Charron M J, Read E, Haut S R, Michels C A
Department of Biology, Queens College, Flushing, New York.
Genetics. 1989 Jun;122(2):307-16. doi: 10.1093/genetics/122.2.307.
The MAL gene family of Saccharomyces consists of five multigene complexes (MAL1, MAL2, MAL3, MAL4, and MAL6) each of which encodes maltose permease (GENE 1), maltase (GENE 2) and the trans-acting MAL-activator (GENE 3). Four of these loci have been mapped and each is located at or near the telomere of a different chromosome. We compare the physical structure of the MAL loci and their flanking sequences. The MAL loci were shown to be both structurally and functionally homologous throughout an approximately 9.0-kb region. The orientation of the MAL loci was determined to be: CENTROMERE . . . GENE 3-GENE 1-GENE 2 . . . TELOMERE. Telomere-adjacent sequences were found flanking GENE 2 of the MAL1, MAL3 and MAL6 loci. No common repeated elements were found on the centromere-proximal side of all the MAL1, loci. These results suggest that, during the evolution of this polygenic family, the MAL loci translocated to different chromosomes via a mechanism that involved the rearrangement(s) of chromosome termini.
酿酒酵母的MAL基因家族由五个多基因复合体(MAL1、MAL2、MAL3、MAL4和MAL6)组成,每个复合体都编码麦芽糖通透酶(基因1)、麦芽糖酶(基因2)和反式作用的MAL激活剂(基因3)。其中四个基因座已被定位,每个都位于不同染色体的端粒处或附近。我们比较了MAL基因座及其侧翼序列的物理结构。结果表明,在大约9.0 kb的区域内,MAL基因座在结构和功能上都是同源的。MAL基因座的方向确定为:着丝粒……基因3-基因1-基因2……端粒。在MAL1、MAL3和MAL6基因座的基因2侧翼发现了端粒相邻序列。在所有MAL1基因座的着丝粒近端一侧未发现共同的重复元件。这些结果表明,在这个多基因家族的进化过程中,MAL基因座通过一种涉及染色体末端重排的机制转移到了不同的染色体上。