We report the isolation of 153 mouse genes whose expression is dramatically up-regulated during spermiogenesis. We used a novel variation of the subtractive hybridization technique called stepwise subtraction, wherein the subtraction process is systematically repeated in a stepwise manner. We named the genes thus identified as TISP genes (transcript induced in spermiogenesis). The transcription of 80 of these TISP genes is almost completely specific to the testis. This transcription is abruptly turned on after 17 days of age, when the mice enter puberty and spermiogenesis is initiated. Considering that the most advanced cells present at these stages of spermatogenesis are the spermatids, it is likely that we could isolate most of the spermatid-specific genes. DNA sequencing revealed that about half the TISP genes are novel and uncharacterized genes, confirming the utility of the stepwise subtraction approach for gene discovery.
TISP40, a mouse spermatid‐specific gene, encodes a CREB/CREM family transcription factor that is predominantly expressed during spermiogenesis. We report here that TISP40 generates two types of proteins, Tisp40α and Tisp40β, both of which contain a transmembrane domain and localize to the endoplasmic reticulum (ER). In contrast, mutant proteins lacking the transmembrane domain (Tisp40α/βΔTM) primarily localize to the nucleus. Endoglycosidase H treatment shows that the C‐terminus of Tisp40α/β is glycosylated. Protease experiments demonstrate that Tisp40α/β are Type II transmembrane proteins that are released into the nucleus by a two‐step cleavage mechanism called ‘regulated intramembrane proteolysis’ (Rip). Unlike previously published observations, Tisp40α does not bind to the NF‐κB site; instead, it specifically binds to the unfolded protein response element (UPRE). Luciferase assays reveal that Tisp40βΔTM activates transcription through UPRE. Northern blot analysis shows that Tisp40α/βΔTM proteins up‐regulate EDEM (ER degradation of enhancing α‐manosidase‐like protein) mRNA. These observations unveil a novel event in mouse spermiogenesis and show that the final stage of trans‐criptional regulation is controlled by the Rip pathway.
Tektins are a class of proteins that form filamentous polymers in the walls of ciliary and flagellar microtubules. We report here the molecular cloning of a new member of the tektin family, tektin-t, identified from a mouse haploid germ cellspecific cDNA library. Tektin-t mRNA encodes a protein of 430 deduced amino acids possessing RSNVELCRD, the conserved sequence of tektin family proteins. Western blotting showed a single band having a molecular weight of 86 kDa in the mouse testis. Immunohistochemistry of the testis showed that tektin-t is localized in the flagella of elongating spermatids from developmental step 15 to maturity.z 1999 Federation of European Biochemical Societies.
ObjectiveThe purpose of this study was to investigate chemokine profiles and their functional roles in the early phase of fracture healing in mouse models.MethodsThe expression profiles of chemokines were examined during fracture healing in wild-type (WT) mice using a polymerase chain reaction array and histological staining. The functional effect of monocyte chemotactic protein-1 (MCP-1) on primary mouse bone marrow stromal cells (mBMSCs) was evaluated using an in vitro migration assay. MCP-1−/− and C-C chemokine receptor 2 (CCR2)−/− mice were fractured and evaluated by histological staining and micro-computed tomography (micro-CT). RS102895, an antagonist of CCR2, was continuously administered in WT mice before or after rib fracture and evaluated by histological staining and micro-CT. Bone graft exchange models were created in WT and MCP-1−/− mice and were evaluated by histological staining and micro-CT.Results
MCP-1 and MCP-3 expression in the early phase of fracture healing were up-regulated, and high levels of MCP-1 and MCP-3 protein expression observed in the periosteum and endosteum in the same period. MCP-1, but not MCP-3, increased migration of mBMSCs in a dose-dependent manner. Fracture healing in MCP-1−/− and CCR2−/− mice was delayed compared with WT mice on day 21. Administration of RS102895 in the early, but not in the late phase, caused delayed fracture healing. Transplantation of WT-derived graft into host MCP-1−/− mice significantly increased new bone formation in the bone graft exchange models. Furthermore, marked induction of MCP-1 expression in the periosteum and endosteum was observed around the WT-derived graft in the host MCP-1−/− mouse. Conversely, transplantation of MCP-1−/− mouse-derived grafts into host WT mice markedly decreased new bone formation.ConclusionsMCP-1/CCR2 signaling in the periosteum and endosteum is essential for the recruitment of mesenchymal progenitor cells in the early phase of fracture healing.
MYC-mediated early glycolysis negatively regulates proinflammatory responses by controlling IRF4 in inflammatory macrophages Graphical abstract Highlights d MYC is a key player for early glucose metabolism in inflammatory macrophages d MYC links metabolic reprograming to the function of inflammatory macrophages d MYC functions as the activation threshold for inflammatory responses d MYC regulates inflammatory cytokines, in part, by controlling
We conducted a simple resource allocation game known as the ultimatum game (UG) with preschoolers to examine the role of cognitive and emotional perspective-taking ability on allocation and rejection behavior. A total of 146 preschoolers played the UG and completed a false belief task and an emotional perspective-taking test. Results showed that cognitive perspective taking ability had a significant positive effect on the proposer’s offer and a negative effect on the responder’s rejection behavior, whereas emotional perspective taking ability did not impact either the proposer’s or responder’s behavior. These results imply that the ability to anticipate the responder’s beliefs, but not their emotional state, plays an important role in the proposer’s choice of a fair allocation in an UG, and that children who have not acquired theory of mind still reject unfair offers.
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