Project description:The undifferentiated spermatogonial population of mouse testis is known to be functionally heterogeneous and contain both stem cells and committed progenitor cells. However, gene expression patterns marking these distinct cell fractions are poorly defined. We found that a subset of undifferentiated spermatogonia were marked by expression of an Oct4-GFP transgene but properties of these cells were unclear. Undifferentiated cells were therefore isolated from adult testes and seperated according to expression of Oct4-GFP for gene expression analysis by microarray. Our goal was to correlate Oct4-GFP expression with that of known markers of stem and committed progenitor cells to determine which undifferentiated cell populations were marked by Oct4-GFP.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Microarray analysis was performed in order to detail the gene expression profiles in murine b-2M-SPa-6+c-kit-undifferentiated and b-2M-SPa-6+c-kit+ differentiating spermatogonia. These data were used to compare human and mouse transcriptomes of undifferentiated spermatogonia.
Project description:In adult mouse testis, undifferentiated spermatogonia include GFRα1+ and NGN3+ populations. The former mainly act as self-renewing stem cells that support steady-state spermatogenesis. Whilst, the latter are primed for differentiation, but retain the potential of self-renewal and contribute to regeneration and post-transplantation colony formation (Nakagawa et al. science .2010; Hara et al. cell stem cell. 2014). And, NGN3+ cells can differentiate to KIT+ cells, which are also mentioned differentiated spermatogonia, by retinoic acid signal. The gene expression profiles of GFRα1+, NGN3+ and KIT+ spermatogonia, as well as the whole testis samples, were investigated here by microarray (Ikami et al. development. 2015).
Project description:Undifferentiated spermatogonia comprise a pool of stem cells and progenitor cells that show heterogeneous expression of markers, including the cell surface receptor GFRα1. Technical challenges in isolation of GFRα1+ versus GFRα1- undifferentiated spermatogonia have precluded the comparative molecular characterization of these subpopulations and their functional evaluation as stem cells. Here, we develop a method to purify these subpopulations by FACS and show that GFRα1+ and GFRα1- undifferentiated spermatogonia both demonstrate elevated transplantation activity while differing principally in receptor tyrosine kinase signaling and cell cycle. We identify the cell surface molecule MCAM as differentially expressed in these populations and show that antibodies to MCAM allow isolation of highly enriched populations of GFRα1+ and GFRα1- spermatogonia from adult, wild-type mice. In germ cell culture, GFRα1- cells upregulate MCAM expression in response to GDNF/FGF stimulation. In transplanted hosts, GFRα1- spermatogonia yield GFRα1+ spermatogonia and restore spermatogenesis, albeit at lower rates than their GFRα1+ counterparts. Together, these data provide support for a model of a stem cell pool in which the GFRα1+ and GFRα1- cells are closely related, but show key cell-intrinsic differences and can interconvert between the two states based, in part, on access to niche factors.