Three-dimensional analysis tool for segmenting and measuring the structure of telomeres in mammalian nuclei

Quantitative analysis in combination with fluorescence microscopy calls for innovative digital image measurement tools. We have developed a three-dimensional tool for segmenting and analyzing FISH stained telomeres in interphase nuclei. After deconvolution of the images, we segment the individual telomeres and measure a distribution parameter we call ?T . This parameter describes if the telomeres are distributed in a sphere-like volume (?T ? 1) or in a disk-like volume (?T » 1). Because of the statistical nature of this parameter, we have to correct for the fact that we do not have an infinite number of telomeres to calculate this parameter. In this study we show a way to do this correction. After sorting mouse lymphocytes and calculating ?T and using the correction introduced in this paper we show a significant difference between nuclei in G2 and nuclei in either G0/G1 or S phase. The mean values of ?T for G0/G1, S and G2 are 1.03, 1.02 and 13 respectively.