We investigate mutations in trβ2, a splice variant of thrb, identifying changes in function, structure, and behavior in larval and adult zebrafish retinas. Two N-terminus CRISPR mutants were identified. The first is a 6BP+1 insertion deletion frameshift resulting in a truncated protein. The second is a 3BP in frame deletion with intact binding domains. ERG recordings of isolated cone signals showed that the 6BP+1 mutants did not respond to red wavelengths of light while the 3BP mutants did respond. 6BP+1 mutants lacked optomotor and optokinetic responses to red/black and green/black contrasts. Both larval and adult 6BP+1 mutants exhibit a loss of red-cone contribution to the ERG and an increase in UV-cone contribution. Transgenic reporters show loss of cone trβ2 activation in the 6BP+1 mutant but increase in the density of cones with active blue, green, and UV opsin genes. Antibody reactivity for red-cone LWS1 and LWS2 opsin was absent in the 6BP+1 mutant, as was reactivity for arrestin3a. Our results confirm a critical role for trβ2 in long-wavelength cone development.

ERG Recording Raw Data Isolated amplitudes from cone photoreceptors were collected through ERG electrode recordings. These datasets include the information for the stimulus flash including irradiance and wavelength. Responses are shown as the raw cone PIII amplitude response and the normalized response. Isolated zebrafish eyes were stimulated with each wavelength at varied irradiance levels. This stimulus information is then listed along with the corresponding response on the same line of the spreadsheet. The protocol runs through 70 stimuli per fish eye. Recordings are separated into datasets by genotype (6BP+1/3BP/WT) and developmental stage (larval/adult). There are only 6BP+1 and WT adults as 3BP mutants did not survive to adulthood.

These datasets provide the irradiance, wavelength, and respective amplitude response for 70 stimulus points per fish eye. There are 9 wavelengths: 650, 610, 570, 530, 490, 450, 410, 370, and 330. Repetition of wavelength stimuli allows for log step increases in irradiance level within each wavelength. Amplitude responses and their corresponding stimulus wavelength and irradiance level can be used for modeling the physiological properties of the cones. We used Origin Lab for analysis, but other programs can use this data easily. Normalized amplitudes are provided to control for non-biological variation between recordings. There are no missing values.