genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...

, HAPPY Mapping, first proposed by Paul H. Dear and Peter R. Cook in 1989, is a method used to study the linkage between two or more

DNA sequences A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the ...

. According to th
Single Molecule Genomics Group
it is ''"Mapping based on the analysis of approximately HAPloid DNA samples using the PolYmerase chain reaction"''. In

genomics Genomics is an interdisciplinary field of molecular biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes as well as its hierarchical, ...

, HAPPY mapping can be applied to assess the

synteny In genetics, the term synteny refers to two related concepts: * In classical genetics, ''synteny'' describes the physical co-localization of genetic loci on the same chromosome within an individual or species. * In current biology, ''synteny'' m ...

and orientation of various DNA sequences across a particular genome - the generation of a "genomic" map. As with linkage mapping, HAPPY mapping relies on the differential probability of two or more DNA sequences being separated. In genetic mapping, the probability of a recombination event between two genetic loci on the same

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

is directly proportional to the distance between them. HAPPY mapping replaces recombination with fragmentation - instead of relying on recombination to separate genetic loci, the entire genome is fragmented, for example, by radiation or mechanical shearing. If the DNA is broken on a random basis, the longer the distance between two DNA sequences, the higher the chances of it to break between the two, and vice versa. HAPPY mapping retains the benefits of genetic mapping while removing some of the problems associated with recombination. I.e., the need for polymorphism, and breeding. Also, recombination can be locale specific whereas breakage of genomic DNA by radiation or mechanical shearing seems to be more random. It has been used to genetically map several organisms. HAPPY mapping has also been adapted to allow the precise analysis of copy-number variation, and in particular the analysis of copy-number changes in cancer.

References

{{Reflist Genetic mapping Genomics