ABSTRACT
HEK293 cells were used as the cell model to investigate the role of human aminopeptidase N (hAPN) in the invasion of porcine deltacoronavirus (PDCoV) into human cells. The proliferation of PDCoV on HEK293 cells was firstly identified by RT-qPCR/RT-PCR. And then, hAPN knockout cell line was constructed by CRISPR/Cas9 technology and cell viability of HEK293 hAPN knockout and wild-type cells was verified by CCK-8 assay. Effect of hAPN knockout and overexpression on PDCoV replication was detected by RT-qPCR and Western blot. Meanwhile, interaction of PDCoV S protein and hAPN protein was analyzed by homology modeling and molecular docking. Results showed that PDCoV virus copies rapidly increased at 12-36 h and reached peak level at 36 h, it could propagate at least for passage 2 on HEK293 cells. There was no significant difference in cell viability between hAPN knockout cells and wild-type cells. Knockout of hAPN inhibit PDCoV replication and overexpression of hAPN enhance PDCoV replication. Homology modeling and molecular docking analysis showed S1 protein could bind hAPN domain II. Residues TYR92, THR51, THR48, PHE16 and MET14of S1 protein receptor binding motif 1 (RBM1) can form hydrogen bonds with residues PHE490, GLN531, ARG528 and SER529 of hAPN. This study indicates that hAPN plays a critical role in HEK293 cells during PDCoV infection, which provides new theoretical evidence for further studies on the mechanism of PDCoV entry into host cells and cross-species transmission.
ABSTRACT
This article discusses the strategies done by the dairy sector in Switzerland to maintain and even have surplus milk supply during the Covid-19 pandemic. Some of the strategies implemented during the pandemic are milk production tests, inspection of the origin of milk, registration of calves, and insemination using top performing dairy bulls.
ABSTRACT
The purpose of this report was to document the immediate impact of the COVID-19 pandemic on dairy cattle farming in Ethiopia and draw recommendations for enhancing dairy farming and the dairy sector's resilience to such pandemics and other market shocks. It presents the results of a rapid survey of the impact of the COVID-19 pandemic on smallholder and medium-scale dairy cattle farmers in Ethiopia during the period between 5 September and 11 October 2020. A total of 1815 farmers who are part of the African Dairy Genetics Gains (ADGG) programme from five regions of Ethiopia, and one city administration participated in the study. Majority of the respondents reported that dairy farming input supply and service provision such as feed, veterinary services, animal vaccines, artificial insemination and daily hired labour had all decreased during the pandemic. More than half (60%) of the respondents reported a decrease in the total volume of milk produced per household, which was linked to the shortage of feed and other services. Forty-six percent of the respondents reported selling milk at a lower price compared to periods before the pandemic. Decreasing demand for milk by direct consumers, cooperatives and processors is one potential reason for the lower milk sales price. In conclusion, service providers and input suppliers (both government and private sector) working in collaboration with the Ministry of Agriculture are important in safeguarding farmers from shocks which result from man-made or natural disasters such as those brought about by the COVID-19 pandemic. Additionally, supporting dairy cooperatives and processors to produce at full capacity and linking dairy farmers to microfinance providers so they can access credit will ensure sustained profitability of their dairy farms.