Acta Medica Okayama 117 14 2004 Differential localization of the centromere-specific proteins in the major centromeric satellite of Arabidopsis thaliana 2963 2970 EN Fukashi Shibata Minoru Murata <p>The 180 bp family of tandem repetitive sequences, which constitutes the major centromeric satellite in Arabidopsis thaliana, is thought to play important roles in kinetochore assembly. To assess the centromere activities of the 180 bp repeats, we performed indirect fluorescence immunolabeling with antibodies against phosphorylated histone H3 at Serl0, HTR12 (Arabidopsis centromeric histone H3 variant) and AtCENP-C (Arabidopsis CENP-C homologue) for the A. thaliana cell cultures. The immunosignals from all three antibodies appeared on all sites of the 180 bp,repeats detected by fluorescence in situ hybridization. However, some of the 180 bp repeat clusters, particularly those that were long or stretched at interphase, were not fully covered with the signals from anti-HTR12 or AtCENP-C. Chromatin fiber immunolabeling clearly revealed that the centromeric proteins examined in this study, localize only at the knobs on the extended chromatin fibers, which form a limited part of the 180 bp clusters. Furthermore, outer HTR12 and inner phosphohistone H3 (Ser1O) localization at the kinetochores of metaphase chromosomes suggests that two kinds of histone H3 (a centromere variant and a phosphorylated form) might be linked to different roles in centromere functionality; the former for spindle-fiber attachment, and the latter for chromatid cohesion.</p> No potential conflict of interest relevant to this article was reported.

‰ªŽR‘åŠwŽ‘Œ¹�¶•¨‰ÈŠwŒ¤‹†�Š Acta Medica Okayama 0916-930X 6 1 1999 Differential Screening of Rye-type cDNAs from a Common Wheat Carrying the Rye Midget Chromosomes 53 64 EN Minoru Murata Occurrence of the midget chromosome in a common wheat with rye cytoplasm [(cereale)-Chinese Spring (CS)] indicates that the chromosome carries the essential gene(s) for maintaining the function of rye cytoplasm. To elucidate the interaction between the midget chromosome and rye cytoplasm, in this study, an attempt was made to isolate rye-type cDNAs from a cDNA library of (cereale)-CS by differential screening. Two replica filters from each plate were hybridized with digoxigenin (DIG)-labeled wheat CS cDNAs and with DIG-labeled rye cDNAs,respectively. Out of ca. 20,000 plaques, 27 were hybridized more strongly with rye cDNAs than with CS cDNAs. These clones were classified into six classes (‡T-‡Y) by blot hybridization. The majority of the clones (21 out of 27) was belonged to the same class (1), showing rye-type RFLP (restriction fragment length polymorphism). The DNA sequence of clone CrClA in class ‡T, was very similar to that of wheat ribulose 1,5-bisphosphate carboxylase,large subnit gene, rbcL(94.5% homology). However, the 3' end of CrClA was shorter than that of wheat rbcL, and terminated at TAA instead of TAG, like the rbcL of Aegilops crassa. In the clone CrC5.4, the first half of the sequence was similar to that of one rice EST clone, the functions of which are not known, and the latter was similar to the reverse sequence of maize 4.5S-23S ribosomal RNA. This suggests that CrC5.4 had been derived from two defferent cDNAs of (cereale)-CS. Three other clones had homology to the chlorophyll a/b binding protein genes (cab) of wheat, maize and tomato, and one to wheat rbcS (ribulose1,5-bisphosphate carboxylase small subnit gene). However, no clear polymorphisms were detected between wheat and rye by using those clones as probes. No potential conflict of interest relevant to this article was reported.