Silvestri, G, Rathje, CC, Harvey, SC, Gould, RL, Walling, GA, Ellis, PJI, Harvey, KE and Griffin, DK (2021) Identification of optimal assisted aspiration conditions of oocytes for use in porcine in vitro maturation: A re‐evaluation of the relationship between the cumulus oocyte complex and oocyte quality. Veterinary Medicine and Science, 7 (2). 465 - 473. ISSN 2053-1095

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The quality of porcine oocytes for use in IVF is commonly graded according to the number of layers of cumulus cells (CCs) surrounding the oocyte; together these form the cumulus oocyte complex (COC). At least three compact layers of CCs is regarded as important for efficient IVP. To test this, oocytes were scored according to cumulus investment, with grade A representing COCs with three or more cumulus layers including granulosa cell‐cumulus oocyte complexes, grade B those with an intact corona radiata surrounded by another layer of cumulus cells and grades C and D representing COCs with lower CC investment. These oocytes were then monitored for in vitro maturation (IVM), as assessed by tubulin immunostaining for meiotic progression, the development of a cortical granule ring, and by glutathione levels. Results indicate that grading correlates closely with nuclear maturation and cytoplasmic maturation, suggesting that grading oocytes by cumulus investment is a reliable method to predict IVM success. Importantly, Grade A and B oocytes showed no significant differences in any measure and hence using a cut‐off of two or more CC layers may be optimal. We also determined the effect of assisted aspiration for oocyte retrieval, comparing the effect of needle size and applied pressure on the retrieval rate. These data indicated that both variables affected oocyte recovery rates and the quality of recovered oocytes. In combination, these experiments indicate that grade A and B oocytes have a similar developmental potential and that the recovery of oocytes of these grades is maximised by use of an 18‐gauge needle and 50 mmHg aspiration pressure.

Item Type: Article
Additional Information: This is the final published version of the article (version of record). It first appeared online via Wiley at - please refer to any applicable terms of use of the publisher.
Uncontrolled Keywords: In vitro production; Morphology; Oocyte; Pig
Subjects: S Agriculture > SF Animal culture
Depositing User: Symplectic
Date Deposited: 30 Apr 2021 09:53
Last Modified: 11 Jun 2021 11:36

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