Expression of FoxP2 during zebrafish development and in the adult brain

Abstract

Fox (forkhead) genes encode transcription factors that play important roles in the regulation of embryonic patterning as well as in tissue specific gene expression. Mutations in the human FOXP2 gene cause abnormal speech development. Here we report the structure and expression pattern of zebrafish FoxP2. In zebrafish, this gene is first expressed at the 20-somite stage in the presumptive telencephalon. At this stage there is a significant overlap of FoxP2 expression with the expression of the emx homeobox genes. However, in contrast to emx1, FoxP2 is not expressed in the pineal gland or in the pronephric duct. After 72 hours of development, the expression of zebrafish FoxP2 becomes more complex in the brain. The developing optic tectum becomes the major area of FoxP2 expression. In the adult brain, the highest concentrations of the FoxP2 transcript can be observed in the optic tectum. In the cerebellum, only the caudal lobes show high levels of Foxp2 expression. These regions correspond to the vestibulocerebellum of mammals. Several other regions of the brain also show high levels of Foxp2 expression. KEY WORDS: Emx, forkhead, FoxP2, homeobox, speech, telencephalon, zebrafish Forkhead proteins are important transcriptional regulators that are involved in pattern formation during vertebrate development as well as in tissue specific gene expression and tumorogenesis (Accili and Arden, 2004, Carlsson and Mahlapuu, 2002, Dirksen and Jamrich, 1992, Dirksen and Jamrich, 1995, El-Hodiri et al., 2001, Erickson, 2001, Kaufmann and Knochel, 1996, Lai et al., 2001, Lai et al., 1990, Lehmann et al., 2003, Li and Vogt, 1993, Tseng et al., 2004.FOXP2, a member of the Foxp subfamily of Fox genes, is the only gene shown to be involved in speech and language development in humans (Bruce and Margolis, 2002, Enard et al., 2002, Fisher et al., 1998, Katoh, 2004, Lai et al., 2001, Lu et al., 2002, Saleem et al., 2003, Shu et al., 2001, Wang et al., 2003, Zhang et al., 2002. Mutations in this gene result in impaired linguistic and grammatical skills that, together with diminished control of complex face and mouth movements, lead to disrupted speech (Hurst et al., 1990. A recent study showed expression of FoxP2 in the entire adult brain of birds and crocodiles (Haesler et al., 2004). In this paper, we provide information about the isolation, sequence and expression pattern of zebrafish FoxP2 during development and in adult brain.Foxp2 is somewhat of an unusual protein in that it contains Int. J. Dev. Biol. 50: 435-438 (2006) a forkhead and zinc finger domain. PCR and degenerate primers were used to isolate a cDNA fragment of the zebrafish FoxP2 gene that encodes both of these domains of the protein.After sequencing the isolated PCR fragment, we found that our sequence has a high homology to several zebrafish EST fragments in the GenBank database. Figure 1 shows the comparison of the deduced amino acid sequence of the zebrafish to the mouse and human FOXP2 protein. This comparison shows that the FoxP2 protein is highly ...

Characterization of grass carp (Ctenopharyngodon idellus) Foxp1a/1b/2: Evidence for their involvement in the activation of peripheral blood lymphocyte subpopulations

“…To date, the studies regarding the Foxp1 and Foxp2 expression in fish species are very limited except some recent studies in zebrafish [4,16,17] and medaka [5]. They showed that fish Foxp1 and Foxp2 were expressed during embryonic development and neural development, which is consistent with the findings in mouse [20], frog [21], and bird [22].…”

“…The expression patterns of Foxp1 and Foxp2 in embryonic development have also been investigated in zebrafish [16,17]. However, the functional roles of Foxp subfamily in fish immunity still remain unknown, and even the information about Foxp gene regulation in fish is limited.…”

FoxP2 Expression in a Highly Vocal Teleost Fish with Comparisons to Tetrapods

“…Prominent FoxP2 mRNA label in zebrafish is reported in general for the ventral telencephalon and the preoptic area, with more specific sites identified in the diencephalon (dorsal thalamus, ventral posterior tuberculum), the midbrain (periventricular pretectum, TeM, TS), the medulla (superior reticular nucleus, medial octavolateralis nucleus), and the caudal lobe of the cerebellum [Shah et al, 2006;see Bonkowsky and Chien, 2005, for studies during embryogenesis]. For midshipman, we recognize label in several divisions of the ventral telencephalon and the preoptic area and in cerebellar Purkinje cells of the caudal lobe (Table 1).…”

“…Studies of teleost fish have been limited to nonvocal/nonsonic species of medaka (Orizyas latipes), zebrafish (Danio rerio), and weakly electric fish (Apteronotus leptorhynchus) [Shah et al, 2006;Itakura et al, 2008;Harvey-Girard et al, 2012]. The current study maps FoxP2 mRNA expression in the brain of the highly vocal plainfin midshipman (Porichthys notatus) that has been the subject of comprehensive mapping of the central vocal, auditory, and neuroendocrine systems that modulate vocal-acoustic behaviors [ Fig.…”

Human brain evolution: From gene discovery to phenotype discovery

“…The similarities in anatomical localization extend to other vertebrates as well, including birds and reptiles (72,73). FOXP2 orthologs are also expressed in the brains of amphibians and fish (74)(75)(76)(77).…”