Limits...
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

Results of PCR array analyses of bovine plasma miRNAs.(A) Distribution of Cq values. The percentage shown is the number of miRNAs in each category divided by the total number of miRNAs assayed. (B) The expression level (mean ± SEM of 2^(40-Cq)) of the top 10 miRNAs during each of Days 0, 8 and 16 of the oestrous cycle (n = 8 heifers).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4920432&req=5

pone.0158160.g003: Results of PCR array analyses of bovine plasma miRNAs.(A) Distribution of Cq values. The percentage shown is the number of miRNAs in each category divided by the total number of miRNAs assayed. (B) The expression level (mean ± SEM of 2^(40-Cq)) of the top 10 miRNAs during each of Days 0, 8 and 16 of the oestrous cycle (n = 8 heifers).

Mentions: A total of 211 miRNAs were detected at Cq < 35 across all samples (Fig 3A). The miRNAs which were most abundant in plasma (Fig 3B) in our experiment are reportedly expressed at high levels in blood cells, including erythrocytes (miR-451, miR-16b), leukocytes (miR-150, miR-27a, miR-23a) and thrombocytes (miR-223, miR-20a, miR-24) and are putatively released into the plasma through apoptosis, lysis or active shedding [41, 42, 14]. Out of the 20 most abundant miRNAs in each of the sequencing and PCR array datasets, only six (miR-451, miR-486, miR-22-3p, miR-92a, miR-191 and miR-140) were common to both datasets (20% overlap). A very abundant miRNA in the sequencing dataset (miR-21-5p) could not be compared as it was not included in the PCR array. However, considering the 150 most abundant miRNAs, 104 (70%) were detected by both platforms; out of the 46 miRNAs which were present only in the sequencing dataset, 35 were not represented on the PCR array, explaining a large part of the apparent lack of overlap in detected miRNAs between the two platforms. Further explanation for differences in the most abundant miRNAs is provided in the form of platform-specific biases involving, for example, sequencing adaptor ligation bias and differences in primer efficiency, which determine the relative abundance for a given miRNA [43, 44].


Circulating microRNA Profiles during the Bovine Oestrous Cycle.

Ioannidis J, Donadeu FX - PLoS ONE (2016)

Results of PCR array analyses of bovine plasma miRNAs.(A) Distribution of Cq values. The percentage shown is the number of miRNAs in each category divided by the total number of miRNAs assayed. (B) The expression level (mean ± SEM of 2^(40-Cq)) of the top 10 miRNAs during each of Days 0, 8 and 16 of the oestrous cycle (n = 8 heifers).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0158160.g003: Results of PCR array analyses of bovine plasma miRNAs.(A) Distribution of Cq values. The percentage shown is the number of miRNAs in each category divided by the total number of miRNAs assayed. (B) The expression level (mean ± SEM of 2^(40-Cq)) of the top 10 miRNAs during each of Days 0, 8 and 16 of the oestrous cycle (n = 8 heifers).
Mentions: A total of 211 miRNAs were detected at Cq < 35 across all samples (Fig 3A). The miRNAs which were most abundant in plasma (Fig 3B) in our experiment are reportedly expressed at high levels in blood cells, including erythrocytes (miR-451, miR-16b), leukocytes (miR-150, miR-27a, miR-23a) and thrombocytes (miR-223, miR-20a, miR-24) and are putatively released into the plasma through apoptosis, lysis or active shedding [41, 42, 14]. Out of the 20 most abundant miRNAs in each of the sequencing and PCR array datasets, only six (miR-451, miR-486, miR-22-3p, miR-92a, miR-191 and miR-140) were common to both datasets (20% overlap). A very abundant miRNA in the sequencing dataset (miR-21-5p) could not be compared as it was not included in the PCR array. However, considering the 150 most abundant miRNAs, 104 (70%) were detected by both platforms; out of the 46 miRNAs which were present only in the sequencing dataset, 35 were not represented on the PCR array, explaining a large part of the apparent lack of overlap in detected miRNAs between the two platforms. Further explanation for differences in the most abundant miRNAs is provided in the form of platform-specific biases involving, for example, sequencing adaptor ligation bias and differences in primer efficiency, which determine the relative abundance for a given miRNA [43, 44].

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