The central symmetry system runs in the middle region of the wing and is centered on the discal location. The boundary symmetry system runs along the distal region of the wing, usually parallel to the wing edge (Fig. 1.2).
Shape of the Parafocal Elements
The hypothesis then is that the shape of the parafocal elements is determined by a gradient left behind by the process that formed the focus. A double source in focus, one producing the eye spot (b) and the other producing the parafocal element and proximal arc-shaped band of the boundary symmetry system (c–g).
Fusion and Separation of Ocelli and Parafocal Elements
Modes of Pattern Evolution
Brakefield P, Gates J, Keys D, Kesbeke F, Wijngaarden P, Monteiro A, French V, Carroll S (1996) Development, plasticity and evolution of butterfly eyespot patterns. Otaki JM (2011) Generation of butterfly wing eyespot patterns: a model for morphological determination of eyespot and parafocal element.
Introduction
Members of the last eight tribes have the largest body sizes within the Satyrinae and also show remarkable variation in wing pattern. Most species of Satyrinae are small-bodied and relatively uniform in appearance, such as members of the tribe Satyrinae (85% of species in the subfamily, Pe~na and Wahlberg 2008).
Central Symmetry System Dislocations in Forewing and Hind Wing
Five topics are briefly described and illustrated and, as much as possible, discussed within the context of butterfly natural history and behaviour. Gray arrows indicate the multi-colored bar associated with the f element. c) Opsiphanes sallei, note detail of venation showing precostal cell present at base of hind wing. d)Caligo illioneusmale set on leaf (photo by David Powell).
Variation in Ventral Hind Wing Ocelli
Finally, hind wing ocelli are uniquely dislocated distally in the transparent Haeterini genera by being located very close to the wing margin (Fig.2.3e–f). The male clearly displayed the ventral hindwing ocelli to the female as he repeatedly dived closer and closer to her.
The Color Band Between Elements f and g
Hill and Vaca (2004) have shown that the tornus of the hindwing of Pierella lucia is weaker than the surrounding wing areas, supporting the deflection hypothesis (see beak markings in Figure 2.3a). For example, members of the Brassolini vary in the orientation of this band (compare Catoblepia and Caligo; Fig. 2.8a–b). For comparison, note that fandg are also clearly visible on the hindwing of Pierella lucia (Fig. 2.3c), where a pale band is expressed only ventrally.
Sexual Dimorphism and Mimicry
The genus Pierella provides an excellent example of how different WPEs and associated bands can be modified by evolution to give rise to broadly distinctive species-specific patterns (Fig. 2.3b–d). Figures 2.6c,d,f eng illustrate a series of such changes, using color-coded wing pattern elements in selected Amathusiini. Although some WPEs can be identified in Elymnias species that have complex Danaini-like dorsal patterns, they are generally difficult to interpret (Fig. 2.4a-c).
Transparency
Concluding Remarks
Schwanwitsch BN (1924) On the plan of the wing pattern in Nymphalids and certain other families of the Rhopaloeerous Lepidoptera. Schwanwitsch BN (1925) On a remarkable dislocation of the components of the wing pattern in a Satyrid genusPierella. These approaches will provide new lines of research for studying the evolution of camouflage patterns and the underlying flexibility of the NGP.
Introduction
From the point of view of comparative morphology, the crucial question is how effective the NGP scheme is in understanding lepidoteran camouflage patterns. Furthermore, if certain camouflage patterns are exemplified by NGP, what information can this scheme provide for understanding. Finally, a research roadmap is proposed for further macroevolutionary studies on the origin and diversification of camouflage patterns.
Morphological Foundations of the Nymphalid Ground Plan
Third, the scheme of the NGP is used to discuss a flexible construction logic of leaf imitation patterns. For example, the wing patterns of some papilionids are intensively fragmented by dislocation and thus difficult to connect to the NGP (Mallet1991). Previous studies have revealed the molecular mechanisms underlying eyespots (ocelli), one of the NGP elements in butterfly wings (Carroll et al. 1994;.
