Human Y chromosomes share similar characteristics with those of gorillas, a new study found.
The Y chromosome of mammals is the most difficult-to-assemble component of the genome, one of the two found in males. Because this is critical to addressing male infertility problems, it is important to understand and dig into the details.
In an effort to create a technology that can help detect the DNA sequence of the Y chromosome in gorillas, researchers from Penn State embarked on a study to do just that. Along the way, they discovered an interesting fact: human Y chromosomes are more similar to that of gorillas.
"Surprisingly, we found that in many ways the gorilla Y chromosome is more similar to the human Y chromosome than either is to the chimpanzee Y chromosome," says study author Kateryna Makova.
In the parts of the chromosome where the scientists can align the species of gorillas, chimpanzees and humans, they were able to prove a long-known fact that humans are more closely related to chimpanzees. However, the Y chromosome of chimpanzees looks like it has undergone more modifications in gene numbers and have more repetitive factors than gorillas or humans.
When the scientists looked into the Y chromosome sequence of gorillas, more portions can be aligned to the Y chromosomes of humans than to the chimpanzees.
Why Difficult To Sequence
There are various reasons why the mammalian Y chromosome is very hard to sequence. Firstly, the chromosome can be found in only one copy and comprises only about 1 to 2 percent of the entire genetic material found in male cell.
Secondly, the chromosome has significantly numerous repeated sequences or regions where As, Cs, Ts and Gs are identical for millions of bases in a row.
Simply put, Makova says sequencing the Y chromosome is like solving a jigsaw puzzle without knowing what the final photo would be like. The puzzle-solver is given a massive amount of puzzle pieces but only one or two in every hundred are useful, plus the important pieces look so identical.
Now, the researchers were able to develop a conduit for sequencing the Y chromosome that is more accurate than previous techniques. Such method also decreases the challenges associated with sequencing the chromosome.
Specifically, the scientists created genetic markers that can be used to compare the genetic association among male gorillas hence, help in conservation genetics initiatives that focus on species preservation.
The study was published in the online version of the journal Genome Research on March 2.