3. Semmelhack, J.L., Donovan, J.C., Thiele, T.R.,
Kuehn, E., Laurell, E., and Baier, H. (2015). A larval zebrafish. eLife 3, http://dx.doi.org/10. 7554/eLife.04878. eye tells the frog’s brain. Proc. Inst. Mec. l Eng.
H J. Eng. Med. 47, 1940–1951. opment of the retinofugal projections in the embryonic and larval zebrafish (Brachydanio rerio). J. Comp. Neurol. 346, 583–600. s 1 ie e .o ll t weliminated entirely, by laser ablation of the retinal ganglion cell axons within AF7.
These data suggest that selectivity for prey-like stimuli is already present in retinal ganglion cell axons targeting AF7, and that AF7 plays a role in regulating hunting behaviour. Anatomical reconstruction of singly labelled cells showed that two morphological subtypes of retinal ganglion cell innervate AF7, and that these cells also send collateral branches to the superficial layer (stratum opticum) of the tectum, consistent with the fact that some responses to prey-like stimuli were also seen in RGCs innervating the tectum.
By labelling single neurons in the vicinity of AF7, Semmelhack et al.  reconstructed the anatomy of potential postsynaptic partners of retinal ganglion cell axons targeting AF7. They identified cells that projected to the optic tectum and a second type of neuron that projected to the nucleus of the medial longitudinal fasciculus (nMLF) and hindbrain, areas that are important for controlling swim direction and speed (Figure 1) [13–15]. In future studies, it will be important to establish that these cells are bone fide targets of retinal ganglion cells within AF7 and to determine their tuning properties and neurotransmitter identity. Addressing these questions will provide valuable insight into how retinally-derived information about the presenceof prey is transformedbycircuits within AF7 to modulate prey capture.
Bianco and Engert  and Semmelhack et al.  reach different conclusions about the optimal stimulus for triggering hunting.
This may be because the two groups did not explore exactly the same stimulus space, or that important experimental conditions were not identical in each study. An alternative explanation is that the two studies focussed on different stages of the visual pathway,
Semmelhack et al.  on retinal ganglion cells, and Bianco and Engert  on tectal neurons. The differences they see may reflect the different response properties of neurons at different stages of the sensorimotor pathway. The two studies may therefore be complementary rather
Dispatchesthan contradictory. Together they certainly provide significant new insight into the circuitry underlying a complex visually-driven behaviour and raise some fascinating questions for the future. How
Cu4. Bianco, I.H., Kampff, A.R., and Engert, F. (2011). Prey capture behavior evoked by simple visual stimuli in larval zebrafish. Front.
Sys. Neurosci. 5, 101. 5. Borla, M.A., Palecek, B., Budick, S., and
O’Malley, D.M. (2002). Prey capture by larval zebrafish: evidence for fine axial motor control.
Brain Behav. Evol. 60, 207–229. 6. McElligott, M.B., and O’Malley, D.M. (2005).
Prey tracking by larval zebrafish: axial kinematics and visual control. Brain Behav.
Evol. 66, 177–196. 7. Patterson, B.W., Abraham, A.O., MacIver,
M.A., andMcLean, D.L. (2013). Visually guided
Epithelial Cell Divi
Marta Clemente-Ruiz1 and Marco Mila´n 1Institute for Research in Biomedicine, Parc C 08028 Barcelona, Spain 2ICREA, Parc Cientific de Barcelona, Baldiri R *Correspondence: marco.milan@irbbarcelona http://dx.doi.org/10.1016/j.cub.2015.02.008
Aneuploidy is deleterious at the ce promote tumorigenesis. Two new s underscore the cellular and tissueaccumulation of aneuploid cells in sy sues upon changes in centrosome n
Aneuploidy — an abnormal number of chromosomes or parts of chromosomes — is deleterious at the rrent Biology 25, R269–R293, March 30, 2015 ª13. Orger, M.B., Kampff, A.R., Severi, K.E.,
Bollmann, J.H., and Engert, F. (2008). Control of visually guided behavior by distinct populations of spinal projection neurons.
Nat. Neurosci. 11, 327–333. 14. Severi, K.E., Portugues, R., Marques, J.C.,
O’Malley, D.M., Orger, M.B., and Engert, F. (2014). Neural control and modulation of swimming speed in the larval zebrafish.
Neuron 83, 692–707. 15. Thiele, T.R., Donovan, J.C., and Baier, H. (2014). Descending control of swim posture by a midbrain nucleus in zebrafish. Neuron 83, 679–691. ion: Keeping in Check ,2,* ntific de Barcelona, Baldiri Reixac, 10, ixac, 10-12, 08028 Barcelona, Spain rg ular and organismal level and can udies in Drosophila imaginal discs ide mechanisms that prevent thededicated visual pathway for prey detection in 12. Burrill, J.D., and Easter, S.S., Jr. (1994). Devel-do the tectum and AF7 together coordinate the various aspects of prey capture, and how are prey capture circuits modulated by attention, motivational state and input from other sensory modalities are questions to keep the field busy for quite some time.
REFERENCES 1. Chen, S.K., Badea, T.C., and Hattar, S. (2011).
Photoentrainment and pupillary light reflex are mediated by distinct populations of ipretinal ganglion cells. Nature 476, 92–95. 2. Bianco, I.H., and Engert, F. (2015). Visuomotor transformations underlying hunting behaviour in zebrafish. Curr. Biol. 25, 831–846. gradation of prey capture movements in larval zebrafish. J. Exp. Biol. 216, 3071–3083. 8. Trivedi, C.A., and Bollmann, J.H. (2013).
Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture.
Front. Neural Circ. 7, 86. 9. Muto, A., Ohkura, M., Abe, G., Nakai, J., and
Kawakami, K. (2013). Real-time visualization of neuronal activity during perception. Curr. Biol. 23, 307–311. 10. Roeser, T., and Baier, H. (2003). Visuomotor behaviors in larval zebrafish after GFP-guided laser ablation of the optic tectum. J. Neurosci. 23, 3726–3734. 11. Lettvin, J.Y., Maturana, H.R., McCulloch,