The innate immune system as a window into sponge-microbe

interactions

Jo BayesSandie Degnan

School of Biological SciencesUQ

Questions

1. How does Amphimedon acquire its symbionts?

2. How does the bacterial community of Amphimedon change throughout its lifecycle?

3. How does innate immune gene expression change throughout Amphimedon’s lifecycle?

Ancient, abundant, invisible life forms

Microbial-metazoan interactions•Marine bacteria - freeliving

- pathogenic - symbiotic

• Bacteria 3.5 bya• Sponges 650 mya

Amphimedon queenslandica

• Heron Island• Indo-Pacific distribution• Hermaphroditic

spermcast spawner• Broods embryos

• First Poriferan genome Srivastava et al. 2010

• Alpha - proteobacteria bacteria sequenced

Questions

1. How does Amphimedon acquire its symbionts?

2. How does the bacterial community of Amphimedon change throughout its lifecycle?

3. How does innate immune gene expression change throughout Amphimedon’s lifecycle?

Microbial -metazoan interactionsSymbiont transmission

• Vertical - Poribacteria• Horizontal

Questions

1. How does Amphimedon acquire its symbionts?

2. How does the bacterial community of Amphimedon change throughout its lifecycle?

3. How does innate immune gene expression change throughout Amphimedon’s lifecycle?

Microbial communities

PC larvae Post larvae Adult FSW AdultShark Bay Seawater

PC larvae

Post larvae

Adult

FSW Adult

Least similar

Most similar

Questions

1. How does Amphimedon acquire its symbionts?

2. How does the bacterial community of Amphimedon change throughout its lifecycle?

3. How does innate immune gene expression change throughout Amphimedon’s lifecycle?

Innate Immunity: A first line recognition system

Vertebrates•Innate and Adaptive•Memory cells

Invertebrates•Innate•Alternative adaptive ?

Innate Immunity: A first line recognition system

•Pattern Recognition Receptors

•Microbial Associated Molecular Patterns

Gram positive Gram negative

Gene family MAMPs detected Gene(s) in Amphimedon

Homologues

Vertebrates Invertebrates

LBL LPS: G –ve bacteria 3

NLR PGN: G+ve and -ve 2

C-lectin Carbohydrates 1

Amphimedon innate immune genes of interest

Amphimedon innate immune gene expression

Embryo Larvae Post larvae Adult0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

LBL

Gene

Exp

ress

ion

Embryo Larvae Post larvae Adult0

0.1

0.2

0.3

0.4

0.5

C-lectin

Gene

Exp

ress

ion

Embryo Larvae Post larvae Adult0

1

2

3

4

5

6

7

NLR

Gene

Exp

ress

ion

Conclusions•Symbiotic microbes acquired via vertical and horizontal transmission•Symbiotic from transitory community•Immune genes induced or developmental?•Benthos•Feeding

Thank you...

•Sandie Degnan•Bernie Degnan(School of Biological Sciences, UQ)•Phil Hugenholtz (Australian Centre of Ecogenomics)•Degnan lab

http://web.me.com/degnanlab1/DegnanLab/Home.html

http://ecogenomic.org/users/jo-bayes