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Background Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiologic agent of coronavirus disease 2019 (COVID-19), is rapidly acquiring new mutations. Analysis of these mutations is necessary for gaining knowledge regarding different aspects of therapeutic development. Previously, we have reported a Sanger method-based genome sequence of a viral isolate named SARS-CoV-2 NIB-1, circulating in Bangladesh. The genome has four novel non-synonymous mutations in V121D, V843F, A889V, and G1691C positions. Results Using different computational tools, we have found V121D substitution has the potential to destabilize the non-structural protein-1 (NSP-1). NSP-1 inactivates the type-1 interferon-induced antiviral system. Hence, this mutant could be a basis of attenuated vaccines against SARS-CoV-2. V843F, A889V, and G1691C are all located in nonstructural protein-3 (NSP-3). G1691C can decrease the flexibility of the protein. V843F and A889V might change the binding pattern and efficacy of SARS-CoV-2 papain-like protease (PLPro) inhibitor GRL0617. V843F substitution in PLPro was the most prevalent mutation in the clinical samples. This mutation showed a reduced affinity for interferon-stimulated gene-15 protein (ISG-15) and might have an impact on innate immunity and viral spread. However, V843F+A889V double mutant exhibited the same binding affinity as wild type PLPro. A possible reason behind this phenomenon can be that V843F is a conserved residue of PLPro which damaged the protease structure, but A889V, a less conserved residue, presumably neutralized that damage. Conclusions Mutants of NSP-1 could provide attenuated vaccines against coronavirus. Also, these mutations of PLPro might be targeted to develop better anti-SARS therapeutics. We hope our study will help to get better insides during the development of attenuated vaccine and PLPro inhibitors.

ABSTRACT A coding-complete genome sequence of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolate was revealed. The sample for the virus was isolated from a female patient from Dhaka, Bangladesh, suffering from coronavirus disease-2019 (COVID-19).

The experiment was conducted on 97 breeding bulls at the central cattle breeding and dairy farm, Savar, Dhaka to find out the physical and chemical properties of different bull semen. Out of 97 bulls, 9 were Local (L), 9 were Friesian (F), 13 were Sahiwal (SL), 12 were Local×Friesian (L×F), 10 were Sahiwal×Friesian (SL×F), 26 were Local×Friesian×Friesian (LF1×F), 18 were Local×Friesian× Friesian×Friesian (LF2×F) bulls. The semen of different crossbred and local bulls was examined for ejaculate volume, concentration, pH and motility percent of sperm before and after freezing. It was observed that, the maximum average ejaculate was obtained from SL×F and the mean value was 12.9 ml. However, the minimum average ejaculate was obtained from LF×F and the mean value was 7.4 ml. Before freezing, the maximum average sperm concentration was obtained from SL and the mean value was 1858.4 million/ml. The minimum average sperm concentration was obtained from LF1×F and the mean value was 1286.6 million/ml. The maximum average pH was obtained from LF2×F and the mean value was 6.5. The maximum average motility was obtained from SL and the mean value was 68.8%. However, the minimum average motility was obtained from L×F and the mean value was 63.7%. After freezing, sperm concentration, pH and motility reduced substantially irrespective of type of breed. It could therefore be inferred that freezing of semen should be undertaken with special care to maintain optimum semen quality.http://dx.doi.org/10.3329/bjas.v41i1.11968

An experiment was carried out to evaluate the performance of 22 lentil (Lens culinaris M.) genotypes for their yield and yield contributing characters at phenotypic level, relationship and diversity among the individuals and characterize the germplasm through phenotypic markers. ANOVA table revealed that significant variation was found among the genotypes for the characters plant height, days to maturity, number of primary branches plant -1 , number of secondary branches plant -1 , height of the lowest pod and 100-seed weight. Yield plant -1 was positively correlated with pods plant -1 , seeds pod -1 , seeds plant -1 and 100-seed weight. Considering yield plant -1 LM-123-7 was the best followed by LM-132-7, ICARDA-2348 and LM-13-1. Days to flowering, days of maturity and 100-seed weight showed high heritability. Path analysis revealed that pods plant -1 and 100-seed weight had positive direct effects on yield plant -1 . The genotypes were grouped into five clusters based on Euclidean distance following Ward's method and the highest intra-cluster distance was found in cluster IV and inter-cluster distance between the cluster IV and cluster V. Study of selection indices through discriminate functions observed that LM-123-7 ranked as the best followed by LM-132-7, LM-21-6, LM-24-3 and LM-14-2 and suggests that the highest scoring genotypes might be recommended for farmer's cultivation for better yield.