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Ovine Brucellosis, caused by Brucella ovis bacteria, is a pathognomonic reproductive infectious disease of sheep that causes epididymitis in rams (male sheep) and placental inflammation in ewes (female sheep) leading to reduced fertility. The specific molecular process that causes alterations in genome of sheep during brucellosis is not yet fully understood. This study aimed to identify key host genes associated with the pathogenesis of ovine brucellosis caused by B. ovis. The GSE35614 dataset containing six healthy and six Brucella ovis infected sample of rams in the chronic phase 2 was obtained from the NCBI GEO database to examine and detect any differences in gene expression (DEGs). Functional and pathway enrichment analyse of the DEGs were performed along with the construction of protein-protein interaction network. Next, functional modules and hub genes were clustered and identified respectively, using the MCODE plugin. As a result, a total of 316 differentially expresses genes were filtered according to the provided cut-off criteria. The enriched DEGs were related to extracellular matrix interaction, cell adhesion mediated by integrin, angiogenesis, and inflammatory response. Furthermore, the hub gene analysis resulted in five hub genes namely, FN1, FBN1, CDH1, CD44, and SPP1, were up-regulated during the infection which could lead to reproductive disorders in sheep. In conclusion, the DEGs, functional and pathways terms, along with hub genes identified in the current study can provide prospective targets for the early diagnosis and treatment of brucellosis and provide insight into the molecular mechanism underlying the alterations that occur during brucellosis in sheep.

Background and Aim: Pestivirus, a genus of the Flaviviridae family, comprises viruses that affect bovines, sheep, and pigs. Symptoms, including hemorrhagic syndromes, abortion, respiratory complications, and deadly mucosal diseases, are produced in infected animals, which cause huge economic losses to the farmers. Bovine viral diarrhea virus-1, bovine viral diarrhea virus-2, classical swine fever virus, border disease virus, Bungowannah, Hobi-like, and atypical porcine pestivirus belonging to the Pestivirus genus were selected for the study. This study aimed to estimate the codon usage bias and the rate of evolution using the glycoprotein E2 gene. Furthermore, codon usage bias analysis was performed using publicly available nucleotide sequences of the E2 gene of all seven Pestiviruses. These nucleotide sequences might elucidate the disease epidemiology and facilitate the development of designing better vaccines. Materials and Methods: Coding sequences of the E2 gene of Pestiviruses A (n = 89), B (n = 60), C (n = 75), D (n = 10), F (n = 07), H (n = 52), and K (n = 85) were included in this study. They were analyzed using different methods to estimate the codon usage bias and evolution. In addition, the maximum likelihood and Bayesian methodologies were employed to analyze a molecular dataset of seven Pestiviruses using a complete E2 gene region. Results: The combined analysis of codon usage bias and evolutionary rate analysis revealed that the Pestiviruses A, B, C, D, F, H, and K have a codon usage bias in which mutation and natural selection have played vital roles. Furthermore, while the effective number of codons values revealed a moderate bias, neutrality plots indicated the natural selection in A, B, F, and H Pestiviruses and mutational pressure in C, D, and K Pestiviruses. The correspondence analysis revealed that axis-1 significantly contributes to the synonymous codon usage pattern. In this study, the evolutionary rate of Pestiviruses B, H, and K was very high. The most recent common ancestors of all Pestivirus lineages are 1997, 1975, 1946, 1990, 2004, 1990, and 1990 for Pestiviruses A, B, C, D, F, H, and K, respectively. This study confirms that both mutational pressure and natural selection have played a significant role in codon usage bias and evolutionary studies. Conclusion: This study provides insight into the codon usage bias and evolutionary lineages of pestiviruses. It is arguably the first report of such kind. The information provided by the study can be further used to elucidate the respective host adaptation strategies of the viruses. In turn, this information helps study the epidemiology and control methods of pestiviruses.

Background and Aim: Classical swine fever (CSF), caused by CSF virus (CSFV), is a highly contagious disease in pigs causing 100% mortality in susceptible adult pigs and piglets. High mortality rate in pigs causes huge economic loss to pig farmers. CSFV has a positive-sense RNA genome of 12.3 kb in length flanked by untranslated regions at 5' and 3' end. The genome codes for a large polyprotein of 3900 amino acids coding for 11 viral proteins. The 1300 codons in the polyprotein are coded by different combinations of three nucleotides which help the infectious agent to evolve itself and adapt to the host environment. This study performed and employed various methods/techniques to estimate the changes occurring in the process of CSFV evolution by analyzing the codon usage pattern. Materials and Methods: The evolution of viruses is widely studied by analyzing their nucleotides and coding regions/ codons using various methods. A total of 115 complete coding regions of CSFVs including one complete genome from our laboratory (MH734359) were included in this study and analysis was carried out using various methods in estimating codon usage bias and evolution. This study elaborates on the factors that influence the codon usage pattern. Results: The effective number of codons (ENC) and relative synonymous codon usage showed the presence of codon usage bias. The mononucleotide (A) has a higher frequency compared to the other mononucleotides (G, C, and T). The dinucleotides CG and CC are underrepresented and overrepresented. The codons CGT was underrepresented and AGG was overrepresented. The codon adaptation index value of 0.71 was obtained indicating that there is a similarity in the codon usage bias. The principal component analysis, ENC-plot, Neutrality plot, and Parity Rule 2 plot produced in this article indicate that the CSFV is influenced by the codon usage bias. The mutational pressure and natural selection are the important factors that influence the codon usage bias. Conclusion: The study provides useful information on the codon usage analysis of CSFV and may be utilized to understand the host adaptation to virus environment and its evolution. Further, such findings help in new gene discovery, design of primers/probes, design of transgenes, determination of the origin of species, prediction of gene expression level, and gene function of CSFV. To the best of our knowledge, this is the first study on codon usage bias involving such a large number of complete CSFVs including one sequence of CSFV from India.

Outbreaks of very high pathogenic avian influenza (H5N1) viruses are being reported in poultry in almost all countries including Asia. It has been reported that the spread is very fast and found that this virus is spreading in avian species for several years. In this study, the evidence of positive selection prominent to mutations were analyzed for the Hemagglutinin (HA) and Neuraminidase (NA) nucleotide sequences of H5N1 avian influenza from chicken, duck, and goose across Asia. H5N1 avian influenza viruses are being a severe risk to public health. Detection of positive selection sites in Hemagglutinin (HA) and Neuraminidase (NA) genes will help to trace the evolutionary path of these viruses from different poultry hosts. The positive/ diversifying selection (dN/dS (ω) >1) was found to be showing significant signals in the mutation of HA and NA genes and is evolving rapidly. The cumulative dN/dS (ω) ratio was found ranging from 0.21 to 0.23 in the HA gene and 0.16 to 0.25 in the NA gene of Avian Influenza Virus from chicken, duck, and goose. Furthermore, statistical Bayesian model methods were applied to interpret the genetic diversity of H5N1 strain, the evolutionary rates were ranging from 2.36x10-3 to 5.19x10-3 in the HA gene and 2.28x10-3 to 6.25x10-3 in the NA gene from chicken, duck, and goose respectively, which revealed a rapid evolution in these viruses with respect to their genetic ancestor. Substitution rates and selection pressure in these three different hosts indicate that their dynamics of mutation and replication remain similar among the species studied and are important for evolution.