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Transcriptome profiling of Arabian horse blood during training regimens

View Article: PubMed Central - PubMed

ABSTRACT

Background: Arabian horses are believed to be one of the oldest and most influential horse breeds in the world. Blood is the main tissue involved in maintaining body homeostasis, and it is considered a marker of the processes taking place in the other tissues. Thus, the aim of our study was to identify the genetic basis of changes occurring in the blood of Arabian horses subjected to a training regimen and to compare the global gene expression profiles between different training periods (T1: after a slow canter phase that is considered a conditioning phase, T2: after an intense gallop phase, and T3: at the end of the racing season) and between trained and untrained horses (T0). RNA sequencing was performed on 37 samples with a 75-bp single-end run on a HiScanSQ platform (Illumina), and differentially expressed genes (DEGs) were identified based on DESeq2 (v1.11.25) software.

Results: An increase in the number of DEGs between subsequent training periods was observed, and the highest amount of DEGs (440) was detected between untrained horses (T0) and horses at the end of the racing season (T3). The comparisons of the T2 vs. T3 transcriptomes and the T0 vs. T3 transcriptomes showed a significant gain of up-regulated genes during long-term exercise (up-regulation of 266 and 389 DEGs in the T3 period compared to T2 and T0, respectively). Forty differentially expressed genes were detected between the T1 and T2 periods, and 296 between T2 and T3. Functional annotation showed that the most abundant genes up-regulated in exercise were involved in pathways regulating cell cycle (PI3K-Akt signalling pathway), cell communication (cAMP-dependent pathway), proliferation, differentiation and apoptosis, as well as immunity processes (Jak-STAT signalling pathway).

Conclusions: We investigated whether training causes permanent transcriptome changes in horse blood as a reflection of adaptation to conditioning and the maintenance of fitness to compete in flat races. The present study identified the overrepresented molecular pathways and genes that are essential for maintaining body homeostasis during long-term exercise in Arabian horses. Selected DEGs should be further investigated as markers that are potentially associated with racing performance in Arabian horses.

Electronic supplementary material: The online version of this article (doi:10.1186/s12863-017-0499-1) contains supplementary material, which is available to authorized users.

No MeSH data available.


Significantly up-regulated genes during analysed training periods in Arabian horse blood that belong to the FoxO signalling pathway (KEGG ecb04068). Pathway presents the genes identified as differentially expressed (adjusted p-value < 0.05) between the T2 vs. T3 periods (bold highlight) and between T0 vs. T3 (pink highlight)
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Fig1: Significantly up-regulated genes during analysed training periods in Arabian horse blood that belong to the FoxO signalling pathway (KEGG ecb04068). Pathway presents the genes identified as differentially expressed (adjusted p-value < 0.05) between the T2 vs. T3 periods (bold highlight) and between T0 vs. T3 (pink highlight)

Mentions: Pathway analysis was performed with DAVID and KEGG software using as an input a set of differentially expressed genes (fold change of at least ± 1.3; adjusted p-value < 0.05) between subsequent training periods: T1 vs. T2; T2 vs. T3 and T0 vs. T3. The most abundant genes up-regulated in exercise were involved in pathways that are important for the regulation of cell cycle (PI3K-Akt signalling pathway), cell communication (cAMP-dependent pathway), proliferation, differentiation and apoptosis, as well as immunity processes (Jak-STAT signalling pathway). We also observed the exercise-induced expression of genes related to regulation of the actin cytoskeleton, gluconeogenesis (FoxO signalling pathway, insulin signalling pathway), glycerophospholipid metabolism and calcium signalling. The identified genes belonged to the two most overrepresented pathways, the FoxO and PI3K-Akt signalling pathways, which are highlighted in Figs. 1 and 2. Moreover, an increase in the transcriptional activity of genes belonging to the Notch signalling pathway (KAT2B, NCOR2, NOTCH1, NOTCH2 and RBPJ) was identified (Table 4). Due to the relatively low number of detected down-regulated genes, only one pathway was found to be significant, and it contained genes overexpressed at the start of the training schedule (T1): hypertrophic cardiomyopathy (HCM) pathway (CACNB1, TPM1, TPM2, TTN).Fig. 1


