Comparative Study of Metabolites in the Imago of Silkworm, Philosamia Ricini

ISSN 2349-7823
International Journal of Recent Research in Life Sciences (IJRRLS)
Vol. 2, Issue 2, pp: (14-20), Month: April 2015 - June 2015, Available at: www.paperpublications.org
Page | 14
Paper Publications
Comparative Study of Metabolites in the Imago
of Silkworm, Philosamia Ricini
1
ARTI SRIVASTAVA, 2
DWIJENDRA K. GUPTA
1
Presently Head, Department of Biochemistry, Doon (P.G.) Paramedical College, Dehradoon
2
Department of Biochemistry, University of Allahabad, Allahabad.U.P. (India)-211002
Abstract: Acetylcholine is present in higher concentration in insects when compared with most other invertebrates
& vertebrates & functions as a chemical mediator of nervous activity. In the present study, biochemical analysis of
acetylcholine alongwith protein, trehalose and glucose on male and female adult moths of Philosamia ricini have
been made during their 5 day life span. The results demonstrated that head of female adults contains quite higher
concentration of acetylcholine than the male head and shows sexual dimorphism. On the converse, the pattern of
protein content of heads reveals a slight increase in males over that in females. This sexual dimorphic study on
P.ricini adult moths suggests that the cholinergic system of females is more active than that of males.
Keywords: Acetylcholine, Cholinergic system, Eriworm, Imago, Lepidopteron, Nerve conduction.
1. INTRODUCTION
The imago stage of Philosamia ricini represents adult stage and completes its life cycle. It is the reproductive stage where
adults mate and female laid eggs 1
. Moths have limited flight capability and as functional mouth parts are missing, they
are unable to feed. In comparison to vertebrates, the nervous system of invertebrates is not so well developed. The
cholinergic system, concerned with the enzymes controlling the metabolism of the nerve transmitter substance, provides a
fundamental insight into the initiation and elaboration of neural function during the sequential stages of insect
development. Evidence for the presence and the function of the cholinergic system in insects has been reviewed by
O’Brien, Colhoun, Chadwick, Smallman and Treherne 2
. Previous investigators have shown that various neurosecretory
hormones like acetylcholine, acetylcholine esterases, choline acetylase etc. play a vital role in the nerve conduction of
various insects like Apis, Periplaneta etc. Strong evidence has been forwarded for one of the functions of acetylcholine as
a chemical mediator of nervous activity. It is thought of as a neurotransmitter agent. Although the presence of
acetylcholine has been detected in many insects 3
, the highest activity has been demonstrated in the most active insects
such as Apis and Musca 4
.
The present study was taken into account to see the sex specific differences in case of nerve conduction in the
lepidopteron, Philosamia ricini.In vertebrates, acetylcholine, which is neurotransmitter agent 5
, plays a vital role in
preganglionic transmission of the automatic nervous system, at a nerve ending of the parasympathetic system & in the
brain 6
.
2. MATERIALS AND METHOD
Virgin male and female moths were sorted immediately after emergence. The wings and the legs of the male and female
imago were clipped off carefully. Then, head and trunk region was collected separately on different days i.e. 1st
day, 2nd
day, 3rd
day & 4th
day.
Next, a 20 % (w/v) homogenate of the above collected portions was prepared in 50 mM tris buffer (pH 7.0) 7
.The
homogenate was next centrifuged at 10,000 rpm at 40
C for 30 minutes. Supernatant was collected for the quantitative
estimation of metabolites.

