Browsing by Author "Bringloe, Trevor, T."

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    Detecting Alaria esculenta and Laminaria digitata (Laminariales, Phaeophyceae) gametophytes in red algae, with consideration of distribution patterns in the intertidal zone
    (Taylor and Francis, 2019) Bringloe, Trevor, T.; Bartlett, Charlotte, A.B.; Bergeron, Emma, S.; Cripps, Katherine, S.A.; Daigle, Nicole, J.; Gallagher, Patrick, O.; Gallant, Alicia, D.; Giberson, Rachel, O.J.; Greenough, Simon, J.; Lamb, Jillian, M.; Leonard, Thomas, W.; MacKay, Jane, A.; McKenzie, Alexander, D.; Persaud, Shana, M.; Sheng, Tianqi; Stack Mills, Alexa, M.E.; Moore, Tanya, E.; Saunders, Gary, W.
    Kelp ecology is heavily biased toward the conspicuous sporophyte stage, whereas understanding of the microscopic gametophyte remains limited. Given that kelp gametophytes are known to grow in/on other species of algae, we sought to determine if species-specific polymerase chain reaction could detect kelp gametophytes in situ from coextracted host DNA. Upon verifying our molecular results, we also assessed distributional patterns of the kelp gametophytes according to site, host species, and vertical placement in the intertidal zone. We sampled Chondrus crispus, Mastocarpus stellatus, and Palmaria palmata (Florideophyceae) at Wallace Cove, New Brunswick, Canada, on 13 September 2016, where kelp sporophytes were abundant, and at an adjacent location without obvious sporophyte presence, L'Etete, on 26 September 2016. Species-specific primers were used to assess the presence of Alaria esculenta and Laminaria digitata DNA from coextracted red algal DNA. We successfully amplified kelp DNA from the host tissue of each red algal species, indicating that gametophytes were present at Wallace Cove and L'Etete during the fall of 2016, with significantly less gametophyte presence at L'Etete. Although no significant differences in gametophyte presence occurred according to host species, P. palmata had significantly less gametophyte presence when sampled from its upper range in the intertidal. Microscopy and additional field observations confirmed the presence of brown endophytes in a variety of hosts, including C. crispus and P. palmata. Our study showcases a simple method for detecting kelp gametophytes, with our preliminary results demonstrating that the distributional and ecological range of kelp gametophytes is broader than that of the sporophytic counterparts.
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    Trans-Arctic speciation of Florideophyceae (Rhodophyta) since the opening of the Bering Strait, with consideration of the “species pump” hypothesis
    (Wiley, 2019) Bringloe, Trevor, T.; Saunders, Gary, W.
    Aim The opening of the Bering Strait initiated significant biotic interchange that is postulated to have played a major role in phylogeographical patterns of northern marine flora and fauna. In addition, the “species pump” hypothesis asserts that glaciation events promoted speciation due to repeated isolation of populations over the past 2.6 million years. Here, trans-Arctic speciation events in red marine macroalgae (Florideophyceae) were assessed using time-calibrated phylogenies, and the applicability of the “species pump” hypothesis was considered. Location Species records and sequence data for trans-arctic genera of marine macroalgae were amalgamated and supplemented with sampling from the Northwest Atlantic, Northern Alaska (Beaufort Sea), Norway, and Nome, Alaska (Bering Sea; 2014–2017). Methods Bayesian and maximum likelihood phylogenies were variously built using the 5′ end of the cytochrome c oxidase subunit I gene (COI-5P), and/or the full-length nuclear internal transcribed spacer region (ITS), and/or the ribulose-1 5-biphosphate carboxylase large subunit gene (rbcL), and nodes were timed using calibrated COI-5P and rbcL molecular clocks. The final dataset represented approximately 184 species, broadly representing 14 trans-arctic lineages. Results Pacific to Atlantic migration and subsequent speciation was inferred in 11 cases, whereas the opposite scenario, atlantic to pacific, was inferred once; only three speciation events appeared to occur during the Pleistocene. Main conclusions Our results are in agreement with previous studies in that trans-arctic speciation events postdated the opening of the Bering Strait with a clear pacific to atlantic bias. Evidence for the “species pump” (as applied to trans-arctic interchange) was lacking given the frequency of trans-arctic speciation events was not amplified during the Pleistocene.