Looking for mysterious dark genes

  In the universe, more than 95% are dark matter and dark energy, but unfortunately, scientists in various countries have tried their best to see the mysterious figure of dark matter, and have not found traces of dark energy. But in the genetic universe of species, scientists have discovered a gene similar to dark matter, which they call dark genes.
  ”Missing” gene expression was still
  dark gene was originally found in the body in the gerbil, gerbils live in barren dry desert in a rodent.
  In fact, the researchers studied the original purpose of gerbils to solve the puzzle of why gerbils can survive in the desert. To this end, the researchers sequenced the entire genome of gerbils, hoping to find a “secret weapon” for gerbils to survive in the desert. Unfortunately, the sequencing results did not find this “secret weapon”, but the results surprised the researchers and surprised them.
  Because the results of genome sequencing show that the gerbil genome has “missed” many genes vital to survival! These include the Pdx1 gene, which promotes the synthesis of insulin and promotes the development of the pancreas (the site of insulin synthesis). If this gene is missing, it will lead to incomplete pancreatic development and insulin deficiency, and it is easy to develop diabetes.
  To re-validate whether the Pdx1 gene is really “missing”, the researchers also gave gerbils standard foods for rodents and then observed their condition. It has been found that gerbils tend to be more obese than other rodents and are prone to diabetes, which seems to indicate that there is no Pdx1 gene in gerbils.
  While the researchers were preparing to write down the conclusion that there was no Pdx1 gene in gerbils, other researchers found that its pancreas developed completely and normally secreted insulin. In addition, they also found RNA that should be transcribed from the Pdx1 gene in gerbils. Why did the gene sequencing and feeding experiments show that the gerbils lacked this gene? This evokes the researchers’ strong curiosity.
  The original gene is just “hidden”
  With the curiosity of the gerbil, the researchers explored the RNA that should be transcribed from the Pdx1 gene. The researchers found that the number of cytosines and guanines on these transcribed RNAs is much higher than that of other genes, and they are two types of bases. According to the principle of base pairing, cytosine and guanine on the gene and transcribed RNA are paired. When there is guanine on the transcribed RNA, there is cytosine on the gene; when there is cytosine on the transcribed RNA, the gene is on the gene. There are birds. It is concluded that if the Pdx1 gene is present, it should contain a large amount of cytosine and guanine.
  In order to find the Pdx1 gene in the genome, the researchers broke the gerbil gene into a genetic separation machine, and the Pdx1 gene rich in cytosine and guanine precipitated to the bottom due to its mass, so that the gene could be obtained.
  With unremitting efforts, the researchers finally found the Pdx1 gene. They found that the biggest difference between this gene and other genes is that there are many more cytosines and guanines on the gene than other genes, and it is difficult to find high levels of cytosine and guanine due to the original gene sequencing technology. The gene, so this gene was not found during the sequencing process.
  Why is it different from other genes? The researchers decided to find out why.
  Dark gene can escape evolutionary change direction
  after this gene did a lot of research, researchers believe that a large number of reasons cytosine and guanine, cytosine generated to produce a large number of gerbils occur in vivo gene mutation and guanine.
  We know that evolution often begins with genetic mutations. First, random mutations occur in genes, and mutations in genes can cause changes in the traits of the species. Then, natural selection is like a filter that filters out genes that produce unfavorable species and leaves genes with dominant traits. Evolution will find a clear direction under the influence of natural selection. Therefore, natural selection can be said to be the only “driver” of genetic mutation, and the direction of evolution is only determined by natural selection.
  However, these mutations are both good and bad due to a large number of mutations in the dark gene. Natural selection can’t filter out all the harmful mutations, and some harmful mutations will be missed by natural selection and transmitted in the species, which may change the evolutionary trajectory of the species.
  Mutation of the Pdx1 gene results in the synthesis of insulin that does not regulate blood glucose levels. For ordinary species, “insulin that cannot regulate blood sugar levels” is an unfavorable mutation, because if insulin does not lower blood sugar, after eating normal foods in ordinary species, the blood sugar in the species cannot be reduced, and it is easy to develop diabetes or even death.
  But for gerbils, this is a favorable variant, because gerbils usually live in the desert, food is extremely scarce, it can only eat very nutritious foods, these foods can provide very little sugar, if insulin Continue to lower the blood sugar of the gerbil, it can not survive at all.
  In fact, dark genes are not non-existent genes, but like dark matter and dark energy, it is only a gene that exists but is not discovered by humans. When a dark gene has a large number of mutations, it may become another “driver” of species evolution, and may also control the direction of evolution. The evolution brought about by dark genes is a paradise or a hell for species, and further research is needed.
  What is the base pairing principle?
  A gene is a DNA fragment with genetic information. When a gene is expressed, RNA is linked to one strand of DNA through a base, and genetic information on the DNA can flow into the RNA through the base. There are five bases in RNA and DNA, namely adenine (A), thymine (T) (DNA-specific), cytosine (C), guanine (G), and uracil (U) (RNA-specific). .
  In order to stabilize the connection between RNA and DNA, bases form a relatively stable hydrogen bond by pairing. Only bases that can form the same number of hydrogen bonds will be paired. AT, TA, and AU, UA will form two hydrogen bonds, and CG and GC will form three hydrogen bonds. This is the principle of base pairing.