Celina Juliano


Position Title
Assistant Professor

Department of Molecular and Cellular Biology, College of Biological Sciences

Life Sciences Addition 3253

Research Interests


Hydra is in a constant state of development, with all cells being replaced every 20 days by active stem cell populations. We are using single cell RNA sequencing to uncover the developmental trajectories and shed light on the regulatory control of development.


Hydra has remarkable regenerative ability, including the ability to regenerate from a small piece of tissue or even reassemble from dissociated single cells. We are interested in understanding how injury signals trigger developmental pathways during regeneration. 

Stem Cells

We are interested in understanding the molecular mechanisms that allow Hydra stem cells to continually replace cells in an essentially “immortal” animal. We study the function of the PIWI-piRNA pathway in Hydra stem cells, which we hypothesize is required to maintain genomic integrity.


Grad Group Affiliations

  • Biochemistry, Molecular, Cellular and Developmental Biology
  • Integrative Genetics and Genomics

Specialties / Focus

  • Developmental Biology
  • Gene Regulation
  • RNA
  • Stem Cell Biology


  • 2015 Post Doctoral Fellow Yale University
  • 2010 Ph.D. Brown University
  • 1997 B.S. University of Miami


Siebert S, Farrell JA, Cazet JF, Abeykoon Y, Primack AS, Schnitzler CE, and Juliano CE (2018). Stem cell differentiation trajectories in Hydra at single-cell resolution. bioRxiv preprint:  https://doi.org/10.1101/460154

Dupre C, Grasis JA, Steele RE, Schnitzler CE, and Juliano CE (2017). Hydroidfest 2016: Celebrating a renaissance in hydrozoan research. Evo Devo. 8(7).

Siebert and Juliano CE (2017). Sex, Polyps, and Medusae: Determination and maintenance of sex in cnidarians. Mol Reprod Dev. 84(2):105-119

Fresques T, Swartz SZ, Juliano C, Morino Y, Kikuchi M, Akasaka K, Wada H, Yajima M, and Wessel G (2016). The diversity of nanos expression in echinoderm embryos supports different mechanisms in germ cell specification. Evol Dev. 18:4, 267-78. PMCID: PMC4943673

Juliano CE and Hobmayer B (2016). Meeting report on "Animal Evolution: New Perspectives From Early Emerging Metazoans", Tutzing, September 14-17, 2015. Bioessays Online Version January 22.

Juliano CE, Lin H, and Steele RE (2014). Generation of Transgenic Hydra by Embryo Microinjection. J. Vis. Exp. (91) https://www.jove.com/video/51888/generation-of-transgenic-hydra-by-embryo-microinjection

Juliano CE, Reich A, Liu N, Götzfried J, Zhong M, Uman S, Reenan RA, Wessel GM, Steele RE, and Lin H (2014). PIWI Proteins and PIWI-interacting RNAs function in Hydra somatic stem cells. PNAS 111(1):337-342. PMCID: PMC3890812

Mani SR and Juliano CE (2013). Untangling the web: the diverse functions of the PIWI/piRNA pathway. Mol Reprod Dev. 80(8):632-664. 

Song JL, Stoeckius M, Maaskola J, Friedländer M, Stepicheva N, Juliano C, Lebedeva S, Thompson W, Rajewsky N, Wessel GM (2012). Select microRNAs are essential for early development in the sea urchin. Dev. Biol. 362(1):104-113. PMCID: PMC3254792

Juliano C*, Wang J*, and Lin H (2011). Uniting germline and stem cells: The function of Piwi proteins and the piRNA pathway in diverse organisms. Annu Rev Genet. 45:447-469. (*Co-first authors). PMCID: PMC3832951

Gustafson EA, Yajima M, Juliano CE, and Wessel GM (2011). Post-translational regulation by gustavus contributes to selective Vasa protein accumulation in multipotent cells during embryogenesis. Dev Biol. 349:440-450. PMCID: PMC3053044

Juliano CE, Swartz SZ, and Wessel GM (2010). A conserved germline multipotency program. Development. 137(24):4113-4126. PMCID: PMC2990204

Juliano C and Wessel GM (2010). Versatile germline genes. Science. 329(5992):640-641. PMCID: PMC3088100

Juliano CE, Yajima M, and Wessel GM (2010). Nanos is required to maintain multipotency in the small micromere lineage of the sea urchin embryo. Dev Biol. 337(2):220-232. PMCID: PMC2812692

Juliano CE, and Wessel GM (2009). An evolutionary transition of vasa regulation in echinoderms. Evolution and Development 11:5, 560-573. PMCID: PMC3034130

Voronina, E., Lopez, M., Juliano, C.E., Gustafson, E., Song, J.L., Extavour, C., George, S., Oliveri, P., McClay, D., Wessel., G.M. (2008). Vasa protein expression is restricted to the small micromeres of the sea urchin, but is inducible in other lineages early in development. Dev Biol. 314:276-286. PMCID: PMC2692673

Juliano CE, Voronina E, Stack C, Aldrich M, Cameron AR, Wessel GM. (2006). Germ line determinants are not localized early in sea urchin development, but do accumulate in the small micromere lineage. Dev Biol. 300:406-415.