The assembly was constructed by integrating long-read sequencing data from PacBio HiFi reads with Hi-C scaffolding techniques. This methodological approach allowed the researchers to anchor the genetic sequences onto larger chromosomal structures. The final assembly size is approximately 1.91 gigabases, with a scaffold N50 of 63.2 megabases, indicating a high level of contiguity. Quality assessments using the BUSCO benchmarking tool recovered 98.2% of complete metazoan single-copy orthologs, suggesting that the assembly is both complete and accurate for comparative genomic studies.

A key feature of the assembly is its organization into 31 pseudochromosomes. Using Hi-C data, 99.92% of the total assembly length was successfully anchored onto these chromosomal structures. This high percentage of anchored data provides a reliable framework for analyzing the physical arrangement of genes and regulatory elements. The resolution of the assembly allows for precise mapping of genomic features, which is essential for understanding the structural organization of the genome in this gastropod species.

Phylogenetic analyses were conducted to clarify the evolutionary position of the white jade snail relative to other giant African snails. By examining single-copy nuclear orthologues and complete mitochondrial genomes, the researchers determined that the white jade snail shares a closer genetic relationship with wild A. fulica than with Achatina immaculata. This finding supports the classification of the white jade snail as a domesticated or farmed variant of A. fulica rather than a distinct species. The phylogenetic results help to contextualize the genetic differences observed between the farmed and wild populations within the broader framework of their shared ancestry.

Genome-wide synteny analyses revealed a largely conserved chromosomal correspondence between the farmed white jade snail and wild A. fulica. The study found near one-to-one collinearity across most chromosomes, indicating that the overall structural architecture of the genome has remained stable despite the process of farming. However, the researchers did detect several localized structural variations. These variations, while limited in scope, suggest that specific regions of the genome may have undergone changes that could be associated with the selection pressures experienced during farming. The conservation of synteny provides a stable baseline against which functional differences can be compared.

Comparative gene family analyses indicated potential functional divergence between the two populations at both the gene and pathway levels. In the white jade snail, candidate functional shifts were primarily associated with processes related to detoxification, molecular transport, metabolism, and pigmentation. These pathways are often linked to adaptation to controlled environments and dietary changes, which are common in farmed organisms. The enrichment of these functions suggests that the white jade snail may have undergone genetic changes that support its survival and growth in captivity, potentially influencing traits such as growth rate and coloration.

In contrast, wild A. fulica showed an enrichment of functions related to environmental responsiveness, signaling, and immune-associated processes. This pattern is consistent with the challenges faced by wild populations, which must constantly adapt to variable environmental conditions and pathogen exposure. The difference in enrichment patterns highlights the distinct selective pressures acting on farmed versus wild snails. While the farmed strain may have reduced the need for robust immune responses due to controlled conditions, the wild population retains a genomic profile geared toward survival in a complex and often hostile natural environment.

Despite the differences in functional enrichment, the study noted that gene families associated with environmental responsiveness and immunity were broadly retained in the white jade snail. This retention suggests that the farmed population has not lost the genetic capacity to respond to environmental stressors or pathogens, even if the expression or regulation of these genes may differ from that of the wild population. The preservation of these gene families indicates a degree of genomic stability and suggests that the white jade snail retains a baseline level of physiological resilience. This finding is important for understanding the long-term sustainability of farming practices and the potential for the farmed strain to adapt to new challenges.

The chromosome-level genome of the white jade snail serves as a valuable resource for future comparative genomics studies. It provides a detailed reference for investigating the candidate genomic basis underlying farming-associated traits. By comparing the farmed genome with that of wild A. fulica and other related species, researchers can identify specific genetic variants that contribute to domestication and adaptation. This resource will facilitate studies on the molecular mechanisms of growth, metabolism, and stress response in gastropods. The availability of this high-quality assembly will likely accelerate research into the biology of Achatina species and their management in agricultural and experimental settings.

Subject of Research: Genomics

Article Title: Chromosome-level genome of the white jade snail reveals conserved genomic architecture and functional divergence relative to wild Achatina fulica

Article References: Liu, H., Niu, Y., Li, S., Fang, Y., & Li, G. (2026). Chromosome-level genome of the white jade snail reveals conserved genomic architecture and functional divergence relative to wild Achatina fulica. BMC Genomics. https://doi.org/10.1186/s12864-026-13355-w

Image Credits: AI Generated

DOI: 10.1186/s12864-026-13355-w

Keywords: Genomics, Achatina fulica, Comparative Genomics, Gastropods, Genome Assembly, Chromosome-level, genome, white, jade, snail, reveals, conserved