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Factor in oocyte assists reprogramming Unfertilized eggs contain components that can dedifferentiate other cells that have gone down the path toward a specific cell fate. Gonzalez-Muñoz et al. show that the protein-folding factor ASF1A facilitates this reprogramming event and it acts at a particular phase of germ cell division termed metaphase II. ASF1A helps turn differentiated cells such as human adult dermal fibroblasts into undifferentiated pluripotent stem cells. Science , this issue p. 822

Somatic cell nuclear transfer (SCNT) technology has recently been used to generate animals with a common genetic composition. In this study, we report the derivation of a pluripotent embryonic stem (ES) cell line (SCNT-hES-1) from a cloned human blastocyst. The SCNT-hES-1 cells displayed typical ES cell morphology and cell surface markers and were capable of differentiating into embryoid bodies in vitro and of forming teratomas in vivo containing cell derivatives from all three embryonic germ layers in severe combined immunodeficient mice. After continuous proliferation for more than 70 passages, SCNT-hES-1 cells maintained normal karyotypes and were genetically identical to the somatic nuclear donor cells. Although we cannot completely exclude the possibility that the cells had a parthenogenetic origin, imprinting analyses support a SCNT origin of the derived human ES cells.

The potential of cloning depends in part on whether the procedure can reverse cellular aging and restore somatic cells to a phenotypically youthful state. Here, we report the birth of six healthy cloned calves derived from populations of senescent donor somatic cells. Nuclear transfer extended the replicative life-span of senescent cells (zero to four population doublings remaining) to greater than 90 population doublings. Early population doubling level complementary DNA-1 (EPC-1, an age-dependent gene) expression in cells from the cloned animals was 3.5- to 5-fold higher than that in cells from age-matched (5 to 10 months old) controls. Southern blot and flow cytometric analyses indicated that the telomeres were also extended beyond those of newborn (

The annual economic value of livestock and poultry sales in the United States currently exceeds $132 billion ( 1 ), yet only about 0.04% ($32.15 million) ( 2 ) of the $88 billion Department of Agriculture (USDA) budget in fiscal year 2007 ( 3 ) was allocated to its competitive grants program for research that directly involves agriculturally important domestic animals. By contrast, the Department of Health and Human Services (DHHS) apportioned 4.1% ($29.5 billion) of its $716 billion budget in fiscal year 2008 to the National Institutes of Health (NIH) of which ∼80% supported extramural research ( 4 ). Whether this direct comparison between USDA and DHHS is appropriate may be debatable; still, it clearly illustrates the huge disparity in total budget available for research grants focused on animal agriculture, about 1/918th that for human health. The private sector does invest in agricultural research and development, but, understandably, such funds are highly focused on commercial interests and not on basic research of the kind we discuss.

The possibility of cloning humans has raised questions as to whether nuclear transfer can be used to reproducibly generate healthy adult animals. Reports in the popular and scientific press on genetic, immunological, and other developmental problems raise the question of whether there are “any

Parthenogenesis is the process by which an egg can develop into an embryo in the absence of sperm. This process has been characterized to some extent in nonhuman primates ([1][1], [2][2]); however, to date, no primate parthenogenetic embryonic stem (ES) cell lines have been derived. Although

Human embryonic stem (hES) cells are unique in their demonstrated potential to differentiate into all cell lineages. Reports by T. Wakayama et al. (“Differentiation of embryonic stem cell lines generated from adult somatic cells by nuclear transfer,” 27 Apr., p. [740][1]) and N. Lumelsky et al. (“Differentiation of embryonic stem cells to insulin-secreting structures similar to pancreatic islets, “ScienceExpress, [26 Apr., 10.1126][2]) testify to the enormous promise of ES cell research. The editorial “Disappearing stem cells, disappearing science,” by Irving L. Weissman and David Baltimore (27 Apr., p. [601][3]) emphasizes the implications of this research for human health. Weissman and Baltimore point out that hES cells are currently the most promising source of cells for tissue regeneration research. They also note that this area has enormous potential for shedding light on some of the greatest mysteries of early human development. During this same week, the U.S. Department of Health and Human Services suddenly asked the National Institutes of Health (NIH) to cancel a planned first meeting of a committee that was to review applications from scientists seeking federal funds for hES cell research. This announcement heightens concerns that the Bush administration may eventually block implementation of the NIH's guidelines supporting this research. We hope that these fears are groundless and that the Bush administration will use this additional time to move toward support of the guidelines. Whatever the outcome, however, these delays have a real cost in terms of human suffering. According to data from the Centers for Disease Control's National Center for Health Statistics, approximately 3,000 Americans die every day from diseases that in the future may be treatable with ES-derived cells and tissues. We believe that these urgent health needs provide strong moral grounds for pursuing ES cell research. In addition, at least three ethical considerations recommend federal funding for this research. First, withdrawal of support will slow this research, but not stop it from going forward. Private organizations and overseas researchers will fill the void. In some cases, they will do so without the kinds of comprehensive ethical oversight provided by U.S. human subjects regulations. Second, prohibiting such funding will not prevent the destruction of embryos. Each year, thousands of spare embryos created in infertility procedures are routinely destroyed at the request of their progenitors. A very small number of these embryos could be used to produce immortal stem cell lines that could be grown and used for research without ever using more embryos. The relevant ethical question is whether these spare embryos will simply be thrown away or used for human benefit. Third, and finally, we note that the United States is a religiously and ethically pluralistic nation. Many of those who oppose ES cell research base their position on religious views not shared by other citizens. As much as possible, the government should try to avoid taking sides in these debates and confine itself to policies that promote public health and welfare. ES cell research within the framework of the NIH guidelines is such a policy. [1]: /lookup/doi/10.1126/science.1059399 [2]: http://www.sciencemag.org/cgi/content/short/1058866v1 [3]: /lookup/doi/10.1126/science.292.5517.601

Last month, 70 members of the U.S. Congress, including Henry Hyde, Chairman of the House Judiciary Committee, and J. C. Watts Jr. Republican Conference Chairman, signed a letter urging the federal government to ban all research on stem cells obtained from human embryos and fetuses. The letter calls upon the U.S. Department of Health and Human Services (DHHS) to reverse National Institutes of Health (NIH) Director Harold Varmus's decision to allow funding of pluripotent stem cell research. The lawmakers object “in the strongest possible terms” to Varmus's decision, as well as to the memorandum issued in January by DHHS General Counsel Harriet Rabb, which served as the legal basis for Varmus's position. In their letter, the members of Congress state, “Any NIH action to initiate funding of such research would violate both the letter and spirit of the federal law banning federal support for research in which human embryos are harmed or destroyed.” Federal laws and regulations, they claim, have protected human embryos and fetuses “from harmful experimentation at the hands of the Federal government” for more than two decades. “This area of law has provided a bulwark against government's misuse and exploitation of human beings in the name of medical progress. It would he a travesty for this Administration to attempt to unravel this accepted ethical standard.”