Ultrastructural characterization of fresh and cryopreserved in vivo produced ovine embryos

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Romao, RJ (Author) Other; rocha, a (Author) ICBAS; sousa, m (Author) ICBAS; Bettencourt, EMV (Author) Other; Bettencourt, CM (Author) Other; Silva, JNCE (Author) Other; Ferreira, P (Author) Other; de Matos, CP (Author) Other; Oliveira, E (Author) Other

Journal

Title: Theriogenology

Vol. 71

Pages: 947-958

ISSN: 0093-691X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 11 Citations

Other information

Authenticus ID: P-003-MD0

DOI: 10.1016/j.theriogenology.2008.10.019

Abstract (EN): Controlled slow freezing and vitrification have been successfully used for ovine embryo cryopreservation. Selection of embryos for transfer is based on stereomicroscopical embryo scoring after thawing, but the subjectivity inherent to this selection step has been demonstrated by ultrastructural studies of controlled slow frozen, in vivo produced ovine morulae aid blastocysts. These studies have shown that certain abnormalities remain undetected by stereomicroscopy only. In the present study, using ovine in vivo produced morulae and blastocysts, we have studied the ultrastructural alterations induced by open pulled straw vitrification (OPS) and controlled slow freezing, compared stereomicroscopical embryo scoring with light microscopy evaluation of embryo's semithin sections, and related the ultrastructural cellular damage with the embryo classification by stereomicroscopical embryo scoring of embryos' and semithin section evaluation by light microscopy. The ultrastructural lesions found for OPS-vitrified and controlled slow frozen embryos were similar, independently of embryo stage. A significant higher number of grade 3 embryos was found at stereomicroscopical scoring after controlled slow freezing (P = 0.02), and a significant higher number of grade 3 blastocysts was found at semithin sectioning after OPS vitrification (P=0.037). The extension Of Ultrastructural damage, especially of mitochondria and cytoskeleton, was related to the semithin classification but not to stereomicroscopical scoring at thawing, This suggests that semithin scoring is a useful tool for predicting ultrastructural lesions and new improvements in cryopreservation and thawing methods of ovine embryos are still warranted, including in the case of blastocysts cryopreserved by OPS vitrification.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12