Dynamic proteome signatures in gametes, embryos and their maternal environment

Abstract

Comprehensive molecular analysis at the level of proteins represents a technically demanding, but indispensable, task since several post-transcriptional regulation mechanisms disable a valid prediction of quantitative protein expression profiles from transcriptome analysis. In crucial steps of gamete and early embryo development, de novo transcription is silenced, meaning that almost all macromolecular events take place at the level of proteins. In this review, we describe selected examples of dynamic proteome signatures addressing capacitation of spermatozoa, in vitro maturation of oocytes, effect of oestrous cycle on oviduct epithelial cells and embryo-induced alterations to the maternal environment. We also present details of the experimental strategies applied and the experiments performed to verify quantitative proteomic data. Far from being comprehensive, examples were selected to cover several mammalian species as well as the most powerful proteomic techniques currently applied. To enable non-experts in the field of proteomics to appraise published proteomic data, our examples are preceded by a customised description of quantitative proteomic methods, covering 2D difference gel electrophoresis (2D-DIGE), nano-liquid chromatography combined with tandem mass spectrometry, and label-free as well as stable-isotope labelling strategies for mass spectrometry-based quantifications.

Effects of Fertility on Gene Expression and Function of the Bovine Endometrium

“…Ultimately, progesterone-induced changes in endometrial gene expression alter the composition of histotroph and, in turn, growth and development of the conceptus [57], [59]–[61]. The significance of endometrial secretions in acquisition of endometrial receptivity and embryo implantation is well documented in humans and domestic animals [28], [62], [63]. However, it is not well understood which genes and biological pathways in the endometrium are crucial to establish endometrial receptivity and support conceptus elongation in cattle.…”

“…Future experiments will need to explore differences in the endometrial secrotome as it has a major influence on growth and development of histotroph growth and development of the conceptus [57], [59]–[61]. The significance of endometrial secretions in acquisition of endometrial receptivity and embryo implantation is well documented in humans and domestic animals [28], [62], [63].…”

Global proteomic characterization of uterine histotroph recovered from beef heifers yielding good quality and degenerate day 7 embryos

“…To discern the most biologically pertinent proteomic profiles, and considering the low number of animals per group (n=3), thresholds were applied to characterise high confidence targets present in the viable or degenerate groups. These included: 1) signal presence in all three animals in either group; or 2) identification with at least one unique peptide per sample (as mentioned above); similar criteria as utilized in previous studies [30,32,33]. This classification identified a total of 40 high confidence proteins; 26 proteins in the viable group, 10 in the degenerate group and 4 common to both groups (Table 1; Supplemental Table 1).…”

Hosting the preimplantation embryo: potentials and limitations of different approaches for analysing embryo - endometrium interactions in cattle

“…Important further biological activities are induced by embryonic signals during early pregnancy. Endometrial responses to the presence of an elongating embryo have been recently targeted in numerous singular and global transcriptome analyses (Bauersachs Feature Article et al 2005Klein et al 2006;Mitko et al 2008;Carter et al 2010;Walker et al 2010;Clemente et al 2011;Mamo et al 2011;Forde et al 2011b, as well as proteome analyses (Berendt et al 2005;Arnold and Frohlich 2011;Mullen et al 2012). The endometrium undergoes regulation of cellular turnover and adhesion and extracellular matrix remodelling to prepare the endometrium for the attachment and implantation of the conceptus, an endometrial vascular supply and histotroph synthesis.…”