The enteric nervous system (ENS) is principally derived from vagal neural crest cells that migrate caudally along the entire length of the gastrointestinal tract, giving rise to neurons and glial cells in two ganglionated plexuses. Incomplete migration of enteric neural crest-derived cells (ENCDC) leads to Hirschsprung disease, a congenital disorder characterized by the absence of enteric ganglia along variable lengths of the colorectum. Our recent data [1] support an essential role for the avian ceca, present at the junction of midgut and hindgut, in hindgut ENS development, since ablation of the cecal buds leads to incomplete ENCDC colonization of the hindgut. In situ hybridization shows bone morphogenetic protein-4 (BMP4) highly expressed in the cecal mesenchyme, leading us to hypothesize that cecal BMP4 is required for hindgut ENS development. To test this, we modulated BMP4 activity using embryonic intestinal organ culture techniques and retroviral infection in ovo. We show that overexpression or inhibition of BMP4 in the ceca disrupts hindgut ENS development, with GDNF playing an important regulatory role. Our results suggest that these two important signaling pathways are required for normal ENCDC migration and enteric ganglion formation in the developing hindgut ENS.

This trial was carried out to find out the effects of the parent flocks and the hatching time of broiler chickens on the production traits and bacteriota development of animals. Two times 730 hatching eggs were collected from two different parent flocks with age of 22-23 and 65-66 weeks. In the hatchery both groups were divided into two subgroups, when the day-old chickens were separated according to their hatching time. A feeding trial was carried out afterwards, using the 4 treatments in 6 replicate floor pens, feeding commercial starter, grower, and finisher diets, that contained all the nutrients according to the breeder’s recommendations. The day-old chickens of the parent older flock and those hatched later were heavier and this advantage of the birds remained until end of the production period. The different age and origin of parent flocks failed to modify the microbiological parameters of the chicken’s ceca. However, the hatching time significantly influenced the different bacteriota diversity indices. The late hatched chickens showed higher Bacteroidetes and Actinobacteria and lower Firmicutes abundances at day 11. These treatments resulted differences in the main families, Ruminococcaceae, Lactobacillaceae, Bacteroidaceae. These differences could not be found at day 39.