Attracting Abundance
- 125 -
The Law
Belief - XXXVII
In this post we will learn about genome imprinting. It is epigenetic process.
We inherit two copies of every gene - one from each of our biological parents. Usually both copies of genes are active in cells. There are a few exceptional cases where only one copy of the gene is active and the other copy is suppressed. Such genes till the last known discovery count to about one hundred; the estimate is that such genes may ultimately add up to a few hundreds. Which copy of which gene is active depends on the parent from which that gene has originated; some genes are active only when they are inherited from mother and others when they have originated from the father. So, imprinted genes violate the rule of inheritance that requires that both copies are equally expressed. Maternally imprinted genes are expressed when inherited from the father and similarly paternally imprinted genes are expressed when inherited from the mother.
Note: Some examples of usual rule are as follows:
- If a child inherits a gene for Blood group A from one parent and for Blood group B from the other parent, then the Blood group of the child will be AB
- If a child inherits the gene encoding hemoglobin A from either parent and the gene encoding hemoglobin S from the other parent, the child's red blood cells will contain roughly equal amounts of the two types of hemoglobin.
On the genes that are imprinted, a tag is placed such that the cell recognizes whether the imprint belongs to a maternal gene or a parental gene. Such tagging or stamping is done during the formation of of egg in the mother and sperm in the father i.e. well before the conception stage. The stamping process is called methylation, which we have already learnt previously is a chemical reaction that attaches molecules of methyl groups to certain segments of DNA. these molecules are the tags or stamps that identify which copy of gene was inherited from the mother and which was inherited from the father.
All the cells in a resulting child will have the same set of imprinted genes from both its father and its mother EXCEPT for those cells that are destined to go on to make gametes. All imprints — both maternal and paternal — are erased in them. This essentially means that the parental imprints are not trans-generational; these are limited to the child only.
Note: Some examples of imprinted genes are as follows:
Attracting Abundance
- 125 -
The Law
Belief - XXXVII
In this post we will learn about genome imprinting. It is epigenetic process.
We inherit two copies of every gene - one from each of our biological parents. Usually both copies of genes are active in cells. There are a few exceptional cases where only one copy of the gene is active and the other copy is suppressed. Such genes till the last known discovery count to about one hundred; the estimate is that such genes may ultimately add up to a few hundreds. Which copy of which gene is active depends on the parent from which that gene has originated; some genes are active only when they are inherited from mother and others when they have originated from the father. So, imprinted genes violate the rule of inheritance that requires that both copies are equally expressed. Maternally imprinted genes are expressed when inherited from the father and similarly paternally imprinted genes are expressed when inherited from the mother.
Note: Some examples of usual rule are as follows:
- If a child inherits a gene for Blood group A from one parent and for Blood group B from the other parent, then the Blood group of the child will be AB
- If a child inherits the gene encoding hemoglobin A from either parent and the gene encoding hemoglobin S from the other parent, the child's red blood cells will contain roughly equal amounts of the two types of hemoglobin.
On the genes that are imprinted, a tag is placed such that the cell recognizes whether the imprint belongs to a maternal gene or a parental gene. Such tagging or stamping is done during the formation of of egg in the mother and sperm in the father i.e. well before the conception stage. The stamping process is called methylation, which we have already learnt previously is a chemical reaction that attaches molecules of methyl groups to certain segments of DNA. these molecules are the tags or stamps that identify which copy of gene was inherited from the mother and which was inherited from the father.
All the cells in a resulting child will have the same set of imprinted genes from both its father and its mother EXCEPT for those cells that are destined to go on to make gametes. All imprints — both maternal and paternal — are erased in them. This essentially means that the parental imprints are not trans-generational; these are limited to the child only.
Note: Some examples of imprinted genes are as follows:
- IGF2— the gene encoding the insulin-like growth factor-2: In humans (and other mammals like mice and pigs) the IGF2 copy inherited from the father (paternal) is expressed; the copy inherited from the mother is not. If both copies should begin to be expressed in a cell, that cell may develop into a cancer
- IGF2r— the gene encoding the cell receptor for Igf-2: In mice the IGF2r copy inherited from the mother is expressed; that from the father is not.
- DIRAS3-- maternally imprinted gene -- is a putative tumor suppressor gene whose function is abrogated in breast cancer as well as ovarian cancer.
You can visit this website page to see a complete list of genes that are confirmed as imprinted and predicted as imprinted in humans.
- IGF2— the gene encoding the insulin-like growth factor-2: In humans (and other mammals like mice and pigs) the IGF2 copy inherited from the father (paternal) is expressed; the copy inherited from the mother is not. If both copies should begin to be expressed in a cell, that cell may develop into a cancer
- IGF2r— the gene encoding the cell receptor for Igf-2: In mice the IGF2r copy inherited from the mother is expressed; that from the father is not.
