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Control of pupal commitment in the imaginal disks of Precis coenia (Lepidoptera: Nymphalidae).

Publication ,  Journal Article
Nijhout, HF; Kremen, C
Published in: Journal of insect physiology
March 1998

When final (5th) instar larvae of Precis coenia were treated with the juvenile hormone analog (JHA) methoprene, they underwent a supernumerary larval molt, except for certain regions of their imaginal disks, which deposited a normal pupal cuticle. Evidently those regions had already become irreversibly committed to pupal development at the time JHA was applied. By applying JHA at successively later times in the instar, the progression of pupal commitment could be studied. Pupal commitment in the proboscis, antenna, eye, leg and wing imaginal disks occurred in disk-specific patterns. In each imaginal disk there were distinct initiation sites where pupal commitment began during the first few hours of the final larval instar, and from which commitment spread across the remainder of the disk over a 2- to 3-day period. The initiation sites were not always located in homologous regions of the various disks. As a rule, pupal commitment also spread from imaginal disk tissue to surrounding epidermal tissue. The regions of pupal commitment in all disks except those of the wings, coincided with the regions of growth of the disk. Only portions of the disk that had undergone cell division and growth underwent pupal commitment. Shortening the growth period did not prevent pupal commitment in the wing imaginal disk, indicating that, in this disk at least, a normal number of cell divisions was not crucial in reprogramming of disk cells for pupal cuticle synthesis. The apparent growth spurt of imaginal disks that occurs during the last part of the final larval instar is merely the final stage of normal and constant exponential growth. Juvenile hormone (JH) and ecdysteroids appeared to play little role in the regulation of normal imaginal disk growth. Instead, growth of the disks may be under intrinsic control. Interestingly, even though endogenous fluctuation in JH titers do not affect imaginal disk growth, exogenous JHA proved able to inhibit both pupal commitment, cell movement, and growth of the disks during the last larval instar. This function of JH could be important under certain adverse conditions, such as when metamorphosis is delayed in favor of a supernumerary larval molt.

Duke Scholars

Published In

Journal of insect physiology

DOI

EISSN

1879-1611

ISSN

0022-1910

Publication Date

March 1998

Volume

44

Issue

3-4

Start / End Page

287 / 296

Related Subject Headings

  • Entomology
  • 3208 Medical physiology
  • 3109 Zoology
  • 0608 Zoology
  • 0606 Physiology
  • 0604 Genetics
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Nijhout, H. F., & Kremen, C. (1998). Control of pupal commitment in the imaginal disks of Precis coenia (Lepidoptera: Nymphalidae). Journal of Insect Physiology, 44(3–4), 287–296. https://doi.org/10.1016/s0022-1910(97)00121-2
Nijhout, H. F., and C. Kremen. “Control of pupal commitment in the imaginal disks of Precis coenia (Lepidoptera: Nymphalidae).Journal of Insect Physiology 44, no. 3–4 (March 1998): 287–96. https://doi.org/10.1016/s0022-1910(97)00121-2.
Nijhout HF, Kremen C. Control of pupal commitment in the imaginal disks of Precis coenia (Lepidoptera: Nymphalidae). Journal of insect physiology. 1998 Mar;44(3–4):287–96.
Nijhout, H. F., and C. Kremen. “Control of pupal commitment in the imaginal disks of Precis coenia (Lepidoptera: Nymphalidae).Journal of Insect Physiology, vol. 44, no. 3–4, Mar. 1998, pp. 287–96. Epmc, doi:10.1016/s0022-1910(97)00121-2.
Nijhout HF, Kremen C. Control of pupal commitment in the imaginal disks of Precis coenia (Lepidoptera: Nymphalidae). Journal of insect physiology. 1998 Mar;44(3–4):287–296.
Journal cover image

Published In

Journal of insect physiology

DOI

EISSN

1879-1611

ISSN

0022-1910

Publication Date

March 1998

Volume

44

Issue

3-4

Start / End Page

287 / 296

Related Subject Headings

  • Entomology
  • 3208 Medical physiology
  • 3109 Zoology
  • 0608 Zoology
  • 0606 Physiology
  • 0604 Genetics