Journal of experimental zoology. Part A, Ecological and integrative physiology最新文献

Parkinson's disease (PD) is the second most common neurodegenerative disorder, marked by oxidative damage to dopaminergic neurons in the substantia nigra, resulting in motor and non-motor symptoms. Antioxidant supplements have emerged as a potential therapeutic strategy, particularly for forms unresponsive to Levodopa. Due to the limitations of human studies, animal models, especially Drosophila, have been widely used to investigate sporadic and familial PD. This systematic review and meta-analysis aimed to evaluate the effectiveness of antioxidants in mitigating PD symptoms. We searched PubMed, Web of Science, and Google Scholar for studies published between 2000 and December 4, 2024, excluding reviews and irrelevant models or diseases. Methodological quality was assessed using the SYRCLE tool, and 82 studies met the inclusion criteria. A random-effects model was applied using MetaEasy. Antioxidants such as terpenoids (effect size = 3.23), flavonoids (1.68), plant extracts (2.95), and others like vitamin C, melatonin, and Gastrodin (3.61) significantly improved PD outcomes. However, high heterogeneity across studies persisted. This variability may reflect differences in study design and execution. This heterogeneity may arise due to the methodological variations across studies. Our meta-analysis highlighted the potential role of antioxidants in managing PD referring to key considerations for future research in this area.

Artificial light at night (LAN) is expanding globally, changing the natural landscape and imposing novel ecological pressures on wildlife. Birds, like most organisms, use natural light information to regulate their daily and seasonal behaviors, including the precise timing for migration and reproduction. The presence of LAN has, however, blurred the day-night boundaries thereby leading to misinterpretation and physiological and behavioral desynchronization. This review synthesizes current knowledge of how LAN affects migratory birds, with a focus on their orientation and navigation, attraction to urban centers, increased risks of collisions, altered nocturnal predator-prey dynamics, disrupted foraging behavior, and interference with hormonal rhythms that are critical for migratory preparedness. In addition to highlighting these direct and indirect ecological consequences, we critically examined the existing mitigation strategies aimed at reducing the impact of LAN. With this, we have identified that while a few research focus on understanding LAN effects and its mitigation methods, there is a significant knowledge gap in understanding its mechanistic pathways and long-term fitness consequences for migratory birds. Furthermore, the body of applied knowledge available to mitigate LAN effects is still very limited. We conclude by identifying and discussing several key areas for future work.

The muskrat (Ondatra zibethicus) is a small, semi-aquatic rodent notable for its scent glands, which secrete a substance containing muscone. Melatonin (MLT) has been demonstrated to reduce oxidative stress, inflammation, and apoptosis. However, its role in the development of muskrat scent glands remains unclear. This study investigated the effects of 20 mg MLT on the scent glands of muskrat. The results showed that administration of 20 mg MLT resulted in polarized changes in gland weight: some individuals (M-A group) exhibited a decrease in gland weight, while others (group M-B) showed an increase. We observed that MLT treatment significantly upregulated the mRNA levels of PI3K, Bcl-2, and JNK in the scent glands of the M-A group. However, MLT did not demonstrate significant activation of the downstream signaling pathways of PI3K (Akt, p21, CDK1, and Cyclin B1), mitochondrial apoptosis markers (Bax, Caspase9, CytC), or the FGF 20-H-Ras-MAPK 1 signaling axis. Our findings provide preliminary insights into the impact of MLT on the development and secretion of scent in muskrat, offering important reference points for future related research.

The serine/threonine phosphatase PP1γ2 plays a critical role in modulating epididymal sperm maturation and motility. Our previous work demonstrated that PP1γ2 regulates these processes in tree shrews via phosphorylation and dephosphorylation. This study further investigates the interactions among PP1γ2, SRC tyrosine kinase, and protein kinase A (PKA), along with their molecular mechanisms in regulating epididymal sperm motility in tree shrews.Using Western blotting, immunokinase assays, co-immunoprecipitation, and Ser/Thr phosphatase activity assays, we characterized key signaling dynamics. Results showed that Ser/Thr phosphatase activity was significantly higher in caput than in cauda epididymal spermatozoa (p < 0.05). Inhibiting PKA and SRC significantly increased Ser/Thr phosphatase activity and reduced cauda sperm motility (p < 0.05). Conversely, SRC activation with sc-3052 significantly reduced phosphatase activity in caput sperm (p < 0.05). We also found that SRC interacts with PP1γ2 in caudal sperm, and that both SRC and PKA activities were higher in caudal than in caput sperm, with SRC acting downstream of PKA. These results suggest that SRC kinase regulates sperm motility by inhibiting PP1γ2-mediated Ser/Thr phosphatase activity, under the regulatory control of PKA. This study provides a foundation for further investigation into PP1γ2's functions and reproductive regulatory mechanisms in tree shrew sperm.

Infectious diseases represent a major threat to the survival of endangered sea turtles. The immune response in these animals is configured early in development and is heavily influenced by the incubation environment. While maternal traits are known to influence offspring immune function in some reptiles, their role in shaping immune responses in sea turtle hatchlings remains poorly understood. The hemolytic capacity, a key component of the innate immune system, shows stability across incubation environments, suggesting that it might be shaped by maternal factors rather than by environmental variation. Herein, the relationship between the hemolytic capacity of hatchlings challenged with lipopolysaccharide (LPS) and maternal characteristics, including hemolytic response and body size, was studied. Blood samples and morphologic measurements were collected from nesting females over 2 years. Each clutch was entirely relocated to individual shaded nests for incubation. Upon emergence, one hatchling per nest was injected intraperitoneally with phosphate-buffered saline (PBS) and another hatchling with LPS. 4 h later, hatchlings were euthanized and blood samples were collected. The results showed that hatchling's hemolytic capacity was positively associated with maternal hemolysis and body mass, but negatively linked to maternal straight carapace length. Lipopolysaccharide challenge did not significantly modify the hemolytic capacity of hatchlings. Although based on a limited sample size due to the species’ protected status and technical constraints of ecoimmunological research in wild animals, these findings suggest a possible influence of maternal attributes on offspring immune function. They also suggest that hemolytic capacity is a robust early-life immune defense in hatchlings.

Light is an important factor affecting the behavior and physiology of organisms. As a phototactic organism, studying the effects of different colors of light on the mating, development, and reproduction of Drosophila melanogaster helps elucidate the important influence of spectral sensitivity on organisms. This study explored the effects of white light (400 lux, control), green light (400 lux, wavelength to which fruit flies are most spectrally sensitive), red light (400 lux, wavelength to which fruit flies are least spectrally sensitive), and dim-green light (225 lux, green-band irradiance matched to the white control) on the sexual vitality, development, and reproductive capacity of fruit flies under group-housed conditions. The results revealed that 1 h of green light exposure per day significantly shortened mating latency and mating duration, accelerated pupation time, raised the egg‑to‑pupa conversion rate, and increased the number of offspring. In contrast, there was no significant difference in various indicators between the white, red, and dim-green light groups. This study explored the important role of light intensity and spectral sensitivity in regulating the mating and reproduction processes of fruit flies and provides more evidence for comparative research on the behavioral and physiological effects of light on different organisms.