- DIRAS3-- maternally imprinted gene -- is a putative tumor suppressor gene whose function is abrogated in breast cancer as well as ovarian cancer.
You can visit this website page to see a complete list of genes that are confirmed as imprinted and predicted as imprinted in humans.
Uniparental disomy (UPD) occurs when a person receives two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent. UPD can occur as a random event during the formation of egg or sperm cells or may happen in early fetal development.
In many cases, UPD likely has no effect on health or development. Because most genes are not imprinted, it doesn’t matter if a person inherits both copies from one parent instead of one copy from each parent. In some cases, however, it does make a difference whether a gene is inherited from a person’s mother or father. A person with UPD may lack any active copies of essential genes that undergo genomic imprinting. This loss of gene function can lead to delayed development, intellectual disability, or other health problems.
Several genetic disorders can result from UPD or a disruption of normal genomic imprinting. The most well-known conditions include Prader-Willi Syndrome, which is characterized by uncontrolled eating and obesity, and Angelman Syndrome, which causes intellectual disability and impaired speech.
When the cell divides the daughter cells retain the imprinting thereby maintaining continuity. It is also worth re-emphasizing that while genomic imprinting occurs to a small number of genes which are clustered together on very small areas on the chromosomes. So why is there so much attention to genetic imprinting? Well we have learnt that genetics is a result of our genes. We have also learnt that we have received the genes from our biological parents. But what we are learning now is that we have genes that we are never going to use, and that was decided before we were conceived. There is a process of modifying the action of the DNA code without modifying the DNA code itself.
We also understand that some of the heritable diseases are not due to DNA mutations i.e. for a hereditary disease to happen the DNA code need not get tampered by mistakes of transcription. These diseases can happen due to epigenetic reasons also.
Imprinted genes are specially sensitive to environmental signals because the imprinted genes have only one active copy and no back-up; any epigenetic change will have a greater impact on gene expression.
Environmental signals have significant impact on the imprinting process itself. As we have learnt that imprinting happens during maturation of eggs and sperms in the parents. Diet, hormones and toxins can all affect the process impacting the expression of genes in the next generation.
The fact that genome imprinting takes place in the final stages of egg and sperm maturation, this is the time when the real actions that, determine the character of life of the child, start well before the child is conceived. The environmental experience of the parents at this time influences the character of the child's life. This is a big surprise. I am not sure how many parents are aware of this till this day. I have talked to a few and none of them were aware of this aspect. Combine this with with our learning in the previous post on the learning, habituation and memory of fetus, and we have recipe for what the parents can do and how large is their sphere of control and influence in creating a health child - physically and psychologically.
Parents are the creators of the most precious things on this planet - the human life form. The character of the new human life - both physiologically and psychologically - is influenced to a large extent by the parents. The parents define the "starting block" of an individual which can be remolded by the individual by his own life experiences. There is an abundance of scientific research work available on the awareness of the fetus and the effect of environment on the fetal life. I have given reference to a number of such research work in my previous post just to prove the point that the awareness, memory and habituation of the fetus and the effect of environment are being established by traditional scientific work and not by the much maligned "new age" thinking. I, personally, have been trying to increase the awareness of the parents on these developments so that they are empowered to make conscious decisions about their off springs. A stressed mother with a chronically activated HPA axis is bad news for the mother and the fetus inside her womb. We have learnt that a chronically activated HPA axis causes ingestion of the stress hormone, cortisol, in to the blood stream of the mother which ultimately finds its way in to the blood stream of the fetus. We have learnt about some of the adverse effects of high cortisol like it impedes growth, causes more blood & nutrients to flow towards the flight-or-fight organs like muscles of legs and arms, constricts the blood vessels in the fore brain - the creative or conscious part of the brain causing more blood flow to the hind brain - the subconscious or habitual part of the brain. All these manifest in to deficiencies - physiological and psychological - in the later life of the fetus in the process of it becoming an adult. Will the adversity of stress hormone be limited to what has been discussed or ar there more things to consider? The research work says more. The IQ gets impeded because of change in blood flow in the brain of the fetus. It has been scientifically estimated that the IQ is determined to an extent of 34% by the genetics of both the parents, the balance comes from the experience of the fetus inside the mother's womb.
I had always been intrigued by one question - how is that my two children are so different when they are creations of the same pair of genes? This post answers that question. The answer may not be complete as all answers are limited by the knowledge acquired by mankind till the day of the answer. Dr, Bruce Lipton has very aptly framed the answer in his book "Biology of Belief" where he says "We are not the same parents for all of our children". Starting from genome imprinting to conception and the experience that the parents conjoined to provide to the fetus and the infant created the differences between our children.
the next post will be concluding post in this series. The next post will also deal with parental responsibilities in creating a "healthy" child; the word "healthy" encompasses physiology and psychology.
