One of the problems in cloning human beings is finding a source of human eggs. Scientists report that they have now achieved the production of precursory human eggs in vitro from human stem cells.
Science published a study by Chika Yamashiro, Kotaro Sasaki, Yukihiro Yabuta, Yoji Kojima, Tomonori Nakamura, Ikuhiro Okamoto, Shihori Yokobayashi, Yusuke Murase, Yukiko Ishikura, Kenjiro Shirane, Hiroyuki Sasaki, Takuya Yamamoto and Mitinori Saitou on 20th September, 2018 in which a mixture of human, pluripotent stem cells and embryonic, ovarian somatic cells from mice were cultured in vitro for about four months. The stem cells "differentiated progressively into oogonia-like cells" the Japanese team reports.
This study indicates that human oocytes might be produced from human somatic cells in the future, making the production of human clones quicker, cheaper and easier than previously.