We suggest : ( 1 ) histone must maintain some acetylation level whether the associating - gene is activated or inactivated ; ( 2 ) acetylation and deacetylation are global in these genes " chromosomal domains ; ( 3 ) but uneven ; ( 4 ) and the level will change according to the development stage 通过我们的实验，我们认为无论基因表达与否，都首先在其基因组上维持了一定的组蛋白乙酰化水平，这种乙酰化水平同时也是一个整体的概念，而且在不同的基因区域上，组蛋白乙酰化水平是有一定的波动性，另外这种乙酰化水平可以随着发育阶段的不同根据基因表达的要求发生变化。
The research on the condition of kid ' s suckling indicates that the highest milk - dotting activity ( 26108su / g ) was obtained for the whole suckling section , whereas proteolytic activity were no significant different between the whole suckling and random section ( p > 0 . 05 ) , but proteolytic activity ( 1925u / g ) was highest for the complete grass - feeding , which demonstrated suckling could stimulate the continuous secretion of chymosin in the abomasum 羔羊哺乳状况研究表明，全哺乳组凝乳活性最高( 26108su g ) ，蛋白水解活性与随机哺乳组无明显差别( p 0 . 05 ) ，而全喂草料组蛋白水解活性最高( 1925u g ) ，这表明哺乳能够刺激皱胃中凝乳酶的持续分泌。
However , it is difficult to relate the histone acetylation level with the gene expression level . we indicate , although histone acetylation acts to enhance the access of transcription - associated protein to dna , the activation of gene expression only need containing some acetylation level , but the hyperacetylation and underacetylation would effect the gene expression , so as to the abnormal development 而在克隆牛中组蛋白乙酰化水平虽然有所降低，但如果这种降低仍然为基因的表达提供了足够的基础，这就对基因的正常表达造不成很大影响；但如果组蛋白乙酰化水平过高或过低，可能要影响到其他因子的作用，从而影响了基因表达的调节，最终导致生物个体发育异常。
