Experimental vaccination of sheep and cattle against tick infestation using recombinant 5'-nucleotidase.

Limited prior evidence suggests that 5'-nucleotidase, an ectoenzyme principally located in the Malpighian tubules of the tick Rhipicephalus (Boophilus) microplus, could be an effective antigen in an anti-tick vaccine. To assess this, recombinant 5'-nucleotidase was expressed in Escherichia coli and used in vaccination trials with both sheep and cattle. Vaccinated sheep were challenged with freshly moulted adult ticks.

Expression of intracellular calcium signalling genes in cattle skin during tick infestation.

It is widely acknowledged that changes in intracellular calcium ion (Ca(2+)) concentration provide dynamic signals that control a plethora of cellular processes, including triggering and mediating host defence mechanisms. In this study, quantitative real-time PCR was used to analyse gene expression of 14 Ca(2+) signalling proteins in skin obtained from high tick-resistant (HR) and low tick-resistant (LR) cattle following artificial challenge with cattle tick (Rhipicephalus (Boophilus) microplus). Up-regulation of numerous genes was observed in both HR and LR skin following tick challenge, however substantially higher transcription activation was found in HR tissue.

RT-nested PCR detection of Mourilyan virus in Australian Penaeus monodon and its tissue distribution in healthy and moribund prawns.

Mourilyan virus (MoV) is a newly identified virus of Penaeus monodon prawns that is genetically related to the Uukuniemi virus and other phleboviruses of the Bunyaviridae. This paper describes an RT-nested PCR test that can reliably detect between 2 and 6 copies of a synthetic MoV RNA. Total RNA isolated from the lymphoid organ, gills and haemocytes of P.

The gene encoding the nucleocapsid protein of Gill-associated nidovirus of Penaeus monodon prawns is located upstream of the glycoprotein gene.

The ORF2 gene of Gill-associated virus (GAV) of Penaeus monodon prawns resides 93 nucleotides downstream of the ORF1a-ORF1b gene and encodes a 144-amino-acid hydrophilic polypeptide (15,998 Da; pI, 9.75) containing 20 basic (14%) and 13 acidic (9%) residues and 19 prolines (13%). Antiserum to a synthetic ORF2 peptide or an Escherichia coli-expressed glutathione S-transferase-ORF2 fusion protein detected a 20-kDa protein in infected lymphoid organ and gill tissues in Western blots.

Multiplex RT-nested PCR differentiation of gill-associated virus (Australia) from yellow head virus (Thailand) of Penaeus monodon.

A multiplex RT-nested PCR has been developed to detect and differentiate the closely related prawn viruses, gill-associated virus (GAV) from Australia and yellow head virus (YHV) from Thailand. RT-PCR using primers to conserved sequences in the ORF1b gene amplified a 794 bp region of either GAV or YHV. Nested PCR using a conserved sense primer and either a GAV- or YHV-specific antisense primer to a divergent sequence differentially amplified a 277 bp region of the primary PCR amplicon.