Evolution of altruistic cooperation among nascent multicellular organisms.
Cooperation is a classic solution to hostile environments that limit individual survival. In extreme cases this may lead to the evolution of new types of biological individuals (e.g., eusocial super-organisms).
We examined the potential for interindividual cooperation to evolve via experimental evolution, challenging nascent multicellular “snowflake yeast” with an environment in which solitary multicellular clusters experienced low survival. In response, snowflake yeast evolved to form cooperative groups composed of thousands of multicellular clusters that typically survive selection.
Group formation occurred through the creation of protein aggregates, only arising in strains with high (>2%) rates of cell death. Nonetheless, it was adaptive and repeatable, although ultimately evolutionarily unstable.
Extracellular protein aggregates act as a common good, as they can be exploited by cheats that do not contribute to aggregate production. These results highlight the importance of group formation as a mechanism for surviving environmental stress, and underscore the remarkable ease with which even simple multicellular entities may evolve-and lose-novel social traits.
Selection for synchronized cell division in simple multicellular organisms.
The evolution of multicellularity was a major transition in the history of life on earth. Conditions under which multicellularity is favored have been studied theoretically and experimentally.
But since the construction of a multicellular organism requires multiple rounds of cell division, a natural question is whether these cell divisions should be synchronous or not. We study a population model in which there compete simple multicellular organisms that grow by either synchronous or asynchronous cell divisions.
We demonstrate that natural selection can act differently on synchronous and asynchronous cell division, and we offer intuition for why these phenotypes are generally not neutral variants of each other.
Description: MUC-1 (Mucin-1; also PEM, PEMT, Episialin, tumor-associated mucin, and carcinoma associated mucin) is a 240-450 kDa type I transmembrane glycoprotein. Human MUC-1 is 1255 amino acids (aa) in length and contains a 23 aa signal sequence, a 1135 aa extracellular domain (ECD), a 23 aa transmembrane segment, and a 74 aa cytoplasmic tail. The ECD consists of degenerate tandem repeats and a tandem repeat region, which makes up the major portion of the protein. Potential O-glycosylation sites (serines and threonines) make up more than one-fourth of the amino acids. Splicing variants produce ten isoforms for human MUC-1. Human MUC-1 is 28% aa identical to mouse MUC-1.
Description: T cell immunoglobulin mucin-3 (TIM-3) is a member of the T-cell Immunoglobulin- and Mucin-domain-containing family of type I membrane glycoproteins that regulate autoimmune and allergic disease. TIM-3 is selectively expressed on Th1 cells and interacts with galectin-9. It negatively regulates Th1 responses and affects macrophage activation. The 280 aa mature human TIM-3 contains a V-type Ig-like domain that shows multiple polymorphisms, followed by a mucin-like domain in the 171 aa extracellular region, which shares 60% amino acid identity with mouse TIM-3 ECD. One splice variant of TIM-3 is truncated within the mucin domain and presumably is secreted.
Description: Enables ferritin receptor activity. Acts upstream of or within iron ion transport. Located in cell surface. Is expressed in 4-cell stage embryo; liver; liver left lobe; liver right lobe; and metanephros. Human ortholog(s) of this gene implicated in atopic dermatitis. Orthologous to human HAVCR1 (hepatitis A virus cellular receptor 1).
Description: T-cell immunoglobulin and mucin domain containing 4 (TIMD-4) also known as T-cell membrane protein 4 (TIM-4) is a protein in humans that is encoded by the TIMD4 gene.
Caenorhabditis Sieve: A Low-tech Instrument and Methodology for Sorting Small Multicellular Organisms.
Caenorhabditis elegans (C. elegans) is a well-established model organism used across a range of basic and biomedical research. Within the nematode research community, there is a need for an affordable and effective way to maintain large, age-matched populations of C. elegans.
Here, we present a methodology for mechanically sorting and cleaning C. elegans. Our aim is to provide a cost-effective, efficient, fast, and simple process to obtain animals of uniform sizes and life stages for their use in experiments.
This tool, the Caenorhabditis Sieve, uses a custom-built lid system that threads onto common conical lab tubes and sorts C. elegans based on body size. We also demonstrate that the Caenorhabditis Sieve effectively transfers animals from one culture plate to another allowing for a rapid sorting, synchronizing, and cleaning without impacting markers of health, including motility and stress-inducible gene reporters. This accessible and innovative tool is a fast, efficient, and non-stressful option for maintaining C. elegans populations.
Protein Disaggregation in Multicellular Organisms.
Protein aggregates are formed in cells with profoundly perturbed proteostasis, where the generation of misfolded proteins exceeds the cellular refolding and degradative capacity. They are a hallmark of protein conformational disorders and aged and/or environmentally stressed cells.
Protein aggregation is a reversible process in vivo, which counteracts proteotoxicities derived from aggregate persistence, but the chaperone machineries involved in protein disaggregation in Metazoa were uncovered only recently.
Here we highlight recent advances in the mechanistic understanding of the major protein disaggregation machinery mediated by the Hsp70 chaperone system and discuss emerging alternative disaggregation activities in multicellular organisms.
Toxicity of silver nanoparticles, multiwalled carbon nanotubes, and dendrimers assessed with multicellular organism Caenorhabditis elegans.
Nematode Caenorhabditis elegans (C. elegans) was used to investigate the impact of silver nanoparticles (SNP), multiwalled carbon nanotubes (MWCNT), and polyamidoamine dendrimers (PAMAM) used in concentration of 1010 particle/mL.
Population-based observations and gene expression analysis were employed in this study. SNP and PAMAM caused decrease in the number of live nematodes and their body length, but MWCNT did not affect the population of nematodes.
Gene expression analysis revealed significant changes caused by the presence of all studied nanomaterials, and the results strongly suggest a specific metabolic response of the nematode organism to exposure to various nanomaterials.
It was shown that C. elegans is a very sensitive organism capable to respond specifically to the exposure to some nanomaterials and therefore could be considered as a possible biosensor for early warning of presence of some nanoparticles.
Description: The CFDA SE (carboxyfluorescein diacetate succinimidyl ester) Cell Tracer Kit is usually used in fluorescence analyses as a long-term tracer of cells. The Kit can be used for in vitro and in vivo labeling of cells to determine whether or not a cell is proliferating, especially.
Description: Our Cell Explorer™ fluorescence imaging kits are a set of tools for labeling cells for fluorescence microscopic investigations of cellular functions.
FluoGreen Tracer, Stains Cell Nuclei and Cytoplasm
Description: Intracellular pH plays an important modulating role in many cellular events, including cell growth, calcium regulation, enzymatic activity, receptor-mediated signal transduction, ion transport, endocytosis, chemotaxis, cell adhesion and other cellular processes.
Description: Tau tracer 2 (Pl-2620) is a Tau tracer used for imaging Tau protein aggregates. Tau tracer 2 can be used to diagnose neurodegenerative diseases[1].
Cell Explorerâ„¢ Live Cell Labeling Kit *Green Fluorescence*
Description: Our Cell Explorer™ fluorescence imaging kits are a set of tools for labeling cells for fluorescence microscopic investigations of cellular functions.
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