Krummel Kurt A, Denison Stacy R, Calhoun Eric, Phillips Leslie A, Smith David I
Division of Experimental Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic Cancer Center, Rochester, Minnesota 55905, USA.
Genes Chromosomes Cancer. 2002 Jun;34(2):154-67. doi: 10.1002/gcc.10047.
Recently, several common fragile sites (CFSs) have been cloned and characterized, including the two most frequently observed in the human population, FRA3B and FRA16D. In addition to their high frequency of breakage, FRA3B and FRA16D colocalize with genes crossing large regions of breakage. At FRA3B, the fragile histidine triad (FHIT) gene spans more than 1 Mb, and at FRA16D, the WWOX gene spans more than 750 kb. It has also been shown that in Mus musculus, a CFS Fra14A2 and the mouse Fhit gene are conserved in the orthologous region of the genome. In this study, we positioned the ortholog to WWOX (Wox1) at chromosome band 8E1 in the mouse genome. To determine whether, like Fra14A2 and Fhit, Fra8E1 and Wox1 colocalized in the mouse, we prepared bacterial and yeast artificial chromosome probes, and we hybridized them to aphidicolin-treated mouse metaphase chromosomes. Our data demonstrate that Wox1 colocalizes with Fra8E1. Furthermore, the sequence from this region, including introns, is highly conserved over at least a 100-kb region. This evolutionary conservation suggests that the two most active CFSs share many features, and that CFSs and their associated genes may be necessary for cell survival.
最近，几个常见的脆性位点（CFSs）已被克隆和鉴定，包括在人类群体中最常观察到的两个位点，FRA3B和FRA16D。除了其高断裂频率外，FRA3B和FRA16D与跨越大片段断裂区域的基因共定位。在FRA3B处，脆性组氨酸三联体（FHIT）基因跨度超过1 Mb，在FRA16D处，WWOX基因跨度超过750 kb。研究还表明，在小家鼠中，一个CFS Fra14A2和小鼠Fhit基因在基因组的直系同源区域保守。在本研究中，我们将WWOX的直系同源基因（Wox1）定位在小鼠基因组的8E1染色体带上。为了确定Fra8E1和Wox1是否像Fra14A2和Fhit一样在小鼠中共定位，我们制备了细菌人工染色体和酵母人工染色体探针，并将它们与经阿非科林处理的小鼠中期染色体杂交。我们的数据表明Wox1与Fra8E1共定位。此外，该区域的序列，包括内含子，在至少100 kb的区域内高度保守。这种进化保守性表明，两个最活跃的CFSs具有许多共同特征，并且CFSs及其相关基因可能是细胞存活所必需的。
