Evolution of a relationship: how Ostreococcus tauri ... · Figure 2: Pulsed-field gel...

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Figure 2: Pulsed-field gel electrophoresis of genomic DNA of the three O. tauri viruses OtV5, OtV6, and OtV15. Lane 1: λ DNA low range, lane 2 and 6: λ DNA ladder. OtV5 OtV6 OtV15 1 2 3 4 5 6 Figure 4: Diagram of orthologous ORFs of the three O. tauri viruses OtV5, OtV6, and OtV15. Figure 3: Synteny among the three O. tauri virus genomes based on pairwise alignment .between predicted open reading frames translated into amino acids. 1. Comparing the genomes of OtV6 and OtV15 to that of OtV5 Similar genome size, ~200 kb (Fig.2, Tab. 1) High synteny (Fig. 3); ~ 70% of their genes are orthologs (Fig. 4) OtV6 possess 9 tRNAs, with the unique tRNAs for Leucine, Arginine, and Proline (Tab. 1) JESSICA U. KEGEL 1 , R. THOMAS 2,3 , E. DERELLE 2,3 , M. LAUDIÉ 4 , R. COOKE 4 , N. GRIMSLEY 2,3 U. JOHN 1 , and H. MOREAU 2,3 Evolution of a relationship: how Ostreococcus tauri viruses circumvent host resistance Affiliations 1. Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Bremerhaven, Department of Ecological Chemistry, Am Handelshafen 12, 27570 Bremerhaven, Germany. 2. CNRS, UMR 7232, Observatoire Océanologique de Banyuls, BP44, 66650 Banyuls-sur-Mer, France. 3. UPMC Univ Paris 06, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France. 4. CNRS, UMR 5096, Laboratoire Génome et Développement des Plantes, Université de Perpignan via Domitia, 58, Av Paul Alduy, 66860 Perpignan, France. BREMERHAVEN Am Handelshafen 12 27570 Bremerhaven Telephone: +49(0)471-4831-1467 [email protected] Current funding of JUK: Marie Curie IEF 629682, VINTPRYM Former funding of JUK: DFG fellowship KE 1738/2-1 References (1) http://www.hpa-bioinfotools.org.uk/pise/double_act.html (2) Carver TJ, Rutherford KM, Berriman M, Rajandream MA, Barrell BG and J Parkhill (2005). ACT: the Artemis Comparison Tool. Bioinformatics, 21(16):3422-3 (3) Li L, Stoeckert Jr. CJ, and DS Roos (2003). OrthoMCL: Identification of Ortholog Groups for Eukaryotic Genomes. Genome Research, 13: 2178-2189 (4) Monier A, Chambouvet A, Milner D, Terrado R, Lovejoy C, Derelle E, and T Richards (2014). A virus-encoded transporter portein derived from host phytoplankton can drive fixed nitrogen uptake. Poster@SAME14 conference. 3. Specific genes of OtV6 and OtV15 Highlighted genes of OtV15 with a putative function: (1) cell surface attached carbohydrate-binding domain protein -> probably involved in viral entry (2) beta-1,4-mannosyl-glycoprotein beta-1,4-N- acetylglucosaminyltransferase -> probably involved in anti- apoptosis Highlighted genes of OtV6 with a putative function: (1) ammonium transporter derived from its host O. tauri -> probably involved in maintaining and perhaps enhancing nutrient uptake during infection (2) Alternative oxidase AOX potentially of host origin-> probably lowers ROS production (3) Thrombospondin type 1-like -> probably involved in proapoptotic activity Parameters OtV5 OtV6 OtV15 - draft Genome size (bp) 186 189 195 ORFs (No.) 247 250 235 GC content (%) 42 45 44 tRNAs I,G,Ty,As,Th I,G,Ty,AsTh,L,Ar,P,L I,G,Ty,AsTh BACKGROUND Marine microeukaryotes battle every day with environmental pressures, predators and viruses to survive. To escape and survive certain threats they often have to change their life cycle stage for the cost of a lower growth rate. Although marine viruses are ubiquitous, they cannot replicate without infecting host cells. Therefore they have to evolve as quickly as their host, adapting their infection strategy along the way. Cultures of the green microalgae Ostreococcus tauri demonstrate spontaneous resistance when infected with the virus OtV5. OtV5-resistance cells infected with two recently sequenced OtV viruses revealed a complex pattern of resistance and susceptibility. While one virus could only lyse OtV5-resistant cells, the second was able to lyse both OtV5-susceptible and – resistant cells (Fig. 1). Figure 1: Infection pattern of the three Ostreococcus tauri viruses OtV5, OtV6, and OtV15 infecting O. tauri RCC745 (=S) or OtV5-resistant clones of the same strain (=R). OtV5 OtV6 OtV15 S + + + R R S OR R S OR S S S R R Table 1: Genome properties of the three Ostreococcus tauri viruses OtV5, OtV6, and OtV15 infecting O. tauri RCC745 (=S) or OtV5-resistant clones of the same strain (=R). 2. Phylogeny among Ostreococcus viruses Maximum-likelihood phylogeny of Ostreococcus viruses (infecting O. tauri, O. lucimarinus, and O. mediteraneus) and two viruses infecting Micromonas (MpV1, MPWG) based on the full length of a major capsid protein. Bootstrap values were obtained from 1000 replicates. SUMMARY: The two new Ostreococcus viruses OtV6 and OtV15 show a high synteny with OtV5 despite their significant phylogenetic distance to OtV5. The possession of an ammonium transporter makes OtV6 very unique among the phycodnaviruses and shows the potential of viral involvement in nutrient transfer. OtV15 OtV5 OtV6 OtV5

