[Mechanisms of alternative lengthening of telomeres].

The review considers mechanisms of an alternative lengthening of telomeres (ALT) which possess the second after telomerase but not less important place in telomere length regulation. The general data about ALT are shown. An alternative lengthening of telomeres in normal and cancer cell lines are characterized. Special attention is given to the features of recombinational and retrotranspositional mechanisms of ALT.