New Research Reveals Surprising Differences in DNA Transcription between Yeast and Mammalian Cells
A recent study in the field of genomics has shed light on the intriguing differences in DNA transcription between yeast and mammalian cells. The findings challenge our understanding of genetic transcription across species and have significant implications for genetic engineering and the discovery of new genes.
The study, conducted by researchers at NYU Langone Health, focused on the process by which DNA instructions are converted into RNA and eventually into proteins. While previous research had shown that only a small fraction of the human genome actually codes for genes that direct protein production, scientists were curious about the purpose of the remaining non-gene-related transcription.
To investigate this mystery, the research team inserted a synthetic gene into yeast and mouse stem cells, with the DNA code in reverse order compared to its natural parent. Surprisingly, they found that yeast cells actively transcribe nearly all genes, while mammalian cells naturally repress transcription.
The reverse order of the synthetic gene meant that all the mechanisms that regulate transcription in yeast and mammalian cells were absent. However, the reversed code still exhibited some basic patterns similar to the natural code, such as the frequency of DNA letters and their repetitions. These patterns resulted in the random inclusion of previously unknown code stretches, which led to more frequent transcription in yeast cells and its suppression in mammalian cells.
The study’s corresponding author, Jef Boeke, emphasized that understanding these default transcription differences across species is crucial for deciphering the functions of different parts of the genetic code. This knowledge could guide genetic engineering efforts in yeast, aid in the development of new medicines and gene therapies, and potentially uncover hidden genes.
The researchers also discovered that yeast’s active transcription state may be advantageous for incorporating foreign DNA. When yeast encounters a virus and incorporates its RNA into its genetic material, a new gene may arise with a helpful function, thereby driving faster evolution. Mammalian cells, on the other hand, are more constrained due to their intricate regulatory mechanisms, protecting the integrity of the genetic code.
The study’s methodology involved introducing a synthetic stretch of engineered DNA, the human gene hypoxanthine phosphoribosyl transferase 1 (HPRT1), in reverse coding order into yeast and mouse embryonic stem cells. While widespread transcription occurred in yeast, the same reversed code did not lead to significant transcription in mammalian cells. The researchers attributed this disparity to other fundamental elements in the mammalian genome that actively restrict transcription.
In conclusion, the study highlights the surprising transcriptional differences between yeast and mammalian cells and opens up new possibilities for genetic engineering and research. By understanding the default transcription states in various species, scientists can identify functional parts of the genetic code and potentially engineer novel genes to address medical and biological challenges.
As this field of research progresses, it will be interesting to see how these findings shape the future of genetic engineering and our understanding of evolutionary biology. Furthermore, the study’s implications for gene therapies and the development of new medicines hold promise for addressing a wide range of health issues.