Sexual dimorphism in the compound eye of Heliconius erato: a nymphalid butterfly with at least five spectral classes of photoreceptor.
J Exp Biol
; 219(Pt 15): 2377-87, 2016 08 01.
Article
em En
| MEDLINE
| ID: mdl-27247318
ABSTRACT
Most butterfly families expand the number of spectrally distinct photoreceptors in their compound eye by opsin gene duplications together with lateral filter pigments; however, most nymphalid genera have limited diversity, with only three or four spectral types of photoreceptor. Here, we examined the spatial pattern of opsin expression and photoreceptor spectral sensitivities in Heliconius erato, a nymphalid with duplicate ultraviolet opsin genes, UVRh1 and UVRh2 We found that the H. erato compound eye is sexually dimorphic. Females express the two UV opsin proteins in separate photoreceptors, but males do not express UVRh1. Intracellular recordings confirmed that females have three short wavelength-sensitive photoreceptors (λmax=356, â¼390 and 470â
nm), while males have two (λmax=390 and â¼470â
nm). We also found two long wavelength-sensitive photoreceptors (green, λmaxâ¼555â
nm, and red, λmaxâ¼600â
nm), which express the same LW opsin. The red cell's shifted sensitivity is probably due to perirhabdomal filtering pigments. Sexual dimorphism of the UV-absorbing rhodopsins may reflect the females' need to discriminate conspecifics from co-mimics. Red-green color vision may be used to detect differences in red coloration on Heliconius wings, or for host-plant identification. Among nymphalids so far investigated, only H. erato is known to possess five spectral classes of photoreceptor; sexual dimorphism of the eye via suppression of one class of opsin (here UVRh1 in males) has not - to our knowledge - been reported in any animal.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Borboletas
/
Caracteres Sexuais
/
Células Fotorreceptoras de Invertebrados
/
Olho Composto de Artrópodes
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article