by mitosis, to more spermatogonia and to the diploid, larger,primary spermatocytesthat form the next layer of cells toward the lumen. Primary spermatocytes undergo meiosis and produce the next layer of cells, the haploidsecondary spermatocytes, similar in appearance but smaller than their progenitors....
Figure 1. Long-term maintenance of mouse haESCs through filtration. A, diameters of mouse haESCs with 1C, 2C, or 4C (C, DNA content; mAG, mouse androgenetic haESCs; mPG, mouse parthenogenetic haESCs). B, diagram of the filtration system. C, filters with 5-μm and 8-μm pore size...
The nuclear export receptor CRM1 (XPO1) recognizes and binds specific sequence motifs termed nuclear export signals (NESs) in cargo proteins. About 200 NES motifs have been identified, but over a thousand human proteins are potential CRM1 cargos, and most of their NESs remain to be identified...