Attachment to host tissue is essential for colonization by most mucosal pathogens , such as mycoplasma hyopneumoniae . according to the reported sequence of p97 gene in strain 168 , a pair of primers was designed and the rl region of p97 gene in strain 168f485 was amplicated by pcr 本研究根据已报道的序列为参考，设计一对带有ecor和hind酶切位点的引物，并通过引物的定点突变，利用pcr方法从猪肺炎支原体168f485株扩增到其黏附因子p97基因的抗原决定簇r1区。
Conclusion r1 represent pixel - value of original image range block , r represent mean - value of original image range block , d represent mean - value of original image domain block , d1 represent pixel - value of resumptive image domain block , d represent mean - value of resumptive image domain block . superior perfermance of resumptive image range block is obtained as compared to conventional creative function by one iteration , that is , ) ， d _ i ( i = 1 ， 2 ， … ， n )分别为某一恢复图像定义域块的均值和每一像素的像素值，我们用传统的和改进的生成函数分别进行一次迭代，则用改进的生成函数进行迭代的恢复图像每一值域块的效果较好，即：
