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Circulating microRNA Profiles during the Bovine Oestrous Cycle.

Ioannidis J, Donadeu FX - PLoS ONE (2016)

Bottom Line: This significantly reduces overall herd productivity and constitutes a high economic burden to the dairy industry.Subsequently, we used RT-qPCR (n = 24 samples) to validate the results of high-throughput analyses, as well as to establish the expression profiles of additional miRNAs previously reported to be differentially expressed during reproductive cycles.In summary, our results reveal the dynamic nature of plasma miRNAs during the oestrous cycle and provide evidence of the feasibility of using circulating miRNAs as biomarkers of reproductive function in livestock in the future.

View Article: PubMed Central - PubMed

Affiliation: The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, United Kingdom.

ABSTRACT
Up to 50% of ovulations go undetected in modern dairy herds due to attenuated oestrus behavior and a lack of high-accuracy methods for detection of fertile oestrus. This significantly reduces overall herd productivity and constitutes a high economic burden to the dairy industry. MicroRNAs (miRNAs) are ubiquitous regulators of gene expression during both health and disease and they have been shown to regulate different reproductive processes. Extracellular miRNAs are stable and can provide useful biomarkers of tissue function; changes in circulating miRNA profiles have been reported during menstrual cycles. This study sought to establish the potential of circulating miRNAs as biomarkers of oestrus in cattle. We collected plasma samples from 8 Holstein-Friesian heifers on days Days 0, 8 and 16 of an oestrous cycle and analysed small RNA populations on each Day using two independent high-throughput approaches, namely, Illumina sequencing (n = 24 samples) and Qiagen PCR arrays (n = 9 sample pools, 3-4 samples / pool). Subsequently, we used RT-qPCR (n = 24 samples) to validate the results of high-throughput analyses, as well as to establish the expression profiles of additional miRNAs previously reported to be differentially expressed during reproductive cycles. Overall, we identified four miRNAs (let-7f, miR-125b, miR-145 and miR-99a-5p), the plasma levels of which distinctly increased (up to 2.2-fold, P < 0.05) during oestrus (Day 0) relative to other stages of the cycle (Days 8 and 16). Moreover, we identified several hundred different isomiRs and established their relative abundance in bovine plasma. In summary, our results reveal the dynamic nature of plasma miRNAs during the oestrous cycle and provide evidence of the feasibility of using circulating miRNAs as biomarkers of reproductive function in livestock in the future.

No MeSH data available.


Related in: MedlinePlus

Differential expression analysis of small-RNA sequencing data from Days 0, 8 and 16 of the bovine oestrous cycle (n = 8 heifers).(A) PCA plot. (B) Volcano plot showing the largest fold-change between any 2 of the 3 days analysed for each miRNA. The grey dotted line indicates the 2-fold change threshold and the yellow horizontal line indicates P = 0.05. The plotted data have been log2 transformed.
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pone.0158160.g002: Differential expression analysis of small-RNA sequencing data from Days 0, 8 and 16 of the bovine oestrous cycle (n = 8 heifers).(A) PCA plot. (B) Volcano plot showing the largest fold-change between any 2 of the 3 days analysed for each miRNA. The grey dotted line indicates the 2-fold change threshold and the yellow horizontal line indicates P = 0.05. The plotted data have been log2 transformed.

Mentions: Our differential expression analysis included 181 bovine and human miRNAs, all of which were present with more than 25 RPMM in at least 75% of samples in each experimental group (see Materials and Methods; S1 File). Principal component analysis did not reveal a clear separation of samples according to Day of the oestrous cycle (Fig 2A). Upon statistical analysis we detected an effect of Day of the oestrous cycle on the expression levels of 20 miRNAs (P < 0.05, Table 2; Fig 2B), however the differences involved were generally small (under 1.6-fold) and were not significant after multiple testing adjustment (FDR > 0.1), failing to identify a high-confidence candidate miRNA biomarker of oestrus at this stage of the study.


