Can tardigrades theoretically survive on Mars? Łukasz Kaczmarek Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61-614 Poznań, Poland   Early Earth and ExoEarths: origin and evolution of life Warsaw, Poland 3-7 April, 2017

Tardigrada or water bears Eutardigrada - lacking of dorsal plates, - lacking of cirri, - two double claws on legs (most often), - placoids in pharyngeal bulb present, - terrestrial and freshwater (most often), - ornamented or smooth eggs. Heterotardigrada - dorsal plates present, - cirri present, - four or more single claws or peduncles on legs (most often), - placoids in pharyngeal bulb absent, - terrestrial and marine (most often), - smooth eggs.

Eggs!

On moss!

Tardigrades in extreme environments Almost all terrestrial, freshwater and marine environments deserts (also polar), polar regions. glaciers (cryoconite holes), highest mountains, bottoms of oceans.

Cryptobiosis Anhydrobiosis: Anoxybiosis: Chemobiosis: Cryobiosis: occurs in situations of extreme desiccation Anoxybiosis: occurs in situations oxygen lack Chemobiosis: occurs in response to high levels of environmental toxins Cryobiosis: occurs in reaction to decreased temperature Osmobiosis: response to increased solute concentration

What can anhydrobiotic tardigrades withstand? 9 - 20 years under atmospheric conditions and up to 30 in frozen state in liquid nitrogen (-253°C) (21 months), at 151°C (15 minutes), chemicals: carbon dioxide, hydrogen sulphide, methane, 1-hexanol, methyl bromide gas and 10 minutes in ethanol, low pressure of the thermosphere and the amazing preassure up to 7,500 Mpa (74,019 atm.), microgravity and lack of geomagnetic field radiation: X-rays or heavy ions (4He) (LD50 = 5,000 Gy) and gamma rays (1,000 and 9,000 Gy), UV radiation (75-88kJm-2 ) …

…also hydrated tardigrades can survive in extreme conditions: irradiation, preassure up to 100 MPa, temperatures down to -196oC and up to 38oC ‘‘ …a toughest animals on the Earth’’ (Copley, 1999).

Sleeping Beauty hypothesis tested on rotifers, nematodes and tardigrades time spent in anhydrobiosis is not counted to the animal total life span higher fitness of animals and their offspring Please imagine this amazing feeling when you wake up and you are still young and… you are on different planet or moon... or even in different planetary system!

Possible mechanisms protecting tardigrades synthesis of trehalose, heat shock proteins (HSP), hydrophilic late embryogenesis abundant (LEA) proteins, cytoplasmic abundant heat soluble (CASH) proteins, secretory abundant heat soluble (SASH) proteins mitochondrial abundant heat soluble (MASH) protein reactive oxygen species (ROS), removal of damaged/dysfunctional molecules, and…some morphological and behavioural adaptations

Perspectives protection and repair of DNA dry vaccines extension of life hibernation and interplanetary and interstellar travels survive on other planets and moons

Tardigrades in the space TARDIS (TARDigrada In Space) TARSE (TArdigrade Resistance to Space Effects) RoTaRad (Rotifers, Tardigrades and Radiation) TARDIKISS (Tardigrades in Space)

Earth Similarity Index (ESI) Schulze-Makuch, D., et al. (2011). Astrobiology, 11, 1041.

Tardigrade Similarity Index (TSI) radius 0.5 to 1.9 EU, mass 0.1 to 10 EU, density 0.7 to 1.5 EU, surface temperature ca. 1 to 424K escape velocity 0.4 to 1.4 EU. gravity as 0.16 to 17 EU revolution as 0.61 to 1.88 EU Schulze-Makuch, D., et al. (2011). Astrobiology, 11, 1041. 2017. J. M. Kashyap. Draft version February 14, 2017 Preprint typeset using LATEX style AASTeX6 v. 1.0

Survive on Mars Survive: probably YES Active live: probably NO solar wind cosmic radiation (ionizing radiation) almost lack of atmosphere lack of oxygen lack of geomagnetic field microgravity low atmospheric pressure low temperatures down to −143 °C „high” temperatures up to 35 °C dust storms lack of liquid water soil pH = 7.7 lack of food cryptobiotic cryptobiotic, active cryptobiotic cryptobiotic cryptobiotic, active? Survive: probably YES Active live: probably NO cryptobiotic cryptobiotic cryptobiotic cryptobiotic, active cryptobiotic cryptobiotic But some of algae can also survive in martian condition… and they are perfect food for tardigrades!!! cryptobiotic, active

Conquered!!!

Thank you…also for your attention  I want to thank: My parents (they know for what); Tardigrades because they are so cute and amazing; My students: Weronika, Krzychu, Milena, Marta and few others (thanks to them I have enthusiasm for further work); and my colleagues (especially dr Bartłomiej Gołdyn who is my co-lecturer in the course of the Astrobiology). Thank you…also for your attention 

https://www.youtube.com/watch?v=ecaZFSwMkXI https://www.youtube.com/watch?v=cjV2WP0wkvo