Histological evaluation of the umbilical cord of clone foals

• Grant number: 24/15214-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: June 30, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Claudia Barbosa Fernandes
• Grantee: Natalia Dinoá Leite de Vasconcelos
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/10260-3 - From macro to genes of the chorioalanthoid membrane of pregnant mares of equine clones, AP.R

Abstract

Among the assisted reproduction techniques used in horses, commercial cloning is one of the biotechnologies that helps to preserve genetic with high value and representativeness in the equine industry. However, this biotechnique still has space for improvement in terms of efficiency and reducing losses during the reproductive process. The existence of placental alterations and anomalies in embryonic and fetal development are part of this knowledge gap. Studies on cloning in horses and cattle have shown that there are alterations in the gene expression of these embryos, resulting in changes in placental angiogenesis, accompanied by the presence of edema and significant alterations in the umbilical cord and in the vasculature of the chorioallantoic membrane. Thus, the main objective of this research project is to analyze the histological structure of cloned foal's umbilical cord produced by somatic cell nuclear transfer (SCNT) and compare it with non-cloned foals. Samples of 20 fragments of the allantoic part of the umbilical cord were collected from 20 cloned foals divided into four experimental groups: I) 5 foals produced by AI and ET techniques (control group); II) 5 viable foals produced by SCNT without placental alterations; III) 5 viable foals produced by SCNT with placental alterations; and IV) 5 stillbirths or neonatal deaths up to 12 hours after birth. Histological analyses will be carried out using the Hematoxylin and Eosin (H&E) staining technique and Masson's trichrome to analyze collagen fibers and muscle fibers. The images obtained will be processed using ImageJ software and a descriptive analysis of the results will be carried out.