Investigations on life-cycle and host specificity of the
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Investigations on life-cycle and host specificity of the Malacosporea (Myxozoa) Dr. rer. nat. Daniel Grabner (Dipl. Biol.) 1999-2005 Studium der Biologie an der Eberhard- Karls-Universität Tübingen 2006-2010 Promotion an der Universität Duisburg- Essen, praktische Durchführung der Arbeit an der Tierärztlichen Fakultät der Ludwig-Maximilian-Universität in München und der Veterinärmedizinischen Universität Wien 2010-2011 Stipendium der Japanese Society for Promotion of Science an der Universität von Tokyo seit Mai 2011 wiss. Mitarbeiter im Fachgebiet Angewandte Zoologie/Hydrobiologie der Universität Duisburg-Essen Daniel Grabner betreut durch Prof. Dr. Bernd Sures (Univ. Duisburg-Essen) und Prof. Dr. Mansour El-Matbouli (Vetmeduni Wien) Introduction The Metazoan phylum Myxozoa comprises about 2,000 mostly fish-parasitic species. Typical for this group are life-cycles involving a vertebrate and an invertebrate host. Transmission from one host to the other is achieved by water-born spores. Within the Myxozoa, the class Malacosporea is the most enigmatic and probably most ancient group. These parasites are known to infect fish and freshwater bryozoans, though most malacosporeans have been described only in the invertebrate host. The only complete malacosporean life-cycle is known for Tetracapsuloides bryosalmonae, the parasite causing proliferative kidney disease (PKD) in salmonid fish. This disease can lead to high losses in aquaculture and might also threaten wild populations of brown trout (Salmo trutta). Besides the genus Tetracapsuloides with only a single species, the Malacosporea also contain the genus Buddenbrockia with two described species. Buddenbrockia spp. are known only from the bryozoan host where they either form sac-like stages similar to T. bryosalmonae or worm-like, motile stages. Knowledge about host spectrum, transmission mechanisms and intra-specific differences in susceptibility to malacosporean parasites are scarce. Therefore, it was the aim of the present study to investigate biology and life-cycles of some malacosporeans more intensively. Transmission experiments Resistance of rainbow trout lineages Diversity of malacosporeans As a basis for this work, a laboratory culture of bryozoans was estab- lished from field sam- ples. Route of entry into fish host Laboratory cycle of T. bryosalmonae infected Bryozoa pike not infected at all (!?!) infected and transmitted T. bryoslamonae to Bryozoa infected but no parasite stages developed in bryozoans A new Buddenbrockia species?!? We can be infected by B. plumatellae!! Spores infect fish Fish-malacospores infect bryozoans Where? Mechanism? Which hosts? Resistence? Spores are released via the urine to water Further life cycles? Release of spores to water The penetration of T. bryosalmonae spores into the fish was investigated by in-situ hybridization Scanning electron microscopy of bryozoa-spores of T. bryosalmonae allow further insights in spore morphology Presence of infective stages reveal gill to be the dominant portal of entry for the parasite. Parasite development in kidney of fish stages of T. bryosalmonae Bryozoa-spore of T. bryosalmonae brown trout brook trout rainbow trout grayling stages of Buddenbrockia plumatellae in bryozoans developmental stages of Budden- brockia sp. in carp kidney Molecular phylogeny of known malacosporeans Comparison of 4 rainbow trout and brown trout for their sus- ceptibility to T. bryosalmonae by quantitative real-time PCR. beginning penetration of spores into gill tissue Brown trout (BT) were found to be most susceptible, while one rainbow trout lineage (WT) showed slower increase of parasite numbers than others.
Transcript of Investigations on life-cycle and host specificity of the
Investigations on life-cycle and host specificity of
the Malacosporea (Myxozoa)
Dr. rer. nat. Daniel Grabner (Dipl. Biol.)
1999-2005 Studium der Biologie an der Eberhard- Karls-Universität Tübingen
2006-2010 Promotion an der Universität Duisburg- Essen, praktische Durchführung der Arbeit an der Tierärztlichen Fakultät der Ludwig-Maximilian-Universität in München und der Veterinärmedizinischen Universität Wien
2010-2011 Stipendium der Japanese Society for Promotion of Science an der Universität von Tokyo
seit Mai 2011 wiss. Mitarbeiter im Fachgebiet Angewandte Zoologie/Hydrobiologie der Universität Duisburg-Essen
Daniel Grabner
betreut durch Prof. Dr. Bernd Sures (Univ. Duisburg-Essen) und Prof. Dr. Mansour El-Matbouli (Vetmeduni Wien)
Introduction The Metazoan phylum Myxozoa comprises about 2,000 mostly fish-parasitic species. Typical for this group are life-cycles involving a vertebrate and an invertebrate host. Transmission from one host to the other is achieved by water-born spores. Within the Myxozoa, the class Malacosporea is the most enigmatic and probably most ancient group. These parasites are known to infect fish and freshwater bryozoans, though most malacosporeans have been described only in the invertebrate host. The only complete malacosporean life-cycle is known for Tetracapsuloides bryosalmonae, the parasite causing proliferative kidney disease (PKD) in salmonid fish. This disease can lead to high losses in aquaculture and might also threaten wild populations of brown trout (Salmo trutta). Besides the genus Tetracapsuloides with only a single species, the Malacosporea also contain the genus Buddenbrockia with two described species. Buddenbrockia spp. are known only from the bryozoan host where they either form sac-like stages similar to T. bryosalmonae or worm-like, motile stages. Knowledge about host spectrum, transmission mechanisms and intra-specific differences in susceptibility to malacosporean parasites are scarce. Therefore, it was the aim of the present study to investigate biology and life-cycles of some malacosporeans more intensively.
Transmission experiments
Resistance of rainbow trout lineages Diversity of malacosporeans
As a basis for this work, a laboratory culture of bryozoans was estab-lished from field sam-ples.
Route of entry into fish host
Laboratory cycle of T. bryosalmonae
infected Bryozoa
pike not infected at all (!?!)
infected and transmitted T. bryoslamonae to Bryozoa
infected but no parasite stages developed in bryozoans
A new Buddenbrockia
species?!?
We can be infected by B. plumatellae!!
Spores infect fish
Fish-malacospores infect bryozoans
Where? Mechanism?
Which hosts?
Resistence?
Spores are released via the urine to water
Further life cycles?
Release of spores to water
The penetration of T. bryosalmonae spores into the fish was investigated by in-situ hybridization
Scanning electron microscopy of bryozoa-spores of T. bryosalmonae allow further insights in spore morphology
Presence of infective stages reveal gill to be the dominant portal of entry for the parasite.
Parasite development in kidney of fish
stages of T. bryosalmonae
Bryozoa-spore of T. bryosalmonae
brown trout
brook trout
rainbow trout
grayling
stages of Buddenbrockia plumatellae in bryozoans
developmental stages of Budden-brockia sp. in carp kidney
Molecular phylogeny of known malacosporeans
Comparison of 4 rainbow trout and brown trout for their sus-ceptibility to T. bryosalmonae by quantitative real-time PCR.
beginning penetration of spores into gill tissue
Brown trout (BT) were found to be most susceptible, while one rainbow trout lineage (WT) showed slower increase of parasite numbers than others.
