Male-biased genes in catfish as revealed by RNA-Seq analysis of the testis transcriptome

PLoS One. 2013 Jul 12;8(7):e68452. doi: 10.1371/journal.pone.0068452. Print 2013.


Background: Catfish has a male-heterogametic (XY) sex determination system, but genes involved in gonadogenesis, spermatogenesis, testicular determination, and sex determination are poorly understood. As a first step of understanding the transcriptome of the testis, here, we conducted RNA-Seq analysis using high throughput Illumina sequencing.

Methodology/principal findings: A total of 269.6 million high quality reads were assembled into 193,462 contigs with a N50 length of 806 bp. Of these contigs, 67,923 contigs had hits to a set of 25,307 unigenes, including 167 unique genes that had not been previously identified in catfish. A meta-analysis of expressed genes in the testis and in the gynogen (double haploid female) allowed the identification of 5,450 genes that are preferentially expressed in the testis, providing a pool of putative male-biased genes. Gene ontology and annotation analysis suggested that many of these male-biased genes were involved in gonadogenesis, spermatogenesis, testicular determination, gametogenesis, gonad differentiation, and possibly sex determination.

Conclusion/significance: We provide the first transcriptome-level analysis of the catfish testis. Our analysis would lay the basis for sequential follow-up studies of genes involved in sex determination and differentiation in catfish.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Catfishes / genetics*
  • Female
  • Gene Ontology
  • Genetic Linkage
  • High-Throughput Nucleotide Sequencing*
  • Male
  • Molecular Sequence Annotation
  • Sex Characteristics
  • Sex Determination Processes
  • Spermatogenesis / genetics
  • Testis / metabolism*
  • Transcriptome / genetics*

Grant support

This project was supported by Agriculture and Food Research Initiative (AFRI) Competitive Grants no. 2009-35205-05101, 2010-65205-20356 and 2012-67015-19410 from the USDA National Institute of Food and Agriculture (NIFA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.