Acclimation of Pacific White Shrimp Litopenaeus vannamei to Low-Salinity Aquaculture

M.S. University of Hawaii at Manoa 2016.Includes bibliographical references.Pacific White Shrimp (Litopenaeus vannamei) has been developed for intensive breeding and rearing techniques, and is the globally commercially cultured shrimp species. A process for rearing healthy and viable stocks, capable of thriving in low- salinity grow-out systems furthers the development of intensive production of L.vannamei in the shrimp industry. This research investigated the development of an integrated model to improve health and survival of L.vannamei postlarvae during acclimation to a low-salinity environment by considering four factors, acclimation rate, salinity end-point, ionic and probiotic enhancements. The results showed survival was over 90% with a salinity end-point of 2 ppt at both 2 and 4 day rates. At 0 ppt salinity end-point, survival was 74.4% at 4 days, and 22.2% at 2 days. Probiotic and ionic enhancements did not improve over the non-enhanced, except at the higher 2 ppt salinity end-point at the 4 day rate, indicating potential for long-term benefits

Use of Microalgae-Derived Astaxanthin to Improve Cytoprotective Capacity in the Ileum of Heat-Induced Oxidative Stressed Broilers

The gastrointestinal tract has a pivotal role in nutrient absorption, immune function, and overall homeostasis. The ileum segment of the small intestine plays respective roles in nutrient breakdown and absorption. The purpose of this study was to investigate the impact of heat-induced oxidative stress and the potential mitigating effects of an astaxanthin antioxidant treatment on the ileum of broilers. By comparing the growth performance and gene expression profiles among three groups—thermal neutral, heat stress, and heat stress with astaxanthin—thermal neutral temperature conditions of 21–22 °C and heat stress temperature of 32–35 °C, this research aims to elucidate the role of astaxanthin in supporting homeostasis and cellular protection in the ileum. Results showed both treatments under heat stress experienced reduced growth performance, while the group treated with astaxanthin showed a slightly lesser decline. Results further showed the astaxanthin treatment group significantly upregulated in the cytoprotective gene expression for HSF2, SOD2, GPX3, and TXN, as well as the upregulation of epithelial integrity genes LOX, CLDN1, and MUC2. In conclusion, our experimental findings demonstrate upregulation of cytoprotective and epithelial integrity genes, suggesting astaxanthin may effectively enhance the cellular response to heat stress to mitigate oxidative damage and contribute to cytoprotective capacity

SARS-CoV-2 Non-structural protein 1(NSP1) mutation virulence and natural selection: Evolutionary trends in the six continents

Objective: Rapid transmission and reproduction of RNA viruses prepare conducive conditions to have a high rate of mutations in their genetic sequence. The viral mutations make adapt the severe acute respiratory syndrome coronavirus 2 in the host environment and help the evolution of the virus then also caused a high mortality rate by the virus that threatens worldwide health. Mutations and adaptation help the virus to escape confrontations that are done against it. Methods: In the present study, we analyzed 6,510,947 sequences of non-structural protein 1 as one of the conserved regions of the virus to find out frequent mutations and substitute amino acids in comparison with the wild type. NSP1 mutations rate divided into continents were different. Results: Based on this continental categorization, E87D in global vision and also in Europe notably increased. The E87D mutation has signed up to January 2022 as the first frequent mutation observed. The remarkable mutations, H110Y and R24C have the second and third frequencies, respectively. Conclusion: According to the important role of non-structural protein 1 on the host mRNA translation, developing drug design against the protein could be so hopeful to find more effective ways the control and then treatment of the global pandemic coronavirus disease 2019