This analysis demonstrated that there is a differential representation of these lipids according to their respective groups. In addition, the lipids found are involved in important mechanisms related to endometriosis progress in the ovary. Thus, the metabolomic approach for the study of lipids may be helpful in potential biomarker discovery.

Endometriosis is a chronic gynecological condition that affects 10-32% of women of reproductive age and may lead to infertility. The study of protein profiles in follicular fluid may assist in elucidating possible biomarkers related to this disease. For this, follicular fluid samples were obtained from women with tubal factor or minimal male factor infertility who had pregnancy outcomes after in vitro fertilization (IVF) treatment (control group, n = 10), women with endometriosis (endometriosis group, n = 10), along with the endometrioma from these same patients were included (endometrioma group, n = 10). For proteomic analysis, samples were pooled according to their respective groups and normalized to protein content. Proteins were analyzed by in tandem mass spectrometry (MS(E)) Spectra processing and the ProteinLynx Global Server v.2.5. was used for database searching. Data was submitted to the biological network analysis using Cytoscape 2.8.2 with ClueGO plugin. As a result, 535 proteins were identified among all groups. The control group differentially or uniquely expressed 33 (6%) proteins and equal expression of 98 (18%) proteins was observed in the control and endometriosis groups of which 41 (7%) proteins were further identified and/or quantified. Six (1%) proteins were observed in both the endometriosis and endometrioma groups, but 212 (39%) proteins were exclusively identified and/or quantified in the endometrioma group. There were 9 (1%) proteins observed in both the control and endometrioma groups and there were 139 (25%) proteins common among all three groups. Distinct differences among the protein profiles in the follicular fluid of patients included in this study were found, identifying proteins related to the disease progression and IVF success. Thus, some pathways related to endometriosis are associated with the presence of specific proteins, as well as the absence of others. This study provides a first step to the development of more sensitive diagnostic tests and treatment.

Animal reproductive biotechnology is continually evolving. Significant advances have been made in our understanding of early embryonic mortality and embryo development in domestic animals, which has improved the selection and success of in vitro technologies. Yet our knowledge is still relatively limited such that identifying a single embryo with the highest chance of survival and development for transfer remains challenging. While invasive methods such as embryo biopsy can provide useful information regarding the genetic status of the embryos, morphological assessment remains the most common evaluation. A recent shift, however, favors alternative, adjunct approaches for non-invasive assessment of an embryo's viability and developmental potential. Various analytical techniques have facilitated the evaluation of cellular health through the metabolome, the assessment of end products of cellular metabolism, or by analyzing spent media for small RNAs. This review discusses the application of noninvasive approaches for ascertaining the health and viability of in vitro-produced bovine embryos. A comparative analysis of noninvasive techniques for embryo assessment currently being investigated in cattle and humans is also discussed.

SummarySpent culture medium can provide valuable information regarding the physiological state of a bovine preimplantation embryos through non-invasive analysis of the sum/depleted metabolite constituents. Metabolomics has become of great interest as an adjunct technique to morphological and cleavage-rate assessment, but more importantly, in improving our understanding of metabolism. In this study, in vitro produced bovine embryos developing at different rates were evaluated using proton nuclear magnetic resonance (1H NMR). Spent culture medium from individually cultured embryos (2-cell to blastocyst stage) were divided into two groups based on their cleavage rate fast growing (FG) and slow growing (SG; developmentally delayed by 12–24 h), then analyzed by a 600 MHz NMR spectrometer. Sixteen metabolites were detected and investigated for sum/depletion throughout development. Data indicate distinct differences between the 4-cell SG and FG embryos for pyruvate (P < 0.05, n = 9) and at the 16-cell stage for acetate, tryptophan, leucine/isoleucine, valine and histidine. Overall sum/depletion levels of metabolites demonstrated that embryos produced glutamate, but consumed histidine, tyrosine, glycine, methionine, tryptophan, phenylalanine, lysine, arginine, acetate, threonine, alanine, pyruvate, valine, isoleucine/leucine, and lactate with an overall trend of higher consumption of these metabolites by FG groups. Principal component analysis revealed distinct clustering of the plain medium, SG, and FG group, signifying the uniqueness of the metabolomic signatures of each of these groups. This study is the first of its kind to characterize the metabolomic profiles of SG and FG bovine embryos produced in vitro using 1H NMR. Elucidating differences between embryos of varying developmental rates could contribute to a better understanding of embryonic health and physiology.

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