Invertebrate Models

Biomedical research investigators have used organisms ranging from flies to worms, and from ciliates to marine invertebrates, in order to understand many aspects of human physiology, genetics, aging, development, and disease. The Division of Comparative Medicine supports resources that supply critical research materials and services, such as cultured cell lines, genetic stocks, technical training, and on-line informational systems on these types of model organisms for the benefit of the entire biomedical research community. See our Fact Sheet for an overview of ORIP's Invertebrate program.

A Resource Center for Tetrahymena thermophila
P40 OD010964

Research Emphasis/Objectives

The national Tetrahymena Stock Center (TSC), located at Cornell University, is a centralized repository for storage and distribution of wild type, mutant, and genetically engineered strains of Tetrahymena thermophila, a well-established model organism for basic research in cell biology and genetics. A searchable, interactive website supports ordering and deposition of strains, and provides information to the community at-large on media preparation, basic protocols for growth and maintenance of cell cultures, and links to related web resources. The TSC provides primary support for the Tetrahymena Genome Database (TGD) housed at Bradley University, which provides public access to the annotated genome sequences of T. thermophila macro- and micronuclei via an interactive web-based Wiki, as well as macronuclear sequence information for three related Tetrahymena species (T. malaccensis, T. borealis, and T. ellioti). Current TSC research focuses on improving strategies for micronuclear transformation, and utilizing targeted micronuclear transformation to generate a panel of small, targeted deletions in all five micronuclear chromosomes.

Services Provided


The TSC currently maintains a collection of nearly 3000 strains, including an array of wild type strains; strains carrying naturally occurring and induced mutations affecting a wide range of biological activities; strains carrying defined chromosomal modifications, such as deletion lines, single and multiple nullisomics, and unisomics in two different genetic backgrounds; genetically engineered lines with well- defined modifications, such as gene disruptions, gene replacements, knock-outs and knock-ins; naturally occurring genetically polymorphic strains, such as strains B, C3, D, E, and F; panels of B-C3 meiotic segregants and terminal assortants used in mic and mac genetic mapping; well characterized “star” strains of various genetic backgrounds lacking a functional germinal nucleus and essential for work involving genomic exclusion; and a variety of isolates from natural populations. A list of available strains and information about TSC stocks can be obtained from the TSC website.

Biological Materials

The TSC currently supplies 21 plasmids commonly used in Tetrahymena, and is in the process of acquiring more plasmids from Tetrahymena researchers. As additional plasmids are deposited with the TSC, they will be made available to the Tetrahymena research community.

Genomic Resources

The Tetrahymena Genome Database provides BLAST and GBrowse access to the micronuclear and macronuclear genomes of Tetrahymena thermophila, along with updated gene models based on the 2014 JVCI genome annotation. Gene pages are linked to expression data in the Tetrahymena Functional Genome Database (TetraFGD). New domain, homolog, GO, and other functional annotations are being added to the website based on the new models. Macronuclear sequence databases for three other Tetrahymena species (T. malaccensis, T. borealis, and T. ellioti) are also BLAST searchable on the TGD database.

Biolistic transformation

The TSC offers biolistic transformation services for academic researchers on a fee-for-service basis. Using researcher provided targeting vectors, TSC will carry out transformation into Tetrahymena strains of choice. Technical assistance in the design and targeting of transformation vectors is available for those using the service. 


Stock center scientists are available to provide technical support and information on strain options, basic Tetrahymena culture, and strain maintenance for those new to the Tetrahymena system.

Contact Information

Resource Center for Tetrahymena
Department of Microbiology and Immunology
Cornell University
C5 152 Veterinary Medical Center
Ithaca, NY 14853
Tetrahymena Stock Center
Tetrahymena Genome Database

Principal Investigator

Ted Clark, PhD.
Phone: 607-253-4042
Fax: 607-253-3384

Resource Contact

Donna Cassidy-Hanley, Ph.D.
Phone: 607-253-3407
Fax: 607-253-3384
Bloomington Drosophila Stock Center at Indiana University
P40 OD018537

Research Emphasis/Objectives Photograph of a fruit fly with red eyes

The Center collects, maintains and distributes genetically defined strains of Drosophila melanogaster with significant research value. Emphasis is placed on strains providing experimental tools useful to a broad range of investigations including marker, balancer, mapping, and transposon-tagging strains; mutant alleles of identified genes including a large set of transgene insertion alleles; defined sets of chromosomal deficiencies and duplications; engineered lines for somatic and germline clonal analysis; RNAi lines for targeted gene knockdown; GAL4, UAS, QF, QUAS, LexA and LexAop lines for targeted gene expression; enhancer trap and reporter strains with defined expression patterns for marking tissues; engineered lines for high efficiency transgenesis; fully sequenced wild type strains; and lines for modeling human diseases and health-related processes.

