2.1 Sample collection
Tissue samples were collected between 2017 and 2018 from 13 flocks of
different layer/ broiler parent lines/breeds maintained at
ICAR-Directorate of Poultry Research (DPR), Hyderabad, India. The parent
flocks were used in the production of layer/ broiler or dual
type-colored varieties suitable for backyard poultry rearing. All the
flocks were vaccinated with HVT on day old at in-house hatchery.
Deceased birds from different flocks presented for necropsy showed MD
specific lesions like enlargement of liver, spleen and visceral tumors
etc. All tumor-associated organs including liver, spleen, kidney,
proventriculus and sciatic nerve were collected from MD suspected birds
in 10% neutral buffered formalin for histopathological examination.
Another set was collected and kept frozen at -20˚C until use for DNA
extraction and subsequent use in PCRs. Sample details of the present
study are provided in supplementary table 1.