Trophic and symbiotic links between obligate-glacier water bears (Tardigrada) and cryoconite microorganisms

Insights into biodiversity and trophic webs are important for understanding ecosystem functions. Although the surfaces of glaciers are one of the most productive and biologically diverse parts of the cryosphere, the links between top consumers, their diet and microbial communities are poorly understood. In this study, for the first time we investigated the relationships between bacteria, fungi and other microeukaryotes as they relate to tardigrades, microscopic metazoans that are top consumers in cryoconite, a biologically rich and productive biogenic sediment found on glacier surfaces. Using metabarcoding (16S rDNA for bacteria, ITS1 for fungi, and 18S rDNA for other microeukaryotes), we analyzed the microbial community structures of cryoconite and compared them with the community found in both fully fed and starved tardigrades. The community structure of each microbial group (bacteria, fungi, microeukaryotes) were similar within each host group (cryoconite, fully fed tardigrades and starved tardigrades), and differed significantly between groups, as indicated by redundancy analyses. The relative number of operational taxonomic units (ZOTUs, OTUs) and the Shannon index differed significantly between cryoconite and tardigrades. Species indicator analysis highlighted a group of microbial taxa typical of both fully fed and starved tardigrades (potential commensals), like the bacteria of the genera Staphylococcus and Stenotrophomonas, as well as a group of taxa typical of both cryoconite and fully fed tardigrades (likely part of the tardigrade diet; bacteria Flavobacterium sp., fungi Preussia sp., algae Trebouxiophyceae sp.). Tardigrades are consumers of bacteria, fungi and other microeukaryotes in cryoconite and, being hosts for diverse microbes, their presence can enrich the microbiome of glaciers.

On the roles of intrinsically disordered proteins and regions in cell communication and signaling

For proteins, the sequence → structure → function paradigm applies primarily to enzymes, transmembrane proteins, and signaling domains. This paradigm is not universal, but rather, in addition to structured proteins, intrinsically disordered proteins and regions (IDPs and IDRs) also carry out crucial biological functions. For these proteins, the sequence → IDP/IDR ensemble → function paradigm applies primarily to signaling and regulatory proteins and regions. Often, in order to carry out function, IDPs or IDRs cooperatively interact, either intra- or inter-molecularly, with structured proteins or other IDPs or intermolecularly with nucleic acids. In this IDP/IDR thematic collection published in Cell Communication and Signaling, thirteen articles are presented that describe IDP/IDR signaling molecules from a variety of organisms from humans to fruit flies and tardigrades (“water bears”) and that describe how these proteins and regions contribute to the function and regulation of cell signaling. Collectively, these papers exhibit the diverse roles of disorder in responding to a wide range of signals as to orchestrate an array of organismal processes. They also show that disorder contributes to signaling in a broad spectrum of species, ranging from micro-organisms to plants and animals.

Molecular Swiss Army Knives: Tardigrade CAHS Proteins Mediate Desiccation Tolerance Through Multiple Mechanisms

Tardigrades, also known as water bears, make up a phylum of small but extremely robust animals renowned for their ability to survive extreme stresses including desiccation. How tardigrades survive desiccation is one of the enduring mysteries of animal physiology. Here we show that CAHS D, an intrinsically disordered protein belonging to a unique family of proteins possessed only by tardigrades, undergoes a liquid-to-gel phase transition in a concentration dependent manner. Unlike other gelling proteins such as gelatin, our data support a mechanism in which gelation of CAHS D is driven by intermolecular beta-beta interactions. We find that gelation of CAHS D promotes the slowing of diffusion, and coordination of residual water. Slowed diffusion and increased water coordination correlate with the ability of CAHS D to provide robust stabilization of an enzyme, lactate dehydrogenase, which otherwise unfolds when dried. Conversely, slowed diffusion and water coordination do not promote the prevention of protein aggregation during drying. Our study demonstrates that distinct mechanisms are required for holistic protection during desiccation, and that protectants, such as CAHS D, can act as "molecular Swiss army knives" capable of providing protection through several different mechanisms simultaneously.

Water Bears—The Most Extreme Animals on The Planet (And in Space!)

Can you imagine that there is an eight-legged bear that tolerates colder temperatures than the polar bears do in the Arctic? Can you imagine that this bear is able to grow older than the grizzly bears in North America? And can you imagine that this bear grows by molting, like spiders or snakes? These so-called water bears, scientifically named tardigrades, are the most extreme animals on our planet. They not only survive in ice, but also in boiling water. Moreover, they can stop breathing for long periods and they have even traveled to outer space, surviving without an astronaut’s suit. Since water bears can withstand the harshest conditions on earth and beyond, they may teach us how we can protect ourselves from extreme environmental conditions.

Tardigrades, Water Bears, Moss Piglets Tardigrada (Spallanzani 1777)

Tardigrades, commonly known as water bears, are a type of microscopic animal found across a vast array of moist and aquatic environments. Tardigrades are known for their extensive resilience due to the fact that they are also found in extreme environments such as Antarctica, deep sea vents, and mud volcanoes. They are commonly used as a model organism for scientific research. Also published on the Featured Creatures website at http://entnemdept.ufl.edu/creatures/MISC/tardigrade.html

Biology, Adaptability, and The Economic Applications of Tardigrades In Future

Tardigrades are small microscopic creatures also known as moss piglets or water bears. They are extremophiles and well known for its survivability. After successfully ruling the space tardigrades are now expected to save lives. From being a ‘survivor’ tardigrade is now headed to be a ‘savior’. This survivability is due to a special type of sugar known as “Trehalose”. Trehalose can be found in extremophiles organisms including tardigrades. The unique feature of this sugar is the ability to preserve biological molecules. One of the big applications of the tardigrades are the “dry vaccine”. Our world is struggling through a big crisis of covid-19 vaccine, it is next to impossible to make the highest demanded vaccine available to every corner of the earth at the low-temperature range in such a short period of time, and according to WHO half of the vaccines get wasted due to the cold chain method So, we can implement these dry vaccines for covid-19, to reduce the freezing cost, increasing the shelf life of vaccine and make every vaccine reach to needy in a live condition. Now, trehalose is not only confined to preserve vaccines but this can help in preserve the organs that are going to be used either for transplantology or organ donation. This special protein is yet to give a new turn to not only the medical field and to save human life but tardigrades can be implemented for plants in increasing the tolerance to a stressful environment for future climate changes and space settlement hence this paper provides an overview regarding the application and economical aspects of the tardigrades