Services Provided

Approximately 60,000 fly strains are currently in distribution. Up-to-date stock lists are available for searching, browsing, or downloading/copying at the Internet site.

New users must contact the center for a Bloomington user number (BUN) before ordering via a web-based automated ordering system. One small starter culture is provided of each requested stock; larger cultures cannot be provided. Visit the website for information on ordering stocks and current fees. Stock center scientists are available to answer questions about strains, use of the website and database files, and Drosophila genetics for researchers new to the field.

Contact Information

Bloomington Drosophila Stock Center
Department of Biology
Indiana University
1001 East 3rd Street
Bloomington, IN 47405-7005
Bloomington Drosophila Stock Center at Indiana University

Co-Principal Investigators

Kevin R. Cook, Ph.D.
Phone: 812-856-1213
Fax: 812-855-2577
Kathleen A. Matthews, Ph.D.
Phone: 812-855-5782
Fax: 812-855-2577

Other/Resource Contacts

Annette L. Parks, Ph.D.
Phone: 812-856-5113
Fax: 812-855-2577
Thom Kaufman, Ph.D., Director
Phone: 812-855-3033
Fax: 812-855-2577
Caenorhabditis Genetics Center
P40 OD010440

Research Emphasis/Objectives

The Caenorhabditis Genetics Center (CGC) acquires, maintains, and distributes genetic stocks and information about stocks of the small free-living nematode Caenorhabditis elegans for use by investigators initiating or continuing research on this genetic model organism. Stocks are also provided for educational purposes. CGC staff strive to enhance genetic tools available to researchers, including marking balancer chromosomes with fluorescent reporter genes. The CGC maintains a searchable strain database accessible from the CGC website. This site also provides general information about C. elegans and links to key websites of use to scientists, including WormBase.

Services Provided

The CGC collection contains nearly 19,000 nematode strains. The goal is to include at least one allele of every gene, all available chromosome rearrangements, and selected multiple-mutant stocks for genetic mapping. Certain transgenic strains also are available, including strains that express various fluorescent protein reporter fusions. The CGC also has stocks of nematode species closely related to C. elegans and bacterial strains necessary for nematode growth and for performing RNA interference experiments. Information about CGC stocks can be obtained from the CGC website or WormBase.

Contact Information

Caenorhabditis Genetics Center
Department of Genetics and Cell Biology
University of Minnesota
6-160 Jackson Hall
321 Church St., SE
Minneapolis, MN 55455
Caenorhabditis Genetics Center (CGC)

Principal Investigator

Head Curator

Aric Daul, Ph.D.
Phone: 612-625-2265
Center for C. elegans Anatomy
R24 OD010943

Research Emphasis/Objectives

The Center does ultrastructural research on the anatomy and development of the model organism, Caenorhabditis elegans. Transmission and scanning electron microscopic (TEM and SEM) studies are conducted in collaboration with established C. elegans researchers and with new students and postdoctoral fellows. Tissue defects in selected mutant alleles are compared with normal nematode tissues.

Electron microscopic (EM) techniques are being developed and improved for Caenorhabditis elegans studies, including better fixations and embeddings for immunoEM and histochemical studies. Special emphasis is being placed on electron tomography methods for viewing cell organelles in three dimensions, and on SEM preparation methods (FIB/SEM, ATUM) for whole animal reconstruction from serial sections.

An archive of TEM images has been assembled for the normal animal—adults, larvae, embryos, and in both sexes. The data are being used to create an online database (WORMATLAS) featuring a Handbook of Anatomy, a Glossary, and the Slideable Worm, where all tissues are displayed in relation to the whole body. Our online Community Forum answers queries regarding EM methods and specific details of nematode anatomy. An online searchable image database (WORMIMAGE) presents thousands of original micrographs from the TEM Archive. Our goal is to make the information free to all researchers and teachers interested in nematode anatomy and development.

Current Research

Several major themes are being followed. These include the ultrastructural anatomy of aging, axon guidance, cell death and autophagy, intercellular fusion, and gonadal development. Synaptic wiring in wild type and mutant animals is studied in serial thin sections; a principal effort is to complete the neuronal wiring of the adult male nervous system.

