Tanaka M, Hirai H, LoVerde P T, Nagafuchi S, Franco G R, Simpson A J, Pena S D
Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
Mol Biochem Parasitol. 1995 Jan;69(1):41-51. doi: 10.1016/0166-6851(94)00182-m.
Schistosoma mansoni has 7 pairs of autosomal chromosomes and one pair of sex chromosomes (ZZ for a male worm and ZW for a female), of a haploid genome size of 2.7 x 10(8) bp. We initiated the molecular genetic approach for the detailed characterization and understanding of the evolutionary biology of schistosomes. We have constructed a yeast artificial chromosome (YAC)-library with partially digested parasite genomic DNA, and the chromosome location of each insert was detected by fluorescent in situ hybridization (FISH). The library contains > 2283 clones with an average insert size of 358 kb, which represents a 2.6-fold coverage of the genome (> 7.2 x 10(8) bp). 100 randomly selected YAC clones were localized by FISH and found to be distributed widely among all chromosomes. The assembly of 14 YACs distributed almost the whole region of chromosome 3. Generated expressed sequenced tags (ESTs) derived from a unidirectional cDNA library were also used for further characterization of the YAC inserts. These results indicate that an extensive contig assembly of the entire chromosomes and a reasonably detailed gene map should be feasible in the near future.
曼氏血吸虫有7对常染色体和1对性染色体（雄虫为ZZ，雌虫为ZW），单倍体基因组大小为2.7×10⁸ bp。我们启动了分子遗传学方法，以详细表征和理解血吸虫的进化生物学。我们用部分酶切的寄生虫基因组DNA构建了一个酵母人工染色体（YAC）文库，并通过荧光原位杂交（FISH）检测每个插入片段的染色体定位。该文库包含>2283个克隆，平均插入片段大小为358 kb，代表基因组的2.6倍覆盖（>7.2×10⁸ bp）。通过FISH对100个随机选择的YAC克隆进行定位，发现它们广泛分布于所有染色体中。14个YAC的组装几乎覆盖了3号染色体的整个区域。从单向cDNA文库产生的表达序列标签（EST）也用于进一步表征YAC插入片段。这些结果表明，在不久的将来，对整个染色体进行广泛的重叠群组装和绘制合理详细的基因图谱应该是可行的。
