Linghong Zhu

The Chinese giant salamander (CGS, Andrias davidianus) is an endangered aquatic amphibian in China. Using environmental DNA (eDNA), this study aimed to monitor the spatial distribution of this species in Zhejiang Province, providing a scientific basis for species assessment, evaluation of reintroduction effectiveness, and non-invasive monitoring. Based on historical records of species presence, 18 representative water localities were selected for sampling. Among these localities, eDNA signals of the CGS were detected at nine. After excluding sampling sites affected by historical CGS releases and surrounding breeding farms, Jinzi Peak and Huyuan were inferred as candidate potentially natural stream habitats within the province. Additionally, eDNA monitoring was conducted at two release sites, Gutian Mountain and Banshanyuan, for two consecutive years. Results revealed lower detection rates in both areas in the second year of monitoring, potentially attributed to low survival rates, dispersal and disappearance, or sampling variability. A principal component analysis (PCA) of water quality factors (including parameters such as NH₃-N, TN, TP, COD) revealed distinct geographic clustering of CGS-positive and CGS-negative sampling sites that corresponded to their separation in topographic space, suggesting that the measured physicochemical conditions may be associated with the CGS eDNA detection probability. This study demonstrates that eDNA is a feasible and efficient method for surveying CGS in Zhejiang Province. Further, it provides an efficient non-invasive monitoring approach for endangered amphibians, with broad application prospects.

Background/Objectives: BABY BOOM (BBM), a transcription factor from the APETALA2 (AP2) protein family, plays a critical role in somatic embryo induction and apomixis. BBM has now been widely applied to induce apomixis or enhance plant transformation and regeneration efficiency through overexpression or ectopic expression. However, the structural and functional evolutionary history of BBM genes in plants is still not well understood. Methods: The protein sequences of 10 selected plant species were used to locate the branch of BBM-Like by key domain identification and phylogenetic tree construction. The identified BBML genes were used for further conserved motif identification, gene structural analysis, miRNA binding site prediction, cis-acting element prediction, collinear analysis, protein–protein interaction network construction, three-dimensional structure modeling, molecular docking, and expression pattern analysis. Results: A total of 24 BBML proteins were identified from 10 representative plant species. Phylogenetic relationship analysis displayed that BBML proteins from eudicots and monocots were divided into two clusters, with monocots exhibiting a higher number of BBMLs. Gene duplication events indicated that whole genome/segmental duplication were the primary drivers of BBML genes’ evolution in the tested species, with purifying selection playing a key role during evolution processes. Comparative analysis of motif, domains, and gene structures revealed that most BBMLs were highly evolutionarily conserved. The expression patterns of BBML genes revealed significant tissue specificity, particularly in the root and embryo. We also constructed protein–protein interaction networks and molecular docking models to identify functional pathways and key amino acid residues of BBML proteins. The functions of BBMLs may differ between monocots and eudicots, as suggested by the functional enrichment of interacting proteins. Conclusions: Our research delved into the molecular mechanism, evolutionary relationships, functional differentiation, and expression patterns of BBML genes across plants, laying the groundwork for further investigations into the molecular properties and biological roles of BBMLs.