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The Phan Rang sheep, considered the sole indigenous breed of Vietnam, are primarily concentrated in the two central provinces of Ninh Thuan and Binh Thuan, with Ninh Thuan accounting for more than 90% of the country's sheep population. These provinces are known for their high temperatures and frequent droughts. The long-standing presence of the Phan Rang sheep in these regions suggests their potential resilience to heat stress-a trait of increasing interest in the face of global climate change. Despite the breed's significance, a critical knowledge gap hinders conservation and breeding programs. To address this, our study employed a two-pronged approach. First, we collected body conformational data to aid in breed identification. Second, we analyzed mitochondrial DNA (D-loop) and Y chromosome markers (SRY and SRYM18) to elucidate the maternal and paternal lineages. Among the 68 Phan Rang sheep analyzed for their D-loop, 19 belonged to mitochondrial haplogroup A, while 49 belonged to haplogroup B. The haplogroups can be subdivided into 16 unique haplotypes. All 19 rams surveyed for their paternal lineages belonged to haplotypes H5 and H6. These findings strongly support the hypothesis of dual origins for the Phan Rang sheep. This study presents the first genetic data for the Phan Rang breed, providing crucial insights for future research and conservation efforts.

Chitinases are enzymes that catalyze the degradation of chitin, a major component of the cell walls of pathogenic fungi and cuticles of insects, gaining increasing attention for the control of fungal pathogens and insect pests. Production of recombinant chitinase in a suitable host can result in a more pure product with less processing time and a significantly larger yield than that produced by native microorganisms. The present study aimed to express the synthetic chi42 gene (syncodChi42), which was optimized from the chi42 gene of Trichoderma asperellum SH16, in Escherichia coli to produce 42 kDa chitinase (Ta-CHI42); then determined the activity of this enzyme, characterizations and in vitro antifungal activity as well as its immunogenicity in mice. The results showed that Ta-CHI42 was overexpressed in E. coli. Analysis of the colloidal chitin hydrolytic activity of purified Ta-CHI42 on an agar plate revealed that this enzyme was in a highly active form. This is a neutral chitinase with pH stability in a range of 6-8 and has an optimum temperature of 45°C with thermal stability in a range of 25-35°C. The chitinolytic activity of Ta-CHI42 was almost completely abolished by 5 mM Zn2+ or 1% SDS, whereas it remained about haft under the effect of 1 M urea, 1% Triton X-100 or 5 mM Cu2+. Except for ions such as Mn2+ and Ca2+ at 5 mM that have enhanced chitinolytic activity; 5 mM of Na+, Fe2+ or Mg2+ ions or 1 mM EDTA negatively impacted the enzyme. Ta-CHI42 at 60 U/mL concentration strongly inhibited the growth of the pathogenic fungus Aspergillus niger. Analysis of western blot indicated that the polyclonal antibody against Ta-CHI42 was greatly produced in mice. It can be used to analyze the expression of the syncodChi42 gene in transgenic plants, through immunoblotting assays, for resistance to pathogenic fungi., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: To explore Saccharomyces cerevisiae as an expression platform for dengue oral immune complex vaccine development., Results: Molecular engineering was applied to create a fusion gene construct (scEDIII-PIGS) consisting of a yeast codon optimized sequence encoding for a synthetic consensus dengue envelope domain III (scEDIII) followed by a modified IgG Fc domain (PIGS). Northern blot showed transcription of the target gene, with a temporal expression pattern similar to those from previous work. Western blot showed assembly of various immune complexes from monomer to hexamer. Partial purification of scEDIII-PIGS was also attempted to demonstrate the feasibility of yeast system for immune complex vaccine development. Approximately 1 mg of scEDIII-PIGS can be produced from 1 l culture., Conclusion: This work demonstrated for the first time that various immunocomplex structures of our target protein could be efficiently produced in S. cerevisiae for future application in developing oral and injectable vaccines against various pathogens., (© 2021. The Author(s).)

Background: Dengue is listed as a neglected tropical disease by the Center for Disease Control and Preservation, as there are insufficient integrated surveillance strategies, no effective treatment, and limited licensed vaccines. Consisting of four genetically distinct serotypes, dengue virus (DENV) causes serious life-threatening infections due to its complexity. Antibody-dependent enhancement by pre-existing cross-reactive as well as homotypic antibodies further worsens the clinical symptoms of dengue. Thus, a vaccine conferring simultaneous and durable immunity to each of the four DENV serotypes is essential to restrict its escalation. In deeply affected resource-limited countries, oral vaccination using food-grade organisms is considered to be a beneficial approach in terms of costs, patient comfort, and simple logistics for mass immunization. The current study used a mouse model to explore the immunogenicity of an oral dengue vaccine candidate prepared using whole recombinant yeast cells (WC) and cell-free extracts (CFE) from cells expressing recombinant Escherichia coli heat-labile toxin protein B-subunit (LTB) fused to the consensus dengue envelope domain III (scEDIII). Mice were treated orally with recombinant WC and CFE vaccines in 2-week intervals for 4 weeks and changes in systemic and mucosal immune responses were monitored., Results: Both WC and CFE dosage applications of LTB-scEDIII stimulated a systemic humoral immune response in the form of dengue-specific serum IgG as well as mucosal immune response in the form of secretory sIgA. Antigen-specific B cell responses in isolated lymphoid cells from the spleen and Peyer's patches further indicated an elevated mucosal immune response. Cellular immune response estimated through lymphocyte proliferation assay indicated higher levels in CFE than WC dosage. Furthermore, sera obtained after both oral administrations successfully neutralized DENV-1, whereas CFE formulation only neutralized DENV-2 serotype, two representative serotypes which cause severe dengue infection. Sera from mice that were fed CFE preparations demonstrated markedly higher neutralizing titers compared to those from WC-fed mice. However, WC feeding elicited strong immune responses, which were similar to the levels induced by CFE feeding after intraperitoneal booster with purified scEDIII antigen., Conclusions: CFE preparations of LTB-scEDIII produced strong immunogenicity with low processing requirements, signifying that this fusion protein shows promise as a potent oral vaccine candidate against dengue viral infection.

In this study, we report the manganese peroxidase production ability from a Fusarium sp. strain using an inexpensive medium of agriculture residues of either rice straw or wood chips as carbon source. The highest manganese peroxidase activity on rice straw medium and on wood chips was 1.76 U/mL by day 9 and 1.91 U/mL by day 12, respectively.