Consequently, the proximity ligation in a 3C protocol clinical diagnostic enhance subsequent clinical application occurs within non-lysed nuclei in a chromatin cage stabilized by formaldehyde cross-links. In such a chromatin cage the probability of ligation of the ends of all restriction fragment located in a spatial proximity will likely be similar if not the same. Yet, we have found that the yield of circularized anchor fragment exceeds at least 10 times the yield of the ligation products of this fragment. Furthermore, the yield of the circularized anchor fragment was about the same in HindIII-3C and MboI-3C experiments. Thus, it was not affected by the presence of additional cohesive ends available for ligation. The simplest explanation for these observations is that a significant portion of the anchor fragments is not cross-linked to any other restriction fragment. The probability of cross-linking of different regions of a folded chromatin fiber may depend on various factors including the efficiency of the cross-linking reaction per se and the actual frequency with which the target DNA fragments interact in the nucleus. In this regard, it should be noted that most cells in the population used for this study are erythroid precursors that transcribe the Hbb-b1 and Hbb-b2 genes ; interactions between the beta-globin genes and their enhancers might be anticipated for all these cells. In this light, the low frequencies of ligation observed in our experiments may well reflect that these interactions are not stable or uniform enough to support the cross-linking of the corresponding fragments of a chromatin fiber in the majority of cells present in the population. Several previous observations also strongly suggest that the interactions between the promoters and enhancers of beta-globin genes are short-lived and dynamic. Additional experiments will be necessary to obtain further insights into the nature of interactions between DNA regulatory elements. Whatever is the reason for low levels of the ligation products in the 3C experiments, this can be a source of different artifacts. The lower is the level of the semantic signal, the higher is the possibility to disturb the message by unaccounted factors. There are many factors that can affect the efficiency of the proximity ligation. Besides the spatial proximity of the restriction fragments under study, the condition of the cohesive ends should determine their ability to reach each other and be ligated.During the desiccation process, the embryos gradually lost water and the size of the embryos decreased. At the end of desiccation process, somatic embryos had significantly shrank and contained only 12?C15% water which was equivalent to that in true seeds. The dried somatic embryos were transferred to K MS medium for germination and rapidly enlarged to the same size as before desiccation. Within ten days, the embryos turned green and started to produce roots. Shoots subsequently developed and normal plantlets formed. The average germination rate of somatic embryos subjected to desiccation treatment was 34.8%.