Localization of cytoplasmic dynein light-intermediate chain mRNA in the rat testis using in situ hybridization

Expression of cytoplasmic dynein light-intermediate chain mRNA in the rat testis was examined using in situ hybridization. The ribonucleotide probe, referred to the 5' end of open reading frame (6-515 nucleotids) of cytoplasmic dynein light-intermediate chain 53/55 (LIC-2) of the rat brain (Hughes et al., 1995. J. Cell Sci., 108: 17-24), was used. All spermatogenic cells were positive. Pachytene spermatocytes in later stages (after-stage VII) were the most intensely positive and round spermatids were also intense. These findings indicated that all spermatogenic cells may store the light-intermediate chain signal, and spermatocytes may produce it during later stages. The reaction in Sertoli cells was constant in intensity during the spermatogenic cycle, indicating that the light-intermediate chain mRNA signal may have no relation to the stage-dependent organelle transport, and that there may be post-translational regulation of the light-intermediate chain. In interstitium, only a few positive cells were observed. Northern blot hybridization demonstrated that one major band (2.0 kb) and two minor bands (4.4 kb and 3.5 kb) were detected in the testis, while one major band (4.4 kb) and one minor band (3.5 kb) were in the brain. This indicated that there are at least 3 isoforms in cytoplasmic dynein light-intermediate chain 53/55.