Scientists have found that mitochondrial DNA genes determine not only the predisposition to certain diseases, but also allow you to control eating behavior. The research results are published in the journal Nature Metabolism.
Many of the characteristics that make people so different are often reflections of small differences in DNA. And we are talking not only about external signs, but also about such individual characteristics of each person as sleep duration, appetite, physical endurance and others. This also applies to the predisposition to certain diseases.
But in order to confidently say which changes in the genotype lead to specific changes in the external manifestations - in the phenotype - scientists must build the so-called genetic reference panels.
The standardized genetic reference panel currently only exists for the Drosophila melanogaster fruit fly. The Drosophila DGRP Reference Panel includes more than 200 fly lines, each with a fully sequenced genome, allowing scientists to conduct studies of genotype-phenotype relationships.
In both fruit flies and humans, most of the DNA is tightly packed inside the cell nucleus. But mitochondria, organelles of cells responsible for energy production, also have their own DNA with their own set of genes.
It is believed that it is with the differences in mitochondrial genes that diseases such as obesity, type 2 diabetes, multiple sclerosis and schizophrenia are associated. But so far, very little is known about how changes in the mitochondrial genome are associated with variations in phenotypes.
Swiss scientists led by Bart Deplancke of the Federal Polytechnic School in Lausanne have conducted extensive research linking differences in mitochondrial DNA to external traits in DGRP fruit fly lines.
"Until now, studies of the Drosophila genotype have focused mainly on genetic variants in the nucleus, and mitochondrial DNA has been very poorly covered," the Deplancke school said in a press release. lines of flies."
The researchers re-sequenced mitochondrial genomes from 169 fruit fly lines, which allowed them to identify 231 variants of the gene. They then identified 12 mitochondrial DNA haplotypes - groups of variants that are always inherited together. Interestingly, these haplotypes have been associated with a number of metabolic phenotypes and diseases. Associations have been found with stress, metabolic options, and eating behavior.
To confirm their findings, the authors transplanted the mitochondrial genome from high food intake males to those that ate little. The feeding behavior of the flies has changed.
"Metabolic processes are largely regulated by mitochondrial haplotypes," Deplanke says. "Therefore, it is important to include them in studies of genotype-phenotype relationships."