Namaste
See you soon
Prabir
Uniparental disomy (UPD) occurs when a person receives two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent. UPD can occur as a random event during the formation of egg or sperm cells or may happen in early fetal development.
In many cases, UPD likely has no effect on health or development. Because most genes are not imprinted, it doesn’t matter if a person inherits both copies from one parent instead of one copy from each parent. In some cases, however, it does make a difference whether a gene is inherited from a person’s mother or father. A person with UPD may lack any active copies of essential genes that undergo genomic imprinting. This loss of gene function can lead to delayed development, intellectual disability, or other health problems.
Several genetic disorders can result from UPD or a disruption of normal genomic imprinting. The most well-known conditions include Prader-Willi Syndrome, which is characterized by uncontrolled eating and obesity, and Angelman Syndrome, which causes intellectual disability and impaired speech.
When the cell divides the daughter cells retain the imprinting thereby maintaining continuity. It is also worth re-emphasizing that while genomic imprinting occurs to a small number of genes which are clustered together on very small areas on the chromosomes. So why is there so much attention to genetic imprinting? Well we have learnt that genetics is a result of our genes. We have also learnt that we have received the genes from our biological parents. But what we are learning now is that we have genes that we are never going to use, and that was decided before we were conceived. There is a process of modifying the action of the DNA code without modifying the DNA code itself.
We also understand that some of the heritable diseases are not due to DNA mutations i.e. for a hereditary disease to happen the DNA code need not get tampered by mistakes of transcription. These diseases can happen due to epigenetic reasons also.
Imprinted genes are specially sensitive to environmental signals because the imprinted genes have only one active copy and no back-up; any epigenetic change will have a greater impact on gene expression.
Environmental signals have significant impact on the imprinting process itself. As we have learnt that imprinting happens during maturation of eggs and sperms in the parents. Diet, hormones and toxins can all affect the process impacting the expression of genes in the next generation.
The fact that genome imprinting takes place in the final stages of egg and sperm maturation, this is the time when the real actions that, determine the character of life of the child, start well before the child is conceived. The environmental experience of the parents at this time influences the character of the child's life. This is a big surprise. I am not sure how many parents are aware of this till this day. I have talked to a few and none of them were aware of this aspect. Combine this with with our learning in the previous post on the learning, habituation and memory of fetus, and we have recipe for what the parents can do and how large is their sphere of control and influence in creating a health child - physically and psychologically.
Parents are the creators of the most precious things on this planet - the human life form. The character of the new human life - both physiologically and psychologically - is influenced to a large extent by the parents. The parents define the "starting block" of an individual which can be remolded by the individual by his own life experiences. There is an abundance of scientific research work available on the awareness of the fetus and the effect of environment on the fetal life. I have given reference to a number of such research work in my previous post just to prove the point that the awareness, memory and habituation of the fetus and the effect of environment are being established by traditional scientific work and not by the much maligned "new age" thinking. I, personally, have been trying to increase the awareness of the parents on these developments so that they are empowered to make conscious decisions about their off springs. A stressed mother with a chronically activated HPA axis is bad news for the mother and the fetus inside her womb. We have learnt that a chronically activated HPA axis causes ingestion of the stress hormone, cortisol, in to the blood stream of the mother which ultimately finds its way in to the blood stream of the fetus. We have learnt about some of the adverse effects of high cortisol like it impedes growth, causes more blood & nutrients to flow towards the flight-or-fight organs like muscles of legs and arms, constricts the blood vessels in the fore brain - the creative or conscious part of the brain causing more blood flow to the hind brain - the subconscious or habitual part of the brain. All these manifest in to deficiencies - physiological and psychological - in the later life of the fetus in the process of it becoming an adult. Will the adversity of stress hormone be limited to what has been discussed or ar there more things to consider? The research work says more. The IQ gets impeded because of change in blood flow in the brain of the fetus. It has been scientifically estimated that the IQ is determined to an extent of 34% by the genetics of both the parents, the balance comes from the experience of the fetus inside the mother's womb.
I had always been intrigued by one question - how is that my two children are so different when they are creations of the same pair of genes? This post answers that question. The answer may not be complete as all answers are limited by the knowledge acquired by mankind till the day of the answer. Dr, Bruce Lipton has very aptly framed the answer in his book "Biology of Belief" where he says "We are not the same parents for all of our children". Starting from genome imprinting to conception and the experience that the parents conjoined to provide to the fetus and the infant created the differences between our children.
the next post will be concluding post in this series. The next post will also deal with parental responsibilities in creating a "healthy" child; the word "healthy" encompasses physiology and psychology.
Namaste
See you soon
Prabir
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