生物谷报道：据4月13日《生殖：配子生物学》杂志刊登的一项研究报告，人骨髓细胞第一次被分化成早期精子细胞，这项科学进步将帮助研究者更多理解精子起源。
在实验中，研究者从男性志愿者骨髓中分离间充质干细胞。这些细胞以前被发现可以分化为其他组织细胞如肌细胞。这些干细胞在实验室被培养诱导分化成男性生殖细胞，即精子细胞。遗传标记显示存在部分分化的精子细胞即精原细胞，男性生殖细胞发育的早期阶段。在大多数男性，精原细胞最终分化发育为成熟，有功能的精子细胞，但是这一过程在实验中尚未实现。
这项研究由Karim Nayernia教授主持，Nayernia教授原属德国Göttingen 大学，现就职于英国纽卡斯尔生命科学中心的英格兰东北部干细胞研究所（NESCI）。谈到新发表的论文，Nayernia教授说，“我们对于这项发现很激动，尤其是我们早期研究鼠的工作提示我们可以进一步深入研究。”此前，Nayernia教授对小鼠的研究中，从鼠的骨髓细胞也分化出了精原细胞。这些细胞被移植到睾丸中，观察到它们进行了早期减数分裂（细胞分裂），尽管他们没有进一步分化成成熟的精子细胞（《实验室研究》）。而在2006年7月，宣称从小鼠胚胎干细胞中分化出精子细胞，用这些细胞与小鼠卵子受精，诞生了七个新生命（《发育细胞》）。Nayernia教授也因此获得了世人瞩目。
“我们下一目标是看是否在实验室里能使精原细胞分化成成熟的精子细胞，这大约需要3~5年的时间。我们正在与研究所其它科学家合作开展这项工作。”Nayernia教授说，在伦理和社会允许的范围内，需要进行长期的科学研究，才能把研究推进到下一阶段即探讨其在人类生殖治疗中有无潜在的应用价值。
原文出处：
http://www.eurekalert.org/pub_releases/2007-04/uonu-esc041107.php
Public release date: 12-Apr-2007
Early-stage sperm cells created from human bone marrow
Breakthrough will help scientists understand more about how sperm cells are created
Human bone marrow has been used to create early-stage sperm cells for the first time, a scientific step forward that will help researchers understand more about how sperm cells are created.
The research published today (Friday, April 13 2007), in the academic journal Reproduction: Gamete Biology, was carried out in Germany* by a team of scientists led by Professor Karim Nayernia, formerly of the University of G鰐tingen but now of the North-east England Stem Cell Institute (NESCI), based at the Centre for Life in Newcastle upon Tyne.
For the experiment, Prof Nayernia and his team took bone marrow from male volunteers and isolated the mesenchymal stem cells. These cells have previously been found to grow into other body tissues such as muscle.
They cultured these cells in the laboratory and coaxed them into becoming male reproductive cells, which are scientifically known as 慻erm cells? Genetic markers showed the presence of partly-developed sperm cells called spermatagonial stem cells, which are an early phase of the male germ cell development. In most men, spermatagonial cells eventually develop into mature, functional sperm but this progression was not achieved in this experiment.
Earlier research led by Prof Nayernia using mice, published in Laboratory Investigations, also created spermatagonial cells from mouse bone marrow. The cells were transplanted into mouse testes and were observed to undergo early meiosis - cell division - the next stage to them becoming mature sperm cells, although they did not develop further.
Talking about his newly published research paper, Prof Nayernia, of Newcastle University, said : "We抮e very excited about this discovery, particularly as our earlier work in mice suggests that we could develop this work even further.
"Our next goal is to see if we can get the spermatagonial stem cells to progress to mature sperm in the laboratory and this should take around three to five years of experiments. I抣l be collaborating with other NESCI scientists to take this work forward.
Prof Nayernia says a lengthy process of scientific investigation is required within a reasonable ethical and social framework to be able to take this work to its next stage or to say if it has potential applications in terms of fertility treatments in humans.
Prof Nayernia gained worldwide acclaim in July 2006 when he announced in the journal Developmental Cell that he and colleagues had created sperm cells from mouse embryonic stem cells and used these to fertilise mice eggs, resulting in seven live births.
作者简介：
Prof. Karim Nayernia
Prof of Stem Cell Biology
Stem Cells Derived From Testis Show Promise For Treating A Wide Variety Of Medical Conditions
Research Interests
In its most general sense, our research program seeks to elucidate molecular mechanisms underlying development and differentiation of germline stem cells. Within this framework, we are exploring three general issues:
1) Potential of embryonic and adult stem to differentiate to male germ cells
2) Potential of spermatogonial stem cells to differentiate to somatic stem cells and development of therapeutically approaches.
3) Functional analysis of genes involved in germline stem cell proliferation and differentiation.
4) The role of germline stem cell proteins in tumorigenesis.
Other Expertise
Functional analysis of genes involved in germ cell development
Molecular aspect of tumor formation
Projects
Germ cells as a new and promising source of stem cells for regenerative medicine
Project Leaders: Professor Karim Nayernia
Selected Publications
Guan K., Nayernia K., Maier L.S., Wagner S., Wolf F., Li M., Engel W. and Hasenfuss G.P. Pluripotency of spermatogonial stem cells from adult mouse testis. Nature 2006, 440, 1199-1203. Nayernia K., Lee J.H., Drusenheimer N., Nolte J., Wulf G., Schwandt I., Ralf D., Müller C.H., Gromoll J., Engel W. Derivation of germ cells from bone marrow stem cells. Lab Invest 2006, 86, 654-663. Lee J.H., Schütte D., Wulf D., Füzesi L., Radzun H.J., Schweyer S., Engel W., Nayernia K. Stem Cell Protein Piwil2 is Widely Expressed in Tumors and Inhibits Apoptosis through Activation of Stat3/Bcl-XL Pathway. Mol Hum Genet 2006, 15(2), 201-211. Lee J.H., Engel W., Nayernia K. Stem Cell Protein Piwil2 Modulates Expression of Murine Spermatogonial Stem Cell Specific Genes. Mol Reprod Dev 2006, 73(2), 173-179.
