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出典:Wikipedia
出典:『Wikipedia』 (2011/07/21 21:33 UTC 版)
A housekeeping gene is typically a constitutive gene that is required for the maintenance of basic cellular function, and are found in all cells of an organism. Although some housekeeping genes are expressed at relatively constant levels (such as HSP90 and Beta-actin), other housekeeping genes may vary depending on experimental conditions. The origin of the term "housekeeping gene" remains obscure. Literature from 1976 used the term to describe specifically tRNA and rRNA. Interpreting gene expression data can be problematic, with most human genes registering 5-10 copies per cell (possibly representing error). Housekeeping genes are expressed in at least 25 copies per cell and sometimes number in the thousands.