一个国际科研团队在4月1日出版的英国《自然》（Nature）杂志上撰文指出，他们成功地对俗称“珍珠鸟”的斑胸草雀的基因组进行了测序。由于斑胸草雀学习唱歌的过程同人类学习说话类似，因此，该测序结果将有助于研究人类的语言学习过程。
美国华盛顿大学的卫斯理沃伦领导的该科研小组由美国、英国和德国等多国研究人员组成。斑胸草雀属于鸣禽，是用于研究脊椎动物的脑、行为和演化的一种动物模型，其基因组有约12亿个碱基对，不到人类基因组的一半。之前科学家认为，大约有100种基因与斑胸草雀唱歌有关，但科学家现在发现，至少有800多种基因同其相关。当“珍珠鸟”学习歌唱时，大脑中的这些基因会产生非常复杂的“网络反应”，最终帮它学会特有的“歌声”。
幼年斑胸草雀学习唱歌的方式同人类婴儿学习说话的方式一样，都是通过模仿其长辈的说话方式来学习，这意味着，斑胸草雀可作为理解人类的学习和记忆的参照物。参与研究的英国牛津大学药物研究协会功能染色体小组的专家克里斯庞廷说，斑胸草雀能够提供一个窗口，让我们了解人类的诸如孤独症、中风、口吃、帕金森症等言语失常病症的病源。
庞廷表示，更重要的是，“珍珠鸟”在学习歌唱的过程中激活的基因的工作方式同表达蛋白的基因不同，相反，它们属于基因组的非编码部分，也就是所谓的“垃圾DNA”。在人类基因组中，已探明功能表达蛋白的基因只占3%，其余多数功能不清的基因现被误认为是垃圾DNA。对斑胸草雀基因组的分析也进一步表明，所谓的“垃圾DNA”并非垃圾，它们实际上具有非常重要的生物功能。
“珍珠鸟”基因组是继2004年鸡基因组测序完成之后第二个被测定的鸟类基因组。据悉，在鸟类中首先测定鸡的基因组有畜牧养殖业等方面的考虑，而实际上，“珍珠鸟”的基因组更靠近鸟类大家庭基因树的主干，因此，对两者的基因组进行对比也将有助于研究鸟类进化。研究人员表示，将鸡的基因组与“珍珠鸟”的基因组进行比较后发现，有神经功能、参与叫声认知处理的基因在雀科这个分支中一直在快速演化。
目前，科学家已经绘制出了两种禽鸟的基因组，接下来，他们希望在今年年底解码鹦鹉的基因组。
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《自然》发表论文摘要（英文）
Nature 464, 757-762 (1 April 2010) | doi:10.1038/nature08819; Received 30 September 2009; Accepted 6 January 2010
The genome of a songbird
Wesley C. Warren1, David F. Clayton2, Hans Ellegren3, Arthur P. Arnold4, LaDeana W. Hillier1, Axel Künstner3, Steve Searle5, Simon White5, Albert J. Vilella6, Susan Fairley5, Andreas Heger7, Lesheng Kong7, Chris P. Ponting7, Erich D. Jarvis8, Claudio V. Mello9, Pat Minx1, Peter Lovell9, Tarciso A. F. Velho9, Margaret Ferris2, Christopher N. Balakrishnan2, Saurabh Sinha2, Charles Blatti2, Sarah E. London2, Yun Li2, Ya-Chi Lin2, Julia George2, Jonathan Sweedler2, Bruce Southey2, Preethi Gunaratne10, Michael Watson11, Kiwoong Nam3, Niclas Backström3, Linnea Smeds3, Benoit Nabholz3, Yuichiro Itoh4, Osceola Whitney8, Andreas R. Pfenning8, Jason Howard8, Martin Völker11, Bejamin M. Skinner12, Darren K. Griffin12, Liang Ye1, William M. McLaren6, Paul Flicek6, Victor Quesada13, Gloria Velasco13, Carlos Lopez-Otin13, Xose S. Puente13, Tsviya Olender14, Doron Lancet14, Arian F. A. Smit15, Robert Hubley15, Miriam K. Konkel16, Jerilyn A. Walker16, Mark A. Batzer16, Wanjun Gu17, David D. Pollock17, Lin Chen18, Ze Cheng18, Evan E. Eichler18, Jessica Stapley18, Jon Slate19, Robert Ekblom19, Tim Birkhead19, Terry Burke19, David Burt20, Constance Scharff21, Iris Adam21, Hugues Richard22, Marc Sultan22, Alexey Soldatov22, Hans Lehrach22, Scott V. Edwards23, Shiaw-Pyng Yang24, XiaoChing Li25, Tina Graves1, Lucinda Fulton1, Joanne Nelson1, Asif Chinwalla1, Shunfeng Hou1, Elaine R. Mardis1 " Richard K. Wilson1
Top of pageThe zebra finch is an important model organism in several fields1, 2 with unique relevance to human neuroscience3, 4. Like other songbirds, the zebra finch communicates through learned vocalizations, an ability otherwise documented only in humans and a few other animals and lacking in the chicken5—the only bird with a sequenced genome until now6. Here we present a structural, functional and comparative analysis of the genome sequence of the zebra finch (Taeniopygia guttata), which is a songbird belonging to the large avian order Passeriformes7. We find that the overall structures of the genomes are similar in zebra finch and chicken, but they differ in many intrachromosomal rearrangements, lineage-specific gene family expansions, the number of long-terminal-repeat-based retrotransposons, and mechanisms of sex chromosome dosage compensation. We show that song behaviour engages gene regulatory networks in the zebra finch brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. We also show evidence for rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. These results indicate an active involvement of the genome in neural processes underlying vocal communication and identify potential genetic substrates for the evolution and regulation of this behaviour.
