7

The Journal of Lxpenmental Btology 206. 4393-4412

(ł-D-glucose

Trehalose

Clucose-6-phosphate isomerase

±_A_-q Glucosc-6-phosphatc

ff

₀A-o-

O c

Kp3?°

Froctose-6-phosphate - i- 'om

Om m

V

Glutamine:fnictosc-6phosphatc aniinolransferase

Glucosamine-6-phosphate ®    ^ t »

A-acetyl transferase    ^    ''o'    ^ mo\ _h

G lucosaminc - 6 ■ phospliatc

/V-acetyl-

glucosaminc -6 • phosphatc

V

Phosphoacetylglucosamine nuitase

UDP-.Y-acctylglucosaminc ^    ^M 'nh o,

pyrophosphorylasc ^    /U_{0 0}-^/R'o

MjC    0

A.

TT*, „.r~ -

W-acctylglucosaminc-1 -phospliatc

UDP-Af-acetylglucosamine

\

Chitin synthase

Fig. 1. Biosynthesis of chitin in inseets. The pathway starts with trehalose. the main hemolymph sugar in most inseets. and ends with the chitin polymer. The diagrammatic representation is based on previously published pathways (Kramer and Koga. 1986: Cohen. 2001).

Chitin

JU