Altered differential hemocyte count in 3rd instar larvae of Drosophila melanogaster as a response to chronic exposure of Acephate

Abstract

Acephate, an organophosphate (OP) pesticide, was used to investigate the effects of its chronic exposure on hemocyte abundance in a non-target dipteran insect Drosophila melanogaster. For this purpose, six graded concentrations ranging from 1 to 6 μg/ml were selected, which are below the reported residual values (up to 14 μg/ml) of the chemical. 1st instar larvae were fed with these concentrations up to the 3rd instar stage and accordingly hemolymph smears from these larvae were prepared for differential hemocyte count. Three types of cells are found in Drosophila hemolymph, namely, plasmatocytes, lamellocytes and crystal cells. Plasmatocyte count was found to decrease with successive increase in treatment concentrations. Crystal cells showed an increasing trend in their number. Though the number of lamellocytes was very low, a bimodal response was noticed. Lamellocyte number was found to increase with the initial three concentrations, followed by a dose dependent reduction in their number. As hemocytes are directly linked to the immune system of fruit flies, fluctuations in normal titer of these cells may affect insect immunity. Hemocytes share homologies in their origin and mode of action with the immune cells of higher organisms including man. Thus the present findings suggest that immune cells of humans and other organisms may be affected adversely under chronic exposure to Acephate.

Chronic exposure to acephate triggers ROS-mediated injuries at organismal and sub-organismal levels ofDrosophila melanogaster

“…In our previous findings, 30,31 the concentrations of acephate ranging from 1-6 µg mL −1 were observed to affect the normal developmental duration and differential hemocyte count of D. melanogaster. Besides, these concentrations were below the chronic LC 50 value (as evaluated in this study) and far less than the reported acephate residues in vegetables.…”

“…Hence, the THC of the larvae was examined following chronic exposure to acephate. Hemolymph from 10 exposed larvae was bled (following a previously established method) 31 in 20 µl PSS and stained with the same volume of Tb for 10 min. The hemolymph solution was diluted with 20 µl of PSS and loaded over a hemocytometer for THC.…”

Effects of Selenium and Vitamin E on Enzymatic, Biochemical, and Immunological Biomarkers in Galleria mellonella L

“…Toxic substances, such as pesticides and heavy metals, decrease the number of hemocytes 19,53 . Studies have reported that toxic substances can alter the immunological response 54 , inhibit hematopoietic function 55 , decrease mitotic activity 56 , and induce apoptosis 57 . Kim et al 3 .…”

Pesticide–Virus Interactions in Honey Bees: Challenges and Opportunities for Understanding Drivers of Bee Declines

“…First, pesticide exposure can disrupt cellular immune defenses by affecting hemocyte differentiation and function. Larval D. melanogaster fed with acephate (an organophosphate) display altered differential hemocyte counts, with a relative decrease in phagocytosing macrophages/plasmatocytes [152]. Moreover, exposure to the neonicotinoid imidacloprid can reduce phagocytotic function of hemocytes [153,154], and also decrease the survival of fat body cells, which play critical roles in immune responses such as AMP production [155].…”