Identification of Putative Biomarkers for the Early Stage of Porcine Spermatogonial Stem Cells Using Next-Generation Sequencing

PLoS One. 2016 Jan 22;11(1):e0147298. doi: 10.1371/journal.pone.0147298. eCollection 2016.

Abstract

To identify putative biomarkers of porcine spermatogonial stem cells (pSSCs), total RNA sequencing (RNA-seq) analysis was performed on 5- and 180-day-old porcine testes and on pSSC colonies that were established under low temperature culture conditions as reported previously. In total, 10,184 genes were selected using Cufflink software, followed by a logarithm and quantile normalization of the pairwise scatter plot. The correlation rates of pSSCs compared to 5- and 180-day-old testes were 0.869 and 0.529, respectively and that between 5- and 180-day-old testes was 0.580. Hierarchical clustering data revealed that gene expression patterns of pSSCs were similar to 5-day-old testis. By applying a differential expression filter of four fold or greater, 607 genes were identified between pSSCs and 5-day-old testis, and 2118 genes were identified between the 5- and 180-day-old testes. Among these differentially expressed genes, 293 genes were upregulated and 314 genes were downregulated in the 5-day-old testis compared to pSSCs, and 1106 genes were upregulated and 1012 genes were downregulated in the 180-day-old testis compared to the 5-day-old testis. The following genes upregulated in pSSCs compared to 5-day-old testes were selected for additional analysis: matrix metallopeptidase 9 (MMP9), matrix metallopeptidase 1 (MMP1), glutathione peroxidase 1 (GPX1), chemokine receptor 1 (CCR1), insulin-like growth factor binding protein 3 (IGFBP3), CD14, CD209, and Kruppel-like factor 9 (KLF9). Expression levels of these genes were evaluated in pSSCs and in 5- and 180-day-old porcine testes. In addition, immunohistochemistry analysis confirmed their germ cell-specific expression in 5- and 180-day-old testes. These finding may not only be useful in facilitating the enrichment and sorting of porcine spermatogonia, but may also be useful in the study of the early stages of spermatogenic meiosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult Stem Cells / cytology*
  • Animals
  • Base Sequence
  • Cell Differentiation / physiology
  • Gene Expression Regulation / genetics
  • Genetic Markers / genetics
  • High-Throughput Nucleotide Sequencing
  • Male
  • Meiosis / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, RNA
  • Spermatogenesis / physiology*
  • Spermatogonia / cytology*
  • Swine
  • Testis / cytology*

Substances

  • Genetic Markers

Grants and funding

This study was supported by grant PJ011076 from the Next-Generation BioGreen 21 program, Rural Development Administration, Republic of Korea.