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PloS one2015; 10(10); e0139688; doi: 10.1371/journal.pone.0139688

Screening for the Most Suitable Reference Genes for Gene Expression Studies in Equine Milk Somatic Cells.

Abstract: Apart from the well-known role of somatic cell count as a parameter reflecting the inflammatory status of the mammary gland, the composition of cells isolated from milk is considered as a valuable material for gene expression studies in mammals. Due to its unique composition, in recent years an increasing interest in mare's milk consumption has been observed. Thus, investigating the genetic background of horse's milk variability presents and interesting study model. Relying on 39 milk samples collected from mares representing three breeds (Polish Primitive Horse, Polish Cold-blooded Horse, Polish Warmblood Horse) we aimed to investigate the utility of equine milk somatic cells as a source of mRNA and to screen the best reference genes for RT-qPCR using geNorm and NormFinder algorithms. The results showed that despite relatively low somatic cell counts in mare's milk, the amount and the quality of the extracted RNA are sufficient for gene expression studies. The analysis of the utility of 7 potential reference genes for RT-qPCR experiments for the normalization of equine milk somatic cells revealed some differences between the outcomes of the applied algorithms, although in both cases the KRT8 and TOP2B genes were pointed as the most stable. Analysis by geNorm showed that the combination of 4 reference genes (ACTB, GAPDH, TOP2B and KRT8) is required for apropriate RT-qPCR experiments normalization, whereas NormFinder algorithm pointed the combination of KRT8 and RPS9 genes as the most suitable. The trial study of the relative transcript abundance of the beta-casein gene with the use of various types and numbers of internal control genes confirmed once again that the selection of proper reference gene combinations is crucial for the final results of each real-time PCR experiment.
Publication Date: 2015-10-05 PubMed ID: 26437076PubMed Central: PMC4593561DOI: 10.1371/journal.pone.0139688Google Scholar: Lookup
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  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

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This research paper discusses the use of somatic cells from equine (horse) milk for gene expression studies, specifically the identification of the best reference genes for RT-qPCR processes. The study was carried out on milk samples from three different Polish horse breeds.

Objective

The objective of the research was to investigate whether somatic cells derived from horse milk are suitable for gene expression studies. The authors also wanted to identify genes that could serve as reliable reference points for RT-qPCR (Real-Time Quantitative Polymerase Chain Reaction), a common technique used to measure gene expression.

Methods

  • The researchers collected 39 milk samples from three different Polish horse breeds: Polish Primitive Horse, Polish Cold-blooded Horse, and Polish Warmblood Horse.
  • The focus was on extracting RNA from the somatic cells in these milk samples.
  • Seven potential reference genes for RT-qPCR were examined using two different algorithms, geNorm and NormFinder. These genes were selected due to their presumed stability.
  • The real-world application of the selected genes was validated through measuring the relative transcript abundance of the beta-casein gene, which plays a key role in milk production.

Findings

  • Even though the somatic cell count in horse’s milk was relatively low, the extracted RNA was of sufficient quantity and quality for gene expression studies.
  • There were differences in the results provided by geNorm and NormFinder algorithms when identifying the most suitable reference genes. However, KRT8 and TOP2B genes were consistently indicated as the most stable ones by both algorithms.
  • GeNorm analysis suggested a combination of four reference genes (ACTB, GAPDH, TOP2B and KRT8) was required for appropriate RT-qPCR normalization, while NormFinder identified two genes (KRT8 and RPS9) as optimal.
  • The researchers confirmed the importance of selecting the correct combination of reference genes for successful RT-qPCR experiments. Using inappropriate reference genes can distort the final results of gene expression experiments.

Conclusion

This study underscored the potential of horse milk somatic cells as a source for gene expression studies. Further, it identified a set of reference genes that can be used for more accurate RT-qPCR experiments, aiding in future research and potentially lowering the methodological errors in such studies.

Cite This Article

APA
Cieslak J, Mackowski M, Czyzak-Runowska G, Wojtowski J, Puppel K, Kuczynska B, Pawlak P. (2015). Screening for the Most Suitable Reference Genes for Gene Expression Studies in Equine Milk Somatic Cells. PLoS One, 10(10), e0139688. https://doi.org/10.1371/journal.pone.0139688

Publication

ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 10
Issue: 10
Pages: e0139688

Researcher Affiliations

Cieslak, Jakub
  • Department of Horse Breeding, Poznan University of Life Sciences, Poznan, Poland.
Mackowski, Mariusz
  • Department of Horse Breeding, Poznan University of Life Sciences, Poznan, Poland.
Czyzak-Runowska, Grazyna
  • Department of Small Mammals Breeding and Raw Materials of Animal Origin, Poznan University of Life Sciences, Poznan, Poland.
Wojtowski, Jacek
  • Department of Small Mammals Breeding and Raw Materials of Animal Origin, Poznan University of Life Sciences, Poznan, Poland.
Puppel, Kamila
  • Department of Animal Science, Cattle Breeding Division, Warsaw University of Life Sciences, Warsaw, Poland.
Kuczynska, Beata
  • Department of Animal Science, Cattle Breeding Division, Warsaw University of Life Sciences, Warsaw, Poland.
Pawlak, Piotr
  • Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Poznan, Poland.

