Cincinnati--Published today in the Proceedings of the National Academy of Sciences,
a genetic study of 'Polynesian origins: Insights from the Y chromosome"
gives scientific evidence that traces the migration of prehistoric
ancestors from the heart of the agricultural mainland of Southeast
Asian to the thousands of Polynesian islands that stretch 6,000 miles
off the southeast coast. Conducted by researchers from China, the US,
England, and Australia, this research disputes earlier theories that
traced ancestral roots of Polynesian people to Taiwan. Ranjan Deka,
PhD, associate professor, University of Cincinnati (UC) Department of
Environmental Health, is the leading investigator of this study. Other
major investigators are: Li Jin, PhD, and Bing Su, PhD, from the
University of Texas Health Science Center at Houston.
the prehistoric migration and genetic structure of human populations
helps scientists to find disease-causing genes, the next step of which
is to develop therapies to treat genetic disorders at the molecular
level," says Deka, who studies genetic variation at the UC Medical
Center. Creating a genetic profile of people who live in remote areas
such as the Polynesian Islands helps scientists to identify what
specific genes predispose their population to certain diseases such as
diabetes, while using DNA to trace their relationship to ancestors.
researchers of this study based their conclusions on DNA analysis from
the human Y chromosome. The Y chromosome determines the persons of the
male sex and is transmitted by fathers to their sons as a single copy.
All other chromosomes contain two copies, with one inherited from the
mother and the other from the father. Mitochondrial DNA (mtDNA--from
outside the nucleus) are passed on only through the mother and have a
higher rate of mutation than DNA from the Y chromosome. Although both Y
chromosome and mtDNA research can be used to create genetic profiles of
specific populations, mtDNA have a higher rate of mutation than DNA
from the Y chromosome. "The new research refutes earlier theories that
were based on mtDNA research which linked present day Polynesians with
historic populations found in Taiwan," says Deka.
recombination phase of gamete formation, when genes from each parent
are randomly exchanged to create the egg or sperm, only the Y
chromosome keeps its inherited legacy intact. Deka and his
collaborators used a new type of DNA marker that remains stable over
generations and can provide a true chronicle or lineage of past
evolutionary genetic histories of specific populations. For more
information about this study or Deka's current research to find genes
of adult onset diabetes among the Samoans of Polynesia, contact
firstname.lastname@example.org via email, or by calling him at (513) 558-5989.