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Paper Publications
Acetylcholine was estimated according to Metcalf 8
, total protein was determined by the method of Lowry etal 9
while
trehalose was determined by that of Wyatt & Kalf 10
.Glucose was assayed according to Nelson & Somogy11
.
All assays were made in duplicate sets on two individual homogenates and the mean values have been calculated.
3. RESULTS AND DISCUSSION
The above study on the imago of the Philosamia ricini on different days was undertaken to see if any sex specific
differences occurs in the case of nerve conduction. The studies on insects shown significant differences in head and trunk
of both the imagoes of Philosamia ricini.
While comparing the data of different metabolites in male head of P.ricini, the significant variation of protein contents
reveals a slight increase in males over that in females. High concentration of acetylcholine has been observed in the head
tissue of adult Philosamia ricini larvae.
As shown in (Table 2; Figure 2), the very low content of acetylcholine in heads (3.0 mg/ml) revealed by a newly emerged
male adult rises on day 2 to reach a concentration of 13.25 mg/ml. The content further increases significantly (27.25
mg/ml) on day 3 but decreases conspicuously on the last day of its life span. The significant increase in acetylcholine
concentration could be attributed to the general increase in structural and functional proteins associated with growth.
Adult female heads of P. ricini, show an increase in the acetylcholine content on day 1 over that in males .It again
increases significantly on day 2 (38.70%) and with a sharp decrease on day 3 (4.83%), it further increases on day 4. This
reveals that the heads of female adults manifest higher concentration of acetylcholine than in the male heads. This
suggests that the cholinergic system of females is more active than that of males.
Trehalose, which is major carbohydrate and plays the source of energy, increases in day 3 of males head over that in
females (Table 3; Figure 3) while it decreases in day 1, day 2 and day 4 when compared to heads of female
imago.However, in trunk region female contains higher level on all four days when compared with male (Table 6; Figure
6).
Analytics carried out on trunk of male moth of Eri worm showed significant increase in total protein on day 2, which
decreases on day 3, and again shows a remarkable increase on day 4 (Table 5 ; Figure 5), while in female moth protein
content decreases on day 2 (25.35%) when compared with day 1 in trunk region of P.ricini imago. Again a remarkable
sharp increase was observed in day 3 but decreases on last day.
Acetylcholine plays an essential role in the transmission of nerve impulses and it is found almost negligible in the
abdominal tissue of male and female adults of Philosamia ricini.
The data also describes percentage increase and decrease over day 1 of both the imagoes in all the parameters carried out.
Table 1: Variation in protein content of head portion of P. ricini adults.
Age of
Imago
(Days)
Total Protein
(mg/ml)
Male
Imago
% increase or
decrease over day 1 Female
Imago
% increase or
decrease over day 1
1 30.75 ± 0.74 - 33.0 ± 0.5 -
2 64.0 ± 1.0 108.13 % 23.0 ± 0.5 30.3 %
3 40.75 ± 0.74 32.52 % 47.75 ± 0.75 44.69 %
4 54.75 ± 0.25 78.04 % 54.0 ± 1.5 63.63 %
Values expressed as Average ± S.E.M. (N = 2)

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Table 2 : Variation in acetylcholine content of head portion of P. ricini adults.
Age of
Imago
(Days)
Acetylcholine
(mg/ml)
Male
Imago
% increase or
decrease over day
1
Female
Imago
% increase or
decrease over day 1
1 3.0 ± 0.5 - 15.5 ± 0.5 -
2 13.25 ± 0.25 341.66 % 21.5 ± 0.5 38.70 %
3 27.25 ± 0.25 808.33 % 14.75 ± 0.27 4.83 %
4 11.375 ± 0.12 279.06 % 17.75 ± 0.26 14.51 %
Table 3 : Variation in trehalose content of head portion of P. ricini adults.
Age of
Imago
(Days)
Trehalose
(mg/ml)
Male
Imago
% increase or
decrease over day
1
Female
Imago
% increase or
decrease over day
1
1 0.65 ± 0.05 - 0.7 ± 0.14 -
2 0.85 ± 0.05 30.76 % 0.875 ± 0.13 25.0 %
3 1.25 ± 0.05 92.30 % 0.95 ± 0.05 35.71 %
4 1.05 ± 0.05 61.53 % 1.23 ± 0.03 75.71 %
Table 4 : Variation in glucose content of head portion of P. ricini adults.
Age of
Imago
(Days)
Glucose
(mg/ml)
Male
Imago
% increase or
decrease over day
1
Female
Imago
% increase or
decrease over day 1
1 0.85 ± 0.15 - 1.4 ± 0.1 -
2 1.45 ± 0.15 70.58 % 2.0 ± 0.2 42.85 %
3 1.90 ± 0.10 123.52 % 2.65 ± 0.15 89.28 %
4 1.70 ± 0.1 100.0 % 2.45 ± 0.25 75.0 %
Table 5 : Variation in total protein of trunk portion of P. ricini adults.
Age of
Imago
(Days)
Total protein
(mg/ml)
Male
Imago
% increase or
decrease over day 1 Female
Imago
% increase or
decrease over
day 1
1 19.25 ± 0.75 - 26.125 ± 0.37 -
2 47.25 ± 0.25 145.45 % 19.5 ± 0.5 25.35 %
3 36.0 87.012 % 39.0 ± 0.5 49.28 %
4 42.75 ± 0.25 122.07 % 33.625 ± 0.12 28.7 %

