Interphase nuclear structure and heterochromatin in Cicer species.

Abstract

Interphase nuclear structure has been investigated using various techniques of light , phase contrast, fluorescence and electron microscopy . These studies have indicated several interest ing features of the interphase nuclei (once thought to be resting nucleus) like non -random ar rangement of chromosomes, somatic association and specific orientation of chromosomes maintaining their telophasic configurations (Patankar and Ranjekar 1984) . Interphase nuclear organization of plants is species specific , however, it's determinants are not clearly known, al though the role of nuclear DNA content and repititive DNA sequences has been suggested (Lafontaine 1974, Nagl andFusenig 1979). To study interphase nuclei BSG-technique has been applied for heterochromatin visualization in many monocotyledonous plants . Among dicotyledons, interphase nuclear structure has been studied in Anemone (Marks and Schweizer 1974). However, recently interphase nuclear structure in five dicots (Joshi and Ranjekar 1982) and in five species of Phaseolus (Patankar and Ranjekar 1984) has been studied using the HCl -Giemsa technique.Thus the aim of present investigation was to study the interphase nuclear structure and heterochromatin in meristematic and differentiated cells of six Cicer species employing two different staining techniques and also to know the role of nuclear DNA content in structural organization of interphase nuclei.

Interphase Nuclear Structure and Heterochromatin in Two Species of Corchorus and Their F1 Hybrid.

“…Similar type of re sults were reported in Cicer by Kabir and Singh (1989). Nagl (1979) has suggested that in plants, the variation in the proportion of heterochromatin between meristematic and differentiat ed cells can serve as an indication of differential DNA replications.…”

“…Chromocentre numbers in two species of Corchorus and their hybrid were more or less same, which were, however, found to reduce than the expected number of 14. This might be due fusion or overlapping of chro mocentres indicating the somatic association of chromosomes (Kabir and Singh 1989). The number of chromocentres in the nuclei of F, was found to be somewhat closer to the male parent than that of the female parent.…”

Somatic association of chromosomes and other mitotic abnormalities inVanilla planifolia(Andrews)

“…(KABIR and SINGH 1989). The close proximity of some of these prochrosomes to each other in Vanilla planifolia might be indicating the initiation of somatic association even in interphase.…”

Molecular Markers and Cell Cycle Inhibitors Show the Importance of Cell Cycle Progression in Nematode-Induced Galls and Syncytia

“…All interphase nuclei of giant cells and several nuclei of syncytia contained more than the expected number of 10 chromocenters. Chromocenters were also larger than those in nuclei of neighboring cells, probably because of overlapping, fusion, or polyteny (Kabir and Singh, 1989). A detailed confocal analysis of these nuclei will reveal whether somatic association of chromosomes and/or polyploidy occurs in nuclei of feeding cells.…”