Gene count

Schaffner, K. F. (2001), Do genes count , in J. Z. Sadler (Ed.), Descriptions and Prescriptions Values, Mental Disorders and the DSMs, Johns Hopkins University Press, Baltimore, MD, in press. 

The amount of sample required is quite small as little as 10 mole is typical So many peptides and proteins have been sequenced now that it is impossible to give an accurate count What was Nobel Prize winning work m 1958 is routine today Nor has the story ended Sequencing of nucleic acids has advanced so dramatically that it is possible to clone the gene that codes for a particular protein sequence its DNA and deduce the structure of the protein from the nucleotide sequence of the DNA We 11 have more to say about DNA sequencing m the next chapter... 

Tag Count Percent Tag Sequence Gene Description BAC Locus... 

Ginsberg SD, Elarova I, Ruben M, Tan F, Counts SE, et al. 2004. Single-cell gene e3q>ression analysis implications for neurodegenerative and neuropsychiatric disorders. Neuro-... 

This allele counting approach can be used for a locus that has any number of alleles. If, for example, our locus has three possible alleles, and if each genotype can be observed directly, we can still count the alleles within each genotype to obtain a gene frequency. Suppose the following genotype counts are observed ... 

Because males have only one X chromosome, gene frequency estimation for X-Hnked traits differs from that of autosomal traits. Consider hemophilia A (Chapter 1), which is an X-linked recessive disease. If a male s X chromosome has a factor VIII mutation, he will have hemophilia A. If his X chromosome does not have the mutation, he will not develop the disease. Thus, the gene frequency for hemophilia A is obtained simply by counting the proportion of affected males in the population (i.e., the proportion of X chromosomes containing the mutation). Approximately one in 10,000 males has hemophilia A. Thus, the gene frequency for this disease, q, is 1/10,000. 

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