title: Imprinting is also a mechanism for immediate or delayed hemizygous expression of several uniparental haplotypes selected from the genome of each sex.
abstract: A peculiar and interesting aspect of monoallelic or hemizygous expression, resulting from genomic imprinting, should be a likeness or resemblance for some phenotypic traits between relatives inheriting identical active genes or domains. Although the word "likon," a neologism, is reminiscent of the above implication, it is here proposed for use in a broader sense, namely, to designate a haplotype or part of a haplotype of an imprinted domain. As learned from earlier studies of imprinting and uniparental disomies, haplotypes at loci of such domains may be expressed (E) or unexpressed (U) in somatic cells; they may also be transmitted to be expressed or not in the next generation by germ cells "acting" (A) or marked to be "resting" (R) for such loci. Thus the soma/germinal status of "likons" might for each genitor be abbreviated as EA, UA, ER, and UR. In an evolutionary sense the assumption is that the same monoallelically expressed loci and domains when carried by two or more relatives should be the source of identical transcripts contributing to a closely similar phenotype. If so, the overall phenotype would be distinct if arising from some 10 to 20 imprinted genes or domains potentially gaining expression from the germ cells of either one or the other sex in humans. The result may have evolutionary implications by narrowing the scope of random individual variation and by strengthening assortative and associative values (physical, behavioral, and instinctual) in one's own lineage and species.
authors.forename: E
authors.initials: E
authors.lastname: Engel
mesh_terms: D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D005260:Female; D006580:Genetic Carrier Screening; D015894:Genome, Human; D018392:Genomic Imprinting; D006239:Haplotypes; D006801:Humans; D008297:Male; D008957:Models, Genetic; D010375:Pedigree