atoh8 expression pattern in early zebrafish embryonic development

Abstract

Atonal homologue 8 (atoh8) is a basic helix-loop-helix transcription factor expressed in a variety of embryonic tissues. While several studies have implicated atoh8 in various developmental pathways in other species, its role in zebrafish development remains uncertain. So far, no studies have dealt with an in-depth in situ analysis of the tissue distribution of atoh8 in embryonic zebrafish. We set out to pinpoint the exact location of atoh8 expression in a detailed spatio-temporal analysis in zebrafish during the first 24 h of development (hpf). To our surprise, we observed transcription from pre-segmentation stages in the paraxial mesoderm and during the segmentation stages in the somitic sclerotome and not—as previously reported—in the myotome. With progressing maturation of the somites, the restriction of atoh8 to the sclerotomal compartment became evident. Double in situ hybridisation with atoh8 and myoD revealed that both genes are expressed in the somites at coinciding developmental stages; however, their domains do not spatially overlap. A second domain of atoh8 expression emerged in the embryonic brain in the developing cerebellum and hindbrain. Here, we observed a specific expression pattern which was again in contrast to the previously published suggestion of atoh8 transcription in neural crest cells. Our findings point towards a possible role of atoh8 in sclerotome, cerebellum and hindbrain development. More importantly, the results of this expression analysis provide new insights into early sclerotome development in zebrafish—a field of research in developmental biology which has not received much attention so far.

Exposure to Tetrabutylammonium Bromide Impairs Cranial Neural Crest Specification, Neurogenic Program, and Brain Morphogenesis

“…atoh8 expression is primarily restricted to paraxial mesoderm, specifically the sclerotome region of the somites. At later stages, it is also expressed in the hindbrain, trunk, and tail . Thus, paraxial mesodermal derivatives are not affected by TBAB treatment.…”

“…At later stages, it is also expressed in the hindbrain, trunk, and tail. 51 Thus, paraxial mesodermal derivatives are not affected by TBAB treatment.…”

Chicken Hypothalamic and Ovarian DNA Methylome Alteration in Response to Forced Molting

“…However, decreased expression of SCAMP3, a regulatory gene in the hypothalamus (3-vs.-5), can inhibit the occurrence of breast and liver cancer, promoting individual health [ 36 ]. ATOH8 was also found during the same period, and its reduced expression can promote animal embryo development [ 37 ]. Therefore, these five genes can serve as important biomarkers for regulating aging and redevelopment during different periods of FM, as well as key reference genes for subsequent functional verification.…”

Atoh8 in Development and Disease

“…The loss of Atoh8 during chondrogenesis resulted in the reduction of skeletal size [ 41 ]. Another study performed most recently on Zebrafish reiterated these findings revealing the expression of Atoh8 in the sclerotomes very early during development [ 42 ].…”