The pluripotency factor LIN28 marks undifferentiated spermatogonia in mouse

• Main Authors: Kaestner Klaus H, Wu Xin, Zheng Ke, Wang Peijing
• Format: Article
• Language: English
• Published: BMC 2009-06-01
• Series: BMC Developmental Biology
• Online Access: http://www.biomedcentral.com/1471-213X/9/38

<p>Abstract</p> <p>Background</p> <p>Life-long production of spermatozoa depends on spermatogonial stem cells. Spermatogonial stem cells exist among the most primitive population of germ cells – undifferentiated spermatogonia. Transplantation experiments have demonstrated the functional heterogeneity of undifferentiated spermatogonia. Although the undifferentiated spermatogonia can be topographically divided into A_s(single), A_pr(paired), and A_al(aligned) spermatogonia, subdivision of this primitive cell population using cytological markers would greatly facilitate characterization of their functions.</p> <p>Results</p> <p>In the present study, we show that LIN28, a pluripotency factor, is specifically expressed in undifferentiated spermatogonia (A_s, A_pr, and A_al) in mouse. <it>Ngn3 </it>also specifically labels undifferentiated spermatogonia. We used <it>Ngn3</it>-GFP knockin mice, in which GFP expression is under the control of all <it>Ngn3 </it>transcription regulatory elements. Remarkably, <it>Ngn3</it>-GFP is only expressed in ~40% of LIN28-positive A_s(single) cells. The percentage of <it>Ngn3</it>-GFP-positive clusters increases dramatically with the chain length of interconnected spermatogonia.</p> <p>Conclusion</p> <p>Our study demonstrates that LIN28 specifically marks undifferentiated spermatogonia in mice. These data, together with previous studies, suggest that the LIN28-expressing undifferentiated spermatogonia exist as two subpopulations: <it>Ngn3</it>-GFP-negative (high stem cell potential) and <it>Ngn3</it>-GFP-positive (high differentiation commitment). Furthermore, <it>Ngn3</it>-GFP-negative cells are found in chains of <it>Ngn3</it>-GFP-positive spermatogonia, suggesting that cells in the A_alspermatogonia could revert to a more primitive state.</p>