Evolution and Biological Meaning of Genomic Wastelands (RCRO): Proposal of Hypothesis
Differences of subterminal regions of chromosomes between humans and African apes have long been a matter of great interest in cytogenetics because of the absence and presence, respectively, of large heterochromatin blocks. I tried to dissect such mysterious heterochromatic blocks of African apes using molecular techniques. Thus far, four DNA components were found as elements constructing the subtelomeric heterochromatin (terminal retrotransposable compound repeated DNA organizations, RCROs). Of the four components, one (subterminal satellite, StSat) was localized by PRINS reaction on chromosomes of chimpanzee, bonobo, gorilla, siamang, and rhesus macaque. Here, I discuss hypothetical evolutionary aspects of the terminal RCROs, their intragenomic dispersion, and their biological meaning. These aspects will probably become important clues at the chromosomal level in post-genomic research to elucidate human evolution.
KeywordsRepetitive Sequence Subtelomeric Region Euchromatic Region Heterochromatic Block Ectopic Recombination
Fluorescence in situ hybridization
Human endogenous retrovirus
Primed in situ
Retrotransposable compound repeated DNA organization
Primate biomaterials were supplied from KUPRI, Japan; JMC, Japan; and Ouji Zoo, Japan, through the GAIN project; PSSP, IPB, Indonesia; and PBZT, Madagascar. I thank Dr. A Koga for his critical reading of the manuscript and valuable comments, and Dr. Elizabeth Nakajima for revision of the English. This research was supported in part by the Global COE Program (A06 to Kyoto University) of the Ministry of Education, Culture, Sports, Science and Technology-Japan and a grant of the Japan Society for the Promotion of Science (20405016, 22247037).
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