Molecular Tools for Aiding and Breeding of Aquaculture Species Masters in Aquaculture and Fisheries...
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Molecular Tools for Aiding and Breeding of Aquaculture Species Masters in Aquaculture and Fisheries Genetic and Selection 2014 Tamara Moedas nº 47853; Catarina Ferreira nº 35671
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Transcript of Molecular Tools for Aiding and Breeding of Aquaculture Species Masters in Aquaculture and Fisheries...
Molecular Tools for Aiding and Breeding of Aquaculture Species
Masters in Aquaculture and Fisheries Genetic and Selection
2014Tamara Moedas nº 47853; Catarina Ferreira nº 35671
Molecular Tools
• Allozyme markers;
• Mitochondrial DNA markers (mtDNA);
• Restriction fragment length polymorphism (RFLP);
• Random amplified polymorphic DNA (RAPD);
• Amplified fragment length polymorphism (AFLP);
• Microsatellite markers;
• Single nucleotide polymorphism (SNP);
• Expressed sequence tags (ESTs).
Allozyme Markers
• Advantages:
o Low cost;o the rapid technique;o Ease to use;o Usually used in fishery
genetics.
• Disadvantages:
o Heterozygote deficiencies due to null alleles;
o Limited number of available allozyme loci precludes their use in large-scale genome mapping;
o Changes in DNA sequence reduce the level of detectable variation
o Are not selectively neutral.
Mitochondrial DNA Markers
• Advantages:
o High levels of polymorphism;
o It evolves much faster than coding regions of DNA;
o Multiple copies in each cell.
• Disadvantages:
o Back mutation;o Parallel substitution;o Rate heterogeneity or
mutational hot spots.
Restriction fragment length polymorphism (RFLP)
• Advantage:
o Codominant markers.
• Disadvantages:
o Low level of polymorphism;
o Low power in revealing genetic variation;
o Difficult and time-consuming to develop markers in species lacking molecular information.
Random Amplified Polymorphic DNA Markers (RAPD)
• Advantages:
o High levels of polymorphisms;
o Allows the simultaneous analysis of many loci;
o Markers are inherited in dominant fashion.
• Disadvantage:
o Special equipment.
Amplified Fragment Length Polymorphism (AFLP)
• Advantages:
o Analysis many loci simultaneously;
o Revealed polymorphisms;
o Inherited as dominant markers;
o High reproducibility.
• Disadvantage:
o Special equipment.
Microsatellite markers
• Advantages:
o Hight Abundant in all species;
o Distributed in the genome on all chromosomes;
o Loci are small;o Polymorphic;o Codominant markers.
• Disadvantage:
o Hight expensive.
Single Nucleotide Polymorphism (SNP)
• Advantages:
o Most abundant polymorphism in organism;
o Reveal hidden polymorphism;
o Co-dominant markers.
• Disadvantages:
o Requires specialized equipment;
o Large-scale analysis, depends on the availability of expensive, cutting-edge equipment.
Expressed sequence tags (ESTs)
• Advantages:
o Identify genes and analyze their expression by expression profiling;
o Rapid and at genes expressed in specific tissue types;
o Development of cDNA microarrays;
o Great value in genome mapping.
o Disadvantage:
o Identification of polymorphic ESTs is necessary for genome mapping.
Conclusions
Markers Linking Mapping
Population Studies
Maternal Linkage
Hybrid Identific
-ation
Physical Mapping
Comparati- ve
MappingPolymorph
-ism
AllozymeMarkers LOW
mtDNA
RFLP LOW
RAPD INTERMEDIATE
AFLP HIGH
Microsat-ellites
markersHIGH
SNP HIGH
EST’s LOW
Biblography• Liu, Z. J., Cordes, J. F., 2004. “DNA marker technologies and their
applications in aquaculture genetics”. Aquaculture 238, pp. 1-37;
• Magoulas, A.. “Application of molecular markers to aquaculture
and broodstock management with special emphasis on
microsatellite DNA”. CIHEM-Options Mediterraneennes, pp. 153-
168;• Chauhan,T., Rajiv, K.,2010. “Molecular markers and their
applications in fisheries and aquaculture”. University of Delhi, Delhi, India.
