Sexual secrets

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

Sexualzelle, /. (Biol.) germ cell, sexuell, a. sexual, sezemieren, v.t. secrete, sezieren, v.t. dissect. 

AVP plays a central role in water homeostasis of terrestrial mammals, leading to water conservation by the kidney. OT is primarily involved in milk ejection, parturition and in sexual and maternal behaviour. Both hormones are pqDtides secreted by the neurohypophysis, and both act also as neurotransmitters in the central nervous system (CNS). The major hormonal targets for AVP are the renal tubules and vascular myocytes. The hormonal targets for OT are the myoepithelial cells... 

Outside the uterus, oxytocin has long been known to be essential for milk secretion. In recent years, however, there has also been a growing body of evidence that oxytocin plays a role in the brain in modulation of maternal, sexual and social behaviour. 

Hormonal influences may be limited to sexually relevant cues, since not all scent marks are socially relevant in all situations (Petrulis et al., 1995 and 1997). Chemoinvestigation by male hamsters of the female-indicator compound DMDS was independent of T. and did not differ from that of females. In contrast, the frequency of chemoinvestigation by castrates to vaginal secretion (containing DMDS) was enhanced by T. intact males investigated FHVS five times more than they do the females. 

Fig. 7.2(a) Inter-sexual, direct scent transfer signal- injection , by scarification of female s skin. Male salamander transfers chin-gland secretion (inset) with dimorphic tooth-scraper (from Arnold, 1977). 

Macrides F., Johnson P.A. and Schneider S.P. (1977). Responses of the male golden hamster to vaginal secretion and dimethyl disulfide attraction versus sexual behaviour. Behav Biol 20, 377-386. 

Hypogonadism A condition resulting from or characterized by abnormally decreased functional activity of the gonads, with retardation of growth and sexual development or reduced or absent secretion of hormones from the sex glands resulting in low testosterone levels in men. 

Chia, Mantak. Taoist secrets of love cultivating male sexual energy / Mantak Chia written with Michael Winn. New York Aurora Press, 1984. xix, 285 p. ISBN 0943358191... 

Some lepidopteran species secret methyl-branched chemicals for their sexual communication. These have been abbreviated with Me to indicate the position of the methyl group. Disparlure (Me2,epo7-18 H) is a well-known pheromone identified from Lymantria dispar [3] and two other species in the same genus, L.fumida [95] and L. monacha [96]. L. monacha also secrets an... 

Contrary to the structure similarity of the pheromones secreted by taxonomical related moths, some differences are necessary for their sexual communication systems to play an important role in their reproductive isolation. In addition to further modifications of the various structures, diversity of the lepidopteran sex pheromones is generated by blending multiple components. Innumerable pheromone blends are based not only on combinations of different components but also on variations in the mixing ratio. A pioneer study with Adoxophyes spp. (Tortricidae Tortricinae) had already proposed this concept in the early 1970s. While the smaller tea tortrix (A. honmai) and the Japanese summerfruit tortrix (A. oranafasciata) had been considered to be variant strains with different host preferences in the same species, Tamaki et al. found that females of the former pest insect in the tea garden secreted Z9-14 OAc and Zll-14 OAc in a ratio of 7 4 but females of the latter defoliator of apple trees secreted them in a ratio of 13 4 [127,128]. Furthermore, two other components (Ell-14 OAc and MelO-12 OAc) were subsequently identified from the former species [129]. 

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