Highlights d Adult-born neuron (ABN) activity during sleep can be seen using Ca 2+ imaging d ABNs active after learning reactivate in subsequent rapid eye movement (REM) sleep d Optogenetic manipulation of ABN activity in REM sleep impairs memory consolidation d This effect may be mediated by ABN synaptic plasticity

Single intraperitoneal injection of busulfan at 20 mg/kg body weight to mature male mice induced the deletion of the spermatogenic cells, followed by the restoration of the spermatogenesis by the surviving undifferentiated spermatogonia. The changes of the protein contents in testis during these processes were analyzed by two-dimensional gel electrophoresis in order to identify the proteins expressed at the specific stages of spermatogenesis. An acidic protein that disappeared and recovered in the same time course as spermatids after the busulfan treatment was identified as CABS1 by mass spectrometry. It was found that CABS1 was specifically expressed in the elongate spermatids at steps 13 to 16 in stages I to VIII of the seminiferous epithelium cycle of the mouse, and then it localized to the principal piece of flagellum of the mature sperm in the cauda epididymis. We have found for the first time that CABS1 is a calcium-binding protein that binds calcium during the maturation in the epididymis.

Abstract. In our previous study (Kawashima et al., Biol Reprod 2009; 80: 1293-1304, we suggested that the first cycle of spermatogenesis recovered from busulfan-induced temporary arrest was a good model system to analyze the proteins expressed at the specific stages of spermatogenesis in the mouse, and this has been confirmed in the present paper. Namely, six-week-old mice were injected with busulfan at 20 mg/kg body weight. The germ cells except for the undifferentiated spermatogonia disappeared by 32 days after injection. The surviving spermatogonia started to proliferate, and spermatogenesis was entirely recovered about 77 days after injection. By proteome analysis of the busulfan-treated testis during the process of recovery of spermatogenesis, we identified a protein that was expected to be expressed in the spermatogenic cells as Superkiller viralicidic activity-2-like-2 (SKIV2L2). Skiv2l2 mRNA was found in the kidney, epididymis and heart as well as the testis. In the testis, Skiv2l2 mRNA was shown to be highly expressed in the spermatocytes at stages I to VI. On the other hand, SKIV2L2 protein was found to be predominantly localized in the nuclei of round spermatids. In accordance with the fact that SKIV2L2 belongs to the Ski2 family within the superfamily 2 of RNA helicases, it has been shown that SKIV2L2 has both the RNA-binding and ATPase activities. Key words: Busulfan, Proteome, RNA helicase, Spermiogenesis (J. Reprod. Dev. 57: [457][458][459][460][461][462][463][464][465][466][467] 2011) permatogenesis is a complex process that consists of three principle phases, mitotic proliferation for stem cell renewal, meiosis and spermiogenesis, which are attained by the spatiotemporally specific expression of proteins [1]. Especially in spermiogenesis, dramatic morphological changes consisting of acrosome and flagellum formation, condensation of the nucleus and removal of extra cytoplasm and organelles should be accomplished by a series of expressions of germ cell-specific genes. Although a number of the germ cell-specific proteins have been identified, most of the essential roles in spermiogenesis remain to be elucidated.Recently, we showed that the proteins expressed in spermatogenic cells can be screened by analysis of spermatogenesis in the busulfan-treated testis [2]. In short, spermatogenesis was temporarily ceased by a single intraperitoneal injection of busulfan at 20 mg/kg body weight in mature male mice. This resulted in the clearance of the spermatogenic cells except for the undifferentiated spermatogonia from the seminiferous tubules. Spermatogenesis was then resumed by the surviving spermatogonia. The spermatogenic cells such as spermatocytes, round spermatids, elongated spermatids and sperm reappeared successively and synchronously to the seminiferous epithelium. On the other hand, the somatic cells maintained their activities to support spermatogenesis even after the busulfan treatment.We tried to identify the proteins expressed at the specific stages of spermatogenesis by proteome analysis ...

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