Does a child's IQ come from the father or the mother? Genetics experts reveal the secret

Have you noticed that we often say "alma mater", "motherland" or "motherland" in our language instead of "father school" or something like that?

From a genetic point of view, the genetic material provided by parents is not equal, and the mother contributes more genetic material!

Animal Cell Structure

For most organisms (eukaryotic organisms), their cells can be divided into two parts: the nucleus and the cytoplasm. Genetic material exists not only in the nucleus, but also in the cytoplasm.

Mitochondria and Genetic Inheritance There are two types of inheritance: Mendelian inheritance (genetic material is located in the cell nucleus) and cytoplasmic inheritance (genetic material is located in the cytoplasm). In Mendelian inheritance, the genetic material comes from the parents; in cytoplasmic inheritance, the genetic material comes from the mother, which is "maternal inheritance."

Mitochondria - the energy factory of the cell

There are a large number of organelles in the cytoplasm, one of which is called "mitochondria", which is the site where eukaryotic organisms carry out oxidative metabolism and the place where carbohydrates, fats and amino acids are finally oxidized to release energy. Simply put, it is a "factory" that converts nutrients into energy.

Using genetics to explain the "motherland" human body has two sets of genomes: nuclear genome and mitochondrial genome . The nuclear genome consists of 23 pairs of chromosomes, including 22 pairs of autosomes and 1 pair of sex chromosomes, with a length of about 3.16 billion base pairs. The mitochondrial genome encodes 37 genes with a total length of about 16,569 base pairs.

As we have just pointed out, the genetic material of cytoplasmic inheritance comes from the mother, so the inheritance of the mitochondrial genome is also maternal inheritance . In addition, the inheritance of the mitochondrial genome has two other characteristics: semi-autonomy and high mutation rate.

Genetic composition of children

So, what impact will this have on children?

First, mothers contribute more genes than fathers : sons have 837 more nuclear genes and 37 more mitochondrial genes; daughters have 37 more mitochondrial genes.

Specifically, mothers contribute more intelligence genes than fathers: 1,500 genes in the human genome are related to intelligence, and 164 genes on the X chromosome are related to intelligence. In addition, mothers contribute more immunity genes than fathers: 2,140 genes in the human genome are related to immunity, and 50 genes on the X chromosome are related to immunity.

Therefore, the intelligence and immunity level of children depends more on the mother.

Mitochondria and genetic diseases Mitochondrial mutations or dysfunction are associated with a variety of diseases, such as hereditary mitochondrial diseases, which are energy metabolism disorders caused by mutations in mitochondrial genes or nuclear genes.

In addition, Leber hereditary optic neuropathy (LHON) is also a mitochondrial genetic disease that causes degeneration of retinal ganglion cells and their axons, leading to acute or subacute central vision loss, which often occurs in young males (20-30 years old).

Studies have shown that the disease is not entirely caused by the mother, but by both parents. So far, among many treatments, gene therapy based on ectopic expression of mitochondrial genes is the most promising treatment for LHON.

(Author: Guan Minxin, Qiushi Chair Professor of Zhejiang University, Vice President of the Chinese Genetics Society. Former Dean of the School of Life Sciences and Deputy Director of the School of Medicine of Zhejiang University. Currently Director of the Institute of Genetics of Zhejiang University.)