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Developmental mechanisms of longitudinal stripes in the J apanese four‐lined snake
Author(s) -
Murakami Arata,
Hasegawa Masami,
Kuriyama Takeo
Publication year - 2018
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.20750
Subject(s) - chromatophore , biology , embryogenesis , embryonic stem cell , melanophore , myotome , developmental stage , anatomy , evolutionary biology , embryo , microbiology and biotechnology , gene , genetics , somite , psychology , developmental psychology
The developmental mechanisms of color patterns formation and its evolution remain unclear in reptilian sauropsids. We, therefore, studied the pigment cell mechanisms of stripe pattern formation during embryonic development of the snake Elaphe quadrivirgata . We identified 10 post‐ovipositional embryonic developmental stages based on external morphological characteristics. Examination for the temporal changes in differentiation, distribution, and density of pigment cells during embryonic development revealed that melanophores first appeared in myotome and body cavity but not in skin surface at Stage 5. Epidermal melanophores were first recognized at Stage 7, and dermal melanophores and iridophores appeared in Stage 9. Stripe pattern first appeared to establish at Stage 8 as a spatial density gradient of epidermal melanophores between the regions of future dark brown longitudinal stripes and light colored background. Our study, thus, provides a comprehensive pigment‐cell‐based understanding of stripe pattern formation during embryonic development. We briefly discuss the importance of the gene expression studies by considering the biologically relevant theoretical models with standard developmental staging for understanding reptilian color pattern evolution.