title: Vascular alterations underlie developmental problems manifested in cloned cattle before or after birth.
abstract: Although assisted reproductive techniques are commonly applied in humans and animals, they are frequently associated with major developmental deficits and reduced viability. To explore abnormalities associated with cloning or nuclear transfer (NT) as the most invasive of these methods, we used a bovine model to characterize abnormalities. Detailed necropsy examinations were done on 13 calves that died soon after birth; in addition, we included data from embryos and fetuses (produced by NT) that terminated prematurely. Bovine clones that survived until the neonatal period differed quantitatively and qualitatively from in-vivo-derived cattle. Although alterations affected a variety of organs (e.g. heart, lung and liver), there was a clear association with abberant vascular developmental during the early intrauterine phase. Therefore, we concluded that vascular problems were key alterations induced by cloning (presumably via epigenetic modifications).
authors.affiliation: Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Paulo Cesar
authors.initials: PC
authors.lastname: Maiorka
authors.affiliation: Department of Surgery, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Phelipe Oliveira
authors.initials: PO
authors.lastname: Favaron
authors.affiliation: Department of Surgery, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Andrea Maria
authors.initials: AM
authors.lastname: Mess
authors.affiliation: Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Caio Rodrigues
authors.initials: CR
authors.lastname: dos Santos
authors.affiliation: Department of Surgery, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Miryan Lanca
authors.initials: ML
authors.lastname: Alberto
authors.affiliation: Faculty of Animal Sciences and Food Engineering, University of São Paulo, Pirassununga, Brazil.
authors.forename: Flavio Vieira
authors.initials: FV
authors.lastname: Meirelles
authors.affiliation: Department of Surgery, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Maria Angelica
authors.initials: MA
authors.lastname: Miglino
mesh_terms: D000818:Animals; D002417:Cattle; D019976:Cloning, Organism / Q000009:adverse effects / Q000662:veterinary*; D053652:Nuclear Transfer Techniques / Q000009:adverse effects / Q000662:veterinary*; D054079:Vascular Malformations / Q000209:etiology / Q000662:veterinary*