Foxl2a and Foxl2b are involved in midbrain-hindbrain boundary development in zebrafish

• Published in: Gene Expression Patterns 2022-12, Vol.46, p.119286-119286, Article 119286
• Main Authors: Zhou, Jian, Yang, Yan-Jing, Gan, Rui-Hai, Wang, Yang, Li, Zhi, Zhang, Xiao-Juan, Gui, Jian-Fang, Zhou, Li
• Format: Article
• Language: English
• Subjects: Animals; brain; Brain ventricular system; Danio rerio; Embryogenesis; Embryonic Development; foxl2; gene expression; Gene Expression Regulation, Developmental; gene regulatory networks; homozygosity; Mesencephalon - metabolism; mesoderm; Midbrain-hindbrain boundary; mutants; pharynx; Rhombencephalon; wnt proteins; Zebrafish; Zebrafish - genetics; Zebrafish - metabolism; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism
• ISSN: 1567-133X; 1872-7298
• DOI: 10.1016/j.gep.2022.119286

Foxl2 plays conserved central function in ovarian differentiation and maintenance in several fish species. However, its expression pattern and function in fish embryogenesis are still largely unknown. In this study, we first presented a sequential expression pattern of zebrafish foxl2a and foxl2b during embryo development. They were predominantly expressed in the cranial paraxial mesoderm (CPM) and cranial venous vasculature (CVV) during somitogenesis and subsequently expressed in the pharyngeal arches after 48 h post-fertilization (hpf). Then, we compared the brain structures among zebrafish wildtype (WT) and three homozygous foxl2 mutants (foxl2a−/−, foxl2b−/− and foxl2a−/−;foxl2b−/−) and found the reduction of the fourth ventricle in the three foxl2 mutants, especially in foxl2a−/−;foxl2b−/− mutant. Finally, we detected several key transcription factors involved in the gene regulatory network of midbrain-hindbrain boundary (MHB) patterning, such as wnt1, en1b and pax2a. Their expression levels were obviously downregulated in MHB of foxl2a−/− and foxl2a−/−;foxl2b−/− mutants. Thus, we suggest that Foxl2a and Foxl2b are involved in MHB and the fourth ventricle development in zebrafish. The current study provides insights into the molecular mechanism underlying development of brain ventricular system. •Foxl2a and Foxl2b play functional roles during zebrafish embryogenesis.•Foxl2a and foxl2b are mainly expressed in CPM and CVV during somitogenesis.•Foxl2a and Foxl2b cooperatively regulate MHB and fourth ventricle pattern.