title: Ultrastructure of vitrified rabbit transgenic embryos.
abstract: The aim of the study was to determine the viability of rabbit transgenic (enhanced green fluorescent protein (EGFP)-positive) embryos cultured in vitro and compare with gene-microinjected (Mi) non-transgenic (EGFP-negative) embryos following vitrification. Non-microinjected and non-vitrified embryos were used as the control. Morphological signs of injury to embryo organelles were determined at the ultrastructural level using transmission electron microscopy (TEM). Morphometric evaluation was performed on cellular organelles using microphotographs obtained by TEM. Intact and Mi embryos recovered from in vivo fertilized eggs at 19-20 hours post coitum (hpc) were cultured for up to 72 hpc (morula stage), evaluated for the EGFP gene integration and then vitrified in 0.25 ml insemination straws in modified EFS (40% ethylene glycol + 18% Ficoll 70 + 0.3 M sucrose) vitrification solution. After 1-3 days the embryos were devitrified, a representative selection of embryos was analyzed by TEM and the remaining embryos were subjected to additional in vitro culture. Observations by TEM showed that the vitrified/warmed EGFP-positive and EGFP-negative embryos had a slight accumulation of cellular debris and lipid droplets compared with the control intact embryos. More severe changes were detected in the membrane structures of the treated embryos, mostly in the cytoplasmic envelope, trophoblastic microvilli, junctional contacts and mitochondria. We suggest that the higher proportion of deteriorated cell structures and organelles in the treated embryos may be due to the vitrification process rather than to mechanical violation (the gene-microinjection procedure), as a detailed inspection of ultrastructure revealed that most damage occurred in the cell membrane structures.
authors.affiliation: Animal Production Research Centre Nitra,95141 Luzianky Near Nitra,Slovak Republic.
authors.forename: P
authors.initials: P
authors.lastname: Chrenek
authors.affiliation: Animal Production Research Centre Nitra,Slovak Republic.
authors.forename: A V
authors.initials: AV
authors.lastname: Makarevich
authors.affiliation: P.J. Šafárik University,Košice,Slovak Republic.
authors.forename: M
authors.initials: M
authors.lastname: Popelková
authors.affiliation: University of Constantine Philosophy,Nitra,Slovak Republic.
authors.forename: J
authors.initials: J
authors.lastname: Schlarmannová
authors.affiliation: P.J. Šafárik University,Košice,Slovak Republic.
authors.forename: S
authors.initials: S
authors.lastname: Toporcerová
authors.affiliation: P.J. Šafárik University,Košice,Slovak Republic.
authors.forename: A
authors.initials: A
authors.lastname: Ostró
authors.affiliation: Technical University,Košice,Slovak Republic.
authors.forename: J
authors.initials: J
authors.lastname: Zivčák
authors.affiliation: Agriculture Biotechnological Centre,Godollo,Hungary.
authors.forename: Zs
authors.initials: Z
authors.lastname: Bosze
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D004622:Embryo, Mammalian / Q000648:ultrastructure*; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D008845:Microinjections; D046529:Microscopy, Electron, Transmission; D009028:Morula; D011817:Rabbits; D058989:Vitrification
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins