Limits...
New insights into the apoptotic process in mollusks: characterization of caspase genes in Mytilus galloprovincialis.

Romero A, Estévez-Calvar N, Dios S, Figueras A, Novoa B - PLoS ONE (2011)

Bottom Line: Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis.Evaluation of the genes' tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells.Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas, Vigo, Spain.

ABSTRACT
Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes' tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs) and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature.

Show MeSH

Related in: MedlinePlus

Phylogenetic analysis of initiator caspases.Neighbor-joining (NJ) phylogenetic tree for initiator caspase proteins. Numbers on branches are bootstrap percentages.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3037946&req=5

pone-0017003-g003: Phylogenetic analysis of initiator caspases.Neighbor-joining (NJ) phylogenetic tree for initiator caspase proteins. Numbers on branches are bootstrap percentages.

Mentions: Initiator caspases were divided into two main groups (Figure 3). The first branch included caspase-2 and -9 while the second included caspase-8 and -10. Vertebrate and invertebrates caspases (-2/-9) mostly separated into other additional sub-groups. Mussel caspase-2 was placed into the caspase-2/9 main branch, close to invertebrate sequences from groups such as cnidarians, nematodes, insects and crustaceans. Mussel caspase-8 was placed into the second main branch (caspases-8/-10), far from the vertebrates but closer to the caspase described in H. diversicolor.


New insights into the apoptotic process in mollusks: characterization of caspase genes in Mytilus galloprovincialis.

Romero A, Estévez-Calvar N, Dios S, Figueras A, Novoa B - PLoS ONE (2011)

Phylogenetic analysis of initiator caspases.Neighbor-joining (NJ) phylogenetic tree for initiator caspase proteins. Numbers on branches are bootstrap percentages.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3037946&req=5

pone-0017003-g003: Phylogenetic analysis of initiator caspases.Neighbor-joining (NJ) phylogenetic tree for initiator caspase proteins. Numbers on branches are bootstrap percentages.
Mentions: Initiator caspases were divided into two main groups (Figure 3). The first branch included caspase-2 and -9 while the second included caspase-8 and -10. Vertebrate and invertebrates caspases (-2/-9) mostly separated into other additional sub-groups. Mussel caspase-2 was placed into the caspase-2/9 main branch, close to invertebrate sequences from groups such as cnidarians, nematodes, insects and crustaceans. Mussel caspase-8 was placed into the second main branch (caspases-8/-10), far from the vertebrates but closer to the caspase described in H. diversicolor.

Bottom Line: Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis.Evaluation of the genes' tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells.Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas, Vigo, Spain.

ABSTRACT
Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes' tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs) and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature.

Show MeSH
Related in: MedlinePlus