Expression patterns of taste receptor type 1 subunit 3 and α-gustducin in the mouse testis during development

Taste receptor type 1 subunit 3 (T1R3) and its associated heterotrimeric G protein alpha-gustducin (G alpha) are involved in sweet and umami sensing in taste cells. They are also strongly expressed in the testis and sperm, but their expression patterns and potential roles involved were previously unknown. In present study, we investigated the expression patterns of T1R3 and G alpha in the mouse testis at critical stages of postnatal life, and throughout the spermatogenic cycle. Our results indicated that T1R3 and G alpha exhibited a stage-dependent expression pattern during mouse development, and a cell-specific pattern during the spermatogenic cycle. Their expressions have been increased significantly from prepubertal to pubertal periods (P < 005), and decreased significantly in aged mice (P < 005). The changes were mainly attributed to the differential expression of T1R3 or G alpha in elongated spermatids and Leydig cells at different stages of the spermatogenic cycle. In addition, the expression of T1R3 and G alpha were first observed in residual bodies of spermatozoa and endothelial cells of blood vessels at post-pubertal mice, while G alpha was located in apoptotic spermatogonia of postnatal mice. These novel expression patterns suggest a role of T1R3 and G alpha in the onset of spermatogenesis, pace of spermatogenic cycle, and aging Of the testis. (C) 2015 Elsevier GmbH. All rights reserved.