Clinico-Chemical Parameters of Fetal Fluids and Maternal Blood in the Bovine Model: Effects of Genetics and Sex and Relationships with Feto-Placental Phenotype

Prenatal growth is influenced by bidirectional exchange between the fetal and maternal systems that programme birth weight and postnatal phenotype. Fetal fluids are essential but unexplored areas for prenatal growth. This study examined allantoic and amniotic fluids and maternal blood in a Bos taurus, Bos indicus bovine model to provide fundamental information that is lacking regarding (i) changes in clinico-chemical parameters of maternal blood in early and midgestation and their relationships with placental-embryo/fetal weights (ii) differences in clinico-chemical parameters of allantoic and amniotic fluids of bovine concepti in early and midgestation, (iii) effects of genetics and sex on clinico-chemical parameters of fetal fluids and their relationships with feto-placental phenotype, and (iv) the effects of conceptus sex and genetics on maternal blood parameters. Purebred and reciprocal cross Bos taurus, (Bt) and Bos taurus indicus, (Bi) concepti were recovered in early gestation (Day 48, n = 60), and midgestation (Day 153, n = 72), (term ~ 280 days). Fetal fluids and maternal blood were sampled and analysed for clinico-chemical parameters. Insulin-like growth factors and thyroid hormones were assessed in maternal blood. Effects of genetics and sex on the measured parameters were determined using general linear models, and relationships with feto-placental phenotype assessed by linear regression. Breed effects on maternal electrolytes, metabolites and enzymes and their relationships with placental-embryo/fetal weights provide evidence of differences in maternal mineral metabolism, liver and kidney functions that influence conceptus growth. Stage- and genetic-specific differences were seen in clinico-chemical parameters of fetal fluids, which likely reflect differences in feto-placental phenotype. Greater maternal genome effects on fetal fluid in early gestation reflect the significance of placenta and maternal environment and represent maternal-offspring coadaptation. Paternal genome and maternal by paternal genome interactions exert stronger effects on amniotic fluid suggesting greater fetal influence and (epi)genetic regulation in line with the conflict-of-interest hypothesis. Conceptus sex had strong effects on fetal fluid metabolites in early gestation, while parental genome by sex effects influence amniotic fluid parameters at both stages. Furthermore, paternal genome and sex interacted with non-genetic maternal effects to affect fetal fluid parameters at both stages. Significant relationships between maternally controlled allantoic fluid parameters and embryo-placental weights suggest a critical role of allantoic fluid for embryonic development. In midgestation, paternally controlled amniotic fluid Na/K ratio showed significant relationships with fetal weight and fetal fluid volume, suggesting a paternal influence on amniotic fluid water and nutrient transfer. Conceptus sex and genetics affected maternal physiology in a maternal genetics dependent manner by influencing key parameters of maternal mineral metabolism, liver function and thyroid status. In conclusion, this study provides reference values for clinico-chemical parameters of fetal fluids and maternal serum in Bt and Bi concepti in early and midgestation. Results support the hypothesis that fetal fluid parameters are affected by genetics and sex, and are related to feto-placental phenotype, demonstrating their critical role in prenatal growth. This study highlights the importance of considering conceptus sex, genetics and maternal genetics as factors that impact maternal physiology and demonstrates the need for genetic background-specific maternal assessment.

Author dc:creator

• Shuaib, Entesar Saleh Moh

Advisors dc:contributor.advisor

• Hiendleder, Stefan
• Kind, Karen
• McAllister, Milton

• Bos taurus
• Bos indicus
• maternal serum
• fetal fluids
• clinico-chemical parameters
• embryo
• fetus
• placenta

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/2440/129638

OAI identifier oai:identifier

oai:digital.library.adelaide.edu.au:2440/129638