Jul 2026· Comparative Biochemistry and Physiology - Part D:Genomics and Proteomics· Vol 60, pp.
101948
· 0 citations· 73 references
Medicine
TL;DR
The genetic mechanisms of salinity tolerance in grass carp are revealed, which might be optimized through genomic selection, and provides insights for selectively breeding new varieties with greater salinity tolerance.
Abstract
Grass carp (Ctenopharyngodon idella) is one of the most widely cultured freshwater fish species globally. However, the expansion of its farming scale faces severe limitation owing to freshwater scarcity; therefore, the development of strains with greater salinity tolerance is key for expanding production using brackish water resources. To investigate the genetic basis of salinity tolerance in grass carp, a genome-wide association study (GWAS) was conducted using 200 individuals representing extreme phenotypes, namely salinity-tolerant and salinity-sensitive groups. In total, 17 single nucleotide polymorphisms (SNPs) related to salinity tolerance were detected, which were distributed across 11 chromosomes. Through gene annotation, 38 candidate genes were obtained from these loci. Enrichment analysis revealed these candidate genes are primarily implicated in key biological processes, including osmotic regulation, energy metabolism, and stress responses. Analyses of different SNP densities revealed that the 5 K SNP density panel can balance prediction accuracy and computational efficiency. The BayesA model achieved the highest prediction accuracy under the GWAS_Evenly selection strategy, with substantial reductions in mean absolute error and mean square error. This study reveals the genetic mechanisms of salinity tolerance in grass carp, which might be optimized through genomic selection, and provides insights for selectively breeding new varieties with greater salinity tolerance.
Moruga Hill Rice (MHR) is an African rice (Oryza glaberrima Steud.) brought to Trinidad by formerly enslaved African Americans and has been grown for many generations in Trinidad at subsistence and commercial scale. Despite its historical and agricultural significance, genomic resources specific to MHR remain unexplored, and its genetic composition, evolutionary history, and potential agronomic traits have not been characterized. This current study presents the first draft genome assembly of the MHR genome using a hybrid sequencing approach. The MHR genome size was found to be ~372.9 Mb with 56,073 predicted genes. Variant analysis revealed a total of 3,318,242 variants, of which 2,440,476 were SNPs, and 877,766 were InDels. Several candidate genes encoding proteins with orthology to previously characterized biotic resistance and abiotic stress-responsive genes in rice were identified. Potential gene families identified prompt further investigation of their roles in MHR drought and salt stress responses. Phylogenomic analysis of O. glaberrima landraces suggests that MHR shares close genetic affinity with the IRGC−104595 Malian landrace, consistent with historical records. This assembly thus expands the African rice genomic repository, providing a foundation to understand the genetic architecture underlying key phenotypic traits and identifying potential novel gene sources in MHR for rice improvement in the Caribbean region.
Uddesh M. Sahadeo, Omar Ali, A. Ramsubhag et al.· BioTech· 0 citations
The swimming crab (Portunus trituberculatus) is a commercially important marine aquaculture species. After multiple generations of selective breeding, the third improved variety in China, “Huangxuan No 2” (HX2), was successfully developed in 2018. Compared to the original wild populations, HX2 exhibits enhanced resistance to low salinity stress and growth RATE. However, the genomic characteristics underlying these selected traits remain largely unexplored. To investigate the genetic variation associated with artificial selection, we genotyped 90 individuals from the HX2 strain and two wild populations (C and D) using a high-density SNP array. A total of 43,314 single nucleotide polymorphisms (SNPs) were identified, which were evenly distributed across the genome in 1 Mb windows. Genetic diversity analysis showed that HX2 and wild populations were similar but overall low in diversity levels. Population structure analysis and fixation index (Fst) values revealed low-to-moderate genetic differentiation between HX2 and the wild populations, whereas no differentiation was observed between the two wild populations. Using the wild populations as a reference, we identified 24 genomic regions under potential selection in HX2 based on the Fst between populations and the nucleotide diversity ratio (π-ratio), encompassing 425 candidate genes. Enrichment analysis indicated that these genes are primarily involved in pathways related to immune response, infection, signal transduction, and metabolism. Notably, genes associated with stress tolerance (e.g., GPX3, HMGCS1, Duox), immunity (e.g., LAMB1, HSPG2), and growth (e.g., Cht5) were identified. These findings provide valuable insights into the genomic signatures of artificial selection and offer fundamental resources for further genetic improvement of P. trituberculatus.
This comprehensive review demonstrates that shifting from reactive field evaluation to marker-driven, genomics-assisted precision design provides the definitive molecular framework required to engineer high-yielding, climate-resilient, and disease-proof cacao cultivars, thereby permanently safeguarding the long-term economic sustainability of global cocoa supply chains.
Atharva Gangurde, Adesina Christiana, Franc Olivier Nzogang· International Journal of Inn...· 0 citations
Salinity is an important environmental factor affecting the physiological homeostasis of freshwater fish, yet the underlying mechanisms in grass carp (Ctenopharyngodon idella) gills remain unclear. Therefore, grass carp were exposed to different salinity levels for 60 days, and gill responses were evaluated using histopathological, ion regulatory, antioxidant, transcriptomic, and metabolomic analyses. Histological observations showed that high salinity (8 g/L) caused marked structural damage to the gill lamellae. Specifically, Na+ and Ca2+ concentrations and Na+/K+-ATPase activity significantly decreased, while K+ concentration and Ca2+-ATPase activity increased, revealing disrupted ion homeostasis. Salinity exposure also led to decreased antioxidant enzyme activities. Integrated omics analysis further demonstrated that a total of 2447 differentially expressed genes and 268 differentially expressed metabolites were identified, with significant enrichment in pathways related to biosynthesis of amino acids, arachidonic acid metabolism, glutathione metabolism, PPAR signaling, and calcium signaling. Notably, the PPAR and calcium signaling pathways showed positive enrichment under salinity stress, suggesting their potential involvement in the regulation of lipid metabolism, energy allocation, and cellular stress responses. Our findings indicated amino acid biosynthesis and arachidonic acid metabolism as key pathways involved in the adaptation of grass carp gills to salinity stress. Overall, chronic salinity exposure caused structural alterations, disrupted ion regulation, altered antioxidant status, and marked transcriptomic and metabolomic changes in grass carp gills, offering new insight into salinity adaptation in freshwater fish.
