis. We generated antibodies against the proteins encoded by seven of the genes to facilitate their characterization in male germ cells. Immunoblotting and immunofluorescence analyses revealed that one of these proteins was expressed only in testicular germ cells, three were expressed in both testicular germ cells and testicular sperm, and the remaining three were expressed in sperm of the testicular stages and in mature sperm from the epididymis. Further analysis of the latter three proteins showed that they were all associated with cytoskeletal structures in the sperm flagellum. Among them, MORN5, which is predicted to contain three MORN motifs, is conserved between mouse and human sperm. In conclusion, we herein identify 13 authentic genes with male germ cell-specific expression, and provide comprehensive information about these genes and their encoded products. Our finding will facilitate future investigations into the functional roles of these novel genes in spermatogenesis and sperm functions.