Evolutionary Path: Gradual Evolutionary Steps Toward Leaf Vein-Like Patterns
Suzuki et al. 2014), and the results were consistent with the analysis of Schwanwitsch (1956) and confirmed the empirical reasoning proposed by Süffert (1927). In such scenarios, PCMs can be used to reconstruct the ancestral states of traits (Schluter et al. 1997; This analysis revealed sequential steps in the evolution of leaf mask patterns from non-mimetic wing patterns within a phylogenetic framework (Fig. 3.4c). ; Suzuki et al. 2014) and provided the first evidence for a gradual evolutionary origin of leaf mimicry (Skelhorn 2015).
Tinkering: The Flexible Building Logic of Leaf Vein-Like Patterns
Thus, tracing ancestral states at different phylogenetic nodes illustrates the sequential transformation of character states of several components that led to complex traits (Figure 3.4b). To answer this question, here I compare the NGP of a leaf vein-like pattern found in the noctuid mothO. Thus, the flexible building logic of Lepidopteran leaf patterns could reflect the tinkering logic of the evolutionary processes behind them.
Modularity: Developmental Modules of the NGP and a Simple Cryptic Pattern
In fact, the central symmetry system of the NGP appears to be a genetically and phenotypically independent unit (Brakefield1984; Paulsen and Nijhout1993; Paulsen and eyespots are developmental units formed by factors distributed from the focus (Nijhout 1980; French and Brakefield To address 1995).This issue is examined the relatively simple masking pattern of the noctuid moth Thyas juno (Fig.3.6b; Suzuki2013) The modularity of the simple patterns corresponds to the original modules of the NGP development.
Evolutionary Origin of De Novo Modules: Rewiring of the NGP Developmental Modules to Generate
Although the study of a practical case is limited, at least in relatively simple camouflage patterns, these results supported the hypothesis that the genetic and developmental architectures underlying camouflage patterns reflect the original developmental modules of the NGP (Fig.3.6a). In addition to this previous perspective, the present review emphasizes the importance of coupling of pattern elements in wing morphological diversification and proposes a new organizing principle, a “recoupling” strategy (i.e. coupling and uncoupling) of the NGP, where a combination of uncoupling and coupling processes "recreates" the correlations between common parts (Fig.3.7a; Suzuki2013).
Next Research Programs
Macroevolutionary Pathways Toward Camouflage Patterns
For example, comparing the evolutionary processes involved in butterfly leaf masquerade and lichen cryptic patterns may reveal common/different evolutionary mechanisms between the different camouflage patterns. Similarly, comparing the evolutionary processes of leaf mask among different taxa may reveal how many pathways are involved in the evolution of lepidopteran leaf patterns and/or address the mechanisms that enable the multiple origins of leaf mimicry in Lepidoptera. In addition to these research directions, it is expected that studying the evolutionary processes and pathways involved in complex and diversified traits will add a new direction in the research field of macroevolution.
Macro-evolvability of the NGP
As shown above, mathematical methods using Bayesian statistics have made it possible to analyze the evolutionary origins and successive steps towards different camouflage patterns (Suzuki et al. 2014; Suzuki 2017). This approach makes it possible to test whether the camouflage patterns arose gradually or suddenly, and to analyze the evolutionary process through which the modifications that create the camouflage patterns accumulated. Addressing such questions will require combining morphological and molecular studies to verify the integrity of the NGP (Martin et al. 2012; Martin and Reed 2014), because the NGP may be difficult to identify in these butterflies.
Body plan Character Map: Genetic and Developmental Architectures of the NGP
Endo K (1984) Neuroendocrine regulation of the development of seasonal forms of the Asian twig butterfly, Polygonia c-aureum. Fukada S, Endo K (1966) Hormonal control of the development of seasonal forms in the butterfly Polygonia c-aureumL. Martin A, Reed RD (2014) Wnt signaling underlies the evolution and development of butterfly wing pattern symmetry systems.
