理查德·e·戴维斯博士学位

基因组很少改变。然而,一些生物进行大规模基因组变化称为DNA消灭,一个程序的过程,消除特定DNA序列的基因组。我们已经表明,18%的寄生线虫的基因组蛔虫消除在体细胞血统在第三到五分裂(4 - 16细胞期),而生殖系基因仍然完好无损。特定的重复和独特的序列(包括~ 1000个基因)在清除过程中丢失,形成体细胞基因组。DNA消除事件是相同的所有个人和在五个不同的细胞谱系。消除基因主要表达在蛔虫生殖系和早期胚胎。比较基因组分析的DNA消除在其他几个寄生线虫(a .蛔虫、弓蛔虫和Parascaris)表明他们也消除1000 - 2000基因(5 - 10%的基因)。总体而言,我们的数据表明,DNA消除寄生线虫是一个重要的、不可逆转的沉默机制的一个子集生殖系和早期胚胎中表达基因体细胞组织。全面的染色体DNA分析消除72年蛔虫证明24生殖系染色体末端DNA断裂发生,所有通过subtelomeric DNA断裂进行重构,末端序列,和治疗新创新的染色体末端的端粒治疗。消除期间纳入微核DNA DNA消除有丝分裂末期和DNA是最终在自噬体退化。 Worm specific Argonautes are on condensed chromosomes during elimination mitoses and are present either on chromosomes that will be retained (WAGO-2) or eliminated (WAGO-3). We hypothesize that the Argonautes and/or their small RNAs contribute to DNA elimination. Ascaris has holocentric chromosomes with multiple centromeric/kinetochore regions distributed along the length of the chromosome in the gametogenic germline. Ascaris holocentric chromosomes are dynamic. During DNA elimination, only those chromosome regions to be retained exhibit extensive deposition of the centromeric histone CENP-A and are holocentric; chromosome regions destined for elimination have lost CENP-A and are not segregated. Thus, both specific sites for DNA breaks and changes in CENP-A localization on the chromosomes are involved in a concerted mechanism to define portions of chromosomes for retention or elimination in programmed DNA elimination.

在DNA消除继续在实验室里工作建斌王在生物化学和细胞和分子生物学在诺克斯维尔的田纳西大学。