Transcript of Evolution of a relationship: how Ostreococcus tauri ... · Figure 2: Pulsed-field gel...

Page 1: Evolution of a relationship: how Ostreococcus tauri ... · Figure 2: Pulsed-field gel electrophoresis of genomic DNA of the three O. tauri viruses OtV5, OtV6, and OtV15.

Figure 2: Pulsed-field gel electrophoresis of genomic DNA

of the three O. tauri viruses OtV5, OtV6, and OtV15. Lane 1: λ DNA low range, lane 2 and

6: λ DNA ladder.

OtV5 OtV6 OtV15 1 2 3 4 5 6

Figure 4: Diagram of orthologous ORFs of the three O. tauri viruses OtV5, OtV6, and OtV15.

Figure 3: Synteny among the three O. tauri virus genomes based on pairwise alignment .between

predicted open reading frames translated into amino acids.

1. Comparing the genomes of OtV6 and OtV15 to that of OtV5

• Similar genome size, ~200 kb (Fig.2, Tab. 1) • High synteny (Fig. 3); ~ 70% of their genes are orthologs (Fig. 4) • OtV6 possess 9 tRNAs, with the unique tRNAs for Leucine,

Arginine, and Proline (Tab. 1)

JESSICA U. KEGEL1, R. THOMAS2,3, E. DERELLE2,3, M. LAUDIÉ4, R. COOKE4, N. GRIMSLEY2,3 U. JOHN1, and H. MOREAU2,3

Evolution of a relationship: how Ostreococcus tauri viruses

circumvent host resistance

Affiliations 1. Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Bremerhaven, Department of Ecological Chemistry, Am Handelshafen 12, 27570 Bremerhaven, Germany. 2. CNRS, UMR 7232, Observatoire Océanologique de Banyuls, BP44, 66650 Banyuls-sur-Mer, France. 3. UPMC Univ Paris 06, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France. 4. CNRS, UMR 5096, Laboratoire Génome et Développement des Plantes, Université de Perpignan via Domitia, 58, Av Paul Alduy, 66860 Perpignan, France.

