Fgf signaling governs cell fate in the zebrafish pineal complex

Clanton, Joshua A.; Hope, K.D.; Gamse, Joshua T.

doi:10.1242/dev.083709

Cited by 34 publications

(56 citation statements)

References 64 publications

(99 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Embryos were raised and staged according to standard protocols (Kimmel et al, 1995 (Gilmour et al, 2002;Choo et al, 2006;Clanton et al, 2013). For later-staged embryos, PTU was used to block the formation of pigment.…”

Section: Fish Lines and Maintenancementioning

confidence: 99%

Pitx2c ensures habenular asymmetry by restricting parapineal cell number

et al. 2014

Self Cite

View full text Add to dashboard Cite

Left-right (L/R) asymmetries in the brain are thought to underlie lateralised cognitive functions. Understanding how neuroanatomical asymmetries are established has been achieved through the study of the zebrafish epithalamus. Morphological symmetry in the epithalamus is broken by leftward migration of the parapineal, which is required for the subsequent elaboration of left habenular identity; the habenular nuclei flank the midline and show L/R asymmetries in marker expression and connectivity. The Nodal target pitx2c is expressed in the left epithalamus, but nothing is known about its role during the establishment of asymmetry in the brain. We show that abrogating Pitx2c function leads to the right habenula adopting aspects of left character, and to an increase in parapineal cell numbers. Parapineal ablation in Pitx2c loss of function results in right habenular isomerism, indicating that the parapineal is required for the left character detected in the right habenula in this context. Partial parapineal ablation in the absence of Pitx2c, however, reduces the number of parapineal cells to wild-type levels and restores habenular asymmetry. We provide evidence suggesting that antagonism between Nodal and Pitx2c activities sets an upper limit on parapineal cell numbers. We conclude that restricting parapineal cell number is crucial for the correct elaboration of epithalamic asymmetry.

show abstract

Section: Fish Lines and Maintenancementioning

confidence: 99%

Pitx2c ensures habenular asymmetry by restricting parapineal cell number

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…Single-cell embryos were injected with 3.8 ng of lamb1a splice-blocking morpholino (lamb1a MO: 5Ј-TAAATCCGTTGACTGCTTTACCTTC-3Ј) or 2 ng of ntl or flh morpholino (Nasevicius and Ekker, 2000;Clanton et al, 2013) in Tris (pH 8.0) and Phenol Red. For midblastula stage injections, lamb1a MO was co-injected with 1:1000 rhodamine dextran as a tracer into the yolk of Tg(XlEef1a:GFP) s854 embryos at 3 hpf (Amack and Yost, 2004).…”

Section: Morpholino Injectionsmentioning

confidence: 99%

Laminin β1a controls distinct steps during the establishment of digestive organ laterality

et al. 2013

View full text Add to dashboard Cite

SUMMARYVisceral organs, including the liver and pancreas, adopt asymmetric positions to ensure proper function. Yet the molecular and cellular mechanisms controlling organ laterality are not well understood. We identified a mutation affecting zebrafish laminin β1a (lamb1a) that disrupts left-right asymmetry of the liver and pancreas. In these mutants, the liver spans the midline and the ventral pancreatic bud remains split into bilateral structures. We show that lamb1a regulates asymmetric left-right gene expression in the lateral plate mesoderm (LPM). In particular, lamb1a functions in Kupffer's vesicle (KV), a ciliated organ analogous to the mouse node, to control the length and function of the KV cilia. Later during gut-looping stages, dynamic expression of Lamb1a is required for the bilayered organization and asymmetric migration of the LPM. Loss of Lamb1a function also results in aberrant protrusion of LPM cells into the gut. Collectively, our results provide cellular and molecular mechanisms by which extracellular matrix proteins regulate left-right organ morphogenesis. KEY WORDS: Asymmetry, Laminin, OrganogenesisLaminin β1a controls distinct steps during the establishment of digestive organ laterality Tatiana Here, we report that laminin plays an essential role in the establishment of L-R asymmetry of the zebrafish liver and pancreas. Laminins are large heterotrimeric glycoproteins, comprising of α, β and γ chains assembled into a cross-shaped molecule with a long arm and three short globular arms (Engel et al., 1981;Miner, 2008). We present a novel mutant allele of the laminin β1a (lamb1a) gene, which encodes a subunit of the ECM protein laminin 1. In this mutant, the liver spans the midline, and the ventral pancreatic bud remains split into bilateral structures. We find that laminin is necessary for controlling cilia length and fluid flow in the KV, and for restricting southpaw expression to the left LPM. Subsequently, lamb1a deficiency disrupts the dynamic deposition of laminin 1 in the LPM epithelium, resulting in a severely disorganized epithelium with abnormal protrusions into the gut, and a failure of asymmetric gut looping. Thus, laminin 1 participates in sequential events that are important for the establishment of L-R asymmetry of visceral organs, including an early role in the KV and a later role in the LPM.

show abstract

“…In addition, reduction of FGF activity induces an increased production of arrestin 3a (Arr3a) þ pineal photoreceptors, suggesting that FGFs operate to control a binary parapineal versus Arr3a þ PhR fate choice. In contrast, reducing tbx2b activity does not affect the numbers of Arr3a þ PhRs (Clanton, Hope, & Gamse, 2013). Finally, FGF signaling is also required at a subsequent step to promote parapineal migration (Regan, Concha, Roussigne, Russell, & Wilson, 2009).…”

Section: Development Of the Pineal Glandmentioning

confidence: 95%

“…transcription factors: gfi-1.2 (growth factor-independent) and sox1a are expressed in the parapineal precursors but not in the pineal gland (Clanton, Hope, & Gamse, 2013;Dufourcq, Rastegar, Strahle, & Blader, 2004). The parapineal gland of channel catfish expresses a specific opsin, parapinopsin, but a few pineal cells also express this opsin (Blackshaw & Snyder, 1997).…”

Section: The Parapineal Organmentioning

confidence: 99%

“…In a tbx2b mutant from beyond (fby), parapineal precursors expressing gfi-1.2 (growth factor-independent) can be identified albeit in smaller numbers, but their migration is impaired (Dufourcq et al, 2004;Snelson, Santhakumar, Halpern, & Gamse, 2008). On the other hand, reduction of FGF activity also results in a decreased number of gfi1.2þ cells and in impaired parapineal migration, but experiments in which both tbx2b and FGF activities are affected show a cumulative phenotype, suggesting that tbx2b and FGF act independently of each other (Clanton, Hope, & Gamse, 2013). Moreover, the regulation of cell numbers and the control of parapineal migration are most likely independent events, as reduction of the number of parapineal precursors using laser ablation does not affect the migration of the remaining cells (Snelson et al, 2008).…”

Section: Development Of the Pineal Glandmentioning

confidence: 99%

See 1 more Smart Citation