Identification of a novel testis-specific gene mtLR1, which is expressed at specific stages of mouse spermatogenesis.
A novel testis-specific gene termed mtLR1 was identified by digital differential display. Sequence analyses revealed that mtLR1 protein contains an amino terminus leucine-rich repeat domain and shows 33% similarities to PIDD which functions in p53-mediated apoptosis. Northern blot analysis showed that mtLR1 mRNA was specifically expressed in adult mouse testis, and RT-PCR results also showed that mtLR1 was exclusively expressed in adult testis and not in spermatogonial cells. The expression of mtLR1 mRNA was developmentally upregulated in the testes during sexual maturation and was, conversely, downregulated by experimental cryptorchidism in vivo. We also showed that the expression of mtLR1 mRNA was relatively highly sensitive to heat stress in vitro. The green fluorescent protein produced by pEGFP-C3/mtLR1 was only detected in the cytoplasm of spermatogonia cell line GC-1 after 24 h posttransfection. Immunohistochemical analysis revealed that the protein is most abundant in the cytoplasm of spermatocytes and round spermatids within seminiferous tubules of the adult testis. The time-dependent expression pattern of mtLR1 in postnatal mouse testes suggested that mtLR1 gene might be involved in the regulation of spermatogenesis and sperm maturation.
Nie
Dong-Song
DS
Human Reproductive and Stem Cell Engineering Institute, Central South University, 88 Xiangya Road, Changsha, Hunan 410078, PR China.
Xiang
Yang
Y
Wang
Jiang
J
Deng
Yun
Y
Tan
Xiao-Jun
XJ
Liang
Yue-Hong
YH
Lu
Guang-Xiu
GX
D000375:Aging / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D003456:Cryptorchidism / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018882:Heat Stress Disorders / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism*; D014018:Tissue Distribution
D011506:Proteins; C498894:mtLR1 protein, mouse