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Diapause in the pea aphid (Acyrthosiphon pisum) is a slowing but not a cessation of development.

Shingleton AW, Sisk GC, Stern DL - BMC Dev. Biol. (2003)

Bottom Line: We found that early stages of embryogenesis progressed at a temperature-independent rate, characteristic of diapause, whereas later stages of embryogenesis progressed at a temperature-dependent rate.Rather, morphological development progressed slowly but continuously throughout embryogenesis.This suggests that the mechanisms limiting developmental rate during diapause may be the same as those controlling developmental rate at other stages of growth.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. ashingle@princeton.edu

ABSTRACT

Background: Many insects undergo a period of arrested development, called diapause, to avoid seasonally recurring adverse conditions. Whilst the phenology and endocrinology of insect diapause have been well studied, there has been comparatively little research into the developmental details of diapause. We investigated developmental aspects of diapause in sexually-produced embryos of the pea aphid, Acyrthosiphon pisum.

Results: We found that early stages of embryogenesis progressed at a temperature-independent rate, characteristic of diapause, whereas later stages of embryogenesis progressed at a temperature-dependent rate. However, embryos maintained at very high temperatures during the temperature-independent stage showed severe developmental abnormalities. Under no temperature regime did embryos display a distinct resting stage. Rather, morphological development progressed slowly but continuously throughout embryogenesis.

Conclusion: Diapause in the pea aphid, and perhaps in many other insects, is a temperature-independent slowing but not a cessation of morphological development. This suggests that the mechanisms limiting developmental rate during diapause may be the same as those controlling developmental rate at other stages of growth.

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Change in proportion of embryos that have undergone katatrepsis with age (days) in embryos maintained under different temperature regimes.
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Figure 4: Change in proportion of embryos that have undergone katatrepsis with age (days) in embryos maintained under different temperature regimes.

Mentions: Late development of the sexually-produced A. pisum embryo, particularly during and after katatrepsis, appeared to be temperature dependent. Embryos maintained at 10°C underwent katatrepsis earlier than embryos maintain at 0–4°C. Katatrepsis commenced after day 63 at 0–4°C but after day 56 at 10°C (figure 4). Because the rate of growth prior to katatrepsis was the same at both temperatures, 10°C embryos that undertook early katatrepsis appeared to do so at a less developed stage; that is embryos just prior to katatrepsis had significantly shorter bodies at 10°C than at 0–4°C (figure 5). Nevertheless, embryos that had just completed katatrepsis were the same size at 10°C as at 0–4°C (figure 5). Development was completed by day 77 at 10°C in contrast to day 100 at 0–4°C.


Diapause in the pea aphid (Acyrthosiphon pisum) is a slowing but not a cessation of development.

Shingleton AW, Sisk GC, Stern DL - BMC Dev. Biol. (2003)

Change in proportion of embryos that have undergone katatrepsis with age (days) in embryos maintained under different temperature regimes.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC184428&req=5

Figure 4: Change in proportion of embryos that have undergone katatrepsis with age (days) in embryos maintained under different temperature regimes.
Mentions: Late development of the sexually-produced A. pisum embryo, particularly during and after katatrepsis, appeared to be temperature dependent. Embryos maintained at 10°C underwent katatrepsis earlier than embryos maintain at 0–4°C. Katatrepsis commenced after day 63 at 0–4°C but after day 56 at 10°C (figure 4). Because the rate of growth prior to katatrepsis was the same at both temperatures, 10°C embryos that undertook early katatrepsis appeared to do so at a less developed stage; that is embryos just prior to katatrepsis had significantly shorter bodies at 10°C than at 0–4°C (figure 5). Nevertheless, embryos that had just completed katatrepsis were the same size at 10°C as at 0–4°C (figure 5). Development was completed by day 77 at 10°C in contrast to day 100 at 0–4°C.

Bottom Line: We found that early stages of embryogenesis progressed at a temperature-independent rate, characteristic of diapause, whereas later stages of embryogenesis progressed at a temperature-dependent rate.Rather, morphological development progressed slowly but continuously throughout embryogenesis.This suggests that the mechanisms limiting developmental rate during diapause may be the same as those controlling developmental rate at other stages of growth.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. ashingle@princeton.edu

ABSTRACT

Background: Many insects undergo a period of arrested development, called diapause, to avoid seasonally recurring adverse conditions. Whilst the phenology and endocrinology of insect diapause have been well studied, there has been comparatively little research into the developmental details of diapause. We investigated developmental aspects of diapause in sexually-produced embryos of the pea aphid, Acyrthosiphon pisum.

Results: We found that early stages of embryogenesis progressed at a temperature-independent rate, characteristic of diapause, whereas later stages of embryogenesis progressed at a temperature-dependent rate. However, embryos maintained at very high temperatures during the temperature-independent stage showed severe developmental abnormalities. Under no temperature regime did embryos display a distinct resting stage. Rather, morphological development progressed slowly but continuously throughout embryogenesis.

Conclusion: Diapause in the pea aphid, and perhaps in many other insects, is a temperature-independent slowing but not a cessation of morphological development. This suggests that the mechanisms limiting developmental rate during diapause may be the same as those controlling developmental rate at other stages of growth.

Show MeSH
Related in: MedlinePlus