The vast majority of theses in this collection are open access and freely available. There are a small number of theses that have access restricted to the WWU campus. For off-campus access to a thesis labeled "Campus Only Access," please log in here with your WWU universal ID, or talk to your librarian about requesting the restricted thesis through interlibrary loan.
Date of Award
Fall 2024
Document Type
Masters Thesis
Department or Program Affiliation
Marine and Estuarian Science
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Arellano, Shawn M.
Second Advisor
Bingham, Brian L., 1960-
Third Advisor
Galati, Nick
Fourth Advisor
Beinart, Roxanne
Abstract
At deep sea hydrothermal vents, niche boundaries are hypothesized to be defined by available enriched vent fluids specific to the metabolic requirements of vent organisms. Research suggests that, via symbiosis, the geochemical restrictions imposed on chemosynthetic endosymbionts may also burden the complementary host. Although knowledge of symbioses in these vent systems continues to increase, the mode of acquisition of symbiotic counterparts for many species remains unclear.
At the Eastern Lau Spreading Center (ELSC), deep sea Paskentanidae snails in the genus Alviniconcha can host up to two symbiont phylotypes intracellularly in adult gill tissue, however little is known about how these symbionts are acquired and retained by the host and the role these symbionts have in defining niche boundaries. The present study investigates symbiont diversity and distribution across three size classes of recently settled hydrothermal vent gastropods, Alviniconcha strummeri, using fluorescence in situ hybridization (FISH).
Collections took place in Spring of 2022 at Tui Malila, an active vent system at the (ELSC) using ROV Jason benthic grabs and specimens were preserved with 4% PFA for FISH. Paraffin-embedded tissues were serially sectioned at 5-mm sections along the length of the organism body. FISH was performed using a series of probe controls, EUB338 I-III, NON338 and a no probe control to capture autofluorescence. Three phylotype-specific probes were used to identify symbionts hosted by Alviniconcha spp. at the ELSC. Two novel oligonucleotide FISH probes were developed to target γ-1 and γ-Lau proteobacteria and the universal campylobacteria probe, Epsi549, was used to target Campylobacteriota.
Early settlers (< 6 mm in length) were shown to host γ-1, γ-Lau, and Campylobacteria symbionts in mouth, foot, and gill tissues. However, at larger size ranges, retention of symbionts may be limited to γ-1 symbionts, and localize primarily in specialized gill structures. Additionally, different spatial patterns in symbiont retention in gill structures of juveniles < 5 mm was seen, with symbiont presence in ‘upper’ showing higher signal of γ -1 symbionts while ’lower’ gill structures had higher signals of Campylobacteria symbionts.
It has been suggested that symbionts play a crucial role in defining niche boundaries for Alviniconcha species in the ELSC. Although the role symbionts have in influencing niche partitioning remains unclear, this study provides unique insight in the acquisition and retention of symbionts hosted in three size ranges of recently settled A. strummeri juveniles at Tu’i Malila in the ELSC. Understanding symbiont acquisition and timing is fundamental in evaluating symbiont pressures on the community structure, connectivity, and driving forces of niche partitioning for host counterparts at the ELSC.
Type
Text
Keywords
Symbiosis, Alviniconcha, Alviniconcha strummeri, fluorescent in situ hybridization
Publisher
Western Washington University
OCLC Number
1474475615
Subject – LCSH
Sea snails; Symbiosis; Fluorescence in situ hybridization.
Format
application/pdf
Genre/Form
masters theses
Language
English
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.
Recommended Citation
McCartha, Michelle Marie, "Investigating symbiont acquisition in deep-sea snails using fluorescent in situ hybridization" (2024). WWU Graduate School Collection. 1344.
https://cedar.wwu.edu/wwuet/1344