Record Details
Field | Value |
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Title | Coevolution of Xiphinema americanum plant parasitic nematodes and their bacterial endosymbionts |
Names |
Smith, McKinley S.
(creator) Denver, Dee (advisor) |
Date Issued | 2015-06-02 (iso8601) |
Note | Honors Bachelor of Science (HBS) |
Abstract | Symbiosis takes place across the domains of life. In the plant-parasitic nematode, Xiphinema americanum species complex, the bacterial endosymbiont, identified as Candidatus Xiphinematobacter americanum, lives in the gut epithelia of mature female nematodes and moves to the ovaries and uterus where it is transmitted to the eggs. This suggests that the symbiont may be vertically transmitted. PCR followed by DNA sequencing was conducted on three loci, using nematode samples from across North America. Two loci were sequenced from the symbiont and the third from the mitochondrial DNA of the nematode. Using these sequences, phylogenetic trees were constructed for the nematode and the symbiont to provide new insights into the taxonomy of the nematode species, and to shed light on the potential for coevolution between the worm and its endosymbiont. A mitochondrial tree was constructed to examine nematode evolution. Mitochondrial phylogenetic analysis for the nematode built from work that suggested there are additional clades within the X. americanum species complex than previously known. The congruent phylogenies derived from these methods strongly suggest that the symbiont is primarily transmitted in a vertical fashion along with the germline of its nematode host. |
Genre | Thesis |
Access Condition | http://creativecommons.org/licenses/by-nc-nd/3.0/us/ |
Topic | symbiosis |
Identifier | http://hdl.handle.net/1957/56212 |