Lysozyme in the midgut of <i>Manduca sexta</i> during metamorphosis

Russell, Virginia; Dunn, Patrick F.

doi:10.1002/arch.940170202

Cited by 67 publications

(43 citation statements)

References 21 publications

(15 reference statements)

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“…However, other tissues, such as epidermis, muscles and mid gut cells may also participate in lysozymes production (Lee & Brey, 1995;Hultmark, 1996). In Manduca sexta mid gut cells lysozymes are developmentally regulated independently of a bacterial infection (Russell & Dunn, 1991).…”

Section: Introductionmentioning

confidence: 99%

Antibacterial activity of lysozyme in the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Mohamed¹,

Elmogy²,

Dorrah³

et al. 2013

Eur. J. Entomol.

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Abstract. The ability of biocontrol agents to overcome the immune defense of pests is a crucial issue. This is the first study of lysozyme activity as an inducible humoral component of the defense of Schistocerca gregaria, which depends on the recognition of the elicitor molecules of pathogens and not on epidermal wounding or a spiking effect. The level of lysozyme activity in fat body, haemocytes and haemolymph plasma of naïve and immunologically challenged 5 th instar S. gregaria was evaluated using the zone of inhibition test against Micrococcus lysodeikticus. Various Gram-positive and Gram-negative bacteria as well as peptidoglycans (PGN) and lipopolysacchrides (LPS) of bacterial cell walls induce and increase in the level of lysozyme activity. Escherichia coli induced an increase in the level of activity of lysozyme in the fat body, haemocytes and plasma, but not in mid gut epithelium, 6-12 h after an immunological challenge and then it decreased to the constitutive level after 72 h. This study revealed that in S. gregaria there is a constitutive and a bacteria-inducible level of lysozyme activity, which protects it against infection by both Gram-negative and Gram-positive bacteria.

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Section: Introductionmentioning

confidence: 99%

Antibacterial activity of lysozyme in the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Mohamed¹,

Elmogy²,

Dorrah³

et al. 2013

Eur. J. Entomol.

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“…Bacteria were grown in 50 ml of nutrient broth in an environmental shaker at 37°C and 100 rpm. Bacteria were used in midlogarithmic or stationary phase at a dose of 2.5-7.0 x 107 colony-forming units per ml (6 (5,8,11,14,17-eicosapentaenoic acid), or palmitic acid (hexadecanoic acid) (Sigma). Control larvae were injected with nutrient broth or 95% ethanol.…”

Section: Methodsmentioning

confidence: 99%

“…The detergent properties ofthese antibacterial proteins disrupt bacterial cell membranes. Insects also synthesize lysozymes, enzymes that directly attack bacteria by hydrolyzing their peptidoglycan cell walls (4,5). Hemocytic responses feature direct interactions between circulating hemocytes and bacteria.…”

mentioning

confidence: 99%

Eicosanoids mediate insect nodulation responses to bacterial infections.

Miller

Nguyễn

Stanley-Samuelson

1994

Proc. Natl. Acad. Sci. U.S.A.

170

124

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We propose that nodule formation is mediated by eicosanoids in insects. Nodulation is the temporally and quantitatively predominant cellular defense response to bacterial infection in insects and other invertebrates. Inhibition of eicosanoid biosynthesis in larvae of the tobacco hornworn Manduca sexta immediately prior to intrahemocoelic infections with the bacterium Serratia marcescens strongly reduced the nodulation response. Inhibition of eicosanoid biosynthesis also reduced formation of cellular aggregates at 1 hr postinfection, which indicates that eicosanoids mediate early stages of nodulation. Separate treatments with specific inhibitors of phospholipase A2, cyclooxygenase, and lipoxygenase reduced nodulation, which supports the view that nodule formation is a complex process involving prostaglandins and lipoxygenase products. The inhibitory effects of the phospholipase A2 inhibitor dexamethasone on nodulation were apparent by 1 hr after infection, and the effects increased, relative to controls, over 24 hr. The dexamethasone effects were expressed in a dosedependent manner, and they were reversed by treating infected insects with eicosanoid-precursor polyunsaturated fatty acids. Treatments with the saturated fatty acid 16:0, which is not an eicosanoid precursor, did not reverse the dexamethasone effects on nodulation. These findings strongly support the identification of nodulation as a specific insect cellular defense mechanism that is mediated by eicosanoids.

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“…However, the increase in lysozyme activity in the hemolymph does not correlate with increases of total protein content of the hemolymph, suggesting that not all hemolymph proteins are under the same regulation. The developmental expression of lysozyme activity in M. sexta hemolymph as examined in this work resembles the time course of lysozyme activity in the midgut epithelium (Russell and Dunn, 1991). Dunn and co-workers consider the possibility that cells of the midgut epithelium release lysozyme into the lumen of the midgut and into the hemolymph at the prepupal stage (Dunn et al, 1994).…”

mentioning

confidence: 97%

Correlation of hemocyte counts with different developmental parameters during the last larval instar of the tobacco hornworm, Manduca sexta

Beetz

Holthusen

Koolman

et al. 2007

Arch Insect Biochem Physiol

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We determined the changes in hemocyte titer and in the abundance of hemocyte types of the tobacco hornworm Manduca sexta during the fourth and fifth larval stadium and the beginning of the pupal stadium. As we analyzed the samples of individual insects at daily intervals, we were able to correlate phenotypical features, body weight, as well as total protein content and lysozyme activity in the hemolymph with the observations on hemocytes. In the course of the fifth larval stadium, the hemocyte titer decreased slightly and declined further after pupation. Using calculated values for total hemocyte numbers, females had about five times and males three times more hemocytes in the circulating population at the beginning of the wandering stage (in the middle of the fifth larval stadium) than immediately after the last larval--larval molt (from the fourth to the fifth larval stadium). This sexual difference was mainly due to an increase in the number of plasmatocytes, which was more prominent in females than in males. Granular cells were dominant in early fifth larval stadium while plasmatocytes were the most abundant cells in pupae. Oenocytoids and spherule cells disappeared during the wandering stage. Lysozyme activity in the hemolymph rose to a maximum during the wandering stage, with females having lysozyme values twice as high as those for males. These changes in lysozyme activity, however, did not correlate with the increase of total hemolymph protein titer which occurred already at the beginning of the wandering stage. We postulate that changes in hemocyte titers are under direct hormonal control, which has to be proven in future experiments.

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Lysozyme in the midgut of Manduca sexta during metamorphosis

Cited by 67 publications

References 21 publications

Antibacterial activity of lysozyme in the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Antibacterial activity of lysozyme in the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Eicosanoids mediate insect nodulation responses to bacterial infections.

Correlation of hemocyte counts with different developmental parameters during the last larval instar of the tobacco hornworm, Manduca sexta

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