The complete mitochondrial genome of Hequ horse.

This research focuses on identifying and determining the complete mitochondrial genome of the Hequ horse breed. The findings included a detailed composition of DNA sequences and the position of the Hequ horse in the broader horse family tree.

Understanding the Mitochondrial Genome of Hequ Horse

The research was aimed at understanding the complete mitochondrial genome, also known as mitogenome, of the Hequ horse. The mitogenome is a small DNA molecule found within cells that carries genes associated with energy production. It is of significant interest in scientific research for its unique characteristics, such as maternal inheritance, high mutation rates, and lack of recombination. In this case, its analysis was crucial to understanding the genetic makeup of the Hequ horse.

• The length of the Hequ horse mitogenome was discovered to be 16,656 base pairs. Base pairs form the building blocks of the DNA molecule and are indicators of genome size.
• It contains 13 protein-coding genes. These genes form the blueprint for protein synthesis in the body – crucial for many biological functions.
• There are 22 transfer RNA (tRNA) genes. tRNA is important in the process of translating the genetic code from the DNA into proteins within cells.
• The mitogenome carries 2 ribosomal RNA (rRNA) genes – integral components of the protein-producing structures known as ribosomes.
• A D-loop region was also identified. This portion of the mitochondrial DNA has a significant role in replication and control of the DNA molecule.

DNA Base Composition

The research also delved into assessing the overall base composition of the H-strand, one of the two strands of the DNA molecule.

• The ‘A’ (adenine) base was found to make up 32.20% of the strand.
• ‘C’ (cytosine) contributed 28.55% of the overall composition.
• ‘G’ (guanine) composed 13.38% of the strand.
• ‘T’ (thymine) accounted for 25.86% of the composition.

Phylogenetic Placement of Hequ Horse

The researchers also used the Maximum-likelihood (ML) methods in the software MEGA 6 to construct a phylogenetic tree, a diagram used to illustrate the evolutionary relationships between different species based on their genetic similarities and differences. They found that the Hequ horse is clustered within the subfamily Equidae, indicating its role and position within the broader horse lineage.