Regeneration enables the regrowth and restoration of missing body parts. It is a common phenomenon among animals. However, only some species exhibit remarkable regeneration capabilities and can regenerate organs such as limbs, lenses or hearts. Regeneration has been widely studied, thereby giving rise to new fields, such as regenerative medicine. Furthermore, regeneration has the potential to be applied to the human body. However, the molecular mechanisms governing this process should be elucidated first. Recent advancements in research methods have led to the identification of numerous signaling pathways involved in regeneration. One of them, the Wnt transduction pathway, is an ancient and evolutionarily conserved pathway that plays an important role in both embryonic development and regeneration. The Wnt pathway plays an important role during the regeneration process, as it is implicated in cell fate determination, cell migration, cell polarity and adult cell homeostasis. To date, two major Wnt pathways have been identified: the canonical (β-catenin dependent) pathway and the non-canonical pathway. The latter pathway can be further divided into planar cell polarity, the Wnt/Ca2+ pathway and the JNK pathway. In this review, we summarize the current state of knowledge regarding the Wnt signaling pathway and its role in regeneration, with a particular emphasis on key model species.

Twenty-five novel EST-derived simple sequence repeat (EST-SSR) markers were developed in the ark shell Scapharca broughtonii. Polymorphisms of these EST-SSR markers were evaluated in 48 wild individuals collected from Shidao, Shandong Province, China. A total of 202 alleles were detected at 25 loci. The numbers of alleles per locus ranged from 4 to 14, with an average of 8.08. The observed and expected heterozygosities varied from 0.2917 to 1.000 and from 0.3570 to 0.9002, respectively. After sequential Bonferroni correction for multiple tests, only one locus was found to deviate from Hardy-Weinberg equilibrium. Twenty-five EST-SSR markers showed a high rate of across-species transferability (100%) in Scapharca subcrenata and a low rate of across-genus transferability (20%) in Tegillarca granosa. These EST-SSRs will be helpful for QTL mapping, molecular breeding and investigation of population genetic diversity in ark shell S. broughtonii and other Scapharca species.

Macrobenthos is widely used as an indicator of ecological health in marine monitoring and assessment. The present study aimed to characterize the interrelationships between the distribution of the macrobenthos community and environmental factors near Xiaoqing Estuary, Laizhou Bay. Responses of species richness to environmental factors were studied using the generalized additive model (GAM) and the Margalef diversity index (d_M) as indicators of species diversity instead of individual indicator species. Six factors were selected in the optimal model by stepwise regression: sediment factors (organic matter, phosphate, nitrate nitrogen, and ammonium nitrogen) and water factors (salinity, and ammonium nitrogen). The response curves generated by the GAM showed a unimodal relationship among taxa diversity, salinity in water, and sediment organic matter. d_M was positively correlated with ammonium nitrogen in water and was negatively correlated with phosphate in the sediment. The model optimized by forward stepwise optimization explained 92.6% of the Margalef diversity index with a small residual (2.67). The model showed good performance, with the measured d_M strongly correlated with the predicted d_M (Pearson R² = 0.845, p < 0.05). The current study examined the combined influence of multiple eco-factors on macrobenthos, and the Margalef diversity index of macrobenthos was predicted by the GAM model in a salinity-stressed estuary.

In order to examine the seasonal variations in the morphological characteristics and diet of Mactra veneriformis in the Northern Yellow River Delta’s intertidal zone and provide a scientific basis for its resource conservation and population restoration, tested clams were collected in four consecutive seasons from summer of 2022 to spring of 2023. Morphological traits were measured, and the DNA of the stomach contents was analyzed using high-throughput sequencing. The tidal differences and seasonal variations in the northern habitat of the Yellow River Estuary significantly affect the morphological characteristics and growth of M. veneriformis. Among the four seasons, significant differences in the morphological characteristics of M. veneriformis were observed between the middle-tide and low-tide zones (p < 0.05). In both middle-tide and low-tide zones, the morphological characteristics and body wet weight of M. veneriformis in winter were significantly higher than those in other seasons (p < 0.05). Moreover, the morphological characteristics of M. veneriformis were extremely significantly influenced by the interaction between tide and season (two-way interaction, p < 0.001). In all seasons, M. veneriformis in the middle- and low-tide zones exhibited positive allometric growth. While there was no significant difference in the stomach content between the spring and summer samples in the same tidal zone (p > 0.05), there was a significant difference between the middle- and low-tide samples in winter (p < 0.05). This suggests that seasonal variations, rather than tidal differences, had a larger impact on the diet of M. veneriformis in the northern Yellow River estuary and that feeding differences may be related to changes in environmental factors, such as temperature. The findings of this study provide initial insights into the feeding ecology of M. veneriformis and offer a scientific foundation for the conservation and management of its resources.

Natural recruitment of Manila clam (Ruditapes philippinarum) often persists in degraded estuaries, yet the environmental thresholds enabling this resilience remain quantitatively undefined. We employed binomial generalized additive model (GAM) coupled with field surveys (n = 168) in the Xiaoqing River estuary (Laizhou Bay, China) to identify critical limits for adult occurrence, which served as a field-based proxy for recruitment potential. Sediment median grain size (D₅₀), salinity (Sal) and dissolved inorganic nitrogen (DIN) were identified as the key factors, collectively explaining 79.30% of the deviance (AUC = 0.98). The probability of occurrence decreased sharply beyond two distinct thresholds: D₅₀ > 95 μm and salinity < 17.50‰. While DIN had a positive effect, it did not offset the strong negative associations with coarse sediment or low salinity. These field-validated thresholds provide quantifiable criteria to guide habitat suitability mapping, activation of early-warning systems against salinity-driven mortality, and site prioritization for ecological restoration in the Xiaoqing River estuary. Our findings offer a framework for developing management strategies to support clam resilience under environmental stress.