Czaban B B, Forer A, Bajer A S
Department of Biology, York University, Ontario, Canada.
J Cell Sci. 1993 Jun;105 ( Pt 2):571-8. doi: 10.1242/jcs.105.2.571.
We used an ultraviolet microbeam to irradiate chromosomal spindle fibres in metaphase Haemanthus endosperm cells. An area of reduced birefringence (ARB) was formed at the position of the focussed ultraviolet light with all wavelengths we used (260, 270, 280, and 290 nm). The chromosomal spindle fibre regions (kinetochore microtubules) poleward from the ARBs were unstable: they shortened (from the ARB to the pole) either too fast for us to measure or at rates of about 40 microns per minute. The chromosomal spindle fibre regions (kinetochore microtubules) kinetochore-ward from the ARBs were stable: they did not change length for about 80 seconds, and then they increased in length at rates of about 0.7 microns per minute. The lengthening chromosomal spindle fibres sometimes grew in a direction different from that of the original chromosomal spindle fibre. The chromosome associated with the irradiated spindle fibre sometimes moved off the equator a few micrometers, towards the non-irradiated half-spindle. We discuss our results in relation to other results in the literature and conclude that kinetochores and poles influence the behaviour of kinetochore microtubules.
我们使用紫外线微光束照射处于有丝分裂中期的血莲胚乳细胞中的染色体纺锤体纤维。在我们使用的所有波长（260、270、280和290纳米）的聚焦紫外光位置形成了一个双折射降低区域（ARB）。从ARB向极的染色体纺锤体纤维区域（动粒微管）不稳定：它们缩短（从ARB到极）的速度要么太快以至于我们无法测量，要么约为每分钟40微米。从ARB向动粒的染色体纺锤体纤维区域（动粒微管）是稳定的：它们在约80秒内长度不变，然后以约每分钟0.7微米的速度伸长。伸长的染色体纺锤体纤维有时生长方向与原始染色体纺锤体纤维不同。与受照射纺锤体纤维相关的染色体有时会从赤道向未受照射的半纺锤体移动几微米。我们结合文献中的其他结果讨论了我们的结果，并得出结论，动粒和极会影响动粒微管的行为。
