Genomes/human genome inherited

Short (2-6 bp), inherited, tandem repeat units of DNA occur about 50,000-100,000 times in the human genome (Chapter 36). Because they occur more frequently—and in view of the routine application of sensitive PCR methods—they are replacing RFLPs as the marker loci for various genome searches. 

A second major area of biochemical importance concerns study of nucleotide polymerization to produce ribonucleic acids (RNA) and deoxyribonucleic acids (DNA). Genes, the basis for inherited characteristics, are contained in DNA double-helical sections incorporated into coiled and supercoiled DNA structures. Genomics, the study of the total genetic assemblage of any species, is now a well-known topic to all, especially with the announcement of the sequencing of the human genome in 2001. More information on this topic is given in Section 2.3.6. 

Over the last decades, as the human genome was sequenced, scientists have assembled a vast library of small DNA-sequence differences that are precisely located within the genome. The marker sequences were used for the reassembly of the sequenced pieces of the 3 billion base pairs. Some of these markers are found within a gene that has changed in people with an inherited condition. Other markers are just that—small sequence differences that may not by themselves contribute to an inherited condition. Depending on their location, they may or may not be inherited by family members with a known inherited condition. These small sequence differences are sometimes just the substitution of one nucleotide for another for example, a G instead of a C. In each person s DNA, there are millions of these single nucleotide polymorphisms, inherited differences among individuals (called SNPs), in about 1 out of every 1,200 bases. 

Recently, a hidden Markov model-based method was developed to identify LOH from tumor samples alone, taking into account SNP intermarker distances, SNP-specific heterozygosity rates, and the haplofype structure of the human genome (31) to filter out false-positive LOH. When both parents share the same haplofype, the children will inherit a long stretch of homozygous geneotypes (32). 

Online Mendelian Inheritance in Man (http //www.ncbi.nih.gov/entrez/ query.fcgi db=OMIM) or the page on human genome resources (http // www.ncbi.nlm.nih.gov/genome/guide/human), whereas the address with only small difference (http //www.ncbi.nlm.nih.gov/Genomes/index.html) would take you to a page with information on other animals. 

Perhaps the greatest impact of rDNA technology lies in ib ability to alter a DNA sequence and create entirely new molecules that, if reintroduced into the genome, can be inherited and propagated in perpetuity. The ability to alter a DNA sequence, literally in a test tube, at the di.scretion of an individual. corporation, or nation, brings with it important questions about ownership, ethics, and social responsibility. There is no question, however, that potential benefits to the treatment of human dLsease are great. 

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