Gephebase: The Database of Genotype-Phenotype Variations
Method: Construction of Gephebase and Identification of Signaling Genes
Association mapping studies are included based on individual judgement, with a strong bias against SNP-phenotype associations that have been confirmed in reverse genetics studies. Association mapping: an advanced genetic method for gephe identification based on genome-wide statistical association between genetic variants and phenotypic traits, generally in a large cohort of unrelated individuals. Linkage mapping: an advanced genetic method for gepha identification based on chromosomal shuffling and crossing using hybrid cross progeny.
A Few Select Genes for Body-Wide Switches in Melanin Production in Tetrapods
This is in contrast to the melanic gain-of-function coding alleles of MC1R, which are dominant, and the difference in allelic effects has been used to infer the genetic basis of melanism (Eizirik et al. 2003). It has been suggested that wild-type Agouti can become an agonist of melanic MC1R variants (McRobie et al. 2014), suggesting that certain MC1R gain-of-function alleles reverse the responsiveness of the receptor to the Agouti ligand itself. In addition to Agouti, the skin epithelium secretes the peptide β-defensin 3/CBD103, which binds strongly to MC1R and has been shown to be responsible for melanism in dogs (Candille et al. 2007).
A few other cases of whole-organism color changes have been shown to be positively selected (Vignieri et al. Deer mice show extensive pigment variation that matches the color of their environment (Manceau et al. 2010). Different regulatory elements are involved in controlling expression of three alternative isoforms in different body regions (Mallarino et al.2016).
Recent Stickleback Fish Adaptations Repeatedly Recruited Ligand Alleles
Several BMP alleles have been linked to increased fertility in domestic sheep (BMP15 and its paralogGDF9) (Monestier et al. 2014) and to fecundity and bone allocation in chicken (BMP2) (Johnsson et al. 2012). The tumor necrosis factor superfamily gene Ectodysplasin A (EDA) harbors cis-regulatory variation that exists at low frequency in the marine population, which has been repeatedly recruited into continental populations to drive platelet count reduction (Colosimo et al. 2005; Jones et al. 2012; O'Brown et al 2015). In addition, a combination of QTL mapping and genome scanning has identified a freshwater-specific allele at the growth/differentiation factor 6 (GDF6) locus, resulting in an increase in the expression of that gene in the developing epithelium and ultimately in a reduction of lateral plate size (Indjeian et al. 2016).
The Wnt Beneath My Wings
The same locus also triggers a change in schooling behavior, as fish from lacustrine habitats have lost the ability to precisely align their body axis when swimming in a group, an effect that is reversed by transgenic overexpression of EDA (Greenwood et al. 2016). As with KITLG, this case opened a window into human evolution, as the hind limb-specific enhancer aGDF6 was found to have been lost in the human lineage, with skeletal modifications being acquired in mice suggesting a potential role in the development of bipedalism (Indjeian et. al.2016). Each allele is associated with spatial shifts in WntA expression that drive variation in pattern shape, particularly in the median.
Ligand Gene Modularity Allows Interspecific Differences
Interestingly, detailed analyzes of the cis-regulatory region of another Wnt locus, this time including wingless (syn.Wnt1;wg) and its successive paralogs Wnt6andWnt10 (Fig. 4.3c), show that three new cis-elements -tissue-specific regulators drive wingless expression and are based on novel color patterns in the wings and thorax of Drosophila guttiferafruit flies (Werner et al.2010; Koshikawa et al.2015). It is noteworthy that wg is also associated with color patterns and wing contours in both flies and butterflies (Macdonald et al. 2010; Martin and Reed2010; Koshikawa et al. 2015) and a redistribution of this gene to new regions of body is likely to drive the evolution of new patterns as well, as it appeared to have occurred during the evolution of larval cuticle patterns in Lepidoptera (Yamaguchi et al. 2013). In short, the various case studies linking insect wing variation and ligand genes highlight the importance of modular cis -regulatory architecture in the complexity of anatomy.
How, When, and Why Ligand Genes Are Likely Drivers of Pattern Variation, or Not
