A high-yield method for the isolation of intact nuclei and chromosomes in suspension from a variable number of pea root tips (1-10) has been developed. This procedure is based on a two-step cell-cycle synchronization of root-tip meristems to obtain a high mitotic index, followed by formaldehyde fixation and mechanical isolation of chromosomes and nuclei by homogenization. In the explant, up to 50% of metaphases were induced through a synchronization of the cell cycle at the G1/S interface with hydroxyurea (1.25 mM), followed, after a 3-h release, by a block in nletaphase with amiprophos-methyl (10 μM). The quality and quantity of nuclei and chromosomes were related to the extent of the fixation. Best results were obtained after a 30-min fixation with 2% and 4% formaldehyde for nuclei and chromosomes, respectively. The method described here allowed the isolation of nuclei and chromosomes, even from a single root tip, with a yield of 1 x 105/root and 1.4 x 105/root, respectively. Isolated suspensions were suitable for flow cytometric analysis and sorting and PRINS labelling with a rDNA probe.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science
Gualberti, G., Doležel, J., Macas, J., & Lucretti, S. (1996). Preparation of pea (Pisum sativum L.) chromosome and nucleus suspensions from single root tips. Theoretical And Applied Genetics, 92(6), 744 - 751. https://doi.org/10.1007/BF00226097