Sordino P, Belluzzi L, De Santis R, Smith W C
Department of Anatomy and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
Philos Trans R Soc Lond B Biol Sci. 2001 Oct 29;356(1414):1573-82. doi: 10.1098/rstb.2001.0919.
Recent advances in the study of the genetics and genomics of urochordates testify to a renewed interest in this chordate subphylum, believed to be the most primitive extant chordate relatives of the vertebrates. In addition to their primitive nature, many features of their reproduction and early development make the urochordates ideal model chordates for developmental genetics. Many urochordates spawn large numbers of transparent and externally developing embryos on a daily basis. Additionally, the embryos have a defined and well-characterized cell lineage until the end of gastrulation. Furthermore, the genomes of the urochordates have been estimated to be only 5-10% of the size of the vertebrates and to have fewer genes and less genetic redundancy than vertebrates. Genetic screens, which are powerful tools for investigating developmental mechanisms, have recently become feasible due to new culturing techniques in ascidians. Because hermaphrodite ascidians are able to self-fertilize, recessive mutations can be detected in a single generation. Several recent studies have demonstrated the feasibility of applying modern genetic techniques to the study of ascidian biology.
尾索动物遗传学和基因组学研究的最新进展表明，人们对这个脊索动物亚门重新产生了兴趣，它被认为是现存脊椎动物最原始的脊索动物亲属。除了其原始特性外，它们繁殖和早期发育的许多特征使尾索动物成为发育遗传学理想的模式脊索动物。许多尾索动物每天都会产出大量透明且在体外发育的胚胎。此外，在原肠胚形成结束之前，胚胎具有明确且特征明显的细胞谱系。再者，据估计尾索动物的基因组大小仅为脊椎动物的5%-10%，并且与脊椎动物相比，其基因数量更少，遗传冗余度更低。遗传筛选是研究发育机制的有力工具，由于海鞘新的培养技术，最近已变得可行。因为雌雄同体的海鞘能够自我受精，所以隐性突变可以在一代中被检测到。最近的几项研究证明了将现代遗传技术应用于海鞘生物学研究的可行性。
