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Juvenile hormone titer versus juvenile hormone synthesis in female nymphs and adults of the German cockroach, Blattella germanica.

Treiblmayr K, Pascual N, Piulachs MD, Keller T, Belles X - J. Insect Sci. (2006)

Bottom Line: In general, a significant positive correlation between rates of hormone synthesis and concentration in the hemolymph is observed.The main disparities appear in the penultimate day of the period of ootheca transport, where titer is high whereas synthesis is low, and on day 6 of the first vitellogenic cycle, where synthesis increases whereas titer decreases.At these stages, the observed disparities between synthesis and titer might be explained by differential action of degradation enzymes.

View Article: PubMed Central - PubMed

Affiliation: Department of Organismic Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. Karl.Treiblmayr@sbg.ac.at

ABSTRACT
Abstract Patterns of juvenile hormone have been intensively studied in the cockroach Blattella germanica under different physiological situations. However, data have been mainly obtained in vitro, and refer to hormone synthesized by isolated corpora allata, whereas information available on hormone concentration in the hemolymph is restricted to adult females. In order to complement our studies in vitro, we have measured juvenile hormone titer in the hemolymph of B. germanica females in four characteristic physiological situations: penultimate and last instar nymphs, adults during the first vitellogenic cycle, and adults transporting egg cases (ootheca). In general, a significant positive correlation between rates of hormone synthesis and concentration in the hemolymph is observed. The main disparities appear in the penultimate day of the period of ootheca transport, where titer is high whereas synthesis is low, and on day 6 of the first vitellogenic cycle, where synthesis increases whereas titer decreases. At these stages, the observed disparities between synthesis and titer might be explained by differential action of degradation enzymes.

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A. Juvenile hormone III (JH) titer in the hemolymph of adult females of Blattella germanica, during the first vitellogenic cycle and during the period of ootheca transport. Values represent the mean ± SEM (n = 3–5). The 7c means 7-day-old females with basal oocytes during chorion formation. JH titer in females that are forming the chorion are further detailed in the inset, showing the values during early chorion formation (7ec), middle chorion formation (7mc) and late chorion formation (7lc). Asterisks mean that JH III was not detectable under our conditions of analysis. B. Rates of JH III synthesis by corpora allata (CA) incubated in vitro from females of B. germanica in the first vitellogenic cycle, according to data previously published (Maestro et al 1994; Cruz et al 2003) (n = 7–15), and during the period of ootheca transport (n = 3–5).
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f02: A. Juvenile hormone III (JH) titer in the hemolymph of adult females of Blattella germanica, during the first vitellogenic cycle and during the period of ootheca transport. Values represent the mean ± SEM (n = 3–5). The 7c means 7-day-old females with basal oocytes during chorion formation. JH titer in females that are forming the chorion are further detailed in the inset, showing the values during early chorion formation (7ec), middle chorion formation (7mc) and late chorion formation (7lc). Asterisks mean that JH III was not detectable under our conditions of analysis. B. Rates of JH III synthesis by corpora allata (CA) incubated in vitro from females of B. germanica in the first vitellogenic cycle, according to data previously published (Maestro et al 1994; Cruz et al 2003) (n = 7–15), and during the period of ootheca transport (n = 3–5).

Mentions: JH III titer was determined in the hemolymph of adult females during the first vitellogenic cycle, and while transporting the ootheca (Fig. 2A). Just after the imaginai molt, JH III titer was similar to that measured in the last day of sixth nymphal instar. Then it increased steadily until about 70 ng/ml was present in 5 day-old females. The titer decreased on day 6, and increased again until it reached about 80 ng/ml in 7 day-old females, when basal oocytes began choriogenesis. Thereafter, JH III titer decreased dramatically to practically undetectable levels, which coincided with the last hours of choriogenesis (Fig. 2A, inset).


Juvenile hormone titer versus juvenile hormone synthesis in female nymphs and adults of the German cockroach, Blattella germanica.

Treiblmayr K, Pascual N, Piulachs MD, Keller T, Belles X - J. Insect Sci. (2006)

A. Juvenile hormone III (JH) titer in the hemolymph of adult females of Blattella germanica, during the first vitellogenic cycle and during the period of ootheca transport. Values represent the mean ± SEM (n = 3–5). The 7c means 7-day-old females with basal oocytes during chorion formation. JH titer in females that are forming the chorion are further detailed in the inset, showing the values during early chorion formation (7ec), middle chorion formation (7mc) and late chorion formation (7lc). Asterisks mean that JH III was not detectable under our conditions of analysis. B. Rates of JH III synthesis by corpora allata (CA) incubated in vitro from females of B. germanica in the first vitellogenic cycle, according to data previously published (Maestro et al 1994; Cruz et al 2003) (n = 7–15), and during the period of ootheca transport (n = 3–5).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2990300&req=5

f02: A. Juvenile hormone III (JH) titer in the hemolymph of adult females of Blattella germanica, during the first vitellogenic cycle and during the period of ootheca transport. Values represent the mean ± SEM (n = 3–5). The 7c means 7-day-old females with basal oocytes during chorion formation. JH titer in females that are forming the chorion are further detailed in the inset, showing the values during early chorion formation (7ec), middle chorion formation (7mc) and late chorion formation (7lc). Asterisks mean that JH III was not detectable under our conditions of analysis. B. Rates of JH III synthesis by corpora allata (CA) incubated in vitro from females of B. germanica in the first vitellogenic cycle, according to data previously published (Maestro et al 1994; Cruz et al 2003) (n = 7–15), and during the period of ootheca transport (n = 3–5).
Mentions: JH III titer was determined in the hemolymph of adult females during the first vitellogenic cycle, and while transporting the ootheca (Fig. 2A). Just after the imaginai molt, JH III titer was similar to that measured in the last day of sixth nymphal instar. Then it increased steadily until about 70 ng/ml was present in 5 day-old females. The titer decreased on day 6, and increased again until it reached about 80 ng/ml in 7 day-old females, when basal oocytes began choriogenesis. Thereafter, JH III titer decreased dramatically to practically undetectable levels, which coincided with the last hours of choriogenesis (Fig. 2A, inset).

Bottom Line: In general, a significant positive correlation between rates of hormone synthesis and concentration in the hemolymph is observed.The main disparities appear in the penultimate day of the period of ootheca transport, where titer is high whereas synthesis is low, and on day 6 of the first vitellogenic cycle, where synthesis increases whereas titer decreases.At these stages, the observed disparities between synthesis and titer might be explained by differential action of degradation enzymes.

View Article: PubMed Central - PubMed

Affiliation: Department of Organismic Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. Karl.Treiblmayr@sbg.ac.at

ABSTRACT
Abstract Patterns of juvenile hormone have been intensively studied in the cockroach Blattella germanica under different physiological situations. However, data have been mainly obtained in vitro, and refer to hormone synthesized by isolated corpora allata, whereas information available on hormone concentration in the hemolymph is restricted to adult females. In order to complement our studies in vitro, we have measured juvenile hormone titer in the hemolymph of B. germanica females in four characteristic physiological situations: penultimate and last instar nymphs, adults during the first vitellogenic cycle, and adults transporting egg cases (ootheca). In general, a significant positive correlation between rates of hormone synthesis and concentration in the hemolymph is observed. The main disparities appear in the penultimate day of the period of ootheca transport, where titer is high whereas synthesis is low, and on day 6 of the first vitellogenic cycle, where synthesis increases whereas titer decreases. At these stages, the observed disparities between synthesis and titer might be explained by differential action of degradation enzymes.

Show MeSH
Related in: MedlinePlus