About 250 specialized cell types are organized into tissues, organs, and organsystems in the body of humans. Differentiation of cells both in structure & function generally depends on gene expression rather than on any changes in the nucleotide sequence of the cell’s genome. The key objective of this paper was to verify that no “junk DNA” at all in the human genome and to confirm the fact that the synthesizer of generations of Homo sapiens & of all other genomic-things is the Genome. The cell types in a multicellular organism become different from one another because they synthesize and accumulate different sets of RNA and protein molecules. They generally do this without altering the sequence of their DNA with the exception of B & T lymphocytes in the immune system. Differentiation occurs because specific genes in each cell are turned on and off in complex regulated pattern. A stem cell is an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into specialized cells. The stem cells derived from a zygote are described as:- totipotent, pluripotent, multipotent, and oligopotent stem cells. In contrast, a unipotent cell is fully specialized and can only reproduce to generate more of its own specific cell type. The primary mechanism by which genes are turned “on” or “off” is through transcription factors. A transcription factor is one of a class of proteins that bind to specific genes on the DNA molecule and either promote or inhibit their transcription. Transcription factors regulate gene expression. Transcription factors affect the binding of RNA polymerase to a particular gene on the DNA molecule. Researchers have recently developed induced pluripotent stem cells (iPSCs) from human adult stem cells. The induced pluripotent stem cells do function like embryonic stem cells. Non-coding RNAs are a group of RNA transcripts that do not necessarily code for proteins instead they perform the task of regulatory functions. The science of genomic-things is superior to all branches of natural science because the scientist himself, who creates all other nonbiological sciences, is a genomic-thing and belongs to biological sciences. The science of genomic-things is a superscience being the science of priority to invest in. In the automatic functional & structural performance of human genome, every component of it is indispensably useful and none of it is junk DNA at all!! 100% of genome’s components, in all species of genomic-things from biological viruses up to humans, are unavoidably useful in the task of synthesizing the individuals & populations of its species in different ecosystems on Earth let alone those of human genome!!!! The genome synthesizes genomic-things & their products using:- proteins (structural & functional) translated from its transcripts, and its transcripts directly without translating. Biological sciences are brought up to the status of superscience (the science of genomic-things) by Feleke’s Genome Model of genomic-things. Scientists of biological sciences are authentically called superscientists because biological sciences which are their fields of study have been spectacularly developed to the status of superscience. Establishing a Global Center of Superscience (GCS) is crucial.
Keywords: Differentiation, Gene expression, Genome, Non-coding RNA, Stem cell, Transcription factors, embryonic stem cell
