生物谷報道：據(jù)4月13日《生殖：配子生物學(xué)》雜志刊登的一項研究報告,，人骨髓細(xì)胞第一次被分化成早期精子細(xì)胞，這項科學(xué)進(jìn)步將幫助研究者更多理解精子起源,。
    在實驗中，研究者從男性志愿者骨髓中分離間充質(zhì)干細(xì)胞,。這些細(xì)胞以前被發(fā)現(xiàn)可以分化為其他組織細(xì)胞如肌細(xì)胞,。這些干細(xì)胞在實驗室被培養(yǎng)誘導(dǎo)分化成男性生殖細(xì)胞，即精子細(xì)胞,。遺傳標(biāo)記顯示存在部分分化的精子細(xì)胞即精原細(xì)胞,，男性生殖細(xì)胞發(fā)育的早期階段。在大多數(shù)男性,，精原細(xì)胞最終分化發(fā)育為成熟,，有功能的精子細(xì)胞,，但是這一過程在實驗中尚未實現(xiàn)。
    這項研究由Karim Nayernia教授主持,，Nayernia教授原屬德國Göttingen 大學(xué),，現(xiàn)就職于英國紐卡斯?fàn)柹茖W(xué)中心的英格蘭東北部干細(xì)胞研究所（NESCI）。談到新發(fā)表的論文,，Nayernia教授說,，“我們對于這項發(fā)現(xiàn)很激動，尤其是我們早期研究鼠的工作提示我們可以進(jìn)一步深入研究,。”此前,，Nayernia教授對小鼠的研究中，從鼠的骨髓細(xì)胞也分化出了精原細(xì)胞,。這些細(xì)胞被移植到睪丸中,，觀察到它們進(jìn)行了早期減數(shù)分裂（細(xì)胞分裂），盡管他們沒有進(jìn)一步分化成成熟的精子細(xì)胞（《實驗室研究》）,。而在2006年7月,，宣稱從小鼠胚胎干細(xì)胞中分化出精子細(xì)胞，用這些細(xì)胞與小鼠卵子受精,，誕生了七個新生命（《發(fā)育細(xì)胞》）,。Nayernia教授也因此獲得了世人矚目。
    “我們下一目標(biāo)是看是否在實驗室里能使精原細(xì)胞分化成成熟的精子細(xì)胞,，這大約需要3~5年的時間,。我們正在與研究所其它科學(xué)家合作開展這項工作。”Nayernia教授說,，在倫理和社會允許的范圍內(nèi),，需要進(jìn)行長期的科學(xué)研究，才能把研究推進(jìn)到下一階段即探討其在人類生殖治療中有無潛在的應(yīng)用價值,。

原文出處：

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.

作者簡介：
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.