TEX14 is essential for intercellular bridges and fertility in male mice

Abstract

Cytokinesis in somatic cells concludes with the formation of a midbody, which is abscised to form individual daughter cells. In contrast, germ cell cytokinesis results in a permanent intercellular bridge connecting the daughter cells through a large cytoplasmic channel. During spermatogenesis, proposed roles for the intercellular bridge include germ cell communication, synchronization, and chromosome dosage compensation in haploid cells. Although several essential components of the midbody have recently been identified, essential components of the vertebrate germ cell intercellular bridge have until now not been described. Herein, we show that testis-expressed gene 14 (TEX14) is a novel protein that localizes to germ cell intercellular bridges. In the absence of TEX14, intercellular bridges are not observed by using electron microscopy and other markers. Spermatogenesis in Tex14 ؊/؊ mice progresses through the transit amplification of diploid spermatogonia and the expression of early meiotic markers but halts before the completion of the first meiotic division. Thus, TEX14 is required for intercellular bridges in vertebrate germ cells, and these studies provide evidence that the intercellular bridge is essential for spermatogenesis and fertility.cytoplasmic bridges ͉ knockout mouse ͉ male infertility ͉ male sterility ͉ ring canals

Premature ovarian failure in nobox-deficient mice is caused by defects in somatic cell invasion and germ cell cyst breakdown

“…2b). Immunostaining with an antibody against TEX14, a novel protein that localizes to germ cell intercellular bridges and is indispensable for the formation of the bridges [16], showed that similar to those of wild-type mice, the bridges of Nobox −/− mice contain TEX14 protein (Fig. 2e).…”

MRG15 is required for pre-mRNA splicing and spermatogenesis

“…In addition, at least Mtap2, Eif4g3, Usp2, Mtap7, Ace, and Tex14 are known to play a role in male fertility (29)(30)(31)(32)(33)(34), and overexpression of Spata17 and Rpgr leads to male infertility (35,36). Therefore, the infertility in the Mrg15 cKO mice could be secondary to alterations in the levels of these proteins.…”

“…Therefore, the infertility in the Mrg15 cKO mice could be secondary to alterations in the levels of these proteins. For example, our group has described the essential roles of TEX14 in male fertility and formation of intercellular bridges (34). The lack of TEX14 leads to the loss of intercellular bridges and the failure of proliferation and differentiation of spermatogonia (34,37).…”

“…For example, our group has described the essential roles of TEX14 in male fertility and formation of intercellular bridges (34). The lack of TEX14 leads to the loss of intercellular bridges and the failure of proliferation and differentiation of spermatogonia (34,37). Although the roles of TEX14 and intercellular bridges during postmeiotic process still remain to be elucidated, abnormal TEX14 might be a cause of the defects in spermatogenesis in the absence of Mrg15.…”

The role of spermatogonially expressed germ cell-specific genes in mammalian meiosis

“…Disruption of Dazl causes arrest of mitotic germ cells in an inbred genetic background (Lin & Page 2005). Tex14 is required for formation of intercellular bridges of germ cells including spermatogonia (Greenbaum et al 2006). Therefore, these three genes (Mvh, Dazl, and Tex14) function in both the mitotic and meiotic phases of germ cell development, which might also be the case for other genes in Table 1.…”