Abstract
Ticks have relatively complex microbiomes, but only a small proportion of the bacterial symbionts recorded from ticks are vertically transmitted. Moreover, co-cladogenesis between ticks and their symbionts, indicating an intimate relationship over evolutionary history driven by a mutualistic association, is the exception rather than the rule. One of the most widespread tick symbionts is Candidatus Midichloria, which has been detected in all of the major tick genera of medical and veterinary importance. In some species of Ixodes, such as the sheep tick Ixodes ricinus (infected with Candidatus Midichloria mitochondrii), the symbiont is fixed in wild adult female ticks, suggesting an obligate mutualism. However, almost no information is available on genetic variation in Candidatus M. mitochondrii or possible co-cladogenesis with its host across its geographic range. Here, we report the first survey of Candidatus M. mitochondrii in I. ricinus in Great Britain and a multi-locus sequence typing (MLST) analysis of tick and symbiont between British ticks and those collected in continental Europe. We show that while the prevalence of the symbiont in nymphs collected in England is similar to that reported from the continent, a higher prevalence in nymphs and adult males is apparent in Wales. In general, Candidatus M. mitochondrii exhibits very low levels of sequence diversity, although a consistent signal of host-symbiont coevolution was apparent in Scotland. Moreover, the tick MLST scheme revealed that Scottish specimens form a clade that is partially separated from other British ticks, with almost no contribution of continental sequence types in this north-westerly border of the tick's natural range. The low diversity of Candidatus M. mitochondrii, in contrast with previously reported high rates of polymorphism in I. ricinus mitogenomes, suggests that the symbiont may have swept across Europe recently via a horizontal, rather than vertical, transmission route.
| Original language | English |
|---|---|
| Pages (from-to) | 52-62 |
| Number of pages | 11 |
| Journal | Ticks and Tick-Borne Diseases |
| Volume | 10 |
| Issue number | 1 |
| Early online date | 31 Aug 2018 |
| DOIs | |
| Publication status | Published - 1 Jan 2019 |
Keywords
- Mitochondrion
- MLST
- Mutualist
- Red deer
- Symbiosis
- Vector
ASJC Scopus subject areas
- Parasitology
- Microbiology
- Insect Science
- Infectious Diseases
Cite this
Multi-locus sequence typing of Ixodes ricinus and its symbiont Candidatus Midichloria mitochondrii across Europe reveals evidence of local co-cladogenesis in Scotland. / Al-Khafaji, Alaa M.; Clegg, Simon R.; Pinder, Alice C.; Luu, Lisa; Hansford, Kayleigh M.; Seelig, Frederik; Dinnis, Ruth E.; Margos, Gabriele; Medlock, Jolyon M.; Feil, Edward J.; Darby, Alistair C.; McGarry, John W.; Gilbert, Lucy; Plantard, Olivier; Sassera, Davide; Makepeace, Benjamin L.
In: Ticks and Tick-Borne Diseases, Vol. 10, No. 1, 01.01.2019, p. 52-62.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Multi-locus sequence typing of Ixodes ricinus and its symbiont Candidatus Midichloria mitochondrii across Europe reveals evidence of local co-cladogenesis in Scotland
AU - Al-Khafaji, Alaa M.
AU - Clegg, Simon R.
AU - Pinder, Alice C.
AU - Luu, Lisa
AU - Hansford, Kayleigh M.
AU - Seelig, Frederik
AU - Dinnis, Ruth E.
AU - Margos, Gabriele
AU - Medlock, Jolyon M.
AU - Feil, Edward J.
AU - Darby, Alistair C.
AU - McGarry, John W.
AU - Gilbert, Lucy
AU - Plantard, Olivier
AU - Sassera, Davide
AU - Makepeace, Benjamin L.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Ticks have relatively complex microbiomes, but only a small proportion of the bacterial symbionts recorded from ticks are vertically transmitted. Moreover, co-cladogenesis between ticks and their symbionts, indicating an intimate relationship over evolutionary history driven by a mutualistic association, is the exception rather than the rule. One of the most widespread tick symbionts is Candidatus Midichloria, which has been detected in all of the major tick genera of medical and veterinary importance. In some species of Ixodes, such as the sheep tick Ixodes ricinus (infected with Candidatus Midichloria mitochondrii), the symbiont is fixed in wild adult female ticks, suggesting an obligate mutualism. However, almost no information is available on genetic variation in Candidatus M. mitochondrii or possible co-cladogenesis with its host across its geographic range. Here, we report the first survey of Candidatus M. mitochondrii in I. ricinus in Great Britain and a multi-locus sequence typing (MLST) analysis of tick and symbiont between British ticks and those collected in continental Europe. We show that while the prevalence of the symbiont in nymphs collected in England is similar to that reported from the continent, a higher prevalence in nymphs and adult males is apparent in Wales. In general, Candidatus M. mitochondrii exhibits very low levels of sequence diversity, although a consistent signal of host-symbiont coevolution was apparent in Scotland. Moreover, the tick MLST scheme revealed that Scottish specimens form a clade that is partially separated from other British ticks, with almost no contribution of continental sequence types in this north-westerly border of the tick's natural range. The low diversity of Candidatus M. mitochondrii, in contrast with previously reported high rates of polymorphism in I. ricinus mitogenomes, suggests that the symbiont may have swept across Europe recently via a horizontal, rather than vertical, transmission route.
AB - Ticks have relatively complex microbiomes, but only a small proportion of the bacterial symbionts recorded from ticks are vertically transmitted. Moreover, co-cladogenesis between ticks and their symbionts, indicating an intimate relationship over evolutionary history driven by a mutualistic association, is the exception rather than the rule. One of the most widespread tick symbionts is Candidatus Midichloria, which has been detected in all of the major tick genera of medical and veterinary importance. In some species of Ixodes, such as the sheep tick Ixodes ricinus (infected with Candidatus Midichloria mitochondrii), the symbiont is fixed in wild adult female ticks, suggesting an obligate mutualism. However, almost no information is available on genetic variation in Candidatus M. mitochondrii or possible co-cladogenesis with its host across its geographic range. Here, we report the first survey of Candidatus M. mitochondrii in I. ricinus in Great Britain and a multi-locus sequence typing (MLST) analysis of tick and symbiont between British ticks and those collected in continental Europe. We show that while the prevalence of the symbiont in nymphs collected in England is similar to that reported from the continent, a higher prevalence in nymphs and adult males is apparent in Wales. In general, Candidatus M. mitochondrii exhibits very low levels of sequence diversity, although a consistent signal of host-symbiont coevolution was apparent in Scotland. Moreover, the tick MLST scheme revealed that Scottish specimens form a clade that is partially separated from other British ticks, with almost no contribution of continental sequence types in this north-westerly border of the tick's natural range. The low diversity of Candidatus M. mitochondrii, in contrast with previously reported high rates of polymorphism in I. ricinus mitogenomes, suggests that the symbiont may have swept across Europe recently via a horizontal, rather than vertical, transmission route.
KW - Mitochondrion
KW - MLST
KW - Mutualist
KW - Red deer
KW - Symbiosis
KW - Vector
UR - http://www.scopus.com/inward/record.url?scp=85052947649&partnerID=8YFLogxK
U2 - 10.1016/j.ttbdis.2018.08.016
DO - 10.1016/j.ttbdis.2018.08.016
M3 - Article
VL - 10
SP - 52
EP - 62
JO - Ticks and Tick-Borne Diseases
JF - Ticks and Tick-Borne Diseases
SN - 1877-959X
IS - 1
ER -