Lakhotia S C, Mishra A, Sinha P
Chromosoma. 1981;82(2):229-36. doi: 10.1007/BF00286107.
We have used the unstable ring X-chromosome of D. melanogaster to generate XX/X0 mosaics in the hybrid progeny from crosses between D. melanogaster females and D. simulans males. The functional properties of the polytene X-chromosome(s) in salivary glands of such X0/XX mosaic hybrid larvae have been analysed by autoradiography after 3H-uridine or 3H-thymidine labelling of the glands. The simulans X-chromosome in the hybrid X0 nuclei displays typical pale staining, enlarged diameter, higher rate of transcription (nearly two times higher than each of the Xs in the XX nuclei in the same gland) and a faster completion of replication as would be the case in the original parental X0 or XY nuclei. In the hybrid XX polytene nuclei, the melanogaster as well as the simulans X functions in the same manner as in female cells of the parents. The nucleolar transcription is also equal in the hybrid XX and X0 nuclei. Thus is seems that despite the evolutionary diversification between these two species, the regulator system which brings about the dosage compensation of X-chromosome activity has been conserved.
我们利用黑腹果蝇的不稳定环状X染色体，在黑腹果蝇雌性与拟果蝇雄性杂交产生的杂种后代中产生XX/X0嵌合体。在对这种X0/XX嵌合杂种幼虫的唾液腺多线X染色体进行3H-尿苷或3H-胸腺嘧啶核苷标记后，通过放射自显影分析了其功能特性。杂种X0细胞核中的拟果蝇X染色体呈现典型的淡染色、直径增大、转录速率较高（比同一腺体中XX细胞核中的每个X染色体几乎高两倍）以及复制完成速度更快，这与原始亲本X0或XY细胞核中的情况相同。在杂种XX多线细胞核中，黑腹果蝇和拟果蝇的X染色体功能与亲本雌性细胞中的相同。杂种XX和X0细胞核中的核仁转录也相等。因此，尽管这两个物种之间存在进化差异，但实现X染色体活性剂量补偿的调节系统似乎得以保留。