Transcriptome profiling of Arabian horse blood during training regimens
Significantly up-regulated genes during analysed training periods in Arabian horse blood that belong to the FoxO signalling pathway (KEGG ecb04068). Pathway presents the genes identified as differentially expressed (adjusted p-value < 0.05) between the T2 vs. T3 periods (bold highlight) and between T0 vs. T3 (pink highlight)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5382464&req=5

Fig1: Significantly up-regulated genes during analysed training periods in Arabian horse blood that belong to the FoxO signalling pathway (KEGG ecb04068). Pathway presents the genes identified as differentially expressed (adjusted p-value < 0.05) between the T2 vs. T3 periods (bold highlight) and between T0 vs. T3 (pink highlight)
Mentions: Pathway analysis was performed with DAVID and KEGG software using as an input a set of differentially expressed genes (fold change of at least ± 1.3; adjusted p-value < 0.05) between subsequent training periods: T1 vs. T2; T2 vs. T3 and T0 vs. T3. The most abundant genes up-regulated in exercise were involved in pathways that are important for the regulation of cell cycle (PI3K-Akt signalling pathway), cell communication (cAMP-dependent pathway), proliferation, differentiation and apoptosis, as well as immunity processes (Jak-STAT signalling pathway). We also observed the exercise-induced expression of genes related to regulation of the actin cytoskeleton, gluconeogenesis (FoxO signalling pathway, insulin signalling pathway), glycerophospholipid metabolism and calcium signalling. The identified genes belonged to the two most overrepresented pathways, the FoxO and PI3K-Akt signalling pathways, which are highlighted in Figs. 1 and 2. Moreover, an increase in the transcriptional activity of genes belonging to the Notch signalling pathway (KAT2B, NCOR2, NOTCH1, NOTCH2 and RBPJ) was identified (Table 4). Due to the relatively low number of detected down-regulated genes, only one pathway was found to be significant, and it contained genes overexpressed at the start of the training schedule (T1): hypertrophic cardiomyopathy (HCM) pathway (CACNB1, TPM1, TPM2, TTN).Fig. 1

View Article: PubMed Central - PubMed

ABSTRACT

Background: Arabian horses are believed to be one of the oldest and most influential horse breeds in the world. Blood is the main tissue involved in maintaining body homeostasis, and it is considered a marker of the processes taking place in the other tissues. Thus, the aim of our study was to identify the genetic basis of changes occurring in the blood of Arabian horses subjected to a training regimen and to compare the global gene expression profiles between different training periods (T1: after a slow canter phase that is considered a conditioning phase, T2: after an intense gallop phase, and T3: at the end of the racing season) and between trained and untrained horses (T0). RNA sequencing was performed on 37 samples with a 75-bp single-end run on a HiScanSQ platform (Illumina), and differentially expressed genes (DEGs) were identified based on DESeq2 (v1.11.25) software.

Results: An increase in the number of DEGs between subsequent training periods was observed, and the highest amount of DEGs (440) was detected between untrained horses (T0) and horses at the end of the racing season (T3). The comparisons of the T2 vs. T3 transcriptomes and the T0 vs. T3 transcriptomes showed a significant gain of up-regulated genes during long-term exercise (up-regulation of 266 and 389 DEGs in the T3 period compared to T2 and T0, respectively). Forty differentially expressed genes were detected between the T1 and T2 periods, and 296 between T2 and T3. Functional annotation showed that the most abundant genes up-regulated in exercise were involved in pathways regulating cell cycle (PI3K-Akt signalling pathway), cell communication (cAMP-dependent pathway), proliferation, differentiation and apoptosis, as well as immunity processes (Jak-STAT signalling pathway).

Conclusions: We investigated whether training causes permanent transcriptome changes in horse blood as a reflection of adaptation to conditioning and the maintenance of fitness to compete in flat races. The present study identified the overrepresented molecular pathways and genes that are essential for maintaining body homeostasis during long-term exercise in Arabian horses. Selected DEGs should be further investigated as markers that are potentially associated with racing performance in Arabian horses.

Electronic supplementary material: The online version of this article (doi:10.1186/s12863-017-0499-1) contains supplementary material, which is available to authorized users.

No MeSH data available.