RNA regulation in male germ cells

​Description of Research

The general goal of our research is to clarify the mechanisms of spermatogenesis and male infertility by investigating the molecular factors that are involved in the differentiation of male germ cells. Germ cells are unique in their capability to give rise to a new organism, which signifies the importance of securing both genetic integrity and correct epigenetic marks in the germline. Male germ cells are characterized by major epigenetic transitions that are accompanied by highly active transcription to produce an exceptionally diverse transcriptome. As a response, prominent ribonucleoprotein (RNP) granules, or germ granules, appear in the cytoplasm of germ cells. Germ granules are required for normal fertility, and they have a central role in RNA regulation, especially in piRNA-targeted RNA control during spermatogenesis. In our research, we aim to elucidate the mechanisms of RNA regulation in male germ cells, as well as their involvement in epigenetic inheritance of acquired diseases. Especially we are interested in the functions of small non-coding RNAs (sncRNA), both DICER-dependent microRNAs (miRNAs) and germline-predominant piRNAs, during spermatogenesis. Our main focus is on germ granules and their roles in germ cell-specific RNA regulation both under normal and pathological conditions.


Members of the research group

Post-doctoral researchers:

  • Matti Lahti
  • Elina Palonen

PhD students:

  • Ram Prakash Yadav
  • Tiina Lehtiniemi
  • Opeyemi Olotu
  • Margareeta Mäkelä
  • Anna-Riina Koskenniemi


  • Juho Asteljoki (student)
  • Elina Louramo (technician)

Selected Publications

  • Pandey RR, Homolka D, Olotu O, Sachidanandam R, Kotaja N, Pillai RS. Exonuclease Domain-Containing 1 Enhances MIWI2 piRNA Biogenesis via Its Interaction with TDRD12. Cell Rep. 2018 24:3423-3432.e4.
  •  MS, Zhang FP, Kotaja N, Sironen A. SPEF2 functions in microtubule-mediated transport in elongating spermatids to ensure proper male germ cell differentiation. Development. 2017 Jul 15;144(14):2683-2693.
  • Matteo Da Ros, Tiina Lehtiniemi, Opeyemi Olotu, Daniel Fischer, Fu-Ping Zhang, Helena Vihinen, Eija Jokitalo, Anu Sironen, Jorma Toppari, Noora Kotaja. FYCO1 and autophagy control the integrity of the haploid male germ cell-specific RNP granules. Autophagy. 2017 Feb;13(2):302-321.
  • Korhonen HM, Yadav RP, Da Ros M, Chalmel F, Zimmermann C, Toppari J, Nef S, Kotaja N. DICER Regulates the Formation and Maintenance of Cell-Cell Junctions in the Mouse Seminiferous Epithelium. Biol Reprod. 2015 Dec;93(6):139.
  • Goh WS, Falciatori I, Tam OH, Burgess R, Meikar O, Kotaja N, Hammell M, Hannon GJ. piRNA-directed cleavage of meiotic transcripts regulates spermatogenesis. Genes Dev. 2015 May 15;29(10):1032-44.
  • Da Ros M, Hirvonen N, Olotu O, Toppari J, Kotaja N. Retromer vesicles interact with RNA granules in haploid male germ cells. Mol Cell Endocrinol. 2015 Feb 5;401:73-83.
  • Meikar O, Vagin VV, Chalmel F, Sõstar K, Lardenois A, Hammell M, Jin Y, Da Ros M, Wasik KA, Toppari J, Hannon GJ, Kotaja N. An atlas of chromatoid body components. RNA. 2014 Apr;20(4):483-95.
  • Kotaja N, Sassone-Corsi P. The chromatoid body: a germ-cell-specific RNA-processing centre. Nat Rev Mol Cell Biol 8(1):85-90, 2007.
  • Kotaja N, Kimmins S, Brancorsini S, Hentsch D, Vonesch JL, Davidson I, Parvinen M, Sassone-Corsi P. Preparation, isolation and characterization of stage-specific spermatogenic cells for cellular and mo-lecular analysis. Nat Methods 1(3):249-54, 2004.​


 Associate professor Noora Kotaja