Arguments to sustain this theory

I. Monozygotic twins.

Identical twins appear by segregation of morula or blastocyst cell population between day fourth and fourteenth after fecundation. For this thing be possible two types of receptors is necessary to be synthesized. These receptors are spread homogenously through entire morula or blastocyst cells population. Thus, two genetically identical cells population will appear, by segregation of the two cells population due to different receptors types.

According to proposed theory this phenomena could be possible by faster interface proteins (type A & B) synthesis. Thus, determination phenomena, by coupling of these two interfaces proteins, will start earlier and two cells population will appear (Fig. 2). Due to various reasons: absence of receptors activation, low concentration of nonhistonic proteins (type 1-II & 2-II), absence of interaction between nonhistonic proteins (type 1-II si 2-II) and genes c,d,e (Fig. 4), cell differentiation will not start. Because these two types of nonhistonic proteins will not activate its own synthesis and will be degraded, process of cell differentiation will fail (Fig. 4). Thus, two cells population will appear with genetic identity. Because the genes, which synthesize interface proteins and nonhistonic proteins 1-I, 1-II, 2-I, 2-II, are still active, the determination and differentiation process will resume at this stage for each population group. This time, nonhistonic protein’s (1-II and 2-II types) concentrations will be high enough for coupling these two phenomena: determination and differentiation and to start embryogenesis process for each zygote (Fig.1, Fig. 4).

However, this process of determination and differentiation decoupling naturally appears along early embryogenesis, but only once, and two identical cells populations with two different kinds of receptors appear. These receptors are quickly degraded, so these two identical populations will be fused at a region which will became median line of the embryo. Thus, symmetric structure of the body appears.

II. Hydatiform mole

The problems raised by hydatiform mole cytogenesis are quite fascinating. As one knows, the genome of hydatiform mole is paternal by origin. The result is failure of differentiation process and forming a structure similar with trophoblast. In conclusion, gradients of different proteins types’ concentration in fertilized egg are not enough to start differentiation process.

According this theory, in order the X site, (which is a nucleoprotein complex rather a simple sequence of DNA, and which is synthesized along ovogenesis) to be functional, it must be unique. It seems to be located on maternal genome. For differentiation phenomena to take place, maternal set of chromosome must be present. If in fertilized eggs only paternal sets of chromosome are present, interface proteins (1-II and 2-II) will not segregate and will coexist in the same cells. These proteins will be continuously synthesized, so will reach high levels and will become active spontaneously. Genes responsible for trophoblastic differentiation will become active genes (first stage of differentiation), while genes for embryonic differentiation will be stocked in first stage of differentiation (Fig. 1 and 4). Thus, the entire population will have trophoblastic features with a high rate of multiplication.