Skip to main content
ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #339711
Title: Circulating microRNA as candidates for early embryonic viability in cattle

Author
item POHLER, KY - University Of Tennessee
item GREEN, JON - University Of Missouri
item MOLEY, LAURA - University Of Missouri
item GUNEWARDENA, S - University Of Kansas Medical School
item HUNG, WEI - University Of Kansas Medical School
item HONG, XIAOMAN - University Of Kansas Medical School
item CHRISTENSON, LANE - University Of Kansas Medical School
item Geary, Thomas
item SMITH, MICHAEL - University Of Missouri

Submitted to: Molecular Reproduction and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2017
Publication Date: 8/21/2017
Citation: Pohler, K.G., Green, J.A., Moley, L.A., Gunewardena, S., Hung, W.T., Hong, X., Christenson, L.K., Geary, T.W., Smith, M.F. 2017. Circulating microRNA as candidates for early embryonic viability in cattle. Molecular Reproduction and Development. 84(8):731-743. doi:10.1002/mrd.22856.

Interpretive Summary: Many cows lose pregnancies in the early stages after conception. Pregnancy cannot be measured in cows until about 30 days after conception. There are no simple blood or urine tests for measuring pregnancy in cows. In order to understand causes of early pregnancy loss we must first identify new ways of measuring pregnancy. This study describes a blood test for identifying pregnant and non-pregnant cows. In addition, this blood test is able to identify cows that are pregnant but unable to support the pregnancy. This test will allow us to identify cows that are likely to lose a pregnancy for further study.

Technical Abstract: Blood borne extracellular vesicles (EVs; i.e. exosomes and microvesicles) carrying microRNA (miRNA) may make excellent biomarkers of disease conditions and different physiologic states, including pregnancy status. We tested the hypothesis that circulating EV-derived miRNA might differentiate pregnancy status of cows that maintained pregnancy to day 30 from non-pregnant cows and those that exhibited embryo loss between days 17-30 of gestation. In this study, cows were randomly assigned to be artificially inseminated (AI) with fertile semen (n= 36) or dead semen (n=8; control group) on day 0 (day of estrus). Blood was collected from all animals on day 0, 17 and 24 and after pregnancy diagnosis on day 30. Cows receiving live sperm were retrospectively classified as pregnant on day 30 (n=17) or those exhibiting embryonic mortality between days 17-30 (n=19). Ultra-centrifugation was used to isolate EVs from serum and nanoparticle tracking and western blot analyses (CD81) confirmed enrichment prior to RNA extraction from the day 17 and 24 samples. MicroRNA sequencing was performed on n=4/day pregnant, embryonic mortality and control cows for a total of 24 independent RNAseq reactions. In total, 214 miRNA were identified in serum, 40 of which were novel. After setting differential abundance parameters for miRNA, we identified 32 differentially abundant loci, representing 27 differentially abundant mature miRNA. At day 17 and 24, specific miRNA (ex. miR-25, -16b and -3596) were identified that differentiated the pregnancy status. In summary, we identified several circulating EV-derived miRNA that differ in abundance between embryonic mortality and pregnant cows.