Sexual dimorphism in immune response: Testing the hypothesis in an insect species with two male morphs
Por:
Ruiz-Guzmán G., Canales-Lazcano J., Jiménez-Cortés J.G., Contreras-Garduño J.
Publicada:
1 oct 2013
Resumen:
It has been proposed that given that males should invest in sexual
traits at the expense of their investment in immune response, females
are better immunocompetent than males. Typically, this idea has been
tested in monomorphic species, but rarely has been evaluated in
polymorphic male species. We used Paraphlebia zoe, a damselfly with two
male morphs: the black-winged morph (Black-W) develop black spots as
sexual traits and the hyaline-winged morph (Hyaline-W) resembles a
female in size and wings color. We predicted that Black-W should have a
lower immune response than Hyaline-W, but that the latter males should
not differ from females in this respect. Nitric oxide (NO) and
phenoloxidase (PO) production, as well as hemolymph protein content,
were used as immune markers. Body size (wing length) was used as an
indicator of the male condition. The results show that, as we predicted,
females and Hyaline-W had higher values of NO than Black-W,
corresponding to differences in size. However, the opposite was found in
relation to PO production. Females had the highest levels of hemolymph
protein content, whereas no differences were found between Black-W and
Hyaline-W. These results partially support the sexual selection
hypothesis and are discussed in the context of the life history of this
species. Black-W, Hyaline-W, and females could express the immune
markers that are prioritized by their particular condition, and probably
neither of them could express all immune markers in an elevated manner,
as this would result in an excessive accumulation of free radicals.
Filiaciones:
Inst Nacl Salud Publ, Ctr Invest Enfermedades Infecciosas, Cuernavaca 62100, Morelos, Mexico
Univ Nacl Autonoma Mexico, Dept Ecol Evolutiva, Inst Ecol, Mexico City 04510, DF, Mexico
Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Mexico
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