farreriovaries at the proliferative stage with Trizol reagents (Takara Bio Inc., Otsu, Japan) according to the manufacturer’s instructions. of the canonical Wnt pathway) were addedin vitroto culture medium made up of testis cells ofC. farreri, the expression of-catenindecreased significantly detected by qRT-PCR (P<0.05), suggesting the canonical Wnt signal pathway exists in the scallop testis. Similarly, when 50 M and 100 M quercetin (an inhibitor of -catenin) were addedin vitroto the culture system,Dax1expression was significantly down-regulated compared with controls (P<0.05), implying the-cateninis an upstream gene ofDax1and is involved in the regulation ofC. farrerispermatogenesis. == Introduction == The Wnt signaling transduction pathway plays an important role in many developmental processes, including vertebrate limb regeneration, nervous system development, body axis formation, and adrenocortical development[1],[2],[3]. Current studies in invertebrates such asDrosophila melanogaster,Caenorhabditis elegans, andHemicentrotus pulcherrimus, and vertebrates such asDanio rerio,Xenopus laevis,Mus musculus, andHomo sapienshave provided abundant information regarding Wnt signaling in signaling transduction and function[4][10]. To date, at least three Wnt Sofosbuvir impurity C intracellular signaling pathways have been recognized: the Wnt/-catenin pathway, the Wnt/planar polarity pathway, and the Wnt/calcium pathway[11],[12],[13]. The Wnt/-catenin pathway, also named the canonical Wnt pathway is the best comprehended, and controls numerous developmental processes including cell fate determination, differentiation, and survival, by stabilizing -catenin[14]. In the absence of a Wnt ligand, cytoplasmic -catenin is usually degraded by interactions with a destruction complex created by three proteins, APC (adenomatous polyposis coli), Axin, and GSK3 (glycogen synthase kinase-3). The presence of Wnt prevents the degradation of -catenin, thus the stabilized -catenin is usually transported to the nucleus and activates gene transcriptions through direct interactions Sofosbuvir impurity C with T-cell factor/lymphoid enhancer factor (Tcf/Lef)[15]. The Wnt/planar polarity pathway and Wnt/calcium pathway are two major noncanonical Wnt pathways. The Wnt/planar polarity pathway (also called the Wnt/JNK pathway) is usually characterized by the activation of jun-N-terminal kinase (JNK) including small GTPases of the Rho family such as RhoA, Rac, or Cdc42[16]. The Wnt/calcium pathway employs the second-messenger systems of G-proteins to mobilize intracellular calcium stores and activate atypical protein kinase C (PKC) and other calcium-responsive pathways[17],[18]. The noncanonical Wnt pathway is required for the formation of vertebrate tissues, maintenance of adult stem cells, and the suppression of tumors[19]. -catenin is usually a key transcriptional effector of the canonical Wnt transmission transduction pathway Rabbit Polyclonal to OR10G9 but also functions as a cell adhesion molecule at the plasma membrane by linking cadherins to -catenin[20]. Structurally, -catenin consists of an N-terminal region, a central region, and a C-terminal region[21]. The N-terminal region contains a consensus site required for the phosphorylation of GSK-. The C-terminal region functions as a transactivator required for the activation of target genes[22]. The central region contains 12 imperfect armadillo Sofosbuvir impurity C repeats (ARM). Each repeat forms three alpha-helixes that are arranged in a compact superhelix[23], which is required for interactions with proteins such as cadherins, Axins, APC, and Tcf/Lef[24],[25],[26],[27],[28]. Recently, increasing numbers of studies have found that -catenin functions in mammalian sex determination and differentiation. In mice, the activation of -catenin in somatic cells of XY gonads effectively blocks testis development, including disruption of testis cord formation, and down-regulates the expression of testis marker genes, finally leading to male-to-female sex reversal. This implies that mouse -catenin is usually a key anti-testis molecule[29]. Furthermore, loss of -catenin in the SF1-positive populace of fetal somatic cells causes morphological defects in ovaries such as the appearance of testis-specific coelomic vessels and the loss of female germ cells, while Sofosbuvir impurity C morphogenesis, Sertoli cell differentiation, or masculinization in testes are not affected, suggesting -catenin is necessary only for Sofosbuvir impurity C ovarian differentiation but is usually dispensable for testis development[30]. Moreover, it is well documented in human embryo kidney 293 (HEK293) cells that-cateninactivates the expression ofDax1through the canonical Wnt pathway. Therefore, the Wnt–catenin-Dax1 signaling pathway exists in.