DNA Fragmentation in Canine Immature Grade 1 Cumulus-Oocyte Complexes

• Type: Article in International Scientific Journal
• Date: 2010

Authors

lopes, g (Author) ICBAS; vandaele, l (Author) Other; rijsselaere, t (Author) Other; van soom, a (Author) Other; rocha, a (Author) ICBAS

Journal

Title: Reproduction in Domestic Animals

Vol. 45

Pages: e275-e281

ISSN: 0936-6768

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 5 Citations

Scientific classification

FOS: Agrarian Sciences > Veterinary science

Other information

Authenticus ID: P-003-0T5

DOI: 10.1111/j.1439-0531.2009.01557.x

Abstract (EN): Contents In this work, we studied the incidence of DNA fragmentation, interpreted as apoptotic changes and assessed by the TUNEL assay, in cumulus cells and oocytes of immature Grade 1 cumulus-oocyte complexes (COCs) obtained from healthy bitches (n = 27) of three age groups: young (1-3 years; n = 13), adult (4-6 years; n = 8) and elderly (7-10 years; n = 6). Age affected (p < 0.05) Grade 1 COCs recovery rates, with young animals yielding more (p < 0.01) Grade 1 COCs than the other two age groups. Conversely, no differences were observed in the incidence of DNA fragmentation (TUNEL-positive) in cumulus cells or oocytes between the three age groups. Overall, more than 80% of Grade 1 COCs presented < 15% of TUNEL-positive cumulus cells and enclosed TUNEL-negative (intact DNA) oocytes. Despite a higher proportion of TUNEL-negative oocytes being found in the germinal vesicle stage, most of the oocytes with nuclear material compatible with meiosis resumption (MR) or with non-identifiable nuclear material (ND) did not present DNA fragmentation. No correlation was observed between DNA fragmentations in oocytes and in cumulus cells. We concluded that the morphological parameters used to classify canine Grade 1 COCs are reliable to select a homogeneous population of COCs with low incidence of DNA fragmentation. Furthermore, these results indicate that DNA fragmentation can only explain a minor proportion of the incidence of MR and degeneration in canine oocytes at collection.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7