Now showing 1 - 3 of 3
  • Publication
    Global proteomic characterization of uterine histotroph recovered from beef heifers yielding good quality and degenerate day 7 embryos
    The objective was to analyze the proteomic composition of uterine flushes collected from beef heifers on day 7 after insemination. Estrus was synchronized in crossbred beef heifers by using a protocol with a controlled intravaginal drug releasing device. Heifers detected in standing estrus (within 24-48 h after removal of controlled intravaginal drug releasing device) were inseminated (estrus = day 0) with frozen-thawed semen from a single ejaculate of a bull with proven fertility. Heifers from which an embryo was recovered (after slaughter on day 7) were classified as either having a viable embryo (morula/blastocyst stage) or a degenerate embryo (arrested at the 2- to 16-cell stage). The overall recovery rate (viable and degenerate combined) was 64%. Global liquid chromatography coupled to tandem mass spectrometry proteomic analysis of the histotroph collected identified 40 high-confidence proteins present on day 7; 26 proteins in the viable group, 10 in the degenerate group, and 4 shared between both groups. Five proteins (platelet-activating factor acetylhydrolase IB subunit γ [PAFAH1B3], tubulin α-1D chain, tubulin β-4A chain, cytochrome C, and dihydropyrimidinase-related protein-2) were unique or more abundant in the histotroph collected from animals with a viable embryo, and 1 protein (S100-A4) was more abundant in the histotroph collected from animals with a degenerate embryo. Of interest, PAFAH1B3, detected only in histotroph from the group yielding viable embryos, belongs to the group of platelet-activating factors that are known to be important for the development of the pre-implantation embryo in other species. To our knowledge this is the first report of PAFAH1B3 in relation to bovine early embryonic development.
      879Scopus© Citations 16
  • Publication
    Altered endometrial immune gene expression in beef heifers with retarded embryos
    The aim of the present study was to compare endometrial gene expression profiles in a group of beef heifers yielding viable or retarded embryos on Day 7 after oestrus as a means of potentially explaining differences in embryo survival rates. Heifers were classified as either: (1) viable, when the embryo collected on Day 7 after oestrus was at the correct developmental stage (i.e. morula/early blastocyst); or (2) retarded, when the embryo was arrested at the 2–16-cell stage. The focus of the present study was on genes that were associated with either the pro- or anti-inflammatory immune response. Endometrial gene expression was determined using quantitative real-time polymerase chain reaction analysis. Expression of the β-defensin (DEFB1), interferon (IFN)-α (IFNA), IFN-γ (IFNG), interleukin (IL)-6 (IL6), IL-10 (IL10), forkhead box P3 (FOXP3) and natural cytotoxicity triggering receptor 1 (NCR1) genes was lower in endometria from viable than retarded heifers. Expression of the nuclear factor of kappa light polypeptide gene enhancer in B cells 1 (NKFB1), transforming growth factor (TGF)-β (TGFB), IFN-γ-inducible protein 16 (IFI16) and IL-21 (IL21) genes was higher in viable than retarded heifers. We propose that small disturbances in the expression of immune genes in the endometrium on Day 7 after oestrus can have detrimental effects on embryo survival.
    Scopus© Citations 20  576
  • Publication
    Characterisation of endometrial gene expression and metabolic parameters in beef heifers yielding viable or non-viable embryos on Day 7 after insemination
    The aim of the present study was to compare the hormonal and metabolic characteristics and endometrial gene expression profiles in beef heifers yielding either a viable or degenerate embryo on Day 7 after insemination as a means to explain differences in embryo survival. Oestrus was synchronised in cross-bred beef heifers (n = 145) using a controlled internal drug release (CIDR)-prostaglandin protocol. Heifers (n = 102) detected in standing oestrus (within 24-48 h after CIDR removal) were inseminated 12-18 h after detection of oestrus (Day 0) with frozen-thawed semen from a single ejaculate of a bull with proven fertility. Blood samples were collected from Day 4 to Day 7 after oestrus to measure progesterone (on Days 4, 5 and 7), insulin and insulin-like growth factor (IGF)-I (on Days 4 and 6) and urea (on Day 7) concentrations. All animals were killed on Day 7. Uterine pH was determined at the time of death. Animals from which an embryo was recovered were classified as either having a viable embryo (morula/blastocyst stage; n = 32) or a retarded embryo (arrested at the two- to 16-cell stage; n = 19). In addition, 14 single-celled unfertilised oocytes were recovered, giving an overall recovery rate of 64%. There was no significant difference in the blood parameters determined or uterine pH at the time of death between heifers with either a viable or retarded embryo. The relative abundance of nine transcripts (i.e. MOGAT1, PFKB2, LYZ2, SVS8, UHRF1, PTGES, AGPAT4, DGKA and HGPD) of 53 tested in the endometrial tissue differed between heifers with a viable or retarded embryo. Both LYZ2 and UHRF1 are associated with regulation of the immune system; PFKFB2 is a mediator in glycolysis; MOGAT, AGPAT4 and DGKA belong to the triglyceride synthesis pathway; and PTGES and HGPD belong to the prostaglandin pathway. Both these metabolic pathways are important for early embryonic development. In conclusion, retarded embryo development in the present study was not related to serum progesterone, IGF-I, insulin or urea concentrations, nor to uterine pH at the time of death. However, altered expression of genes involved in the prostaglandin and triglyceride pathways, as well as two genes that are closely associated with the regulation of immunity, in the endometrium may indicate a uterine component in the retardation of embryo development in these beef heifers.
      826Scopus© Citations 56