A cross-species analysis of microRNAs in the developing avian face

Avian beaks show extreme species-specific variability in morphology, though they develop from the same primordial structures. In both humans and birds, cranial neural crest cells are the primary source of mesenchyme for the frontonasal prominence; previous work has shown that these cells contain molecular information that regulate species-specific facial variation. To determine the molecular basis of avian craniofacial patterning, we have used Next-Generation sequencing to profile all 20-40nt microRNAs from micro-dissected cranial neural crest cells from the frontonasal prominence of three bird species (chickens, quails, and ducks). Samples for each species were isolated at two developmental stages, before (Hamilton Hamburger stage [HH] 20) and after (HH25) morphological distinctions between the species are evident. Overall design: Examination of microRNA expression in frontonasal neural crest cells of 3 bird species at two developmental stages. Includes some biological replicates and one technical replicate.