Hooker C W, Yang W, Becker M M, Waine G J, Kalinna B H, Nimmo K A, McManus D P, Brindley P J
Molecular Parasitology Unit, Queensland Institute of Medical Research, Brisbane, Australia.
Acta Trop. 1995 May;59(2):131-41. doi: 10.1016/0001-706x(94)00089-j.
Paramyosin is an integral muscle protein found in many invertebrates including schistosomes, and is considered an important candidate vaccine antigen in schistosomiasis. The characterisation of natural molecular variation in vaccine antigens including paramyosin is important because strain-specific vaccination may be necessary against schistosomiasis japonica. We have isolated partial cDNAs encoding paramyosin from an adult, Chinese strain Schistosoma japonicum gene library. Two of these cDNAs (B6 and Y6) encode the same region of paramyosin but their nucleotide sequences differ at eight positions and their deduced amino acid sequences differ by an arginine/cysteine substitution, demonstrating intrastrain variation in paramyosin. Southern blot analysis of genomic DNA from the Chinese and Philippine strains of S. japonicum demonstrated strain-related RFLPs at the paramyosin locus, and suggested that more than one copy of the paramyosin gene was present in the S. japonicum genome. PCR-based RFLP analysis which exploited restriction site differences between B6 and Y6 showed that paramyosin genotype B6 was much more common in schistosome populations and verified the existence of introns in the paramyosin gene(s) of S. japonicum.
副肌球蛋白是一种存在于包括血吸虫在内的许多无脊椎动物中的肌肉整合蛋白，被认为是血吸虫病中一种重要的候选疫苗抗原。对包括副肌球蛋白在内的疫苗抗原的天然分子变异进行表征很重要，因为针对日本血吸虫病可能需要进行菌株特异性疫苗接种。我们从一个成年中国株日本血吸虫基因文库中分离出了编码副肌球蛋白的部分cDNA。其中两个cDNA（B6和Y6）编码副肌球蛋白的同一区域，但它们的核苷酸序列在八个位置上不同，其推导的氨基酸序列因精氨酸/半胱氨酸替代而不同，这表明副肌球蛋白存在株内变异。对中国株和菲律宾株日本血吸虫的基因组DNA进行Southern印迹分析，结果表明在副肌球蛋白基因座存在与菌株相关的限制性片段长度多态性（RFLP），并提示日本血吸虫基因组中存在不止一个副肌球蛋白基因拷贝。利用B6和Y6之间的限制性位点差异进行的基于聚合酶链反应（PCR）的RFLP分析表明，副肌球蛋白基因型B6在血吸虫种群中更为常见，并证实了日本血吸虫副肌球蛋白基因中内含子的存在。