MeSH Terms

  • Algorithms
  • Animals
  • Female
  • Gene Expression
  • Genes, Essential
  • Horses / genetics
  • Milk / cytology

Conflict of Interest Statement

Competing Interests: The authors have declared that no competing interests exist.

References

This article includes 29 references
  1. Boutinaud M, Jammes H. Potential uses of milk epithelial cells: a review.. Reprod. Nutr. Dev. 2002;42: 133–147.
    pubmed: 12216959
  2. Cánovas A, Rincón G, Bevilacqua C, Islas-Trejo A, Brenaut P, Hovey RC. Comparison of five different RNA sources to examine the lactating bovine mammary gland transcriptome using RNA-Sequencing.. Sci Rep 2014;4: 5297.
    doi: 10.1038/srep05297pmc: PMC5381611pubmed: 25001089google scholar: lookup
  3. Murrieta CM, Hess BW, Scholljegerdes EJ, Engle TE, Hossner KL, Moss GE. Evaluation of milk somatic cells as a source of mRNA for study of lipogenesis in the mammary gland of lactating beef cows supplemented with dietary high-linoleate safflower seeds.. J. Anim. Sci. 2006;84: 2399–2405.
    pubmed: 16908643
  4. Bonnefont CM, Toufeer M, Caubet C, Foulon E, Tasca C, Aurel MR. Transcriptomic analysis of milk somatic cells in mastitis resistant and susceptible sheep upon challenge with Staphylococcus epidermidis and Staphylococcus aureus.. BMC Genomics 2011;12: 208.
    doi: 10.1186/1471-2164-12-208pmc: PMC3096985pubmed: 21527017google scholar: lookup
  5. Jacobs AA, Dijkstra J, Hendriks WH, van Baal J, van Vuuren AM. Comparison between stearoyl-CoA desaturase expression in milk somatic cells and in mammary tissue of lactating dairy cows.. J Anim Physiol Anim Nutr (Berl) 2012;97: 353–362.
    pubmed: 22369625
  6. Salimei E, Fantuz F. Equid milk for human consumption.. Int. Dairy J. 2012;24: 130–142.
  7. Selvaggi M, Pesce Delfino AR, Dario C. Exon 1 polymorphisms in the equine CSN3 gene: SNPs distribution analysis in Murgese horse breed.. Anim. Biotechnol. 2010; 21: 252–256.
    doi: 10.1080/10495398.2010.509646pubmed: 20967644google scholar: lookup
  8. Kozera B, Rapacz M. Reference genes in real-time PCR.. J. Appl. Genet. 2013;54: 391–406.
    pmc: PMC3825189pubmed: 24078518
  9. Bai WL, Yin RH, Zhao SJ, Jiang WQ, Yin RL, Ma ZJ. Technical note: Selection of suitable reference genes for studying gene expression in milk somatic cell of yak (Bos grunniens) during the lactation cycle.. J. Dairy Sci. 2014;97: 902–910.
    doi: 10.3168/jds.2012-6437pubmed: 24342693google scholar: lookup
  10. Boutinaud M, Rulquin H, Keisler DH, Djiane J, Jammes H. Use of somatic cells from goat milk for dynamic studies of gene expression in the mammary gland.. J. Anim. Sci. 2002;80: 1258–1269.
    pubmed: 12019613
  11. Varshney N, Mohanty AK, Kumar S, Kaushik JK, Dang AK, Mukesh M. Selection of suitable reference genes for quantitative gene expression studies in milk somatic cells of lactating cows (Bos indicus).. J. Dairy Sci. 2012;95: 2935–2945.
    doi: 10.3168/jds.2011-4442pubmed: 22612931google scholar: lookup
  12. Yadav P, Sing DD, Mukesh M, Kataria RS, Yadav A, Mohanty AK. Identification of suitable housekeeping genes for expression analysis in mammary epithelial cells of buffalo (Bubalus bubalis) during lactation cycle.. Livest Sci. 2012;147: 72–76.
  13. Koressaar T, Remm M. Enhancements and modifications of primer design program Primer3.. Bioinformatics 2007;23: 1289–1291.
    pubmed: 17379693
  14. Puppel K, Kuczyńska B, Nałęcz-Tarwacka T, Sakowski T, Gołębiewski M, Kunowska-Slósarz M, Budziński A, Grodzki H. Effect of fish oil and linseed supplementation on the protein composition of milk from cows with different β-lactoglobulin phenotypes.. J. Sci. Food Agric. 2014;94: 1253–1257.
