Proteomic Analysis of Fetal Ovary Reveals That Ovarian Developmental Potential Is Greater in Meishan Pigs than in Yorkshire Pigs

Compared proteomic analysis of 8- and 32-week-old postnatal porcine ovaries

Pigs share many anatomical and physiological features with humans, offering a unique and viable model for biomedical research. Tandem mass tag method followed by mass spectrometry analysis was utilized to identify peptides (47,405), proteins (14,701), and protein groups (7634) in ovaries of 8- and 32-week-old postnatal Banna miniature pigs. After annotation and analysis by Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology, the proteins were identified as being involved in hormone metabolic pathways and maintenance, proliferation, and regulation of stem cells. In addition, we found 638 differentially expressed proteins between ovaries of 8- and 32-week-old postnatal Banna miniature pigs. We used Interactive Pathway Explorer to produce an overview of pig ovarian proteomics. Compared with those of the 8-week-old group, the proteins enriched in metabolism of steroid hormones, metabolism of lipids, and energy metabolism pathway were upregulated in the 32-week-old group, indicating physiological characteristics of sexual maturity. These findings have implications in applications of biomedicine.

SIGNIFICANCE OF THE STUDY

Pigs share many anatomical and physiological features with humans, offering a unique and viable model for biomedical research. In this study, we used tandem mass tag quantitative proteomics to describe, for the first time, protein expression patterns of postnatal pig ovaries. Proteins involved in hormone metabolic pathways and maintenance, proliferation, and regulation of stem cells were identified. With further analysis by Interactive Pathway Explorer, proteins enriched in metabolism of steroid hormones, metabolism of lipids, and energy metabolism pathway were upregulated in the 32-week-old group, indicating physiological characteristics of sexual maturity. These findings have implications in applications of biomedicine.

Effect of High Fat Dietary Intake during Maternal Gestation on Offspring Ovarian Health in a Pig Model

Excessive fat intake is a global health concern as women of childbearing age increasingly ingest a high fat diet. We therefore determined the association of a maternal high fat diet in pregnancy with offspring ovarian health during the gestation and postnatal female offspring in pig a model. Thirty-two Yorkshire gilts with similar bodyweights mated at the third estrus were randomly assigned to two nutrition levels of either a control (CON, crude fat: 7.27%) or a high fat diet (HFD, crude fat: 11.78%). Ovary samples were collected during the fetal (Day 55 (g55) and Day 90 of gestation (g90)) and offspring (prepuberty Day 160 (d160) and age at puberty) period to detect ovary development, antioxidant status and apoptosis cells. Maternal HFD did not influence notch signaling gene expression, which regulates primordial follicle formation and transformation, and ovarian histological effect at g55 and g90. However, maternal HFD reduced the numbers of large follicles at d160 and small follicle numbers upon puberty compared to CON in offspring. The results also revealed that the antioxidant index of total antioxidative capability (T-AOC), cytoplasmic copper/zinc superoxide dismutase (CuZn-SOD), glutathione peroxidase (GPx) activities and mRNA expression were higher in the CON than the HFD at g90 and d160, whereas, malondialdehyde (MDA) concentration was decreased in the CON. Maternal HFD increased the inhibitor of the apoptosis-related gene of B-cell lymphoma-2 (bcl2) mRNA expression at g90 and d160, whereas, pro-apoptotic-related gene bcl-2 assaciated X protein (bax) was reduced. These data show that the maternal high fat diet does not delay fetal ovarian development, but it changes ovarian health by the induction of oxidative stress and accelerating cell apoptosis in offspring.