Table of Contents
ISRN Evolutionary Biology
Volume 2014, Article ID 329736, 6 pages
Research Article

Is Sexual Dimorphism in the Immune Response of Gryllodes sigillatus Related to the Quality of Diet?

1Uiversidad Nacional Autonoma de Mexico FES Iztacala, UBIPRO, Laboratoria de Ecología, Avenida de los Barrios, Number 1 Los Reyes Iztacala, A.P. 314, 54090 México, MX, Mexico
2División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Campus Guanajuato, Noria Alta s/n, Noria Alta, 36050 Guanajuato, GTO, Mexico

Received 24 August 2013; Accepted 30 December 2013; Published 20 March 2014

Academic Editors: M. Friedrich, M. L. Hale, and Y. Park

Copyright © 2014 Adolfo Galicia et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Whereas some authors have proposed that sexual dimorphism in the immune response is fixed, others pose that it is dynamic and depends on diet. The aim of the present study was to explore the second hypothesis. Immunocompetence differences between females and males can be linked to resource availability. We tested this idea by providing a low or high quality diet to two groups of Gryllodes sigilatus during their developmental period. Then, at the adult phase half of each group was challenged with LPS from Serratia marcescens. The size, phenol oxidase (PO), and lytic activity were compared between groups according to diet, sex, and immune challenge. Results show that diet quality favor size in both sexes. However, the overall immune response did not seem to be significantly different based on diet, but instead on sex. Females showed greater phenol oxidase levels than males, but the opposite was found with lytic activity. Perhaps in G. sigillatus the differences in the pathogens commonly confronted by each sex in the distinct habitat of each could explain the differences on PO and lytic activity.