# Preliminary Transcriptomic Insights into the Combined Pathogenesis of Avian Leukosis Virus and Salmonella pullorum Co-Infection

## TL;DR

This study explores how two poultry diseases interact at the genetic level, revealing key genes and pathways involved in their combined effects.

## Contribution

The study identifies novel differentially expressed genes and pathways in co-infected chickens, offering new molecular insights into poultry disease interactions.

## Key findings

- Co-infected chickens showed significant differences in gene expression compared to single-infected groups.
- Genes related to extracellular matrix–receptor interactions, PPAR signaling, and calcium ion signaling were enriched.
- RT-qPCR confirmed the upregulation of MAPK10 and SQLE and downregulation of FOXG1 in co-infected chickens.

## Abstract

Co-infection with avian leukemia and Pullorum Disease poses a serious threat to poultry health. However, the combined pathogenic mechanism remains unclear, and no commercial vaccines or effective drugs are available. This study used transcriptome sequencing to identify differentially expressed genes and pathways related to immunity and tumorigenesis. The findings provide new insights into the co-infection mechanism and offer a theoretical basis for developing integrated control strategies in the poultry industry.

Co-infection with avian leukemia and Pullorum Disease severely compromises poultry health, yet its pathogenic mechanisms remain unclear. We employed transcriptome sequencing to analyze gene expression changes and enriched pathways in kidney, spleen, and liver tissues of Chongqing Chengkou mountain chickens under single-infection (avian leukemia virus or Pullorum Disease) and co-infection conditions. Significant differences were observed in the number and pathways of differentially expressed genes between co-infected and single-infected groups. These genes were predominantly enriched in pathways involving extracellular matrix–receptor interactions, PPAR signaling, and calcium ion signaling. RT-qPCR validation confirmed significant upregulation of MAPK10 and SQLE, alongside downregulation of genes such as FOXG1. This study identifies multiple differentially expressed genes and pathways associated with immunity and tumorigenesis, providing crucial molecular insights into the regulatory mechanisms underlying avian leukemia and Pullorum Disease co-infection.