Harianjogja.com, JAKARTA – We still often do the search for the resemblance of a child to a father or mother. Some children say that they look like their father, but there are also those who look like their mother. So, is it the father or mother who is more genetically contributing?
The answer depends on whether you are asking about the total number of genes a child inherits from mother and father, or whose genes actually dominate. However, scientists don’t think the answer is 50/50.
For example, most people know that genes are carried on DNA strands that are packaged into 23 X or Y-shaped chromosomes. These autosomes are placed in the nucleus of the cell, and the DNA they contain comes from our parents. But these cells actually contain one other chromosome that hides inside the mitochondria.
Mitochondria, or “powerhouses” for cells, generate cellular energy and play an important role in stamina and aging, according to a 2011 study published in the journal Physiological Genomes. Mitochondria also have their own DNA collection and we inherit it only from our mothers.
“It’s a clear example that you are more like your mother than your father,” said Marika Charalambous, a geneticist at King’s College London, as quoted from livescience.com.
Several studies have shown that our mitochondrial DNA which comes from our mothers plays a key role in our immune system. For example, Spanish and Israeli scientists looked at one mitochondrial gene, which is linked to the number of oxygen cells we can use during exercise. Their study, published in 2005 in the Journal of Applied Physiology, found that gene variants associated with lower fitness were found less frequently in elite cyclists and runners than in the general population.
A series of studies have shown the importance of mothers inheriting these and other genes. They found that a mother’s stamina capacity was better at predicting a child’s capacity than that of a father.
But instead of asking which parent contributed more genes, you may be asking which parent’s genes played a bigger role. Most of the surface level differences we see between people are not due to the genes themselves, but because of a series of chemical “switches” that sit on top of our DNA and tell our bodies which parts to read and translate into proteins and which ones to use. should be ignored.
“There is a degree of genetic variation among people that is not just a gene sequence,” Charambalous said.
Most research suggests there are between 100 and 200 genes imprinted in the body, but some studies suggest that there may be more, according to a 2012 article published in the journal PLOS Genetics. These genes are very important in the brain and placenta.
There is some disagreement over whether imprinting is biased by the expression of genes in one parent or another. Evidence suggests that equal numbers of genes are imprinted from mothers and fathers, according to Andrew Ward, a geneticist at the University of Bath in England.
“In the qualities that are responsible for gene printers, in a sense you tend to be more like one of your parents than the other,” Ward told Live Science.
In other words, printing can affect certain characteristics from body size to sleep habits and memory. But because imprinting occurs in relatively few genes and those genes are likely to be in balance between parents, imprinting will not determine whether you bear a striking resemblance to mom versus dad, Ward said.
But research on mice suggests that there may be some imbalances that benefit fathers in this regard. A 2015 study published in the journal Nature Genetics found that printed genes were 1.5 times more likely to be silent on the mother’s side and active on the paternal side. An earlier study published in 2008 in the journal PLOS ONE found similar results. In the brain, most of the printed genes are activated when they come from the father. The opposite happens to the placenta. However, there is no evidence, at least not yet, that this imbalance occurs in humans.