Newsgroup: it.scienza.biologia
Titolo: Raskolnikof bugiardo (era: Per chiarirci)

 Ad esempio nessuno sinora e' riuscito a clonare i topi.
Spudorata menzogna!  Anche i topi sono stati clonati benissimo (ricordate
la famosa "Cumulina"?): leggete ad es. la recente referenza [2].
Conclusione: Raskolnikof si è messo a fare il fisico bigotto alla Zichichi
e a sputare scemenze in campo biologico, quindi è meglio non dargli retta.
Bye,
  -= Ginzo =-
  [1] Nature 2000 Aug 10;406(6796):633-6
 NO is necessary and sufficient for egg activation at fertilization.
 Kuo RC, Baxter GT, Thompson SH, Stricker SA, Patton C, Bonaventura J,
 Epel D
 Neurosciences Program, Stanford University School of Medicine, Stanford
 University, California 94305, USA.
  The early steps that lead to the rise in calcium and egg activation at
 fertilization are unknown but of great interest--particularly with the
 advent of in vitro fertilization techniques for treating male infertility
 and whole-animal cloning by nuclear transfer. This calcium rise is required
 for egg activation and the subsequent events of development in eggs of all
 species. Injection of intact sperm or sperm extracts can activate eggs,
 suggesting that sperm-derived factors may be involved. Here we show that
 nitric oxide synthase is present at high concentration and active in sperm
 after activation by the acrosome reaction. An increase in nitrosation within
 eggs is evident seconds after insemination and precedes the calcium pulse
 of fertilization. Microinjection of nitric oxide donors or recombinant
 nitric oxide synthase recapitulates events of egg activation, whereas
 prior injection of oxyhaemoglobin, a physiological nitric oxide scavenger,
 prevents egg activation after fertilization. We conclude that nitric oxide
 synthase and nitric-oxide-related bioactivity satisfy the primary criteria
 of an egg activator: they are present in an appropriate place, active
 at an appropriate time, and are necessary and sufficient for successful
 fertilization.
 PMID: 10949304, UI: 20403580
  [2] Mol Reprod Dev 2000 Sep;57(1):55-9
 Birth of mice after nuclear transfer by electrofusion using tail tip cells.
 Ogura A, Inoue K, Takano K, Wakayama T, Yanagimachi R
 Department of Veterinary Science, National Institute of Infectious Diseases,
 Tokyo, Japan.
 Mice have been successfully cloned from cumulus cells, fibroblast cells,
 embryonic stem cells, and immature Sertoli cells only after direct injection
 of their nuclei into enucleated oocytes. This technical feature of mouse
 nuclear transfer differentiates it from that used in domestic species,
 where electrofusion is routinely used for nuclear transfer. To examine
 whether nuclear transfer by electrofusion can be applied to somatic cell
 cloning in the mouse, we electrofused tail tip fibroblast cells with
 enucleated oocytes, and then assessed the subsequent in vitro and in vivo
 development of the reconstructed embryos. The rate of successful nuclear
 transfer (fusion and nuclear formation) was 68.8% (753/1094) and the rate
 of development into morulae/blastocysts was 40.8% (260/637). After embryo
 transfer, seven (six males and one female; 2.5% per transfer) normal fetuses
 were obtained at 17.5-21.5 dpc. These rates of development in vitro and in
 vivo are not significantly different from those after cloning by injection
 (44.7% to morulae/blastocysts and 4.8% to term). These results indicate
 that nuclear transfer by electrofusion is practical for mouse somatic cell
 cloning and provide an alternative method when injection of donor nuclei
 into recipient oocytes is technically difficult.
 PMID: 10954856, UI: 20413443
----

 Bentornato.
Grazie!
Bye,
  -= Ginzo =-

PS: So che in giro per Usenet ci sono individui forse poco raccomandabili
che usano nickname come Gonzo e Gizmo, per cui preciso che io non ho niente
a che vedere con costoro.
Bye,
  -= Ginzo =-

 Certamente io non ho intenzione di evolvermi verso il bigottismo.
Pero' potresti evolverti verso l'apertura mentale. Non ti farebbe male.
Con buona pace delle salamandre.
Ciao, Raskolnikof