Multifactorial Analysis of the Follicular Environment is Predictive of Oocyte Morphology in Cattle

Abstract

Numerous attempts have been recently made in the search for a reliable, fast and noninvasive assay for selection of oocytes suitable for in vitro embryo production. Potential markers have been described in the follicle such as follicular fluid (FF) or cumulus cells (CCs). However, the reported findings are contradictory, which may reflect the complexity of metabolism of the ovarian follicle. In the present experiment, a data set from individual follicles of known diameter was obtained: cumulus-oocyte complex (COC) morphology, fatty acid composition and glucose concentration in FF as well as apoptotic index in CCs. The obtained data was statistically analyzed either separately (univariate analysis) or simultaneously (multivariate analysis) to examine its predictive value in morphology assessment of bovine COCs. Although the univariate analysis yielded a complex relation system of the selected parameters, no clear outcome could be established. In multivariate analysis, the concentration of the four fatty acids (C16:0, C16:1, C18:1cis9, C22:5n3) and Δ9-desaturase (16) as well as elongase activities were selected as covariates. This allowed prediction of the morphology of a COC with an accuracy of 72%, which is the most interesting finding of the experiment. The present study indicates that the multifactorial model comprising of selected parameters related to the follicle appeared more effective in predicting the morphology of a bovine COC, which may improve the effectiveness of in vitro production systems.

Lipid Identification and Transcriptional Analysis of Controlling Enzymes in Bovine Ovarian Follicle

“…The interaction between TH and GC is essential for the maintenance of the original architecture and functions of ovarian cells, especially for the synthesis of steroids, which regulates reproductive function, in response to the follicle stimulation hormone (FSH) and luteinizing hormone (LH). The closest follicular environment of the oocyte, including FF, GC, and especially CC, has a crucial impact on the acquisition of oocyte developmental competence [ 12 , 14 , 15 , 16 ] and possesses molecular factors that are predictive of oocyte developmental potential [ 17 , 18 , 19 ].…”

Energy metabolism of follicular environment during oocyte growth and maturation

“…The question however arises what is the proper balance between glucose and fatty acids to obtain the most optimal effect of oocyte quality establishments. In the process of oocyte quality determination, all the elements of follicular environment are involved however follicular fluid and follicular cells are described as being the most crucial for oocyte proper development [7]. In the following review, the follicular environment will be discussed with regard to glucose and fatty acids metabolism and their metabolic balance with the further impact on the wider concept of female fertility.…”

Oleic acid in the modulation of oocyte and preimplantation embryo development

“…Fatty acid composition and glucose content in follicular fluid appear to be generally involved in follicular development (Warzych et al ., 2014). Notably, OlAc in follicular fluid was related to a higher bovine oocyte quality, in terms of COC morphology and follicular diameter (Warzych et al ., 2014).…”

“…Fatty acid composition and glucose content in follicular fluid appear to be generally involved in follicular development (Warzych et al ., 2014). Notably, OlAc in follicular fluid was related to a higher bovine oocyte quality, in terms of COC morphology and follicular diameter (Warzych et al ., 2014). However, the fatty acid composition of follicular fluid was not associated with bovine (Sinclair et al ., 2008) or human (O'Gorman et al ., 2013) oocyte cleavage following in vitro fertilization (IVF).…”