Embed Size (px)
DESCRIPTION
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. Molecular Tools. Allozyme markers; Mitochondrial DNA markers (mtDNA); - PowerPoint PPT Presentation
Citation preview
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 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.
ConclusionsMarkers Linking
MappingPopulation
StudiesMaternal Linkage
Hybrid Identific
-ationPhysical 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.
