Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: Verification of vertical transmission of reproductive gland bacterial symbionts to the egg sheaths of Loligo opalescens
Student Author(s): Thompson, Janelle R.
Faculty Advisor(s): Epel, David
%E Kaufman, Melissa
Pages: 38
Location: Final Papers Biology 175H
Date: June 1997
Abstract: The resistance of Loligo opalescens embryos to predation may be due to symbiotic bacteria which colonize the egg sheath. It has been hypothesized that these symbiotic microbes are transferred to the agg sheath from the accessory nidamental (AN) gland of the mature female. Cultures of bacteria from freshly spawned egg sheath tissue have produced two to three morphological types of bacteria. Sheath and gland isolates of the same morphology were shown to express identical patterns of protease activity, antifungal activity, and H2 S production. Whole cell hybridizations of purified sheath bacteria with 16 s rDNA probes supports the hypothesis that one sheath isolate is the same species as a previously characterized AN gland isolate. RPD PCR analysis confirms the correlation between sheath and gland isolates by showing both produce similar genomic fingerprints. Comparative analysis of 16s r DNA sequences verifies this homology between sheath and gland isolates, indicating vertical transmission of the AN gland symbionts to the egg sheath during spawning.