Chicken Second Branchial Arch Progenitor Cells Contribute to Heart Musculature in vitro and in vivo

Abstract

In the past, the heart muscle was thought to originate from a single source of myocardial progenitor cells. More recently, however, an additional source of myocardial progenitors has been revealed to be the second heart field, and chicken embryos were important for establishing this concept. However, there have been few studies in chicken on how this field contributes to heart muscles in vitro. We have developed an ex vivo experimental system from chicken embryos between stages HH17–20 to investigate how mesodermal progenitors in the second branchial arch (BA2) differentiate into cardiac muscles. Using this method, we presented evidence that the progenitor cells within the BA2 arch differentiated into beating cardiomyocytes in vitro. The beating explant cells were positive for cardiac actin, Nkx2.5, and ventricular myosin heavy chain. In addition, we performed a time course for the expression of second heart field markers (Isl1 and Nkx2.5) in the BA2 from stage HH16 to stage HH21 using in situ hybridization. Accordingly, using EGFP-based cell labeling techniques and quail-chicken cell injection, we demonstrated that mesodermal cells from the BA2 contributed to the outflow tract and ventricular myocardium in vivo. Thus, our findings highlight the cardiogenic potential of chicken BA2 mesodermal cells in vitro and in vivo.

The Emergence of Embryonic Myosin Heavy Chain during Branchiomeric Muscle Development

“…The vertebrate branchiomeric muscles are molecularly, morphologically and evolutionarily distinct from those of the trunk [ 6 ]. This view fits well with the concept that their progenitor cells have the ability to form both types of striated (skeletal and cardiac) muscles [ 1 , 11 , 13 , 14 , 15 , 16 ]. In accordance with these results, immunostaining for the cardiac alpha MyHC revealed its specific presence in the heart and first arch-derived muscles in both humans and rabbits [ 17 ].…”

Implementing a multi‐colour genetic marker analysis technique for embryology education

“…Double whole‐mount in situ hybridization was performed (Yahya, Al Haj, Brand‐Saberi, & Morosan‐Puopolo, 2020; Yahya, Boing, Brand‐Saberi, & Morosan‐Puopolo, 2020; Yahya, Boing, Pu, et al, 2020). Briefly, chicken embryos were fixed in 4% PFA before the staining procedures.…”

New Insights into the Diversity of Branchiomeric Muscle Development: Genetic Programs and Differentiation

“…Each arch comprises a mesodermal core surrounded by neural crest cells, endoderm, and ectoderm, which tightly influence mesodermal cell development [ 26 , 29 ]. The mesodermal core of the pharyngeal arches gives rise to the branchiomeric muscles and significant parts of the heart [ 1 , 6 , 26 , 29 , 30 , 31 , 32 , 33 , 34 ]. The first and second pharyngeal arches give rise to masticatory and facial expression muscles, and posterior pharyngeal arches give rise to non-somitic neck muscles and esophagus striated muscles, respectively ( Figure 1 ) [ 1 , 6 , 25 , 26 , 28 , 31 , 35 ].…”

“…Although Tbx1 is not required for the migration of the pharyngeal mesoderm into the first pharyngeal arch [ 43 ], it is required for the correct patterning of muscles with pharyngeal-mesoderm-derived connective tissue [ 36 ]. Previously, we reported on a fate-mapping experiment based on EGFP-based cell labeling and quail–chicken cell injection that found that chicken second pharyngeal arch progenitor cells contributed to the heart muscle in vivo [ 33 ]. We also reported that the chemokine receptor CXCR4 was required for the migration of pharyngeal mesoderm into the second and most caudal pharyngeal arches, but not the first pharyngeal arch.…”