Coyne R S, Chalker D L, Yao M C
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA.
Annu Rev Genet. 1996;30:557-78. doi: 10.1146/annurev.genet.30.1.557.
The ciliated protozoa divide the labor of germline and somatic genetic functions between two distinct nuclei. The development of the somatic (macro-) nucleus from the germinal (micro-) nucleus occurs during sexual reproduction and involves large-scale, genetic reorganization including site-specific chromosome breakage and DNA deletion. This intriguing process has been extensively studied in Tetrahymena thermophila. Characterization of cis-acting sequences, putative protein factors, and possible reaction intermediates has begun to shed light on the underlying mechanisms of genome rearrangement. This article summarizes the current understanding of this phenomenon and discusses its origin and biological function. We postulate that ciliate nuclear restructuring serves to segregate the two essential functions of chromosomes: the transmission and expression of genetic information.
纤毛原生动物在两个不同的细胞核之间划分种系和体细胞遗传功能的劳动分工。在有性生殖过程中，从生殖（微）核发育出体细胞（大）核，这涉及大规模的基因重组，包括位点特异性染色体断裂和DNA缺失。这个有趣的过程已经在嗜热四膜虫中得到了广泛研究。对顺式作用序列、推定的蛋白质因子和可能的反应中间体的表征已经开始揭示基因组重排的潜在机制。本文总结了目前对这一现象的理解，并讨论了其起源和生物学功能。我们推测纤毛虫的核重组有助于分离染色体的两个基本功能：遗传信息的传递和表达。
