Effect of sexing, conditioning and vitrification biotechniques of pre-implantation equine embryos produced in vivo on embryo viability

• Grant number: 22/14517-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2024
• End date: November 30, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Cezinande de Meira
• Grantee: Giovana Siqueira Camargo
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The in vivo production of equine embryos has a major impact on the livestock industry.equestrian, and together with biotechnologies, such as sexing, conditioning and vitrificationbecome important strategies that enhance transfer programsembryos (ET). However, due to the characteristics of the equine equipment, few studies and/orcost to apply the techniques, their applications are limited. The objective of the project isto evaluate the effect of the use of low cost biotechniques in the packaging, vitrification andsexing of preimplantation embryos on embryonic viability and that areto the field routine. Will be used 5 equine embryos in the blastocyst stageexpanded, randomly divided into 5 groups, being Integrity Group(n=10) - (selected intact embryos to those chosen after harvest); GroupCollapse (n=10) - (embryos collapsed manually with 32G needle services updatedrestrictions after the procedure); Achond Group-25ºC (n=10) - (embryosintact conditioned at 25oC for 24h); PCR-25ºC group (n=10) - (intact embryosconditioned at 25oC for 24h); PCR-VIT group (n=10) - (collapsed embryos with32G needle for sample collection for PCR sexing of blastocoel fluid andvitrified/devitrified). After embryo collection (D8 or D9), in the laboratory,A morphological evaluation of all embryos was performed, those with a previous stagePCR-VIT (Collapse Group, PCR-25ºC Group and VIT Group) will be collapsedmanually with the micro-needle (32G) The extravasated blastocele (BF) fluid will beused as a sample of genetic material for PCR sexing and control withnested PCR. Embryos from the Acond-25ºC Group and the PCR-25ºC Group will be selectedin a conditioning at 25ºC for 24h in isothermal boxes, and the embryos of the GroupPCR-VIT will be selected for the vitrification and devitrification procedure, after thechat. And for embryo viability analysis after the technologies applied, allembryos will arrive in fluorescence microscopy and interference microscopycontrast (DIC).