title: Latrunculin A can improve the birth rate of cloned mice and simplify the nuclear transfer protocol by gently inhibiting actin polymerization.
abstract: Although animal cloning is becoming more practicable, there are many abnormalities in cloned embryos, and the success rate of producing live animals by cloning has been low. Here, we focused on the procedure for preventing pseudo-second polar body extrusion from somatic cell nuclear transfer (SCNT)-derived oocytes. Typically, reconstructed oocytes are treated with cytochalasin B (CB), but here latrunculin A (LatA) was used instead of CB to prevent pseudo-second polar body extrusion by inhibiting actin polymerization. CB caps F-actin, LatA binds G-actin, and both drugs prevent their polymerization. When the localization of F-actin was examined using phalloidin staining, it was abnormally scattered in the cytoplasm of CB-treated 1-cell embryos, but this was not detected in LatA-treated or in vitro fertilization-derived control embryos. The spindle was larger in CB-treated oocytes than in LatA-treated or untreated control oocytes. LatA treatment also doubled the rate of full-term development after embryo transfer. These results suggest that cloning efficiency in mice can be improved by optimizing each step of the SCNT procedure. Moreover, by using LatA, we could simplify the procedure with a higher birth rate of cloned mice compared with our original method.
authors.affiliation: Laboratory for Genomic Reprogramming, Center for Developmental Biology, RIKEN, Kobe, Japan. yterashita@cdb.riken.jp
authors.forename: Yukari
authors.initials: Y
authors.lastname: Terashita
authors.forename: Sayaka
authors.initials: S
authors.lastname: Wakayama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamagata
authors.forename: Chong
authors.initials: C
authors.lastname: Li
authors.forename: Eimei
authors.initials: E
authors.lastname: Sato
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Wakayama
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001723:Birth Rate; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000008:administration & dosage*; D019976:Cloning, Organism; D003571:Cytochalasin B / Q000494:pharmacology; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D053778:Thiazolidines / Q000008:administration & dosage*; D014404:Tubulin / Q000378:metabolism; D015053:Zygote / Q000187:drug effects / Q000378:metabolism
chemical_list: D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D053778:Thiazolidines; D014404:Tubulin; D003571:Cytochalasin B; C037067:latrunculin A