Ultrastructural characterization of the hemocytes of Culex quinquefasciatus (DIPTERA: Culicidae)

Brayner, Fábio André; Araújo, Helena Rocha Corrêa de; Cavalcanti, Maria Taciana Holanda; Alves, Luíz Carlos; Peixoto, Christina Alves

doi:10.1016/j.micron.2004.11.007

Cited by 37 publications

(25 citation statements)

References 16 publications

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“…On the 14th day post‐infection, similar changes were observed for these haemocyte types, except for significant increases in the proportion of granular cells (41.2%). Our results were similar to those obtained previously; however, it is important to note that the exact proportions obtained in the present study differed from those in other studies in part because we identified six types of haemocytes in the perfusated haemolymph (Brayner et al , 2005), instead of only three haemocyte types described by Paily et al 2005).…”

Section: Discussionsupporting

confidence: 84%

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Haemocyte population and ultrastructural changes during the immune response of the mosquito Culex quinquefasciatus to microfilariae of Wuchereria bancrofti

Brayner

Araújo

Santos

et al. 2007

Medical Vet Entomology

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Haemocytes circulating in the haemolymph protect insects against pathogens that enter the haemocoel. Changes in haemocyte morphology and differences in haemocyte counts during the immune response of Culex quinquefasciatus Say (Diptera: Culicidae) to microfilariae of Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae) were investigated in the present study. The mean number of total haemocytes was significantly elevated in infected mosquitoes (P<0.001), reaching a peak on the third day post-infection. Differential counts show that mean numbers of prohaemocytes, plasmatocytes, granular cells and oenocytoids increased significantly after infection with microfilariae granulocytes compared to the control and näive groups of Cx. quinquefasciatus (P<0.05). Changes in proportional counts of haemocytes were also analysed in haemolymph perfusates of Cx. quinquefasciatus infected with W. bancrofti. On the first day post-infection, infected mosquitoes showed an increase in the proportion of prohaemocytes (18.8% compared to 9.6% for the control) and of oenocytoids (7.1% compared to 4.7% control); however, they exhibited lower levels of plasmatocytes (36.6% compared to 42.1% control) and granular cells (36.1% compared to 41.4% control). On day 14 post-infection, similar changes were observed for these haemocyte types, except that the proportion of granular cells was significantly greater than the control (41.2% compared to 31.3% control). Although an enhancement of prohaemocyte numbers was observed, this cellular type did not show any ultrastructural alteration. On the other hand, granular cells, plasmatocytes and oenocytoids presented morphological alterations indicative of innate immunological activation in mosquitoes infected with W. bancrofti.

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Section: Discussionsupporting

confidence: 84%

“…Recently, we described six haemocyte types in Cx. quinquefasciatus haemolymph, by ultrastructural analyses (Brayner et al , 2005).…”

Section: Introductionmentioning

confidence: 99%

Haemocyte population and ultrastructural changes during the immune response of the mosquito Culex quinquefasciatus to microfilariae of Wuchereria bancrofti

Brayner

Araújo

Santos

et al. 2007

Medical Vet Entomology

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“…In almost all groups of individuals cultured in conditions similar to summer, the dominant haemocytes were plasmatocytes. Domination of plasmatocytes in the haemolymph was observed in other insect species such as the ground beetle Carabus lefebvrei (Giglio et al ., ) and the mosquito Culex quinquefasciatus (Brayner et al ., ). In individuals collected in October and during the winter period, we observed changes in the percentage ratio of each haemocyte type.…”

Section: Discussionmentioning

confidence: 97%

Impact of cold on the immune system of burying beetle, Nicrophorus vespilloides (Coleoptera: Silphidae)

et al. 2016

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Insect overwintering is one of the most astonishing phases of the insect life cycle. Despite vast amounts of knowledge available about the physiological mechanisms of this phenomenon, the impact of stress factors on insect immune system functioning during the winter is still unknown. The aim of this study is to analyze how low temperatures influence the immune system of the beetle Nicrophorus vespilloides. The results show that the beetle's immune system is differently modulated by cold induced in laboratory settings than that which occurs in natural conditions. Among beetles cultured in conditions similar to summer, low temperatures, did not influence the number of circulating haemocytes, phenoloxidase activity, haemocytes morphology, and percentage ratio of haemocyte types. In these beetles, differences were noted only in the ability of haemocytes to perform phagocytosis. Individuals acclimated in natural conditions in autumn had a higher level of humoral response and a different percentage ratio of haemocyte types. During the winter period, the number of haemocytes in the beetles decreased, but the percentage ratio of phagocytic haemocytes increased. Furthermore, we noted an increase of phenoloxidase activity. Our study also showed mitotic divisions of haemocytes in haemolymph collected from burying beetles after cold exposure and from burying beetles collected from natural conditions during autumn and winter. Differences in response to low temperatures in laboratory conditions and the natural environment suggest that the simultaneous presence of other stress factors during winter such as desiccation and starvation have a significant influence on the activity of burying beetle's immune system.

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“…The drop was allowed to dry in the dark at 0°C for 10 min and stained with Giemsa (diluted 1:9 in distilled water) for 20–40 min (Brayner et al 2005). To fix the hemocytes, the slides were immersed in a saturated lithium carbonate solution for 5 s and quickly rinsed in distilled water (Brayner et al 2005). Then, the hemocytes were observed under a brightfield microscope.…”

Section: Methodsmentioning

confidence: 99%

Immunological Responses of Sesamia cretica to Ferula ovina Essential Oil

Sadeghi

Raeisi

Jamshidnia

2017

Journal of Insect Science

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The current research was performed aiming to investigate the effects of Ferula ovina essential oil on the fourth instar larval hemogram of Sesamia cretica. Four main sorts of circulating hemocytes, including prohemocytes, plasmatocytes, granulocytes (GRs), and oenocytoides, were identified in the fourth instar larvae. Treatment of the larvae with the concentration of 1000 ppm of the essential oil led to an enhancement of the total hemocyte and GR count followed by a dose-dependent decrease at the concentrations of 2500 and 7000 ppm. Plasmatocyte numbers declined in all the treatments with more significant effects at increased doses. The greatest numbers of GRs, plasmatocytes, and total hemocytes were found after 48 h of treatment. The highest phenol-oxidase activity was recorded 12 h after treatment at the concentration of 2500 ppm. The highest effect on nodule formation was exerted by the concentration of 7000 ppm 12 h after treatment. The results of the present study clearly indicated that the treatment of larvae by the essential oil of F. ovina decreased the numbers of total and differential hemocyte counts although phenol-oxidase activity and the number of nodules showed no decline in the treated larvae. These results demonstrated that Ferula ovina essential oil has a significant effect on the immune ability of the studied insect and can be useful and usable for future research to practical management of this pest.

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Ultrastructural characterization of the hemocytes of Culex quinquefasciatus (DIPTERA: Culicidae)

Cited by 37 publications

References 16 publications

Haemocyte population and ultrastructural changes during the immune response of the mosquito Culex quinquefasciatus to microfilariae of Wuchereria bancrofti

Haemocyte population and ultrastructural changes during the immune response of the mosquito Culex quinquefasciatus to microfilariae of Wuchereria bancrofti

Impact of cold on the immune system of burying beetle, Nicrophorus vespilloides (Coleoptera: Silphidae)

Immunological Responses of Sesamia cretica to Ferula ovina Essential Oil

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