Details:

Journal Title:
BMC Genomics
Personal Author:
Wang, Kailai ; del Castillo, Carmelo ; Corre, Erwan ; Pales Espinosa, Emmanuelle ; Allam, Bassem
Wang, Kailai ; del Castillo, Carmelo ; Corre, Erwan ; Pales Espinosa, Emmanuelle ; Allam, Bassem Less -
NOAA Program & Office:
Sea GrantOAR (Oceanic and Atmospheric Research) ; OAR (Oceanic and Atmospheric Research)
Sea GrantOAR (Oceanic and Atmospheric Research) ; OAR (Oceanic and Atmospheric Research) Less -
Sea Grant Program:
NYSGI/NYEXT (New York Sea Grant)
Description:
Background: The hard clam Mercenaria mercenaria is an important seafood species widely exploited along the eastern coasts of the United States and play a crucial role in coastal ecology and economy. Severe hard clam mortalities have been associated with the protistan parasite QPX (Quahog Parasite Unknown). QPX infection establishes in pallial organs with the lesions typically characterized as nodules, which represent inflammatory masses formed by hemocyte infiltration and encapsulation of parasites. QPX infection is known to induce host changes on both the whole-organism level and at specific lesion areas, which imply systemic and focal defense responses, respectively. However, little is known about the molecular mechanisms underlying these alterations.

Results: RNA-seq was performed using Illumina Hiseq 2000 (641 Million 100 bp reads) to characterize M. mercenaria focal and systemic immune responses to QPX. Transcripts were assembled and the expression levels were compared between nodule and healthy tissues from infected clams, and between these and tissues from healthy clams. De novo assembly reconstructed a consensus transcriptome of 62,980 sequences that was functionally-annotated. A total of 3,131 transcripts were identified as differentially expressed in different tissues. Results allowed the identification of host immune factors implicated in the systemic and focal responses against QPX and unraveled the pathways involved in parasite neutralization. Among transcripts significantly modulated upon host-pathogen interactions, those involved in non-self recognition, signal transduction and defense response were over-represented. Alterations in pathways regulating hemocyte focal adhesion, migration and apoptosis were also demonstrated.

Conclusions: Our study is the first attempt to thoroughly characterize M. mercenaria transcriptome and identify molecular features associated with QPX infection. It is also one of the first studies contrasting focal and systemic responses to infections in invertebrates using high-throughput sequencing. Results identified the molecular signatures of clam systemic and focal defense responses, to collectively mediate immune processes such as hemocyte recruitment and local inflammation. These investigations improve our understanding of bivalve immunity and provide molecular targets for probing the biological bases of clam resistance towards QPX.


Keywords:
[+]
Clams Diseases
Source:
BMC Genomics. 2016; 17: 146.
DOI:
https://dx.doi.org/10.1186/s12864-016-2493-9
Pubmed ID:
26921237
Pubmed Central ID:
PMC4769524
Document Type:
Journal Article
Funding:
Grant no. NA07OAR4170010
Rights Information:
CC BY
Compliance:
PMC
Main Document Checksum:
[+]
urn:sha256:83d196df2db3baf47badbe8b553433b7acab363b3a7c5f69c20dbb085d7296b8
Download URL:
https://repository.library.noaa.gov/view/noaa/27666/noaa_27666_DS1.pdf
File Type:

Supporting Files

• No Additional Files

More +