Differences in erythropoiesis in normal chicken and quail embryos

Abstract

Using antibodies against the fetal and adult forms of alpha- and beta-globin, it has been shown that erythropoiesis in the para-aortic foci (PAF) constitutes a major species-specific difference between chicken and quail embryos. In quail embryos, para-aortic foci are rare, small and rather heterogeneous with regard to their erythropoietic and haemopoietic cell composition. In contrast, the PAFs in chicken embryos are abundant and consist of large numbers of erythropoietic cells. In both species a time difference (approximately 1 day) is observed between the first expression of the fetal alpha- and beta-globin and the adult alpha- and beta-globin in erythropoietic cells. Adult erythropoiesis in both species can be detected first in the stalk of the yolk sac; this is similar to the situation in mammalian and amphibian species. From this time onward the number of circulating adult erythrocytes increases steadily. Whereas in chicken, large intraembryonic foci that can serve as sources for these adult cells arise concomitantly, no such foci can be detected in quail embryos, suggesting that the quail yolk sac is a major source for these adult red blood cells.

Primitive and definitive erythropoiesis in the yolk sac: a birds eye view

“…This is in agreement with data from cell labeling and EM analyses (Jaffredo et al, 1998). Erythropoiesis, however, is not observed at this early period in either intra-vascular or peri-vascular hematopoietic cells associated with the dorsal aorta (Geerts et al, 1993) (H. Nagai and G. Sheng, unpublished data). Our observations also suggest that during this period, most yolk sac vasculature-associated hematopoietic cells undergo definitive erythropoiesis in situ .…”

How HSCs Colonize and Expand in the Fetal Niche of the Vertebrate Embryo: An Evolutionary Perspective

“…Definitive chicken hematopoiesis is initiated at E3-4 by the emergence of intra-aortic clusters of HSCs derived from endothelium (as seen in mammals) (Jaffredo et al, 2000; Bollerot et al, 2005a,b; Yvernogeau and Robin, 2017). HSCs then migrate to the neighboring mesenchyme, ventral to the aorta and located in the PAFs, that support the development of CD45 + cells (Cormier, 1993; Geerts et al, 1993), such as myeloerythroid progenitor cells and immature thymic precursors (that have not yet undergone T-cell receptor rearrangements) (Lampisuo et al, 1999; Jaffredo et al, 2000; Liippo et al, 2000; Saynajakangas et al, 2009). An additional site of embryonic hematopoiesis includes the yolk sac, which also contributes to the expansion and maturation of erythroid and myeloid cells (Guedes et al, 2014).…”