Genes of the Mitochondrial Apoptotic Pathway in Mytilus galloprovincialis

Abstract

Bivalves play vital roles in marine, brackish, freshwater and terrestrial habitats. In recent years, these ecosystems have become affected through anthropogenic activities. The ecological success of marine bivalves is based on the ability to modify their physiological functions in response to environmental changes. One of the most important mechanisms involved in adaptive responses to environmental and biological stresses is apoptosis, which has been scarcely studied in mollusks, although the final consequence of this process, DNA fragmentation, has been frequently used for pollution monitoring. Environmental stressors induce apoptosis in molluscan cells via an intrinsic pathway. Many of the proteins involved in vertebrate apoptosis have been recognized in model invertebrates; however, this process might not be universally conserved. Mytilus galloprovincialis is presented here as a new model to study the linkage between molecular mechanisms that mediate apoptosis and marine bivalve ecological adaptations. Therefore, it is strictly necessary to identify the key elements involved in bivalve apoptosis. In the present study, six mitochondrial apoptotic-related genes were characterized, and their gene expression profiles following UV irradiation were evaluated. This is the first step for the development of potential biomarkers to assess the biological responses of marine organisms to stress. The results confirmed that apoptosis and, more specifically, the expression of the genes involved in this process can be used to assess the biological responses of marine organisms to stress.

Identification and functional characterization of two Bcl-2 family protein genes in Zhikong scallop Chlamys farreri

“…In R. philippinarum, the mRNA levels of two Bcl-2-like genes in hemocytes were 2e3 times more than those of controls three hours after bacteria challenge [13]. In M. galloprovincialis, the Bcl-2-like gene expression and Bax-like gene expression in hemocytes were both significantly up-regulated three hours after exposure to UV light and pifithrin-a hydrobromide treatment [14]. As expected, in our report the expressions of CfBcl-2 and CfBax were both significantly up-regulated after exposure to air, injection with LPS and infection with AVNV (Figs.…”

“…Not all Bcl-2 proteins contain transmembrane domains in molluscs. For example, the mussel Bcl-2-like protein (AGK88246.1) has transmembrane regions [14], whereas the CfBcl-2 and CfBax, together with other Bcl-2-like proteins in the Bcl-2 phylogenetic tree (Fig. 2B) do not.…”

“…The Bcl-2 related proteins have been well described in mammals and in model invertebrates such as the fruit fly Drosophila melanogaster [8,9] and the nematode Caenorhabditis elegans [10,11]. In molluscs, the Bcl-2 family members have been reported only in a few species, including Pacific oyster Crassostrea gigas [12], Manila clam Ruditapes philippinarum [13], Mediterranean mussel Mytilus galloprovincialis [14] and owl limpet Lottia gigantea [15]. In these studies, the complete coding sequences of Bcl-2 related homologies were either identified by traditional experimental techniques or in silico predicted in massive sequencing projects, and the roles of Bcl-2 family genes in immune response and apoptosis were primarily inferred at transcriptional level.…”

The effects of zinc nanooxide on cellular stress responses of the freshwater mussels Unio tumidus are modulated by elevated temperature and organic pollutants

“…Activation of apoptosis is an important mechanism involved in the adaptive responses to stresses (Estévez-Calvar et al, 2013) which also plays an important role in environmental stress responses of mollusks (Terahara and Takahashi, 2008;Sokolova, 2009;Kiss, 2010). Apoptosis is involved in the clearance of damaged cells (Romero et al, 2011).…”

Condition index and hemocyte apoptosis as a health indicator for the Pacific oysters, Crassostrea gigas cultured in the western coastal waters of Korea

“…혈구의 면역학적 기능을 평가하기 위하여는 생 존율(viability), phagocytosis, adhesion rate, release of reactive oxygen species (ROS) 및 apoptosis 등을 주로 분 석한다 (Goedken and Guise, 2004;Delaporte et al, 2007;Bugge et al, 2007). 이들 항목 중 생존율, (Hyun et al, 2008;Estevez-Calvar et al, 2013). 패류에 서도 또한 apoptosis 연구는 Perkinsus marinus에 의한 Dermo disease와 중금속 등에 장기간 노출되었을 때의 영향 등 질병과 관련된 연구들이 주를 이루고 있다 (Cherkasov et al, 2007;Hughes et al, 2010;Foster et al, 2011 (Fig.…”