June 18 (UPI) -- In a proof of concept study, published Thursday in the journal Stem Cell Reports, scientists successfully used human cells featuring Neanderthal DNA to grow tissue in the lab.
Researchers say the work will help to understand the effects of Neanderthal DNA on later human development.
"By selecting cell lines with Neanderthal DNA of interest one can test for effects that can be linked to that Neanderthal DNA, because it can be associated with the particular cell line," senior author J. Gray Camp of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the University of Basel in Switzerland, told UPI in an email.
Genomic analysis suggests all modern humans of non-African descent have approximately 2 percent Neanderthal DNA.
Differences in the genes of modern humans have allowed researchers to reconstruct approximately 40 percent of the Neanderthal genome, but scientists say they aren't sure exactly how these archaic genes influence human development.
"One way to do it is to use 3D organ models, called organoids and those are derived from stem cells," Camp said. "Knowing the Neanderthal DNA content of each line, one can then explore whether developmental processes in organoids derived from a particular cell line with specific Neanderthal variants of interest."
Certain Neanderthal-derived gene variants, or alleles, are more common in modern humans than others.
Human DNA is organized into chromosomes, one from an individual's mother and another from the individuals' father. When an allele is present in the chromosomes from both mom and dad, it is considered homozygous.
By comparing homozygous alleles in cell lines, like those shown to influence skin and hair color, to cell lines without homozygous alleles, scientists can gain a better understanding of how Neanderthal DNA influences development.
For the latest study, researchers showed that stem cell lines featuring Neanderthal-derived homozygous alleles can be used to grow tissue in a Petri dish.
"By testing whether organoids from this line show any developmental differences to organoids derived from lines that do not carry the Neandertal variants of interest can be informative about developmental processes that are impacted by Neandertal DNA," Camp said.
"This approach of studying Neandertal DNA in organoid systems will help us understand how much of the archaic DNA influences our developmental processes and potentially gives us new insight on how these processes might have differed between us and Neandertals," Camp said.
Followup investigations could look at the influence of Neanderthal DNA on human digestion, cognition or the immune response to pathogens.
According to Camp, future studies could also be used to study the influence of other types archaic DNA -- like Denisovan genes found in modern Oceanic human populations -- on the development of different human systems.
"It further gives us a system to study individual Neandertal variants for their phenotypic effects," Camp said. "We are planning to follow both of these paths moving forward."