Juvenile hormone–stimulated synthesis of acyl‐glycerols and vitamin E in female accessory sexual glands of the fire bug, Pyrrhocoris apterus L.

Abstract

Secretory cells of the female accessory sexual glands (AG) of P. apterus grow and produce yellow oily exocrine secretion in response to stimulation by endogenous juvenile hormone (JH) or exogenous treatments by JH analogues. The secretion determines the property of future egg shells by coating the chorion surface of the oocytes that are passing individually through the common uterus during oviposition. Diapausing females with a physiologically inhibited endocrine system or females with artificially removed hormonal sources show inactive ovaries and empty AG without the secretory products. Ovary-ectomised females with the intact neuroendocrine system develop hypertrophic AG loaded with the oily secretion. This shows that there is no direct dependence between formation of the oily secretion in AG and ovarian growth. Chemical analysis of the secretory products revealed the presence of acetylated glycerols, with the most abundant stearoyl-diacetyl-glycerol, stearoyl-acetyl-propionyl-glycerol, and the corresponding derivatives of arachidonic acid. In addition to this, the JH-activated secretory cells of AG also produced gamma- and delta-tocopherols. The possible antioxidant or antimutagenic action of these vitamin E compounds in insect reproduction has been emphasized.

OXIDATIVE STRESS AND THE EVOLUTION OF SEX DIFFERENCES IN LIFE SPAN AND AGEING IN THE DECORATED CRICKET,GRYLLODES SIGILLATUS

“…Finally, female reproductive effort may increase oxidative damage more than male reproductive effort if females divert relatively more of their antioxidants to producing eggs than to somatic maintenance. Studies on a diverse range of taxon have shown that the intake of antioxidants increase egg production in females (e.g., insects—Jedlička et al 2009; amphibians—Ogilvy et al 2012; fish—Mehrad and Sudagar 2010; birds—Blount et al 2003; Bertrand et al 2006; mammals—Zeng et al 2008) and that this may come at the expense of somatic maintenance (e.g., Blount et al 2003; Morales et al 2008), but no study, to our knowledge, has formally compared these relationships across the sexes.…”

The hormonal and circadian basis for insect photoperiodic timing

“…JH normally stimulates synthesis of vitellogenins in the fat bodies and their uptake by developing ovaries, while under diapause inducing conditions this somatotrophic action fails and ovarian development is arrested [66,67]. JH also controls the activity of female accessory sexual glands (AGs) which become atrophic during diapause [68]. In males, the trophia of the AGs modulates mating propensity, again under the control of JH [69].…”

Vitamin D1 versus ecdysteroids: Growth effects on cell regeneration and malignant growth in insects are similar to those in humans

“…These similarities indicate that the role and physiological functions of vitamin D 1 in regeneration and cell divisions described here for Manduca could also be true for human tissues. This statement is further supported by the similar physiological role of vitamin E (γ-and δ-tocopherols) in the regulation of reproduction both in insects and humans (Jedlička et al, 2009).…”