Organogenesis of the respiratory and cardiovascular system of bovine embryos from nuclear transfer and IVF

Author(s)

Míryan Lança Vilia Alberto

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2010-12-13

Examining board members

Maria Angélica Miglino; Paulo Roberto Adona; Flavio Vieira Meirelles; Felipe Perecin; José Manoel dos Santos

• Advisor: Maria Angélica Miglino

Abstract

Morphogenetic changes of cardio-respiratory system of bovine from in vitro fertilization and nuclear transfer is a major factor responsible for high incidence of both periods embryonic, fetal and postnatal mortality. We used techniques of light microscopy to study the development of heart and lung in these animals. We found that in embryos derived from in vitro fertilization, at 28 days of gestation, appears the laryngotracheal tube and its fold through tracheoesophageal septation. In the same period the embryos showed pericardial cavity, atrium divided into left and right, cardiac cone, venous sinus, layer of myocardium and epicardium. In embryos with 36 days of gestational age was observed the tracheal bronchus from a bud in the right lateral portion of the trachea, cranial to its bifurcation. At 44 days of gestation, the lung buds of the embryos showed main bronchi giving rise to budding of segmental bronchi. The sustentation mesenchyme in differentiation contained scattered blood vessels, unlike embryos from TN, which with 68 days of gestation showed lung in pseudoglandular stage, containing bronchioles buds and few blood vessels in histological sections obtained and analyzed. With 70 days, the fetal heart ventricle had significantly large, small atrium and lungs not developed. From our results we conclude that genetic alterations, incomplete information in cellular communications and change in cellular metabolism are likely responsible for the anomalies in the techniques of embryo manipulation, causing a slower and flawed development when compared to embryos in vivo, explaining the high rate of pregnancy loss (AU)