|
Life begins at 45 45岁也能生娃 Hope for older mothers. 高龄母亲的福音。 WHEN it comes to reproduction, men have iteasy. Almost to the end of their lives most have anample supply of sperm. Women are not so lucky.They are born with a supply of eggs that typically runs out when they reach middle age. Thatcould be about to change, however. Researchers have confirmed that women harbourovarian stem cells, and that these can give rise to new eggs. 讲到繁衍，男人表示压力很小。大多数人直到去世前都拥有充足的精子。女人可就没这么幸运了。人到中年，她们就会耗尽出生时携带的卵子。不过，这一情形很快就能得到改变。研究者们证实，女人拥有卵巢干细胞，而这种细胞能成为新的卵细胞的来源。 Stem cells have the ability to divide continuously and to change into different types of cells.Stem cells from adults can produce a variety of cell types, in addition to those that makeup the tissue in which they are found. 干细胞具有不断分裂的潜力，可以分化成许多种类的细胞。成人干细胞不仅可以分化成其来源组织的细胞，还能分化成其它细胞。 In 2004 Jonathan Tilly of Harvard Medical School and his colleagues discovered stem cells inmouse ovaries. Since then it has been shown that these ovarian stem cells can develop intoeggs, be fertilised and produce perfectly healthy mouse pups. But researchers have beenreluctant to believe that something similar might be possible in humans. | 
