Reproduction Abstracts

Introduction: Following IVF, blastocysts produced from oocytes recovered from gilts fed a high fibre diet for the preceding 19 days contained more cells than blastocysts from oocytes of control-fed gilts. Oocytes were collected on day 19 of the gilts’ third oestrous cycle and matured in 10% of their own follicular fluid (FF), suggesting that FF may confer the reproductive benefits. The current study compared the protein composition of pooled FF from six high fibre-fed pigs whose oocytes produced blastocysts and 11 control-fed pigs whose oocytes did not produce blastocysts, in search of biomarkers for fertility or nutritional status.

Materials and methods: Abundant proteins including albumin and transferrin were depleted from FF samples. Remaining proteins were labelled with iTRAQ reagents and detected by liquid chromatography tandem mass spectrometry. Lactate dehydrogenase (LDH) activity and oestradiol concentrations were determined in FF of individual animals (n=40) by enzyme activity assays and RIA respectively. Statistical tests carried out included two-way ANOVA and correlation analyses.

Results and discussion: Out of 352 proteins detected, 21 were differentially expressed between the FF pools, including LDH, glutathione S-transferase and plasma kallikrein. LDH activity did not significantly differ between feeding groups or blastocyst yield but was negatively correlated with follicle size, FF volume and oestradiol concentration (all P<0.05).

Conclusion: This study has shown that the protein composition of FF could be a marker for prior nutrition and/or later fertility. A more comprehensive proteomic study is required to distinguish the effect of diet and later fertility.

Funded by: BBSRC and University of Edinburgh.