Mechanisms Underlying the Formation and Evolution of Vertebrate Color Patterns

Abstract

Vertebrates exhibit a wide range of color patterns, which play critical roles in mediating intra- and interspecific communication. Because of their diversity and visual accessibility, color patterns offer a unique and fascinating window into the processes underlying biological organization. In this review, we focus on describing many of the general principles governing the formation and evolution of color patterns in different vertebrate groups. We characterize the types of patterns, review the molecular and developmental mechanisms by which they originate, and discuss their role in constraining or facilitating evolutionary change. Lastly, we outline outstanding questions in the field and discuss different approaches that can be used to address them. Overall, we provide a unifying conceptual framework among vertebrate systems that may guide research into naturally evolved mechanisms underlying color pattern formation and evolution. Expected final online publication date for the Annual Review of Genetics, Volume 57 is November 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Developmental plasticity and variability in the formation of egg‐spots, a pigmentation ornament in the cichlid Astatotilapia calliptera

“…However, the role of positional information cues is hypothesized to be more important in the development of non-periodic patterns, to define their position in the tissue (Parichy, 2021). Such positional information cues may exist as morphogen gradients, physical tissue architecture, or growth patterns (Kratochwil & Mallarino, 2023). Though positional information and local self-organizing mechanisms can provide alternate explanations for patterning (Green & Sharpe, 2015), they are not mutually-exclusive (Kratochwil & Mallarino, 2023).…”

“…Such positional information cues may exist as morphogen gradients, physical tissue architecture, or growth patterns (Kratochwil & Mallarino, 2023). Though positional information and local self-organizing mechanisms can provide alternate explanations for patterning (Green & Sharpe, 2015), they are not mutually-exclusive (Kratochwil & Mallarino, 2023). To evaluate the role of these mechanisms in egg-spot positioning, we deduce two scenarios with primary roles for self-organizing cellular interactions or positional information, and consider cellular events during egg-spot formation for each scenario.…”

“…Vertebrate pigment patterns are excellent traits in which to address such questions, being extremely diverse within and between species. Importantly, color patterns influence a wide range of ecological interactions and are vital for animal adaptation: they can affect courtship behavior, mate preference, predator avoidance and thermoregulation, among others (Elkin et al, 2023;Kratochwil & Mallarino, 2023).…”

recolorize: An R package for flexible colour segmentation of biological images

“…1. Colour pattern: Spatial variation in the spatiochromatic features of an animal's integument, per Kratochwil and Mallarino (2023)…”

Twenty years on from Developmental Plasticity and Evolution: middle-range theories and how to test them

“…1A,B). For example, vertebrate colour patterns are an outcome of the arrangement of chromatophores, which in turn is determined by properties of cells, and interactions between cells and between cells and other features of their surroundings (Kratochwil and Mallarino, 2023). Models of different complexity can capture the macroscopic outcome of these interactions and make it possible to study how perturbations of the model inputs influence the output pattern (e.g.…”