Differential participation of ventral and dorsolateral mesoderms in the hemopoiesis of Xenopus, as revealed in diploid-triploid or interspecific chimeras

Regulatory Signals and Tissue Interactions in the Early Hematopoietic Cell Differentiation in Xenopus laevis Embryo

“…However, our previous studies using the chimeric animals between the cytogenetically labeled individuals revealed that a small population of hemopoietic precursors are involved in the ventral blood island-derived cells and a significant population of adult lymphocytes and erythrocytes arises from this area. The classical transplantation experiments showed that 70-90% of larval thyomocytes and splenocytes, and 20-30% of adult thyomcytes and splenocytes are derived from the ventral blood islands (Maéno et al ., 1985a). Therefore, it is reasonable to speculate that a small number of hemopoietic stem cells arise at the ventral blood islands and these cells colonize the hemopoietic organs to proliferate and differentiate into peripheral lymphocytes at later stages.…”

“…The classical transplantation studies in amphibian embryos revealed that they have dual embryonic origins of hemopoietic cells that contribute to distinct populations in ontogeny (Kau and Turpen, 1983;Flajnik et al ., 1984;Maéno et al ., 1985a;Zon, 1995). The first population of hemopoietic cells arises from the ventral blood islands in the tailbud embryo, and the second population comes from the dorsal-lateral plate mesoderm where the dorsal aorta, gonad and mesonephros are to differentiate.…”

Involvement of BMP‐4/msx‐1 and FGF pathways in neural induction in the Xenopus embryo

“…Primers used for PCR and cycle number were as follows: Xmsx-1, 5Ј-GCA-GGA-ACA-TCA-CAC-ACT-CC-3Ј and 5Ј-GGG-TGG-GCT-CAT- (Suzuki et al 1993;21 cycles) (Maéno et al 1985), the sections were counterstained with quinacrine.…”

Development of Erythroid Progenitors under Erythropoietin Stimulation inXenopus laevisLarval Liver

“…In the African clawed frog, Xenopus laevis (X. laevis), hematopoiesis occurs first in the analog of yolk sac called the ventral blood island (VBI), and subsequently in the equivalent of the aorta-gonad-mesonephros (AGM) called the dorsal lateral plate (DLP) (Kau and Turpen, 1983;Flajnik et al, 1984;Maeno et al, 1985;Ciau-Uitz et al, 2000). Next, hematopoietic stem cells, which are derived from a part of VBI and DLP, migrate to the liver and maintain their hematopoietic activity until post-metamorphosis (Chen and Turpen, 1995;Turpen et al, 1997).…”