PMID- 18627835
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20091216
LR  - 20190911
IS  - 0040-8166 (Print)
IS  - 0040-8166 (Linking)
VI  - 29
IP  - 6
DP  - 1997 Dec
TI  - Ultrastructural changes in corpora allata during a cycle of juvenile hormone 
      biosynthesis in embryos of the viviparous cockroach, Diploptera punctata.
PG  - 715-25
AB  - We have observed changes with time in the fine structure of corpora allata (CA) 
      during a known cycle of increasing and decreasing juvenile hormone (JH) synthesis 
      in late embryos of Diploptera punctata. A previous report showed that rates of JH 
      release were relatively low in 28-day-old embryos, but CA activity subsequently 
      rose linearly to a peak on about day 42, and thereafter steadily declined to a 
      low level on day 64 just before birth (Holbrook et al., 1997). We now show that, 
      regardless of rate of JH synthesis, CA cells are large and replete with 
      organelles which nevertheless exhibit variable morphology in embryos of different 
      age. Highly active CA cells on day 40 contain abundant ring-form mitochondria, 
      whereas CA cells of low activity on days 28 and 64 contain mitochondria that are 
      rod-shaped or globular. Mitochondrial cristae were scarce and indistinct on day 
      28 but numerous and well developed on day 64. Endoplasmic reticula (ER) are rare 
      on day 28 and appear in increasing numbers when CA activity rises. On day 40, ER 
      are abundant and often exhibit a whorl-like appearance which is not observed on 
      day 28. After day 44, when biosynthetic activity is declining, whorls of ER 
      gradually decrease in number and are ultimately replaced by vesicular smooth ER 
      on day 64. Neurosecretions are found only after day 38, by which time rates of JH 
      synthesis have increased substantially from those of day 28. Except for 
      membranous autophagic vacuoles, which are frequently found when ER whorls 
      disintegrate as rates of JH synthesis decline toward birth, most autophagic 
      vesicles such as multivesicular vesicles and dense bodies occur only sporadically 
      among CA cells at all examined ages. We conclude that synchronous autophagy of 
      exhausted organelles, which results in atrophy of CA cells and long-term arrest 
      of JH synthesis in adult females of D. punctata, does not occur in embryos. The 
      slow cyclic change in rate of JH synthesis in embryonic CA is most likely due to 
      asynchronous autophagic activity and to alterations in certain unique features of 
      intracellular organelles.
FAU - Lee, Y J
AU  - Lee YJ
AD  - Department of Life Science, National Tsing-Hua University, Hsinchu, Taiwan.
FAU - Chiang, A S
AU  - Chiang AS
LA  - eng
PT  - Journal Article
PL  - Scotland
TA  - Tissue Cell
JT  - Tissue & cell
JID - 0214745
EDAT- 2008/07/17 09:00
MHDA- 2008/07/17 09:01
CRDT- 2008/07/17 09:00
PHST- 1997/02/20 00:00 [received]
PHST- 1997/08/12 00:00 [accepted]
PHST- 2008/07/17 09:00 [pubmed]
PHST- 2008/07/17 09:01 [medline]
PHST- 2008/07/17 09:00 [entrez]
AID - S0040-8166(97)80047-X [pii]
AID - 10.1016/s0040-8166(97)80047-x [doi]
PST - ppublish
SO  - Tissue Cell. 1997 Dec;29(6):715-25. doi: 10.1016/s0040-8166(97)80047-x.