High-pressure freezing and microwave protocols are being compared as methods for immunocytochemistry, electron tomography and for mutant analysis.

Services Provided

Advanced training is available on a one-to-one basis to learn EM methods for C. elegans; we prefer that the student have some background in electron microscopy in advance. Techniques include fixation, embedding, serial thin sections, antibody staining, and microscopy.

Our technical staff can help in conducting research projects using these methods. The work is often shared with the collaborating laboratory, so that an outside investigator learns to use the microscope, collect images, and analyze the data. Select portions of the IMAGE Archive are available upon request by FTP or on DVDs.

Contact Information

Center for C. elegans Anatomy
Albert Einstein College of Medicine
1300 Morris Park Avenue
Kennedy Center, Room 601
Bronx, New York 10461

Principal Investigator

David H. Hall, Ph.D.
Phone: 718-430-2195
Fax: 718- 430-8821

Additional Contacts

Zeynep F. Altun, M.D., Ph.D.
Laura A. Herndon, Ph.D.
National Resource for Aplysia
P40 OD010952

Research Emphasis/Objectives

The National Resource for Aplysia provides investigators with laboratory-reared Aplysia californica of known age and standardized environmental background at all stages of development from egg to mature adults, as well as red algae to feed animals.

The primary goal of the resource is to optimize and standardize Aplysia used by NIH investigators. This includes a health monitoring program and studies to optimize larval rearing and diet at all life stages. Current research programs focus on investigating changes associated with aging and onset of senescence. Landmarks of aging will be used to produce quantifiably aged animals for researchers.

Services Provided

Sibling animals of known ages and stages are available to investigators throughout the year. On request, Aplysia and their food (red algae) are shipped via Federal Express, overnight priority. Special cohorts, procedures, or manipulations of animal groups can be arranged by contacting the Resource.

The colony currently contains more than 10,000 laboratory-reared animals at various life stages. All animals are produced from field-collected brood stock or field-collected animals bred to lab reared brood stock, monitored for health, and randomly tested for behavioral responses prior to shipping.

Facility staff will provide advice on setting up marine aquarium facilities for short term holding of Aplysia shipped from the resource.

Guest Investigators and Graduate Students

Guest investigators and graduate students interested in studies of life history, culture, genetics, and neurophysiology are encouraged to inquire. Selection will be based on the relevance of the proposed study and the availability of resources to meet individual needs.

Contact Information

National Resource for Aplysia
Rosenstiel School of Marine and Atmospheric Science
University of Miami
4600 Rickenbacker Causeway
Miami, FL 33149

Principal Investigator

Resource Manager

Phillip Gillette
Phone: 305-421-4941
WormGUIDES: A Resource for Global Understanding in Dynamic Embryonic Systems
R24 OD016474

Research Emphasis/Objectives

The WormGUIDES consortium is engaged in the construction of a 4D interactive database of dynamic behaviors of every cell throughout C. elegans embryogenesis at subcellular and minute-level resolution. The goal is to support examination and analysis of complex tissues at the molecular, cellular, tissue and organismal levels, to enable collaborative efforts of such analyses, and to facilitate sharing of such results.

Services Provided

WormGUIDES consists of computationally constructed models of cells and the embryo, the underlying time-lapse images, as well as Graphical User Interfaces and other software tools to enable analysis and sharing.

The current goal of WormGUIDES is to track the nuclear position of every cell (~1340) and neurite growth of 20 selected neurons. Longer term goals include neurite growth for the entire nervous system, as well as cell fate differentiation and cell shape for other cells by integrating information from other public sources such as the community databases of WormBase and WormAtlas, and contributions from the community.

The technologies developed in association with WormGUIDES, which are open-source and freely available, can be readily used to study complex tissues in other organisms. These include novel microscopy, image analysis software to track cells/cell lineage and trace cell shapes, as well as database schemes to integrate complex information and sharing of Big Data.

Contact Information

Daniel A. Colón-Ramos, Ph.D.
Department of Cell Biology
Yale School of Medicine
295 Congress Avenue, BCMM 436B
New Haven, CT 06510
Phone: 203-737-3438
William A. Mohler, Ph.D.
UConn Health Center
400 Farmington Ave.
Farmington, CT 06030-6403
Phone: 860-985-2719
Zhirong Bao, Ph.D.
Memorial Sloan Kettering Cancer Center
1275 York Ave, Box 416
New York, NY 10065
Phone: 646-639-6027