Limits...
Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus.

Watthanasurorot A, Jiravanichpaisal P, Liu H, Söderhäll I, Söderhäll K - PLoS Pathog. (2011)

Bottom Line: The cytoplasmic tail can generate multiple isoforms.PlDscam can generate more than 22,000 different unique isoforms.Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV.

View Article: PubMed Central - PubMed

Affiliation: Department of Comparative Physiology, Uppsala University, Uppsala, Sweden.

ABSTRACT
The Down syndrome cell adhesion molecule, also known as Dscam, is a member of the immunoglobulin super family. Dscam plays an essential function in neuronal wiring and appears to be involved in innate immune reactions in insects. The deduced amino acid sequence of Dscam in the crustacean Pacifastacus leniusculus (PlDscam), encodes 9(Ig)-4(FNIII)-(Ig)-2(FNIII)-TM and it has variable regions in the N-terminal half of Ig2 and Ig3 and the complete Ig7 and in the transmembrane domain. The cytoplasmic tail can generate multiple isoforms. PlDscam can generate more than 22,000 different unique isoforms. Bacteria and LPS injection enhanced the expression of PlDscam, but no response in expression occurred after a white spot syndrome virus (WSSV) infection or injection with peptidoglycans. Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV. Bacterial specific isoforms of PlDscam were shown to have a specific binding property to each tested bacteria, E. coli or S. aureus. The bacteria specific isoforms of PlDscam were shown to be associated with bacterial clearance and phagocytosis in crayfish.

Show MeSH

Related in: MedlinePlus

High diversity regions of Dscam in freshwater crayfish.A) Diagram showing the locations of putative alternatively spliced exons of PlDscam. The variable regions are indicated at the N-terminal parts of Ig2 (red) and Ig3 (pink) and complete Ig7 (blue) and transmembrane (green) domains in crayfish. The number of alternative exons is presented by bars under the diagram. B–E) Multiple amino acid sequence alignment of PlDscam variable regions of Ig2(B), Ig3(C), Ig7(D) and transmembrane domain (E) aligned by ClustalW, Dark shading indicates the boundary of each domain.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3111544&req=5

ppat-1002062-g002: High diversity regions of Dscam in freshwater crayfish.A) Diagram showing the locations of putative alternatively spliced exons of PlDscam. The variable regions are indicated at the N-terminal parts of Ig2 (red) and Ig3 (pink) and complete Ig7 (blue) and transmembrane (green) domains in crayfish. The number of alternative exons is presented by bars under the diagram. B–E) Multiple amino acid sequence alignment of PlDscam variable regions of Ig2(B), Ig3(C), Ig7(D) and transmembrane domain (E) aligned by ClustalW, Dark shading indicates the boundary of each domain.

Mentions: To identify the variable regions of PlDscam, several regions of the PlDscam were amplified using different primer pairs and the location of each pair of primers is shown in Figure S1. Fifty clones of each of the six amplified regions were selected and sequenced, translated and aligned using ClustalW. Alternatively spliced mRNA segments of the PlDscam were detected in the N-terminal of Ig2 and Ig3, in the entire length of the Ig7 domain, in the transmembrane domain and in the cytoplasmic tail (Figure 2B–E and Figure S1A). In total 12, 29, 32 and 2 alternative spliced forms of the exons encoding Ig2, Ig3, Ig7 and the transmembrane domains, respectively were detected and therefore at least 22,000 different unique isoforms could in theory be generated (Figure 2A–2E). The other domains were highly conserved, especially Ig8-FNIII4. The cytoplasmic tail of PlDscam contains some highly conserved motifs similar to the corresponding area in Dscams of other species (Figure S1B).


Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus.

Watthanasurorot A, Jiravanichpaisal P, Liu H, Söderhäll I, Söderhäll K - PLoS Pathog. (2011)

High diversity regions of Dscam in freshwater crayfish.A) Diagram showing the locations of putative alternatively spliced exons of PlDscam. The variable regions are indicated at the N-terminal parts of Ig2 (red) and Ig3 (pink) and complete Ig7 (blue) and transmembrane (green) domains in crayfish. The number of alternative exons is presented by bars under the diagram. B–E) Multiple amino acid sequence alignment of PlDscam variable regions of Ig2(B), Ig3(C), Ig7(D) and transmembrane domain (E) aligned by ClustalW, Dark shading indicates the boundary of each domain.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3111544&req=5

ppat-1002062-g002: High diversity regions of Dscam in freshwater crayfish.A) Diagram showing the locations of putative alternatively spliced exons of PlDscam. The variable regions are indicated at the N-terminal parts of Ig2 (red) and Ig3 (pink) and complete Ig7 (blue) and transmembrane (green) domains in crayfish. The number of alternative exons is presented by bars under the diagram. B–E) Multiple amino acid sequence alignment of PlDscam variable regions of Ig2(B), Ig3(C), Ig7(D) and transmembrane domain (E) aligned by ClustalW, Dark shading indicates the boundary of each domain.
Mentions: To identify the variable regions of PlDscam, several regions of the PlDscam were amplified using different primer pairs and the location of each pair of primers is shown in Figure S1. Fifty clones of each of the six amplified regions were selected and sequenced, translated and aligned using ClustalW. Alternatively spliced mRNA segments of the PlDscam were detected in the N-terminal of Ig2 and Ig3, in the entire length of the Ig7 domain, in the transmembrane domain and in the cytoplasmic tail (Figure 2B–E and Figure S1A). In total 12, 29, 32 and 2 alternative spliced forms of the exons encoding Ig2, Ig3, Ig7 and the transmembrane domains, respectively were detected and therefore at least 22,000 different unique isoforms could in theory be generated (Figure 2A–2E). The other domains were highly conserved, especially Ig8-FNIII4. The cytoplasmic tail of PlDscam contains some highly conserved motifs similar to the corresponding area in Dscams of other species (Figure S1B).

Bottom Line: The cytoplasmic tail can generate multiple isoforms.PlDscam can generate more than 22,000 different unique isoforms.Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV.

View Article: PubMed Central - PubMed

Affiliation: Department of Comparative Physiology, Uppsala University, Uppsala, Sweden.

ABSTRACT
The Down syndrome cell adhesion molecule, also known as Dscam, is a member of the immunoglobulin super family. Dscam plays an essential function in neuronal wiring and appears to be involved in innate immune reactions in insects. The deduced amino acid sequence of Dscam in the crustacean Pacifastacus leniusculus (PlDscam), encodes 9(Ig)-4(FNIII)-(Ig)-2(FNIII)-TM and it has variable regions in the N-terminal half of Ig2 and Ig3 and the complete Ig7 and in the transmembrane domain. The cytoplasmic tail can generate multiple isoforms. PlDscam can generate more than 22,000 different unique isoforms. Bacteria and LPS injection enhanced the expression of PlDscam, but no response in expression occurred after a white spot syndrome virus (WSSV) infection or injection with peptidoglycans. Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV. Bacterial specific isoforms of PlDscam were shown to have a specific binding property to each tested bacteria, E. coli or S. aureus. The bacteria specific isoforms of PlDscam were shown to be associated with bacterial clearance and phagocytosis in crayfish.

Show MeSH
Related in: MedlinePlus