Projects / Programmes source: ARIS

Identification of genes involved in calcareous rock-boring in date mussel (Lithophaga lithophaga)

Research activity

Code Science Field Subfield
7.00.00  Interdisciplinary research     

Code Science Field
B220  Biomedical sciences  Genetics, cytogenetics 

Code Science Field
4.04  Agricultural and Veterinary Sciences  Agricultural biotechnology 
next generation sequencing, transcriptome, mantle tissue, date mussel
Evaluation (rules)
source: COBISS
Researchers (1)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  28506  PhD Urška Sivka  Biochemistry and molecular biology  Head  2014 - 2017  19 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  1775  OMEGA svetovanje, inženiring, razvoj in raziskovanje d.o.o. (Slovene)  Ljubljana  5808642  293 
The date mussel (Lithophaga lithophaga) is classified in the genus Lithophaga which is characterized by its chemical boring in limestone rocks. It is a pioneer species and is the first to inhabit bare limestone rocks. Tunnels and holes burrowed by the date mussel form a basis for the settlement of endolithic, benthic and other sessile species. Without date mussel burrows it would have been almost impossible for other species to inhabit bare limestone rocks. The date mussel is a very slow growing mollusc. Beside different physiological factors, the rock boring mechanism is also responsible for its slow growth. The rock boring mechanism has already been studied in the middle of the last century. The studies revealed that the secretion of the pallial glands in mantle tissue is responsible for chemical dissolution of limestone rocks. The mechanism of the pallial gland and consequently the rock boring mechanism rely upon a specific genetic background, which may be determined by the existence of specific genes unique to rock boring organisms or specific level of gene expression varying between boring and non boring organisms. The aim of the proposed project is to define genetic background that allows the date mussel to bore into calcareous rocks and assess the possibility of regulation of the genes involved in the boring process. For identification of candidate genes we will perform a comparison of mantle tissue transcriptome between date mussels and Mediterranean mussels (Mytilus galloprovincialis), which lack the ability of boring rocks. Next generation sequencing will be performed to obtain mantle tissue transcriptome of both organisms. Until today transcriptomic studies involved only non boring mussels. The proposed project will be the first transcriptome study of the rock boring mussel. Previous results of mantle tissue transcriptome studies are unanimous and claim that a significant proportion of mantle tissue transcripts are involved in binding, and potentially in secretion, indicating that the mantle is a transcriptionally active tissue, which is actively proliferating.
Significance for science
An increasing number of studies have been using RNAseq to search for candidate genes for a particular phenotypic trait. In recent years the number of transcriptomic studies in molluscs has rapidly increased. Studies have been focused on either identification of candidate genes for a particular phenotypic trait, or on transcriptomic changes where the studied organism was subjected to a different condition. Molluscs are widely used for studying environmental pollution. Several studies have been focused on the transcriptomic change in molluscs caused by environmental pollution (e.g., increased concentration of carbon dioxide or toxins). The information at the genetic and transcriptomic level of date mussel was very scarce. Before this project only 40 nucleotide sequences were reported in the NCBI database, however most of them belonged to rRNA (18s or 28S). 60000 million nucleotide sequences generated in research project improved NCBI database and genetic information about date mussel a lot. Research data is freely available for any additional research study of date mussel in the future. Before project a little was known about chemical boring mechanism. More than 50 years ago some histological studies of date mussel and chemical boring mechanism were conducted and concluded that in chemical boring mechanism some neutral mucoproteins or glycolipoproteins are involved. Globaly this was the first study of chemical boring mechanism from transcriptomic point of view. Results significantly contribute to a better understanding of the chemical boring mechanism in date mussel. The available list of candidate genes could be used in future studies on chemical boring mechanism not only in date mussel but also in other organisms that bore holes by chemical means.
Significance for the country
In Slovenia date mussel is a protected marine species. Harvesting of date mussels from the wild for the purpose of trade had detrimental impact on the species. When date mussels are harvested, the rocks they inhabit are broken and become unsuitable for colonization by marine organisms. The over exploitation of date mussels has caused catastrophic ecological damage. The restoration of littoral communities, once they are destroyed by date mussel extraction, is very slow and often impossible. Date mussels are a very slow growing mussel and are therefore unsuitable for cultivation. Their growing capacity is associated with chemical boring mechanism. With better understanding of chemical boring mechanisms and the possibility of improving their growth capacity and commercial breeding, will help to preserve their habitat and reduce ecological damage caused by illegal harvesting.
Most important scientific results Final report
Most important socioeconomically and culturally relevant results Final report
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