Distribution and development of short‐wavelength cones differ between Macaca monkey and human fovea

Bumsted, Keely; Hendrickson, Anita E.

doi:10.1002/(sici)1096-9861(19990125)403:4<502::aid-cne6>3.3.co;2-e

Cited by 37 publications

(50 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Relative numbers of S cones have been reported previously (Ahnelt et al, 1987;Curcio et al, 1991;Bumsted and Hendrickson, 1999;Roorda et al, 2001). However, the large number of individuals examined with our technique allows an estimate of the interobserver variability in the relative number of S cones at a given retinal location.…”

Section: Arrangement Of S Cones In the Human Retinamentioning

confidence: 99%

Organization of the Human Trichromatic Cone Mosaic

Hofer¹,

Carroll²,

Neitz³

et al. 2005

J. Neurosci.

414

311

View full text Add to dashboard Cite

Using high-resolution adaptive-optics imaging combined with retinal densitometry, we characterized the arrangement of short-(S), middle-(M), and long-(L) wavelength-sensitive cones in eight human foveal mosaics. As suggested by previous studies, we found males with normal color vision that varied in the ratio of L to M cones (from 1.1:1 to 16.5:1). We also found a protan carrier with an even more extreme L:M ratio (0.37:1). All subjects had nearly identical S-cone densities, indicating independence of the developmental mechanism that governs the relative numerosity of L/M and S cones. L:M cone ratio estimates were correlated highly with those obtained in the same eyes using the flicker photometric electroretinogram (ERG), although the comparison indicates that the signal from each M cone makes a larger contribution to the ERG than each L cone. Although all subjects had highly disordered arrangements of L and M cones, three subjects showed evidence for departures from a strictly random rule for assigning the L and M cone photopigments. In two retinas, these departures corresponded to local clumping of cones of like type. In a third retina, the L:M cone ratio differed significantly at two retinal locations on opposite sides of the fovea. These results suggest that the assignment of L and M pigment, although highly irregular, is not a completely random process. Surprisingly, in the protan carrier, in which X-chromosome inactivation would favor L-or M-cone clumping, there was no evidence of clumping, perhaps as a result of cone migration during foveal development.

show abstract

Section: Arrangement Of S Cones In the Human Retinamentioning

confidence: 99%

Organization of the Human Trichromatic Cone Mosaic

Hofer¹,

Carroll²,

Neitz³

et al. 2005

J. Neurosci.

414

311

View full text Add to dashboard Cite

show abstract

“…Anatomical [1][2][3][4][5][6][7][8][9][10] and behavioral [11][12][13] techniques have provided a good understanding of the number and packing arrangement of the S cone submosaic. But identifying the number and arrangement of the L and M cone submosaics has been a considerably less tractable problem.…”

Section: Introductionmentioning

confidence: 99%

Functional consequences of the relative numbers of L and M cones

et al. 2000

View full text Add to dashboard Cite

Direct imaging of the retina by adaptive optics allows assessment of the relative number of long-wavelengthsensitive (L) and middle-wavelength-sensitive (M) cones in living human eyes. We examine the functional consequences of variation in the relative numbers of L and M cones (L/M cone ratio) for two observers whose ratios were measured by direct imaging. The L/M cone ratio for the two observers varied considerably, taking on values of 1.15 and 3.79. Two sets of functional data were collected: spectral sensitivity measured with the flicker electroretinogram (ERG) and the wavelength of unique yellow. A genetic analysis was used to determine L and M cone spectra appropriate for each observer. Rayleigh matches confirmed the use of these spectra. We determined the relative strength of L and M cone contributions to ERG spectral sensitivity by fitting the data with a weighted sum of L and M cone spectra. The relative strengths so determined (1.06 and 3.38) were close to the cone ratios established by direct imaging. Thus variation in L/M cone ratio is preserved at the sites tapped by the flicker ERG. The wavelength of unique yellow varied only slightly between the two observers (576.8 and 574.7 nm). This small variation indicates that neural factors play an important role in stabilizing unique yellow against variation in the L/M cone ratio.

show abstract

“…Cones can be divided into subtypes based on lightwavelength sensitivity that are characteristically distributed in different species. In humans, cones sensitive to long (L), medium (M), and short (S) wavelengths, each expressing a distinct cone opsin, are enriched within the macular region (1,2). The mouse retina expresses only two cone opsins, M and S, which are distributed in opposing gradients along the dorsal-ventral axis, forming spatially distinct populations of M, S, and hybrid M/S cones (3,4).…”

mentioning

confidence: 99%

Active opsin loci adopt intrachromosomal loops that depend on the photoreceptor transcription factor network

Peng¹,

Chen

2011

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Rod and cone opsin genes are expressed in a mutually exclusive manner in their respective photoreceptor subtypes in the mammalian retina. Previous transgenic mouse studies showed that functional interactions between the distal enhancer and proximal promoter of rhodopsin and long/medium-wavelength (L/M) opsin genes are essential for regulating their cell-type-specific transcription. We have used chromosomal conformation capture assays in mouse retinas to investigate the molecular mechanism responsible for this interaction. Here we show that each opsin gene forms intrachromosomal loops in the appropriate photoreceptor subtype, while maintaining a linear configuration in other cell types where it is silent. The enhancer forms physical contacts not only with the promoter but also with the coding regions of each opsin locus. ChIP assays showed that cell-type-specific target binding by three key photoreceptor transcription factors-cone-rod homeobox (CRX), neural retina leucine zipper (NRL), and nuclear receptor subfamily 2, group E, member 3 (NR2E3)-is required for the appropriate local chromosomal organization and transcription of rod and cone opsins. Similar correlations between chromosomal loops and active transcription of opsin genes were also observed in human photoreceptors. Furthermore, quantitative chromosomal conformation capture on human retinas from two male donors showed that the L/M enhancer locus control region (LCR) loops with either the L or M promoter in a near 3:1 ratio, supporting distance-dependent competition between L and M for LCR. Altogether, our results suggest that the photoreceptor transcription factor network cooperatively regulates the chromosomal organization of target genes to precisely control photoreceptor subtypespecific gene expression.neuronal gene expression | enhancer-promoter interaction | chromatin modulation | epigenetic regulation R ods and cones are two types of image-forming photoreceptors that constitute 70% of retinal cells in mice and humans. Rods, representing 95-97% of the photoreceptors, are sensitive to dim light and responsible for night vision. Cones, although constituting only 3-5% of the photoreceptors, sense bright light and mediate color discrimination and visual acuity. These functional differences are attributed, at least in part, to the unique visual pigments made by rods [rhodopsin (Rho)] or cones (cone opsins). Cones can be divided into subtypes based on lightwavelength sensitivity that are characteristically distributed in different species. In humans, cones sensitive to long (L), medium (M), and short (S) wavelengths, each expressing a distinct cone opsin, are enriched within the macular region (1, 2). The mouse retina expresses only two cone opsins, M and S, which are distributed in opposing gradients along the dorsal-ventral axis, forming spatially distinct populations of M, S, and hybrid M/S cones (3, 4).Photoreceptor subtype-specific opsin expression is regulated by interactions between DNA cis-regulatory elements and a network of photoreceptor transc...

show abstract

Distribution and development of short‐wavelength cones differ between Macaca monkey and human fovea

Cited by 37 publications

References 27 publications

Organization of the Human Trichromatic Cone Mosaic

Organization of the Human Trichromatic Cone Mosaic

Functional consequences of the relative numbers of L and M cones

Active opsin loci adopt intrachromosomal loops that depend on the photoreceptor transcription factor network

Contact Info

Product

Resources

About