.png){kind=icon}
.png){kind=icon}
Return
Leucine regulates the mTOR pathway to improve growth and enhance immune responses in Scylla paramamosain challenged with Vibrio parahaemolyticus
.png){kind=icon}
OA
AI
X
M
H
T
X
S
W
Y
Y
Z
T
P
J
DOI：10.1016/j.aninu.2026.03.005.png)
.png){kind=icon}
.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
A 63-d feeding trial was performed to determine the effects of varying dietary leucine levels on the growth, protein metabolism, and disease resistance of Scylla paramamosain against Vibrio parahaemolyticus. A total of 360 juvenile crabs (approximately 50 d after metamorphosis from the megalopa stage and having undergone eight molts; initial weight: 8.65 ± 0.58 g) were randomly assigned to six dietary treatments, with 60 crabs per group, each treatment comprising three replicates of 20 crabs each. Each group was fed one of the six isonitrogenous and isolipidic diets, which were formulated to provide graded leucine levels of 1.81% (control), 2.10%, 2.40%, 2.67%, 2.91%, and 3.18%, respectively. The results showed that crabs fed 2.67% leucine exhibited significantly higher percent weight gain, molting frequency, and protein efficiency ratio, together with a lower feed conversion ratio, than those fed 1.81%, 2.10%, or 3.18% leucine (P < 0.05). Muscle and hepatopancreas protein contents were significantly higher in the 2.67% and 2.91% groups than in the 1.81% group (P < 0.05). Dietary leucine also altered the muscle amino acid profile and enhanced hepatopancreatic digestive enzyme activities (P < 0.05). At 2.67%–2.91%, leucine significantly upregulated selected mTOR-related genes and increased TOR and p70S6K1 protein levels (P < 0.05). Following V. parahaemolyticus challenge, the 2.91% group showed the highest survival and lower hemocyte apoptosis (P < 0.05). The overall survival difference showed a tendency (log-rank P = 0.056), whereas Cox regression indicated a reduced mortality risk versus the 1.81% group (P = 0.024). Compared with the control, leucine supplementation significantly enhanced antioxidant capacity and innate immune enzyme activities, accompanied by increased expression of antioxidant, immune, amino acid transporter, mTOR signaling, and inflammatory-response genes (P < 0.05). Based on PWG against dietary leucine levels, the optimal dietary leucine requirement was determined to be 2.70% for mud crab under the present crab-apartment recirculating aquaculture system rearing conditions, whereas dietary 2.91% leucine was associated with a significantly reduced mortality risk during the 48-h V. parahaemolyticus challenge period (Cox model).
Keywords:
Scylla paramamosain
Leucine
Growth
Protein synthesis
Disease resistance
AI Summary
Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.
Journal
IF:
7.5
Papers:
1.1K
Citations:
6.0K
Organization
No organization information available
Cited Papers