Energy and lipid metabolism gene expression of D18 embryos in dairy cows is related to dam physiological status

Abstract

We analyzed the change in gene expression related to dam physiological status in day (D)18 embryos from growing heifers (GH), early lactating cows (ELC), and late lactating cows (LLC). Dam energy metabolism was characterized by measurement of circulating concentrations of insulin, glucose, IGF-1, nonesterified fatty acids, ␤-hydroxybutyrate, and urea before embryo flush. The metabolic parameters were related to differential gene expression in the extraembryonic tissues by correlation analysis. Embryo development estimated by measuring the length of the conceptuses and the proportion of expected D18 gastrulating stages was not different between the three groups of females. However, embryo metabolism was greatly affected by dam physiological status when we compared GH with ELC and GH with LLC but to a lesser extent when ELC was compared with LLC. Genes involved in glucose, pyruvate, and acetate utilization were upregulated in GH vs. ELC conceptuses (e.g., SLC2A1, PC, ACSS2, ACSS3). This was also true for the pentose pathway (PGD, TKT), which is involved in synthesis of ribose precursors of RNA and DNA. The pathways involved in lipid synthesis were also upregulated in GH vs. ELC. Despite similar morphological development, the molecular characteristics of the heifers' embryos were consistently different from those of the cows. Most of these differences were strongly related to metabolic/hormone patterns before insemination and during conceptus free-life. Many biosynthetic pathways appeared to be more active in heifer embryos than in cow embryos, and consequently they seemed to be healthier, and this may be more conducive to continue development. dairy cow; fertility; energy balance; energy metabolism; conceptus development; gene expression; correlations IN THE MODERN HOLSTEIN cow, calving rates are close to 55-60% in heifers and 35-40% in lactating cows (39,73). Most pregnancy losses occur prior to the period of maternal recognition and maintenance of the corpus luteum, i.e., before days 15-17 (D15-D17) after artificial insemination (AI), and are due to nonfertilization-early embryonic loss (NF-EEL, Refs. 22,35,73). NF-EEL can be estimated in field trials by measuring plasma or milk progesterone concentrations the day of AI and 21-24 days later. The frequency of NF-EEL has been reported to be between 25 and 45% in lactating Holstein cows (26,32,35,52), and it has increased from the 1980s (22).Age/parity, uterine health (nulliparous heifers vs. postpartum cows), and metabolic and endocrine environment are factors that can explain differences in reproductive efficiency. Maternal metabolism is known to influence fertility. Milk production, body condition score (BCS), postpartum BCS variations, negative energy balance (NEB), and quantity and quality of dietary protein supply are related to pregnancy rate (reviews Refs. 15,40,45,65,73,76). This effect might be explained partly by the clearance of progesterone in highproducing dairy cows (22) and by poor oocyte quality (43), which impair fertilization ability and early e...

Genomic analysis of snub-nosed monkeys (Rhinopithecus) identifies genes and processes related to high-altitude adaptation

“…Interestingly, RYR2 has also been reported as a key candidate gene related to high-altitude adaptation in Tibetan wolves 31 . In addition to the overlapping loci, we observed nine candidate high-altitude-related loci that were specific to particular populations, which may contribute to the development of unique and local adaptations [32][33][34][35][36][37][38][39][40][41][42][43][44] (Table 2). Interestingly, ATR (R. bieti specific), which functions in DNA repair, regulates the expression of hypoxia-inducible factor (HIF)-1α, and confers hypoxia tolerance in vitro [33][34][35] , was identified here for the first time to our knowledge in R. bieti as a candidate target of selection in high-altitude adaptation.…”

Progesterone and conceptus-derived factors important for conceptus survival and growth

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