Rast Jonathan P, Smith L Courtney, Loza-Coll Mariano, Hibino Taku, Litman Gary W
Sunnybrook Research Institute and Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Room S-126B, Toronto, Ontario M4N 3M5, Canada.
Science. 2006 Nov 10;314(5801):952-6. doi: 10.1126/science.1134301.
Comparative analysis of the sea urchin genome has broad implications for the primitive state of deuterostome host defense and the genetic underpinnings of immunity in vertebrates. The sea urchin has an unprecedented complexity of innate immune recognition receptors relative to other animal species yet characterized. These receptor genes include a vast repertoire of 222 Toll-like receptors, a superfamily of more than 200 NACHT domain-leucine-rich repeat proteins (similar to nucleotide-binding and oligomerization domain (NOD) and NALP proteins of vertebrates), and a large family of scavenger receptor cysteine-rich proteins. More typical numbers of genes encode other immune recognition factors. Homologs of important immune and hematopoietic regulators, many of which have previously been identified only from chordates, as well as genes that are critical in adaptive immunity of jawed vertebrates, also are present. The findings serve to underscore the dynamic utilization of receptors and the complexity of immune recognition that may be basal for deuterostomes and predicts features of the ancestral bilaterian form.
海胆基因组的比较分析对于后口动物宿主防御的原始状态以及脊椎动物免疫的遗传基础具有广泛影响。相对于其他已被研究的动物物种，海胆具有前所未有的先天性免疫识别受体复杂性。这些受体基因包括222个Toll样受体的庞大文库、一个由200多个富含亮氨酸重复序列的NACHT结构域蛋白组成的超家族（类似于脊椎动物的核苷酸结合寡聚化结构域（NOD）和NALP蛋白），以及一个富含半胱氨酸的清道夫受体大家族。编码其他免疫识别因子的基因数量更为典型。重要的免疫和造血调节因子的同源物也存在，其中许多此前仅在脊索动物中被鉴定出来，还有一些在有颌脊椎动物适应性免疫中起关键作用的基因。这些发现强调了受体的动态利用以及免疫识别的复杂性，而这种复杂性可能是后口动物的基础，并预测了原始两侧对称动物形式的特征。
