Juvenile hormone (JH) is an important growth hormone in insects that has also been implicated in caste determination in termites. Gas chromatography-mass spectrometry was used to establish that the JH in the Formosan subterranean termite, Coptotermes formosanus Shiraki, is JH III. JH III titers were measured in workers, pre-soldiers, and soldiers from samples collected from the field. The average titers of JH III in workers and soldiers were about 13 and 25 pg mg(-1), respectively. However, pre-soldiers contained a significantly higher amount, 596 pg mg(-1). As expected, treatment of workers with a JH-analogue, methoprene, triggered rapid formation of pre-soldiers. However, these pre-soldiers had a very low JH III titer (62 pg mg(-1)). It appears that the application of JHA, while inducing pre-soldier formation, does not increase the endogenous JH III titer. The titer, however, increased as the pre-soldiers aged and before transforming into soldiers.
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http://dx.doi.org/10.1016/j.jinsphys.2004.04.002 | DOI Listing |
Insect Sci
January 2025
Hubei Key Laboratory of Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
Reproductive diapause is an insect survival strategy in which reproduction temporarily halts in response to adverse environmental changes. This process is characterized by arrested ovarian development and lipid accumulation in females. A reduction in juvenile hormone (JH) biosynthesis is known to initiate reproductive diapause, but its regulatory mechanism remains unclear.
View Article and Find Full Text PDFJ Exp Biol
January 2025
Sorbonne Université, Université Paris-Est Créteil, INRAE, CNRS, IRD, Institute for Ecology and Environmental Sciences of Paris, iEES Paris, F-75005, Paris, France.
As in other animals, insects can modulate their odor-guided behaviors, especially sexual behavior, according to environmental and physiological factors such as the individual's nutritional state. This behavioral flexibility results from modifications of the olfactory pathways under the control of hormones. Most studies have focused on the central modulation of the olfactory system and less attention has been paid to the peripheral olfactory system.
View Article and Find Full Text PDFJCEM Case Rep
January 2025
Department of Endocrinology and Metabolism, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
Congenital hypogonadotropic hypogonadism (CHH) can cause delayed secondary sexual characteristics and contribute to juvenile osteoporosis, with multiple causative genes having been reported. We treated a 27-year-old man diagnosed with central hypogonadism, presenting with delayed secondary sexual characteristics and juvenile osteoporosis, using bone resorption inhibitors and testosterone therapy. Genetic testing revealed missense variants both in the fibroblast growth factor receptor 1 () and gonadotropin-releasing hormone receptor () genes, a combination that has not been previously reported.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan. Electronic address:
Epoxide hydrolases (EHs) play pivotal roles in detoxification, catabolism, and signaling by converting epoxides into diols and have been implicated in several diseases, such as cancers and diabetes. EH homologs in insects are designated as Juvenile hormone epoxide hydrolases (JHEHs) due to their catalytic activity toward Juvenile hormone (JH). However, the biological function of JHEHs has been controversial in the fruit fly Drosophila melanogaster.
View Article and Find Full Text PDFVet Res Commun
January 2025
Genetics and Biotechnology, Department of Aquaculture, Faculty of Fish Resources, Suez University, Suez, 43221, Egypt.
Selective breeding is a potent method for developing strains with enhanced traits. This study compared the growth performance and stress responses of the genetically improved Abbassa Nile tilapia strain (G9; GIANT-G9) with a local commercial strain over 12 weeks, followed by exposure to stressors including high ammonia (10 mg TAN/L), elevated temperature (37 °C), and both for three days. The GIANT-G9 showed superior growth, including greater weight gain, final weight, length gain, specific growth rate, and protein efficiency ratio, as well as a lower feed conversion ratio and condition factor compared to the commercial strain.
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