A gene integrates the effects of all SNPs in its sequence span, which benefits the genome-wide association study. To explore gene-level variations affecting economic traits in maize, we extended the SNP-based GWAS analysis software Single-RunKing developed by our team to gene-based GWAS, which used the FaST-LMM algorithm to convert the linear mixed model into simple linear model association analysis. An F-test statistic was formulated to test and identify candidate genes. We compared the statistical efficiency of using 80% principal components (EPC), the first principal component (FPC), and all SNP markers (ALLSNP) as independent variables, which predecessors commonly used to integrate SNPs and represent genes. With a Huazhong Agricultural University (HAU) genomic dataset of 2.65M SNPs from 540 maize plants, 34,774 genes were annotated across the whole genome. Genome-wide association studies with 20 agronomic traits were performed using the software developed here. Another maize dataset from the Ames panel (AP) was also analyzed. The EPC method fits the model well and has good statistical efficiency. It not only overcomes the false negative problem when using all SNP markers for analysis (ALLSNP) but also solves the false positive problem of its corresponding simple linear model method EPCLM. Compared with FPC, the EPC method has higher statistical efficiency. A total of 132 quantitative trait genes (QTG) were identified for the 20 traits from HAU maize dataset and one trait of AP maize.
The shape of the skull plays a crucial role in the evolution and adaptation of species to their environments. In the case of aquaculture fish, the size of the head is also an important economic trait, as it is linked to fillet yield and ornamental value. This study applies our GRAMMAR-Lambda method to perform a genome-wide association study analysis on loci related to head size in catfish. Compared with traditional GWAS methods, the GRAMMAR-Lambda method offers higher computational efficiency, statistical power, and stability, especially in complex population structures. This research identifies many candidate genes closely related to cranial morphology in terms of head length, width, and depth in catfish, including bmpr1bb, fgfrl1b, nipbl, foxp2, and pax5, etc. Based on the results of gene–gene interaction analysis, we speculate that there may be frequent genetic interactions between chromosome 19 and chromosome 29 in bone development. Additionally, many candidate genes, gene families, and mechanisms (such as SOCE mechanisms) affecting skeletal development and morphology have been identified. These findings contribute to our understanding of the genetic architecture of head size and will support marker-assisted breeding in aquaculture, also reflecting the potential application of the GRAMMAR-Lambda method in genetic studies of complex traits.
Despite the recognized involvement of TTC39 family genes in metabolism related to pigment deposition, their evolutionary features and potential roles in body coloration in teleost fish remain largely unexplored. We identified three TTC39 genes in Plectropomus leopardus, conserved domains, and evolutionary relationships. The three genes (TTC39A, TTC39B, and TTC39C) were mapped to different chromosomes, yet they shared similar conserved protein domains. Phylogenetic and collinearity analyses indicated that TTC39 genes are evolutionarily conserved among Danio rerio. Gene structure and motif analyses further highlighted the homology and distributional diversity within the TTC39 family. Quantitative expression assays comparing red and black skin revealed significant upregulation of TTC39A and TTC39B in red skin, suggesting that these genes play a role in regulating skin color. These findings provide a foundation for future studies examining how TTC39 genes regulate red skin coloration in P. leopardus.
The velocity of water can cause differences in the growth of inhabitant fish, thereby functioning as an important aquatic environmental factor. In order to explore the response mechanism of Leopard Coralgrouper (Plectropomus leopardus) under different flow velocities, P. leopardus fish of the same sizes were fed in water characterized by three different flow rates (5 cm/s, 10 cm/s, and 20 cm/s) for 150 d, after which the differences in growth and the levels of liver oxidative stress kinase were analyzed. Additionally, potential underlying regulatory pathways were explored using comparative transcriptomic approaches. The results showed that in the feeding environment involving a flow rate of 10 cm/s, the weight increase of P. leopardus and its liver contents of glutathione peroxidase (GPX), alanine aminotransferase (ALT), and superoxide dismutase (T-SOD) were significantly higher than for the other two groups. After matching the comparative transcriptomic results between group pairs (5 cm/s and 10 cm/s, 5 cm/s and 20 cm/s, and 10 cm/s and 20 cm/s), a total of 225 common differential gene expressions were screened. The KEGG pathway enrichment analysis showed that these genes were mainly involved in protein processing in the endoplasmic reticulum, the TGF-β signaling pathway, fatty acid metabolism, fatty acid synthesis, and other pathways. These results not only provide a theoretical basis for the selection of flow velocity in the culture environment of P. leopardus, but also reveal its potential means of adaption to different flow velocities.
The complete mitochondrial genome of Congrogadus subducens is first presented in this study. The whole mitogenome is a closed circular molecule of 16,881 bp in size, including 13 protein-coding, 22 transfer RNA, 2 ribosomal RNA genes and a non-coding control region. The overall base composition of the mitochondrial DNA is 30.2% for A, 28.6% for T, 26.4% for C and 14.8% for G. The phylogenetic analysis conducted using 18 protein-coding genes showed that C. subducens was most closely related to the Pseudochromidae. This work will be useful for further research on species identification and evolutionary relationships within related species.
Glutathione S-transferases (GSTs) constitute a multifunctional enzyme superfamily ubiquitous across diverse organisms, playing crucial roles in detoxification, antioxidant defense, and stress adaptation. Despite extensive studies in plants and mammals, systematic characterization of GSTs in teleosts, particularly in economically and ecologically significant species, remains limited. In this study, we performed a comprehensive genome-wide analysis of the GST gene family in the Plectropomus leopardus, a high-value aquaculture species vulnerable to environmental stressors such as thermal fluctuation. Through integrated bioinformatics approaches, we identified 24 GST genes unevenly distributed across 14 chromosomes, which were phylogenetically classified into 13 distinct subfamilies, with the MAPEG subfamily being the most abundant. Structural analyses revealed considerable diversity in gene architecture and conserved protein motifs, suggesting functional divergence among members. Expression profiling under controlled heat stress demonstrated tissue-specific upregulation of multiple GST genes in both liver and gill tissues, highlighting their active involvement in thermal response mechanisms. Furthermore, collinearity analysis indicated that segmental duplication events have contributed to the expansion of the GST family in P. leopardus, with strong evolutionary conservation observed among related fish species. Our findings not only provide a genomic foundation for understanding GST-mediated stress adaptation in marine teleosts but also offer potential candidate genes for future molecular breeding efforts aimed at enhancing thermotolerance in aquaculture.