Fantini L, Mudry M D, Nieves M
Grupo de Investigación en Biología Evolutiva, Departamento de Ecología, Genética y Evolución, Universidad de Buenos Aires y CONICET, Buenos Aires, Argentina. luciafantini @ ege.fcen.uba.ar
Cytogenet Genome Res. 2011;135(1):33-41. doi: 10.1159/000330127. Epub 2011 Jul 28.
Genome size or C-value is defined as the total amount of DNA contained within a haploid chromosome set and is regarded as a species-specific constant. Speciation among neotropical primates seems to be accompanied by marked quantitative changes in DNA content. A direct correlation between genome size and the presence of heterochromatin has also been proposed. In this work, we analyzed the genome of a female fertile hybrid between Cebus libidinosus and C. nigritus using interspecies comparative genomic hybridization (iCGH), in order to detect quantitative differences between the hybrid and the parental genomes. We also estimated the genome sizes of C. libidinosus and C. nigritus. Both species, considered subspecies of C. apella until 2001, have a highly homologous karyotype but are easily distinguishable at the chromosomal level due to the noncentromeric heterochromatin block on C. libidinosus chromosome 11. Our findings on C-value quantification support the species status for C. libidinosus and C. nigritus, each having a different genome size. The iCGH analysis of the hybrid revealed quantitative differences in comparison to both parental species. The hybrid genome contains a greater amount of DNA in the heterochromatic blocks related to those in the genomes of both parental species. In view of observations in previous and the present work, some hypotheses about genome dynamics of neotropical primates are proposed and discussed.
基因组大小或C值被定义为单倍体染色体组中所含DNA的总量，并被视为物种特异性常数。新热带灵长类动物之间的物种形成似乎伴随着DNA含量的显著定量变化。也有人提出基因组大小与异染色质的存在之间存在直接关联。在这项工作中，我们使用种间比较基因组杂交（iCGH）分析了白领伶猴和黑伶猴之间一只可育雌性杂交后代的基因组，以检测该杂交后代与亲本基因组之间的定量差异。我们还估计了白领伶猴和黑伶猴的基因组大小。这两个物种在2001年之前都被视为阿氏伶猴的亚种，它们具有高度同源的核型，但由于白领伶猴11号染色体上的非着丝粒异染色质块，在染色体水平上很容易区分。我们关于C值定量的研究结果支持了白领伶猴和黑伶猴的物种地位，它们各自具有不同的基因组大小。对该杂交后代的iCGH分析揭示了与两个亲本物种相比的定量差异。该杂交后代的基因组在与两个亲本物种基因组相关的异染色质块中含有更多的DNA。鉴于之前和当前工作中的观察结果，提出并讨论了一些关于新热带灵长类动物基因组动态的假设。
