It Cuts Both Ways: An Annelid Model System for the Study of Regeneration in the Laboratory and in the Classroom

The mechanisms supporting regeneration and successful recovery of function have fascinated scientists and the general public for quite some time, with the earliest description of regeneration occurring in the 8th century BC through the Greek mythological story of Prometheus. While most animals demonstrate the capacity for wound-healing, the ability to initiate a developmental process that leads to a partial or complete replacement of a lost structure varies widely among animal taxa. Variation also occurs within single species based on the nature and location of the wound and the developmental stage or age of the individual. Comparative studies of cellular and molecular changes that occur both during, and following, wound healing may point to conserved genomic pathways among animals of different regenerative capacity. Such insights could revolutionize studies within the field of regenerative medicine. In this review, we focus on several closely related species of Lumbriculus (Clitellata: Lumbriculidae), as we present a case for revisiting the use of an annelid model system for the study of regeneration. We hope that this review will provide a primer to Lumbriculus biology not only for regeneration researchers but also for STEM teachers and their students.Fil: Martinez Acosta, Veronica G.. University Of The Incarnate Word; Estados UnidosFil: Arellano Carbajal, Fausto. Universidad Autonoma de Queretaro.; MéxicoFil: Gillen, Kathy. Kenyon College; Estados UnidosFil: Tweeten, Kay A.. St. Catherine University; Estados UnidosFil: Zattara, Eduardo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Indiana University; Estados Unidos. National Museum Of Natural History. Departamento de Zoología. Area de Invertebrados; Estados Unido

Structural Organization of DNA in Chlorella Viruses

Chlorella viruses have icosahedral capsids with an internal membrane enclosing their large dsDNA genomes and associated proteins. Their genomes are packaged in the particles with a predicted DNA density of ca. 0.2 bp nm−3. Occasionally infection of an algal cell by an individual particle fails and the viral DNA is dynamically ejected from the capsid. This shows that the release of the DNA generates a force, which can aid in the transfer of the genome into the host in a successful infection. Imaging of ejected viral DNA indicates that it is intimately associated with proteins in a periodic fashion. The bulk of the protein particles detected by atomic force microscopy have a size of ∼60 kDa and two proteins (A278L and A282L) of about this size are among 6 basic putative DNA binding proteins found in a proteomic analysis of DNA binding proteins packaged in the virion. A combination of fluorescence images of ejected DNA and a bioinformatics analysis of the DNA reveal periodic patterns in the viral DNA. The periodic distribution of GC rich regions in the genome provides potential binding sites for basic proteins. This DNA/protein aggregation could be responsible for the periodic concentration of fluorescently labeled DNA observed in ejected viral DNA. Collectively the data indicate that the large chlorella viruses have a DNA packaging strategy that differs from bacteriophages; it involves proteins and share similarities to that of chromatin structure in eukaryotes

Establishment of Cell Cultures from Developing Embryos & Regenerating Tissues in Lumbriculus variegatus

Kay Tweeten, Professor of Biology, received a $1,600 Faculty Research & Scholarly Activities Grant to establish primary cell cultures from tissues extracted from the freshwater oligochaete, Lumbriculus variegatus

Comparison of the Protein Profiles and Analysis of Response of Polyploid and Diploid Populations of Lumbriculus variegatus to Environmental Toxicants

Kay Tweeten, Professor of Biology, received a $1,200 Faculty Research & Scholarly Activities Grant to compare proteins from L. variegatus populations by gel electrophoresis to determine if there were differences in levels of expression of specific proteins between the diploid and polyploid populations and to compare the response of the diploid and polyploid populations to the environmental toxicants cadmium chloride, fluoranthene, lead, and Bioban BP-10

Histological Analysis of Embryonic Development and Generation of Reproductive Structures in Lumbriculus

Kay Tweeten, Professor of Biology, and Shannon Brick, student researcher, received a $2,000 award from the 3M Small Scale Grant program to analyze tissue sections of Lumbriculus embryos at different stages of development to describe the morphology of the embryos. Patterns of cleavage and cell arrangement during gastrulation, neurulation, and organogenesis will be examined. The embryonic stage at which reproductive structures including ovaries and testes develop also will be determined

Role of Cell Division in the Regenerative Process in Lumbriculus variegatus

Kay Tweeten, Professor of Biology, and Barbara Pyle, student researcher, received a $2,000 award from the 3M Small Scale Grant program to determine if and when cell proliferation is recurring in regenerating tissues of Lumbriculus variegatus. Regenerating heads and tails will be analyzed for cell proliferation and the time course of cell proliferation during the regeneration process will be determined

Analysis of Chromosome Number, Protein Profiles, & Responses to Toxicants of Different Populations of Lumbriculus variegatus

Kay Tweeten, Professor of Biology, and Chai Vang, student researcher, received a $2,000 award from the 3M Small Scale Grant program to compare proteins by a sensitive two-dimensional gel electrophoresis technique to determine if there are differences in levels of expression of specific proteins between the diploid and polyploid populations. Because L. variegatus is used extensively as an environmental quality indicator organism, the response of the diploid and polyploid populations to environmental toxicants will also be determined

Role of Cell Division and Apoptosis in the Regenerative Process in Lumbriculus variegatus

Kay Tweeten, Professor of Biology, and Andrea Potthoff, student researcher, received a $2,000 award from the 3M Small Scale Grant program to determine if and when cell proliferation, cell migration, and apoptosis occur during regeneration. The results will help resolve conflicting reports in the literature regarding the role of cell division and migration in the regeneration process

Identification of Heat Shock Proteins in Haloferax volcanii by Antibody Cross

Kay Tweeten, Professor of Biology, and Christine Michels, student researcher, received a $2,000 award from the 3M Small Scale Grant program to explore the immunological cross-reactivity of proteins from Haloferax volcanii with antibodies against bacterial and eucaryal heat shock proteins

Effect of Matrix Metalloproteinase Inhibitors on Regeneration in Lumbriculus

Kay Tweeten, Professor of Biology, and Shakira Tumusiime, student researcher, received a $2,000 award from the 3M Small Scale Grant program to extend the studies on matrix metalloprotease activity and its role in regeneration by exploring the effect of inhibitors of specific matrix metalloproteases on regeneration