Genome to Single-Cell Characterization of the MAPK Family in Bighead Carp Spleen During Aeromona

13 Apr 20264 min read0 viewsJournal Feed

GIST

IntroductionMitogen-activated protein kinases (MAPKs) are central to stress and innate immune signaling in fish, but their genomic composition and infection related transcriptional responses remain unclear in bighead carp (Hypophthalmichthys nobilis).MethodsWe performed a comparative genomic survey across 24 species and characterized MAPK family members in bighead carp based on conserved motifs, gene structure, and synteny. Tissue expression profiling, transcriptome sequencing, qRT-PCR, weighted gene co-expression network analysis (WGCNA), and single-cell RNA sequencing were used to investigate MAPK expression and immune responses following Aeromonas hydrophila challenge.

Cell-cell communication and pseudotime analyses were further applied to dissect infection responsive myeloid populations.ResultsWe identified 382 mapk sequences across 24 species, including 15 high confidence mapk genes in bighead carp, which were classified into the ERK, JNK, and p38 subfamilies. These genes were constitutively expressed across six tissues, with mapk12b and mapk14b showing relatively high expression in spleen and head kidney.

Following A. hydrophila challenge, mapk6 and mapk11 were significantly upregulated, as confirmed by transcriptomic and qRT-PCR analyses.

WGCNA further showed that multiple infection related modules were enriched in mapk family members.

Clinical Editorial

MAPK Landscape Across Species and Focused Profiling in Bighead Carp

These MAPKs show constitutive expression across six tissues, with mapk12b and mapk14b notably abundant in spleen and head kidney.

The study conducts a cross-species genomic survey, identifying 382 MAPK sequences across 24 species, and narrows to 15 high-confidence MAPK genes in bighead carp, categorized into ERK, JNK, and p38 subfamilies.

Infection Model and Multilevel Expression Characterization

Across transcriptomic data and targeted qRT-PCR, mapk6 and mapk11 emerged as significantly upregulated in response to infection.

Bighead carp were challenged with Aeromonas hydrophila to examine MAPK transcriptional dynamics.
Weighted gene co-expression network analysis (WGCNA) indicates several infection-associated modules are enriched for MAPK family members, suggesting coordinated regulation during bacterial challenge.

Single-Cell Resolution of Immune Response

There is notable expansion and activation of Neutrophils-I cells and M1 macrophages following infection.

Single-cell RNA sequencing of 28,348 spleen cells resolved 13 distinct cell types.
In these responsive cell populations, mapk6 and mapk11 expression is elevated, with concurrent enrichment of interferon-stimulated pathways.

Intercellular Communication and Lineage Dynamics

Analyses of cell–cell signaling point to TNF signaling via tnfrsf1b as a contributor to the early antibacterial response.
Pseudotime trajectories reveal a progressive increase in mapk6/mapk11 along myeloid lineages, aligning with the initiation and propagation of the splenic antimicrobial response.

Context and Limitations

Any broader translational implications would require further investigation as not reported here.

The work presents a genome-to-single-cell view of MAPK organization and function in bighead carp, highlighting mapk6 and mapk11 as potential mediators of the early spleen response to bacterial infection.
The source explicitly confines conclusions to the observed transcriptional and cellular changes; it does not provide clinical diagnoses, treatment guidance, or numeric outcomes.