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The effect of water temperature on the pathogenicity of decapod iridescent virus 1 (DIV1) in Litopenaeus vannamei
Get PDFDecapod iridescent virus 1 (DIV1) has caused huge losses to the shrimp breeding industry in recent years as a new shrimp virus. In this study, white leg shrimp, Litopenaeus vannamei, were cultured at different temperatures (26 ± 1 °C and 32 ± 1 °C) and the same salinity, then infected with DIV1 by intramuscular injection to determine the effects of water temperature on viral infection. The DIV1 copy counts in the gills, hepatopancreas, pleopods, intestines, and muscles of L. vannamei were measured in samples collected at 6, 12, and 24 h post-infection (hpi), and the survival rate of L. vannamei was assessed every 6 h after infection. At 96 hpi, the survival rates of L. vannamei in the high (32 ± 1 ℃) and standard (26 ± 1 ℃) water temperature groups were 2.22% and 4.44%, respectively. The peak time of mortality in the high-water temperature group was 6 h earlier than in the standard water temperature group. After 24 hours of DIV1 infection, the DIV1 copy counts in the standard water temperature treatment group were significantly higher than those in the high-water temperature treatment group. The tissues with the highest virus copy counts in the standard and high-temperature groups were the intestines (2.9×1011 copies/g) and muscles (7.0×108 copies/g). The effect of temperature on the pathogenicity of DIV1 differs from that of other previously studied viruses, such as white spot syndrome virus, Taura syndrome virus, and infectious hypodermal and hematopoietic necrosis virus, because the high-water temperature did not mitigate the damage caused by DIV1 infection
The Diachrony of hǎa…mây as a Bipartite Negative Construction in Thai
Get PDFThe present study investigates the diachronic development of the bipartite negative construction hǎa…mây in Thai, aiming to account for its syntactic and semantic peculiarity. Based on the historical data from the Sukhothai period to Modern Thai, I suggest that the development of hǎa…mây construction relates to the grammaticalization of the expression hǎa NP míɁ dây ‘fail to find something’. From around the mid-14th century, hǎa NP míɁ dây came to gain a new function as an irregular negative existential construction under the pressure of the recession of the anterior negative existential form bɔ̀ɔ mii ‘not have, not exist’. This function is especially prominent in the 17th century during which the old negator bɔ̀ɔ shows a continuous decrease in the frequency of use and the newer negator mây was not widely used. When the newer negative existential form mây mii emerged around the early 18th century and eventually prevailed over hǎa NP míɁ dây in the 19th and 20th centuries, hǎa NP míɁ dây gradually lost its function as a negative existential form but survived its evolution into a negative adverbial construction through a syntagmatic change (from hǎa NP to hǎa VP), accompanied by a phonetic reduction (from hǎa…míɁ dây to hǎa…mây ) and a semantic reinterpretation(from ‘fail to find something or not exist, not have’ to ‘not VP as one thought’)
Hepatopancreatic transcriptome response of Penaeus vannamei to dietary ulvan
Get PDFThe study aimed to determine the effect of feeding dietary ulvan on some genes and pathways of Penaeus vannamei juveniles. Feeding a diet containing ulvan at 1.0 g·kg-1 resulted in differentially expressed genes (DEGs) between the treatments and the control group. Ulvan resulted in 53 DEGs with 26 up and 27-down-regulated DEGs. The DEGs were immune-related, while several affected the energy and substrate metabolic pathways. Specific genes upregulated were Glycerol-3-phosphate acyltransferase (GPAT) of the glycerolipid synthesis, centrosomal protein 120 involved in cell cycling and other activities, RNA helicase, an enzyme involved in opening up DNA molecules, ATP-binding cassette, TATA-binding protein, taurine transporter, transcriptional enhancer factor (TEF), C-type lectin among others. Down-regulated genes included gamma-crystallin, which acts as molecular chaperones; catenin alpha, which is involved in adhesion complex; dystrophin, which is involved in scaffolding for several signaling molecules; and maintenance muscle integrity, among others. Top DEGs that affected significantly important pathways include TEAD (transcriptional enhancer factor domain), GSK3B (glycogen synthase Kinase 3 beta), SLC6A1 (i.e., solute carrier Family 6 Member 1), and ADCY2, which affected signal transduction, environmental adaptation as well as the endocrine, immune, nervous, and digestive systems. In conclusion, dietary ulvan resulted in the up-regulation of immune-related DEGs, which could probably be used to adapt to unfavorable conditions and also affected some energy and substrate metabolic pathways that could potentially be used to direct the overall metabolism