Cosmid library of the turkey herpesvirus genome constructed from nanogram quantities of viral DNA associated with an excess of cellular DNA

Review of Poultry Recombinant Vector Vaccines

The control of poultry diseases has relied heavily on the use of many live and inactivated vaccines. However, over the last 30 yr, recombinant DNA technology has been used to generate many novel poultry vaccines. Fowlpox virus and turkey herpesvirus are the two main vectors currently used to construct recombinant vaccines for poultry. With the use of these two vectors, more than 15 recombinant viral vector vaccines against Newcastle disease, infectious laryngotracheitis, infectious bursal disease, avian influenza, and Mycoplasma gallisepticum have been developed and are commercially available. This review focuses on current knowledge about the safety and efficacy of recombinant viral vectored vaccines and the mechanisms by which they facilitate the control of multiple diseases. Additionally, the development of new recombinant vaccines with novel vectors will be briefly discussed.

Methods for the Manipulation of Herpesvirus Genome and the Application to Marek's Disease Virus Research

Herpesviruses are a group of double-strand DNA viruses that infect a wide range of hosts, including humans and animals. In the past decades, numerous methods have been developed to manipulate herpesviruses genomes, from the introduction of random mutations to specific genome editing. The development of genome manipulation methods has largely advanced the study of viral genes function, contributing not only to the understanding of herpesvirus biology and pathogenesis, but also the generation of novel vaccines and therapies to control and treat diseases. In this review, we summarize the major methods of herpesvirus genome manipulation with emphasis in their application to Marek’s disease virus research.

A genomic map of infectious laryngotracheitis virus and the sequence and organization of genes present in the unique short and flanking regions

We present a genomic map of infectious laryngotracheitis virus (ILT) and an 18,912 bp sequence containing the entire unique short region and a portion of the flanking short repeats. In determining the genomic map, an 856 bp region repeated as many as 13 times was identified within the short repeats. The unique short sequence contains nine potential open reading frames (ORFs). Six of these ORFs show homology to other known herpesvirus unique short genes. Using the herpes simplex virus nomenclature, these genes are the US2, protein kinase, and glycoproteins G, D, I, and E (ORF 1, 2, 4, 6, 7, and 8, respectively). Interestingly, an open reading frame with homology to HSV-1 UL47 (ORF 3) is found in the unique short. One very large open reading frame (ORF 5) is present and contains a threonine-rich, degenerate repeat sequence. This gene appears to be unique to ILT among sequenced herpesviruses. Two ORFs were identified within the short repeat (SR) region. SRORF 1 is homologous to a gene (SORF3) found in the unique short region in both MDV and HVT, and appears to be specific to avian herpesviruses. SRORF 2 has homology to HSV US10.

Cosmid cloning and restriction endonuclease mapping of the herpesvirus of turkeys (HVT) genome

The genomic libraries of the herpesvirus of turkeys (HVT) presented to date do not include the entire genome. To construct a complete genomic library, HVT DNA was partially digested with Sau3A and inserted into the double cos site vector pcos2EMBL. The PstI maps derived from the partial Sau3A library demonstrate that the left region of the genome compared to the right area is overrepresented. Similar to the libraries of the HVT genome established earlier, a defined portion of the middle genomic region, however, is not contained in the partial Sau3A library. Cloning of HVT DNA in pcos2EMBL, employing BamHI for the partial digestion step, enabled to find the recombinant cosmid cBL267 which carries the BamHI-C and -D fragment as DNA insertion. As shown by Southern blot hybridization, the BamHI-C fragment ranges in a size to close the gap in the partial Sau3A library and thus guarantees the completeness of the genomic library of HVT which consists of seven overlapping cosmid clones (cBL1, cBL328, cBL11, cBL267, cBL27, cBL33, and cBL34).