A molecular revision of the taxonomic status of mermithid parasites of black flies from Quebec (Canada) |
| |
Authors: | St-Onge Mylène LaRue Bernard Charpentier Guy |
| |
Institution: | a Département de Chimie-biologie, Université du Québec à Trois-Rivières, 3351 Boulevard des Forges, Box 500, Trois-Rivières, Canada G9A5H7 b Laboratoire de Lutte Biologique, Département des Sciences Biologiques, Université du Québec à Montréal, Box 8888, Succ. Centre Ville, Montréal, Que., Canada H3C 3P8 |
| |
Abstract: | The four currently recognized mermithid (Nematoda) species parasitizing black flies (Diptera: Simuliidae) from Northeast America were distinguished using discriminatory PCR primers aimed at COI and 18S rDNA. Isomermis wisconsinensis, Gastromermis viridis and Mesomermis camdenensis were easily differentiated using either genomic target, even for juvenile mermithids damaged beyond morphological recognition. However, specimens from Mesomermis flumenalis being identical in external morphology and producing a unique-sized PCR product were classified by sequence data into four clearly distinguished molecular variants. This quartet was made of two winter and two summer ‘physiological variants’, including one which also belonged to, but diverged early from the rest of the Mesomermis genus. Combining the multiplex PCR and sequencing approaches allowed for the characterization of a multiple parasitism which simultaneously implicated I. wisconsinensis and two M. flumenalis variants. With another instance where parasites were identified by morphology only, this is the first report of black fly parasitism by multiple mermithid species. A phylogenetic tree built by combining our sequences to previous GenBank entries likely indicates a monophyletic origin for the mermithid family, but also suggests that differentiation between parasite genera sometimes occurred before the evolutionary emergence of the actual host group. |
| |
Keywords: | Mermithidae Nematodes Simuliid hosts PCR probes Cryptic species Multiple parasitism |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|