Event Title

Coelomocyte Control of Bacteria Population by Phagocytosis in Eisenia fetida

Location

CSU 253/4/5

Start Date

4-4-2011 11:00 AM

End Date

4-4-2011 12:30 PM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Dorothy Wrigley

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Earthworm immunity is characterized by coelomocytes, leukocytes housed in the coelomic cavity of earthworms. Coelomic cells are a mixed population that phagocytize and detoxify chemicals. Earthworms also have several symbitotic bacteria that are passed from parent to offspring eggs. The population size of the symbionts must be controlled or they would kill the earthworm. My hypothesis is that coelomic cells aid control of bacterial number by phagocytosis. To test this hypothesis coelomic cells binding of a symbiont from earthworm cocoons was examined. The symbiont used was identified as a Citrobacter. Coelomic cells were collected from earthworms, Eisenia fetida. Coelomic cells were mixed with freshly cultured symbionts, and examined for their ability to bind the symbionts. Binding was assessed at 30 minutes and at 60 minutes using a gram stain method. In Phosphate Buffered Saline (PBS) 80% of the coelomic cells bound the symbionts. The greatest adherence was after 30 minute incubation. When glucose was added to PBS the cells binding bacteria decreased to 20%. Other sugars, galactose and mannose, had no affect on adherence. The data indicates that coelomic cells recognize and bind to the symbiont, and adherence is mediated by sugar binding. Two populations of coelomic cells exist. One population adheres rapidly to glass. When this rapid adhering coelomic cell population was excluded from the cell/symbiont suspension adherence increased to 93%. Further research is being conducted to examine coelomic cell adherence with live versus dead bacteria.

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Apr 4th, 11:00 AM Apr 4th, 12:30 PM

Coelomocyte Control of Bacteria Population by Phagocytosis in Eisenia fetida

CSU 253/4/5

Earthworm immunity is characterized by coelomocytes, leukocytes housed in the coelomic cavity of earthworms. Coelomic cells are a mixed population that phagocytize and detoxify chemicals. Earthworms also have several symbitotic bacteria that are passed from parent to offspring eggs. The population size of the symbionts must be controlled or they would kill the earthworm. My hypothesis is that coelomic cells aid control of bacterial number by phagocytosis. To test this hypothesis coelomic cells binding of a symbiont from earthworm cocoons was examined. The symbiont used was identified as a Citrobacter. Coelomic cells were collected from earthworms, Eisenia fetida. Coelomic cells were mixed with freshly cultured symbionts, and examined for their ability to bind the symbionts. Binding was assessed at 30 minutes and at 60 minutes using a gram stain method. In Phosphate Buffered Saline (PBS) 80% of the coelomic cells bound the symbionts. The greatest adherence was after 30 minute incubation. When glucose was added to PBS the cells binding bacteria decreased to 20%. Other sugars, galactose and mannose, had no affect on adherence. The data indicates that coelomic cells recognize and bind to the symbiont, and adherence is mediated by sugar binding. Two populations of coelomic cells exist. One population adheres rapidly to glass. When this rapid adhering coelomic cell population was excluded from the cell/symbiont suspension adherence increased to 93%. Further research is being conducted to examine coelomic cell adherence with live versus dead bacteria.

Recommended Citation

Novak, Anna B.. "Coelomocyte Control of Bacteria Population by Phagocytosis in Eisenia fetida." Undergraduate Research Symposium, Mankato, MN, April 4, 2011.
http://cornerstone.lib.mnsu.edu/urs/2011/poster-session-B/6