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Table 6 : Variation in trehalose of trunk portion of P. ricini adults.
Age of
Imago
(Days)
Trehalose
(mg/ml)
Male
Imago
% increase or
decrease over day
1
Female
Imago
% increase or
decrease over
day 1
1 0.4 ± 0.141 - 1.1 ± 0.2 -
2 0.75 ± 0.05 87.5 % 1.025 ± 0.025 6.818 %
3 0.8 ± 0.14 100.0 % 1.3 ± 0.14 18.18 %
4 0.55 ± 0.05 37.5 % 1.025 ± 0.074 6.818 %
Table 7 : Variation in glucose of trunk portion of P. ricini adults.
Age of
Imago
(Days)
Glucose
(mg/ml)
Male
Imago
% increase or
decrease over day
1
Female
Imago
% increase or
decrease over day
1
1 1.35 ± 0.05 - 1.95 ± 0.25 -
2 1.9 ± 0.3 40.74 % 2.2 ± 0.3 12.82 %
3 2.6 ± 0.2 92.59 % 2.85 ± 0.15 46.15 %
4 2.2 ± 0.3 62.96 % 2.6 ± 0.2 33.33 %
Figure [1] : Variation of Protein content of head part of adult imago of P. ricini

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Figure [2] : Variation in Acetylcholine in head part of adult imago of P. ricini.
Figure [3] : Variation in Trehalose content of head part of adult imago of P. ricini
Figure (4) : Variation in Glucose content of head part of adult imago of P. ricini.

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Paper Publications
Figure [5] : Variation in Protein concentration in the trunk part of adult imago of P. ricini
Figure [6] : Variation in Trehalose content of trunk region of adult imago of P. ricini.
Figure (7): Variation in Glucose content of trunk region of adult imago of P. ricini.

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4. CONCLUSION
The results revealed that head of female adults contain very higher concentration of acetylcholine than the male head.
Variation pattern of protein content of heads reveals a slight increase in males over that in females.
It is concluded that the presence of the cholinergic system and the proteins of head tissue is sex dependant in addition to
involving central nervous system. The presence of acetylcholine and protein in the abdominal tissue of Philosamia ricini
adults was also found to be sex dependent but not involving central nervous system. The cholinergic system of females
seems to be relatively more active than that of males. So, it is concluded that the presence of acetylcholine & protein in
imago of Philosamia ricini is sex dependent.
REFERENCES
[1] Dash Rupesh, Mukherjee Soumer, Kundu S.C. 38: 255-258. (2006)
[2] Smallman B. N., Mansingh A. Annual Review of Entomology 14: 387-408. (1969)
[3] Smallman B. N. J. Physiol., 132,343. (1956)
[4] Metcalf R. L., March R. B. and Maxam M. G. Ann. Ent. Soc. Amer., 48,222. (1955)
[5] Roeder K. D. J. Insect Physiol. 2: 108. (1958)
[6] Gaddun, J.H.; Nature; London: 197; 741. (1963)
[7] Pant R. and Gupta D. K.; Curr. Sci.: Vol.49; 3. (1980)
[8] Metcalf R. J.; J. Econ. Entowd.: 44; 883. (1951)
[9] Lowry O.H., Rosebrough N.J., Farr A. L. & Randall R.J.; J. Biol. Chem. : 193; 266-275. (1951)
[10] Wyatt G.R., Kalf G.F.; Fed. Proc.:15; 388. (1956)
[11] Nelson & Somogy. Estimation of Glucose (1954).

Comparative Study of Metabolites in the Imago of Silkworm, Philosamia Ricini

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Comparative Study of Metabolites in the Imago of Silkworm, Philosamia Ricini