| First Author | Obara Y | Year | 1997 |
| Journal | Zoolog Sci | Volume | 14 |
| Issue | 1 | Pages | 57-64 |
| PubMed ID | 9200979 | Mgi Jnum | J:40293 |
| Mgi Id | MGI:87638 | Doi | 10.2108/zsj.14.57 |
| Citation | Obara Y, et al. (1997) Delayed response of QM- and DA/DAPI-fluorescence in C-heterochromatin of the small Japanese field mouse, Apodemus argenteus. Zoolog Sci 14(1):57-64 |
| abstractText | The small Japanese field mouse Apodemus argenteus has the diploid chromosome number of 46, carrying rather large centromeric C-heterochromatin in most of the 44 autosomes and a large amount of C-heterochromatin in the sex chromosomes: the largest subtelocentric X was heterochromatic in almost two-fifth (whole short arm and proximal part of the long arm) of its entire length and the medium-sized acrocentric Y was totally heterochromatic. The C-heterochromatin (C-positive) areas, other than those of the Y and smallest three pairs, had a unique property of delayed QM-fluorescence, which has not been reported to-date, showing dull QM-fluorescence immediately after exposure to blue light (BL), but gradually turning to bright fluorescence in a few minutes. The fluorescence intensity gradually decreased after attaining its peak, and finally became extinct. A similar pattern of fluorescence was also obtained in DA/DAPI-stained-X chromosome C-heterochromatin, but not in autosomal C-heterochromatin. No such dull-to-bright transition of QM-fluorescence could be obtained by CMA staining, for which the C-positive areas were apparently negative even after overexposure to BL. These facts indicate that the C-positive areas of A. argenteus showing dull-to-bright transition of QM-fluorescence contain A-T rich DNA. The delayed QM-fluorescence was found only in A. argenteus, in thirteen mammalian species so-far examined. Furthermore, this unique property of QM-fluorescence could be artificially altered to non-delayed ordinary type of fluorescence by sequentially pretreating the fixed chromosomes with hydrochloride and barium hydroxide solutions. The cytological implication of the delayed fluorescence in the C-heterochromatin of A. argenteus is briefly discussed. |