    doi: 10.1002/jsfa.6424pubmed: 24114737google scholar: lookup
  15. Jarczak J, Kaba J, Bagnicka E. The validation of housekeeping genes as a reference in quantitative Real Time PCR analysis: application in the milk somatic cells and frozen whole blood of goats infected with caprine arthritis encephalitis virus.. Gene 2014;549(2): 280–285.
    doi: 10.1016/j.gene.2014.07.063pubmed: 25068405google scholar: lookup
  16. Vandesompele J, De Preter K, Pattyn F, Poppe B, Van Roy N, De Paepe A. Accurate normalization of real-time quantitative RT-PCR data by geometric averaging of multiple internal control genes.. Genome Biol. 2002;3: research0034.1–0034.11.
    pmc: PMC126239pubmed: 12184808
  17. Andersen CL, Jensen JL, Ørntoft TF. Normalization of real-time quantitative reverse transcription-PCR data: a model-based variance estimation approach to identify genes suited for normalization, applied to bladder and colon cancer data sets.. Cancer Res. 2004;64: 5245–5250.
    pubmed: 15289330
  18. Čagalj M, Brezovečki A, Mikulec N, Antunac N. Composition and properties of mare’s milk of Croatian Coldblood horse breed.. Mljekarstvo 2014;64: 3–11.
  19. Markiewicz-Kęszycka M, Wójtowski J, Kuczyńska B, Puppel K, Czyżak-Runowska G, Bagnicka E. Chemical composition and whey protein fraction of late lactation mares’ milk.. Int. Dairy J. 2013;31: 62–64.
  20. Caroprese M, Albenzio M, Marino R, Muscio A, Zezza T, Sevi A. Behavior, Milk Yield, and Milk Composition of Machine and Hand-Milked Murgese Mares.. J. Dairy Sci. 2007;90: 2773–2777.
    pubmed: 17517717
  21. Danków R, Wójtowski J, Pikul J, Niżnikowski R, Cais-Sokolińska D. Effect of lactation on the hygiene quality and some milk physicochemical traits of the Wielkopolska mares.. Arch. Tierz. 2006;49: 201–206.
  22. Pecka E, Dobrzański Z, Zachwieja A, Szulc T, Czyż K. Studies of composition and major protein level in milk and colostrum of mares.. Anim. Sci. J. 2012;83: 162–168.
  23. Lemay DG, Hovey RC, Hartono SR, Hinde K, Smilowitz JT, Ventimiglia F. Sequencing the transcriptome of milk production: milk trumps mammary tissue.. BMC Genomics. 2013;14: 872.
    doi: 10.1186/1471-2164-14-872pmc: PMC3871720pubmed: 24330573google scholar: lookup
  24. Sigl T, Meyer HHD, Wiedemann S. Gene expression of six major milk proteins in bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation.. Czech J Anim Sci. 2012;57: 469–480.
  25. Hellemans J, Mortier G, De Paepe A, Speleman F, Vandesompele J. qBase relative quantification framework and software for management and automated analysis of real-time quantitative PCR data.. Genome Biol. 2007;8: R19.
    pmc: PMC1852402pubmed: 17291332
  26. Modesto P, Peletto S, Pisoni G, Cremonesi P, Castiglioni B, Colussi S. Evaluation of internal reference genes for quantitative expression analysis by real-time reverse transcription-PCR in somatic cells from goat milk.. J. Dairy Sci. 2013;96: 7932–7944.
    doi: 10.3168/jds.2012-6383pubmed: 24119819google scholar: lookup
  27. Bionaz M, Loor JJ. Identification of reference genes for quantitative real-time PCR in the bovine mammary gland during the lactation cycle.. Physiol. Genomics. 2007;29: 312–319.
    pubmed: 17284669
  28. Bustin SA, Nolan T. Pitfalls of quantitative real-time reverse-transcription polymerase chain reaction.. J Biomol Tech. 2004;15: 155–166.
    pmc: PMC2291693pubmed: 15331581
  29. Zhai Z, Yao Y, Wang Y. Importance of Suitable Reference Gene Selection for Quantitative RT-PCR during ATDC5 Cells Chondrocyte Differentiation.. PLoS ONE 2013; 8: e64786.