The extent to which immunity, apoptosis and detoxification gene expression interact with 17 alpha-methyltestosterone

Fish Shellfish Immunol. 2017 Jan;60:289-298. doi: 10.1016/j.fsi.2016.11.057. Epub 2016 Nov 27.


Innate immunity is the first line of defence against invasion by foreign pathogens. One widely used synthetic androgen for the production of all-male fish, particularly commercially valuable Nile tilapia, Oreochromis niloticus, is 17 alpha-methyltestosterone (MT). The present study investigates the effect of MT on innate immunity, cellular apoptosis and detoxification and the mortality rate, during and after the feeding of fry with 0-, 40-and 60-mg MT/kg. Expression analysis was completed on interleukin 1 beta (il1β), interleukin 8 (il8), tumour necrosis factor alpha (tnfα), CXC2- and CC-chemokines, interferon (ifn), myxovirus resistance (mx), toll-like receptor 7 (tlr7), immunoglobulin M heavy chain (IgM heavy chain), vitellogenin (vtg), cellular apoptosis susceptibility (cas) and glutathione S-transferase α1 (gstα1). Expression analysis revealed that MT had a significant impact on these genes, and this impact varied from induction to repression during and after the treatment. Linear regression analysis showed a significant association between the majority of the tested gene transcript levels and mortality rates on the 7th and 21st days of hormonal treatment and 2 weeks following hormonal cessation. The results are thoroughly discussed in this article. This is the first report concerning the hazardous effect of MT on a series of genes involved in immunity, apoptosis and detoxification in the Nile tilapia fry.

Keywords: 17 alpha-methyltestosterone; Gene expression; Innate immunity; Monosex fish; Nile tilapia.

MeSH terms

  • Animals
  • Apoptosis*
  • Cichlids / genetics*
  • Cichlids / immunology*
  • Cichlids / metabolism
  • Dose-Response Relationship, Drug
  • Fish Proteins / genetics
  • Fish Proteins / metabolism
  • Gene Expression
  • Immunity, Innate*
  • Inactivation, Metabolic
  • Longevity
  • Male
  • Methyltestosterone / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism


  • Fish Proteins
  • RNA, Messenger
  • Methyltestosterone