Genomic and gene regulatory signatures of cryptozoic adaptation: Loss of blue sensitive photoreceptors through expansion of long wavelength-opsin expression in the red flour beetle -0

<p><b>Copyright information:</b></p><p>Taken from "Genomic and gene regulatory signatures of cryptozoic adaptation: Loss of blue sensitive photoreceptors through expansion of long wavelength-opsin expression in the red flour beetle "</p><p>http://www.frontiersinzoology.com/content/4/1/24</p><p>Frontiers in Zoology 2007;4():24-24.</p><p>Published online 21 Dec 2007</p><p>PMCID:PMC2254409.</p><p></p> and wavelength specificities of opsins that are known to be expressed in the main retina. Tree visualizes phylogenetic relationships between the insect orders to which the four species belong [51]. In the retinal mosaics, colors indicate photoreceptor light specificities in either the UV (violet), blue or green wavelength range. forms eight photoreceptors per ommatidium. The peripheral photoreceptors R1-6 express a LW-opsin. 70% of the Drosophila ommatidia are of the yellow type, in which the central R8 cell express a the LW-opsin paralog Rh6 and the central R7 cells the UV-opsin Rh4. In the remaining pale-type ommatidia, the central R8 cell express the B-opsin Rh5 and the central R7 cells the UV-opsin Rh3 (Fig. 1) [12]. Honeybee and tobacco hornworm moth develop nine photoreceptors per ommatium due to duplication of the R7 cell fate [52]. However, in both species only the two central R7-like more distally located cells exhibit differential opsin expression ranging from UV to LW sensitive opsins. The peripheral photoreceptor cell homologs R1-6 express LW-opsin as does the proximally located central R8 cell homolog. Five different ommatidia types can be distinguished in the tobacco hornworm moth retina, which differ by number of R7-like cells (1–2) or the combination of B- and UV-opsin expressing R-7 cells [12]. In the honeybee, six different ommatidia types occur which either express G-, UV- or B-opsin in both R7-like cells or in any possible combination [24]. In Tribolium, LW-opsin is expressed in all photoreceptor cells. Co-expression of LW- with UV-opsin in R7 is indicated by gradient from violet to green