Construction and expression of gene families

人们一直认为，产生抗体的最原始的动物是圆口动物。我们分离了编码盲鳗“抗体”的基因，并确定了核苷酸序列。令人惊讶的是，它原来是一个基因编码的不是免疫球蛋白，而是补体C3。我们建立了一种利用PCR技术分离原始脊椎动物MHC基因的新方法。利用此方法，我们成功地从鲤鱼中分离了编码MHC I类和II类β的基因，也从鲨鱼中分离了编码MHC I类的基因。我们还发现，在硬骨鱼的水平上，MHC I类基因已经扩展到至少几十个，它们的序列是相当异质的。我们从海绵中分离了两个同源异型盒基因，分别是p211和p212。从结构上看，它们具有高等动物同源异型盒基因的基本特性。我们从水螅中分离了四个同源异型盒基因。从C.优雅从人类中分离到两种新的同源异型盒基因GBX 1和GBX 2。我们将GBX1定位于染色体7q36.1。

It has been believed that the most primitive animal that produces antibodies is cyclostome. We isolated the gene which encodes hagfish "antibodies" and determined the nucleotide sequence. Surprisingly, it turned out to be a gene encoding not immunoglobulin but complement C3. We developed a new method using PCR for isolation of MHC genes from primitive vertebrates. By this method, we have succeeded to isolate genes encoding MHC classI and classIIbeta from carp and also a gene encoding MHC classI from shark. We also showed that at the level of bony fish MHC classI genes have been expanded to at least several tens and their sequences are quite heterogeneous.We examined homeobox-containing genes from various phyla of animals. We isolated two homeobox genes, prox1 and prox2 from sponge. The structure of prox1 and prox2 indicated that they have gained the properties characteristics for each class of homeobox genes isolated from higher animals. We isolated four homeobox genes from hydra. A new kind of homeobox gene was identified from C. elegans. Two kinds of new homeobox genes, GBX1 and GBX2, were isolated from human. We mapped GBX1 to chromosome 7q36.1.