title: Diversity of Meq gene from clinical Marek's disease virus infection in Saudi Arabia.
abstract: OBJECTIVE
  The aim of this study was to demonstrate the genomic features of Meq gene of Marek's disease virus (MDV) recently circulating in Saudi Arabia (SA).
  
  
  METHODS
  Two poultry flocks suffering from mortalities and visceral tumors were presented to the Veterinary Teaching Hospital, King Faisal University, SA. Subjected to different diagnostic procedures: Case history, clinical signs, and necropsy as well as polymerase chain reaction followed by Meq gene sequence analysis.
  
  
  RESULTS
  Case history, clinical signs, and necropsy were suggestive of MDV infection. The Meq gene was successfully detected in liver and spleen of infected chickens. A 1062 bp band including the native Meq ORF in addition to a 939 bp of S-Meq (short isoform of Meq) were amplified from Saudi 01-13 and Saudi 02-13, respectively. The nucleotide and deduced amino acids sequences of the amplified Meq genes of both Saudi isolates showed distinct polymorphism when compared with the standard USA virulent isolates Md5 and GA. The sequence analysis of the S-Meq gene showed a 123 bp deletion representing 41 amino acids between two proline-rich areas without any frameshift. The Meq gene encoded four repeats of proline-rich repeats (PRRs sequences), whereas the S-Meq contains only two PRRs. Interestingly, the phylogenetic analysis revealed that both of SA MDV isolates are closely related to the MDV strains from Poland.
  
  
  CONCLUSIONS
  The two MDV isolates contain several nucleotide polymorphisms resulting in distinct amino acid substitutions. It is suggested that migratory and wild birds, as well as world trading of poultry and its by-products, have a great contribution in the transmission of MDVs overseas.
authors.affiliation: Department of Clinical Studies, College of Veterinary Medicine, King Faisal University, Al-Hufof, 31982, Saudi Arabia; Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, 44519, Zagazig, Egypt.
authors.forename: Mahmoud H A
authors.initials: MH
authors.lastname: Mohamed
authors.affiliation: Central Biotechnology Laboratory, College of Veterinary Medicine, King Faisal University, Al-Hufof, 31982, Saudi Arabia; Department of Virology, Faculty of Veterinary Medicine, Cairo University, 12211, Giza, Egypt.
authors.forename: Ibrahim M
authors.initials: IM
authors.lastname: El-Sabagh
authors.affiliation: Excutive Department of Risk Assessment, Saudi Food and Drug Authority, Saudi Arabia.
authors.forename: Malik A
authors.initials: MA
authors.lastname: Al-Habeeb
authors.affiliation: Central Veterinary Laboratory, Riyadh, Saudi Arabia.
authors.forename: Yousef M
authors.initials: YM
authors.lastname: Al-Hammady
keywords: Marek’s disease virus; Meq gene sequence; Saudi Arabia; deletion; phylogenic analysis