According to a new study, a family of genomic sequences known as “bouncing genes” plays a vital role: they function as “dislocation” switches to genetic expression, using small DNA segments that act as regulatory “standards”.
As long as the Swiss doctor Friedrich Miescher The DNA first isolated in 1869, science has traveled an extraordinary path of discovery of the human genome.
One of the remarkable moments of this journey occurred in the 1940s, when the cytogeneticist Barbara McClintock discovered the transponable elements (ET), also known as “Jumping genes”.
A few decades later, the ambitious revealed that these elements constitute an impressive 45 % of the human genome and managed to proliferate over millions of years thanks to a “copy and necklace” mechanism.
As these sequences are highly repetitive and almost identical, they were discarded as “DNA Garbage” For decades – genetic remains of viruses there are long extinct.
But in recent years, this derogatory view of these sequences has begun to change. Currently, scientists believe that ET play a role in the function of the genome, chromosomal evolution, specialty and diversity.
However, due to their repetitive nature, ETs are still difficult to investigate, explains.
Now, a new international study has discovered a innovative method to analyze these mysterious sequences and revealed hidden patterns responsible for genetic expression. The results of the ones were published last week in the magazine Science Advances.
“Our genome has been sequenced for a long time, but the function of many of its parts remains unknown,” he said Fumitaka Inoueresearcher at the University of Kyoto and co -author of the study at the University. Understanding ETs would solve one of the greatest mysteries of the genome.
In an attempt to better understand ETs, researchers have developed a new method to classify them. Avoiding standard annotation toolsthis study groups the ETs based on both evolutionary relationships and their quality of conservation in the genome of primates.
Focusing on a family of sequences called MER11, the new method allowed scientists Divide the group into subgroupsDenominados Mer11_G1 A Mer11_G4. O Subgrupo G1 RepRESENTAVA AS older evolutionary sequenceswhile the G4 contained the latest.
In analyzing MER11 from this new perspective, researchers were able to compare these new subfamilies with epigenetic markers and found that These groups seemed to have a regulatory function in the genome.
In other words, functioned as swivel switches for genetic expression – particularly in initial human development.
Of course, one thing is to infer one standard and another is to observe it in action. Thus, the team used a known technique lentiMPRA to measure 7000 MER1 sequences using human stem cells and neural cells in the early stages.
The analysis showed that the group with the latest evolutionary sequences (MER11_G4) had the stronger impact on genetic expression. According to the study, this group uses Regulatory “standards” – small segments of DNA that influence development and genetic response.
By tracking the evolution of this group, scientists have demonstrated that DNA originally ancient virus It can actively participate in the form and function of the PLAs of the primates.
Although the journey of understanding the human genome is over 150 years old, it still has the remarkable ability to surprise us with each step, note the authors of the study.