Circulating microRNA Profiles during the Bovine Oestrous Cycle.

Ioannidis J, Donadeu FX - PLoS ONE (2016)

Differential expression analysis of small-RNA sequencing data from Days 0, 8 and 16 of the bovine oestrous cycle (n = 8 heifers).(A) PCA plot. (B) Volcano plot showing the largest fold-change between any 2 of the 3 days analysed for each miRNA. The grey dotted line indicates the 2-fold change threshold and the yellow horizontal line indicates P = 0.05. The plotted data have been log2 transformed.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920432&req=5

pone.0158160.g002: Differential expression analysis of small-RNA sequencing data from Days 0, 8 and 16 of the bovine oestrous cycle (n = 8 heifers).(A) PCA plot. (B) Volcano plot showing the largest fold-change between any 2 of the 3 days analysed for each miRNA. The grey dotted line indicates the 2-fold change threshold and the yellow horizontal line indicates P = 0.05. The plotted data have been log2 transformed.
Mentions: Our differential expression analysis included 181 bovine and human miRNAs, all of which were present with more than 25 RPMM in at least 75% of samples in each experimental group (see Materials and Methods; S1 File). Principal component analysis did not reveal a clear separation of samples according to Day of the oestrous cycle (Fig 2A). Upon statistical analysis we detected an effect of Day of the oestrous cycle on the expression levels of 20 miRNAs (P < 0.05, Table 2; Fig 2B), however the differences involved were generally small (under 1.6-fold) and were not significant after multiple testing adjustment (FDR > 0.1), failing to identify a high-confidence candidate miRNA biomarker of oestrus at this stage of the study.

Bottom Line: This significantly reduces overall herd productivity and constitutes a high economic burden to the dairy industry.Subsequently, we used RT-qPCR (n = 24 samples) to validate the results of high-throughput analyses, as well as to establish the expression profiles of additional miRNAs previously reported to be differentially expressed during reproductive cycles.In summary, our results reveal the dynamic nature of plasma miRNAs during the oestrous cycle and provide evidence of the feasibility of using circulating miRNAs as biomarkers of reproductive function in livestock in the future.

View Article: PubMed Central - PubMed

Affiliation: The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, United Kingdom.

ABSTRACT
Up to 50% of ovulations go undetected in modern dairy herds due to attenuated oestrus behavior and a lack of high-accuracy methods for detection of fertile oestrus. This significantly reduces overall herd productivity and constitutes a high economic burden to the dairy industry. MicroRNAs (miRNAs) are ubiquitous regulators of gene expression during both health and disease and they have been shown to regulate different reproductive processes. Extracellular miRNAs are stable and can provide useful biomarkers of tissue function; changes in circulating miRNA profiles have been reported during menstrual cycles. This study sought to establish the potential of circulating miRNAs as biomarkers of oestrus in cattle. We collected plasma samples from 8 Holstein-Friesian heifers on days Days 0, 8 and 16 of an oestrous cycle and analysed small RNA populations on each Day using two independent high-throughput approaches, namely, Illumina sequencing (n = 24 samples) and Qiagen PCR arrays (n = 9 sample pools, 3-4 samples / pool). Subsequently, we used RT-qPCR (n = 24 samples) to validate the results of high-throughput analyses, as well as to establish the expression profiles of additional miRNAs previously reported to be differentially expressed during reproductive cycles. Overall, we identified four miRNAs (let-7f, miR-125b, miR-145 and miR-99a-5p), the plasma levels of which distinctly increased (up to 2.2-fold, P < 0.05) during oestrus (Day 0) relative to other stages of the cycle (Days 8 and 16). Moreover, we identified several hundred different isomiRs and established their relative abundance in bovine plasma. In summary, our results reveal the dynamic nature of plasma miRNAs during the oestrous cycle and provide evidence of the feasibility of using circulating miRNAs as biomarkers of reproductive function in livestock in the future.

No MeSH data available.


Related in: MedlinePlus