Net form net blotch (NFNB), caused by
Pyrenophora teres
f.
teres
(
Ptt
), is a major constraint to barley production. However, the genetic basis of adult plant resistance (APR) and seedling resistance remains incompletely understood. This study aimed to dissect the genetic architecture of NFNB resistance in a diverse panel of 273 spring barley accessions.
APR was evaluated in two contrasting field environments in Kazakhstan, whereas seedling resistance was assessed under greenhouse conditions using two
Ptt
races. Genotyping with the 50K SNP array yielded 31,834 high-quality SNPs. Genome-wide association analyses were performed using four models – MLM, MLMM, FarmCPU, and BLINK – that accounted for population structure and kinship. Candidate genes within QTL intervals were prioritized using transcriptomic data from 16 barley tissues and co-expression network analysis.
Substantial phenotypic variation was observed, with moderate heritability for APR (
h
2
= 50.6%) and seedling resistance (
h
2
= 41.3%), together with strong genotype × environment and genotype × race interactions. In total, 275 marker–trait associations were detected for APR and 48 for seedling resistance. These associations were consolidated into 57 genome-wide significant (P < 1.57E–6) or multi-model-supported QTLs across all seven barley chromosomes, including 39 APR and 18 seedling-resistance QTLs. Forty QTLs co-localized with known resistance genes (
Rpt1
,
Rpt2
,
Rpt3
,
Rpt4
,
Rpt6
,
Rpt8
,
Rpt9
, and
SPN1
) or previously reported net blotch QTLs, whereas 17 were potentially novel. Transcriptomic integration identified 87 highly expressed genes within APR QTL regions and 42 within seedling-resistance QTLs. The potentially novel QTLs
Q_NB_1H.6
,
Q_NB_2H.3
, and
Q_NB_3H.1
harbored genes encoding proteins previously associated with pathogen resistance and stress responses. Co-expression analysis revealed stage-specific transcriptional patterns, with APR-associated genes enriched in regulatory functions and seedling-resistance genes enriched in metabolic and structural functions.
The results demonstrate that NFNB resistance is polygenic and developmentally stage-dependent, with partly distinct mechanisms underlying adult plant and seedling resistance. The identified QTLs and prioritized candidate genes provide targets for independent validation, functional characterization, and the development of molecular markers to support breeding for durable NFNB resistance in barley.
Y. Genievskaya, A. Maulenbay, A. Zatybekov et al.· Frontiers in Agronomy· 0 citations
Simple Summary To elucidate the poorly understood adaptive mechanisms of Aspiorhynchus laticeps, a critically endangered fish endemic to Xinjiang’s Tarim Basin, under extreme aquatic stress, this study aimed to unravel the evolutionary adaptation patterns of plateau freshwater fish to environmental pressures. By integrating ecological experiments with transcriptome sequencing, we exposed A. laticeps to varied salinity–alkalinity and flow regimes for comparative analysis. We identified 1847 differentially expressed genes that were significantly enriched in TNF/NF-κB immune signaling and metabolic pathways. Experimental evidence confirmed that high saline–alkali stress activates these pathways and modulates target genes to enhance stress tolerance, whereas flow fluctuations regulate energy metabolism through distinct functional genes. This research provides molecular insights for artificial habitat regulation and population conservation of A. laticeps in the Tarim River, and offers a scientific foundation for endangered fish protection, germplasm improvement, and ecological rehabilitation in arid alpine zones. Abstract To understand the adaptive evolution of endangered plateau freshwater fishes to environmental stress and to better explore the underlying mechanisms in Aspiorhynchus laticeps—a critically endangered fish endemic to the Tarim Basin, Xinjiang, China—a combination of ecological experiments and transcriptome sequencing (RNA-seq) technology was used to study the differences in gene expression patterns among individuals under different salinities and flow conditions. This experiment included four treatment groups (CON, H-SA-S, L-SA, L-SA-S). A. laticeps specimens with an average weight of 2.92 ± 0.62 g and a body length of 58.22 ± 5.10 mm were selected, with three biological replicates for a 96 h combined stress treatment. Moreover, the relationships between these differences and the aquatic environment were analyzed. A total of 1847 differentially expressed genes (DEGs), including 935 upregulated genes and 912 downregulated genes, were identified under different aquatic environment stress modes. GO and KEGG enrichment analyses revealed that TNF signal transduction, the NF-κB pathway, and metabolic regulation were significantly enriched among the DEGs (p < 0.05). High salinity–alkali stress significantly activates the TNF/NF-κB pathway, regulates MST1, LOC107702867, LOC113110979 and other genes to enhance the body’s resistance; water flow changes mainly regulate energy metabolism through genes such as NEHOM01_1600 and gptl. These findings provide an important scientific basis for the ecological adaptability, protection, and proliferation of endemic and endangered fish in China, as well as for germplasm innovation to address ecological deterioration in plateau fishes in alpine and arid areas. This study provides a molecular-level theoretical foundation for artificial habitat regulation and the conservation of endangered Aspiorhynchus laticeps populations in the Tarim River.
Huanhuan Wang, Liting Yang, Changcai Liu et al.· Animals· 0 citations