# Structural Analysis of the AlkB Family in Poultry

## TL;DR

This study identifies and analyzes seven AlkB family genes in poultry, revealing their unique structure, evolution, and tissue-specific roles, which could help improve poultry health and farming.

## Contribution

The study provides the first comprehensive structural and functional analysis of the AlkB family in poultry, highlighting unique evolutionary and expression patterns.

## Key findings

- Phylogenetic analysis showed distinct avian and mammalian clusters with conserved 3D structures but low sequence homology in poultry AlkB proteins.
- ALKBH5 showed high activity in muscle and brain tissues and increased during muscle growth, suggesting a role in development.
- ALKBH3, ALKBH5, and FTO expression significantly increased during myoblast differentiation, indicating their involvement in muscle development.

## Abstract

The AlkB family proteins are Fe2+/2-oxoglutarate-dependent dioxygenases that catalyze oxidative demethylation of nucleic acids. The vertebrate AlkB family comprises nine members—ALKBH1, ALKBH2, ALKBH3, ALKBH4, ALKBH5, ALKBH6, ALKBH7, ALKBH8, and FTO. In this study, using computer-based analysis and lab experiments, we identified seven AlkB genes in poultry and compared their evolution, structure, and activity across tissues. These genes are organized uniquely in poultry compared to mammals. ALKBH5, for example, showed high activity in muscle and brain tissues and an increased trend during muscle growth, suggesting its role in development. ALKBH6 and ALKBH7, two AlkB family genes present in mammals but not poultry, may be attributed to the substrate preferences exhibited by AlkB family proteins in poultry. By uncovering these genetic mechanisms, this research supports the breeding of healthier, more resilient poultry, as controlling health and growth in poultry is vital for improving farming and disease resistance.

The objective of this study was to identify the AlkB family genes in poultry using bioinformatics, and to explore their molecular characteristics, evolutionary relationships, and expression patterns to clarify their potential functions in poultry. (1) Methods: The study utilized the NCBI database to obtain chicken genome data, and screened and validated AlkB family members (ALKBH1-5, ALKBH8, and FTO) by hmmsearch and TBtools. MEGA 11.0 was used for phylogenetic analysis, PHYRE2 and I-TASSER predicted protein structures, and the String database was used to construct an interoperability network. Finally, the tissue expression profiles were analyzed by using The Human Protein Atlas online database and qRT-PCR. (2) Results: Phylogenetic analysis revealed distinct avian and mammalian clusters, with chicken AlkB proteins exhibiting low sequence homology but conserved 3D structures compared to mammals. Chromosomal synteny and conserved domains highlighted evolutionary divergence, with ALKBH4 lacking typical AlkB structural motifs. Protein interaction networks linked ALKBH1/2/3/5/8/FTO, underscoring functional coordination in poultry adaptation. Tissue-specific expression showed high AlkB levels in brain tissues, while ALKBH5 dominated in muscle. During differentiation, ALKBH3, ALKBH5, and FTO expression significantly increased during myoblast differentiation. (3) Conclusions: This study identified seven AlkB family genes in poultry, revealing their phylogenetic classification into two subfamilies, conserved structural domains, chromosomal synteny, and tissue-specific expression patterns.