BREMERHAVEN Am Handelshafen 12 27570 Bremerhaven Telephone: +49(0)471-4831-1467 [email protected]

Current funding of JUK: Marie Curie IEF 629682, VINTPRYM

Former funding of JUK: DFG fellowship KE 1738/2-1

References (1) http://www.hpa-bioinfotools.org.uk/pise/double_act.html (2) Carver TJ, Rutherford KM, Berriman M, Rajandream MA, Barrell BG and J Parkhill (2005). ACT: the Artemis Comparison Tool. Bioinformatics, 21(16):3422-3 (3) Li L, Stoeckert Jr. CJ, and DS Roos (2003). OrthoMCL: Identification of Ortholog Groups for Eukaryotic Genomes. Genome Research, 13: 2178-2189 (4) Monier A, Chambouvet A, Milner D, Terrado R, Lovejoy C, Derelle E, and T Richards (2014). A virus-encoded transporter portein derived from host phytoplankton can drive fixed nitrogen uptake. Poster@SAME14 conference.

3. Specific genes of OtV6 and OtV15 Highlighted genes of OtV15 with a putative function: (1) cell surface attached carbohydrate-binding domain protein

-> probably involved in viral entry (2) beta-1,4-mannosyl-glycoprotein beta-1,4-N-

acetylglucosaminyltransferase -> probably involved in anti-apoptosis

Highlighted genes of OtV6 with a putative function: (1) ammonium transporter derived from its host O. tauri ->

probably involved in maintaining and perhaps enhancing nutrient uptake during infection

(2) Alternative oxidase AOX potentially of host origin-> probably lowers ROS production

(3) Thrombospondin type 1-like -> probably involved in proapoptotic activity

Parameters OtV5 OtV6 OtV15 - draft

Genome size (bp) 186 189 195

ORFs (No.) 247 250 235

GC content (%) 42 45 44

tRNAs I,G,Ty,As,Th I,G,Ty,AsTh,L,Ar,P,L I,G,Ty,AsTh

BACKGROUND Marine microeukaryotes battle every day with environmental pressures, predators and viruses to survive. To escape and

survive certain threats they often have to change their life cycle stage for the cost of a lower growth rate. Although marine viruses are ubiquitous, they cannot replicate without infecting host cells. Therefore they have to evolve as quickly as their host, adapting

their infection strategy along the way.

Cultures of the green microalgae Ostreococcus tauri demonstrate spontaneous resistance when infected with the virus OtV5. OtV5-resistance cells infected with two recently

sequenced OtV viruses revealed a complex pattern of resistance and susceptibility. While one virus could only lyse OtV5-resistant cells, the second was able to lyse both OtV5-susceptible and –

resistant cells (Fig. 1).

Figure 1: Infection pattern of the three Ostreococcus tauri viruses OtV5, OtV6, and OtV15 infecting O. tauri RCC745 (=S) or OtV5-resistant clones of the same

strain (=R).

OtV5

OtV6

OtV15

S +

+

+

R

R S OR

R

S OR

S

S

S R

R

Table 1: Genome properties of the three Ostreococcus tauri viruses OtV5, OtV6, and OtV15 infecting O. tauri RCC745 (=S) or OtV5-resistant clones of the same strain (=R).

2. Phylogeny among Ostreococcus viruses

Maximum-likelihood phylogeny of Ostreococcus viruses (infecting O. tauri, O. lucimarinus, and O. mediteraneus) and two viruses infecting Micromonas (MpV1, MPWG) based on the full length of a

major capsid protein. Bootstrap values were obtained from 1000 replicates.

SUMMARY: The two new Ostreococcus viruses OtV6 and OtV15 show a high synteny with OtV5 despite their significant phylogenetic distance to OtV5. The possession of an ammonium transporter makes OtV6 very unique among the phycodnaviruses and shows the potential of viral involvement in nutrient transfer.

OtV15

OtV5

OtV6

OtV5