Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: The effects of digestive bacterial products on the activity of the multixenobiotic resistance protein in the mussel Mytilus californianus
Student Author(s): Narayanan, Divya
Faculty Advisor(s): Epel, David
Pages: 28
Location: Final Papers Biology 175H
Date: June 1998
Keywords: keywords: multixenobiotic (MXR) transport, multidrug resistance (MDR),
digestive gland, mussel
Abstract: Many marine organisms possess a multitoxin, or multixenobiotic, defense mechanism that enables their cells to resist the effects of a variety of environmental pollutants. A membrane transport protein similar to the multidrug resistance protein (MDR) in human tumor cells pumps moderately hydrophobic compounds out of the cell membrane, thus conferring a multixenobiotic resistance (MXR) to cells. One particular strain of marine bacteria isolated from the digestive gland of the mussel Mytilus californianus produces or contains compounds that are potential substrates of the MXR protein in mussel gill tissue. Substances produced by this strain increased the level of rhodamine accumulation in gill tissue and reduced the rate of rhodamine efflux when compared with a marine broth control. This strain was isolated separately from two different mussels collected more than seven weeks apart, indicating that it is endogenous to the mussel gut, either as a regularly ingested dietary bacteria or as a digestive symbiont. The presence of the strain in the mussel digestive gland and its high affinity for MXR suggests a possible evolutionary function for the MXR transporter may be to protect against potential toxins that the mussel encounters during the digestive process.