曼氏血吸虫发育过程中的基因组DNA变异

GENOMIC VARIABILITY BETWEEN ADULT AND CERCARIA OF Schistosoma mansoni

曼氏血吸虫（Ｓｃｈｉｓｔｏｓｏｍａｍａｎｓｏｎｉ）和日本血吸虫（Ｓ．ｊａｐｏｎｉｃｕｍ）成虫和曼氏血吸虫尾蚴基因组ＤＮＡ经限制性内切酶ＢａｍＨＩ消化后，分别与３２ｐ─ｄＣＴＰ标记的来源于核糖体ＤＮＡ的ｐｓＭＨＣＲ５，ｐＳＭＨＣＲ４ＰＳＭ８８９探针杂交。曼氏血吸虫尾蚴和成虫在ｐＳＭＨＣＲ４杂交带型的１．６─２．８ｋｂ之间，存在有明显不同的次杂交带；而ｐＳＭＨＣＲ５和ｐＳＭ８８９的杂交带型，无明显差异。此外，ｐＳＭＨＣＲ５杂交带型中，日本血吸虫成虫无３．０ｋｂ带，可明显区别于曼氏血吸虫。结果表明，在曼氏血吸虫尾蚴至成虫的发育过程中，基因组ＤＮＡ发生缺失或重组。这一发现进一步证实了曼氏血吸虫毛蚴与成虫间存在发育期特异性ＤＮＡ的假设。曼氏血吸虫发育过程中，基因组ＤＮＡ的动态变化可能与其适应环境有关。

Genomic DNA was prepared from Schistosoma mansoni(OZ.A) adult and cercaria,S.mansoni adult(NMRI),S.japonicum adult, and was hybridized to three 32p-labelled probes PSM HCR5,pSM HCR4,pSM 889 after cleavage by restriction endonuclease Bam H Ⅰ,The resulting hybridization banding patterns with pSM HCR4 are significantly different between cercaria and adult of S.mansoni(OZ.A) from 1.6 kb to 2.8 kb except there is a same size 3.0 kb major band.There is a minor band in pSM HCR4 pattern for S.mansoni,which can be identified from S.mansoni adult(OZ.A).Moreover,S.japonicum adult have no 3.0 kb major band in PSM HCR5 pattern,which can be distinguished from S.mansoni.The results showed that there was a drastic change of genomic DNA from cercaria to adult,which maybe related to the adaptation of S.mansoni to extremely different living environment in their life-cycle,and also provides more immediate evidence of existence of dynamic changes in the course of development in S.mansoni.