Evidence of increased substrate availability to in vitro-derived bovine foetuses and association with accelerated conceptus growth

Abstract

Changes in placental development have been associated with foetal abnormalities after in vitro embryo manipulations. This study was designed to investigate bovine conceptus development and substrate levels in plasma and fluids in in vivo-and in vitro-produced (IVP) concepti and neonates. In vivo-produced and IVP embryos were derived by established embryo production procedures. Pregnant animals from both groups were slaughtered on days 90 or 180 of gestation, or allowed to go to term. Conceptus and neonatal physical traits were recorded; foetal, maternal and neonatal blood, and foetal fluids were collected for the determination of blood and fluid chemistry, and glucose, fructose and lactate concentrations. Placental transcripts for specific glucose transporters were determined by quantitative RT-PCR. No significant differences in uterine and conceptus traits were observed between groups on day 90. On day 180, larger uterine, placental and foetal weights, and an increase in placental gross surface area (SA) in IVP pregnancies were associated with increased glucose and fructose accumulation in foetal plasma and associated fluids, with no differences in the expression of components of the glucose transporter system. Therefore, the enlarged placental SA in IVP pregnancies suggests an increase in substrate uptake and transport capacity. Newborn IVP calves displayed higher birth weights and plasma fructose concentrations soon after birth, findings which appeared to be associated with clinical and metabolic distress. Our results indicated larger concepti and increased placental fructogenic capacity in mid-to late IVP pregnancies, features which appeared to be associated with an enhanced substrate supply, potentially glucose, to the conceptus.

Expression profile and protein levels of placental products as indirect measures of placental function in in vitro-derived bovine pregnancies

“…0.850, P , 0.05), and with glucose and fructose accumulations (r . 0.650, P , 0.05) in the uterine compartments (data not shown, Bertolini et al 2004). Positive correlations were observed also between conceptus component weights, substrate (glucose and fructose, data not shown) accumulations and bPAG-1 transcripts (r .…”

“…Concentrations of bPL and bPSPB in the first 60 min postpartum were positively correlated with neonatal and foetal membrane physical traits (r . 0.800, P , 0.05), and correlated with neonatal plasma fructose concentrations (data not shown, Bertolini et al 2004). …”

“…Relative abundance of bPL and bPAG-1 transcripts in day-90 and -180 placentomes A real-time TaqMan PCR (Applied Biosystems, Foster City, CA, USA) was optimized to quantify transcripts for bPL and bPAG-1 genes, following procedures described by Bertolini et al (2002bBertolini et al ( , 2004. The analysis was performed at the Lucy Whittier Molecular Core Facility, School of Veterinary Medicine, University of California, Davis.…”

Epigenetic Defects Related Reproductive Technologies: Large Offspring Syndrome (LOS)

“…Up to 40% of SCNT-derived fullterm calves and lambs have LOS, which is characterized by large size at birth, enlarged umbilical cord, enlarged organs, hydrops of the fetus, lethargy, respiratory distress, muscle fiber composition, cerebellar dysplasia and skeletal and facial malformations (ChavattePalmer et al, 2002;Constant et al, 2006;Fletcher et al, 2007;Loi P et al, 2006;Maxfield et al, 1997;Schmidt et al, 1996;Walker et al, 1996;Young et al, 1998). Also, it is well known that in high frequency of LOS is also frequently observed in calves that developed from in vitro maturation (IVM) and IVF-derived embryos (Behboodi et al, 1995;Reichenbach et al, 1992;Bertolini et al, 2004).…”

Perinatal death associated with ET, IVP and cloning in cattle

“…Conceptuses, fetuses and offspring resulting from those embryos can differ in their viability, morphology and physiology compared with in vivo controls [4][5][6][7][8]. A better understanding of these mechanisms will not only facilitate the refinement of IVP and cloning systems, but may also improve our management of pregnant animals.…”