The biology of parasites from the genus Argulus and a review of the interactions with its host
G. F. Wiegertjes, G. Flik in Host-Parasite Interactions, 2004
Although all argulid species are dioecious, i.e. have separate sexes (Benz and Otting, 1996), the sexes do not differ enormously in terms of their morphology. Separate sexes are distinguishable by examination of the abdominal lobes located at the posterior end of the parasite’s body. Females possess small spermathecae whereas males possess large testes which are clearly visible in live specimens due to the transparent properties of these animals’ exoskeletons. In addition, white eggs can often be seen within the pigmented ovaries located along the midline in adult, female lice. Copulation typically occurs on the host although our observations have revealed that lice will also copulate whilst detached from their host fish, i.e. whilst swimming freely in the water column. Copulation involves the transfer of sperm from the male directly to the female. Sperm cells are then stored in the female’s spermathecae until she fertilizes her eggs during the deposition process (Kollatsch, 1959). Eggs are typically protected by a mucus-like coating which presumably protects them from some smaller predators or opportunistic bacteria and fungi or possibly plays a role in maintaining the hydro-mineral balance of the fertilized eggs.
Gonadotropins in the Female
Paul V. Malven in Mammalian Neuroendocrinology, 2019
In other mammalian species, copulation induces ovulation and the subsequent reproductive cycle because ovulation either does not occur spontaneously or its spontaneous occurrence is not optimum for fertilization of the ovum. Those species in which ovulation only occurs after copulation are sometimes called reflex ovulators, and they include such diverse species as rabbit, ferret, cat, and llama. The secretion of LH in mated females of these species is characterized by an initial large copulation-induced surge as illustrated in Figure 12-3 for rabbits. This discharge of LH in female rabbits lasts for several hours after a single brief copulation and is followed about 10 h later by ovulation. In female cats which may copulate as many as 30 times in 36 h, the induced surge of LH peaked at about 3 h after the first copulation, with further mating activity having no apparent stimulatory effect on LH release (Concannon et al., 1989). The refractoriness of LH release to subsequent copulations apparently involved the neurohormone LHRH because there were still releasable amounts of LH in the adenohypophysis of these female cats. Figure 12-3 also depicts FSH profiles in mated rabbits, and a biphasic profile is evident. The initial period of increased FSH coincided with the post-copulatory surge of LH, but a secondary increase of FSH secretion occurred between 10 and 30 h after copulation, a period when LH secretion was very low.
Diagnosis of Pregnancy and Ante-natal Regimen
Audrey Eccles in Obstetrics and Gynaecology in Tudor and Stuart England, 2018
Sharp noted that women are almost alone among female creatures in desiring copulation after conception, but that it was needful for man that it should be so, because polygamy is forbidden by the laws of God. Culpeper thought it impractical to forbid copulation during pregnancy, ‘for I know well enough the Nature of Man is so vicious, that he must have to do with his Wife, or some body else in that time, or do that which is worse than either’. Still, it was generally agreed that intercourse was not safe unless very moderate, for it was well known that ‘common Whores (who often use Copulation) have never, or very rarely any Children; For the Grass seldom grows in a Path that is commonly trodden in’.17
Aluminum reproductive toxicity: a summary and interpretation of scientific reports
Published in Critical Reviews in Toxicology, 2020
The assessment of Al reproductive toxicity focused on studies in animals due to the lack of prospective or controlled-dose human studies that provide insight into potential Al-induced reproductive toxicity. Table 3 summarizes results of studies of Al reproductive toxicity in females. The cited studies do not consistently use the terms fecundity or fertility or their indexes. The author could not find generally accepted descriptions of these terms related to laboratory animals, as noted in a review of non-clinical fertility study design (Lerman et al. 2009). Four endpoints are used, following published guidelines (Wolterbeek et al. 2004), and the reported results categorized accordingly, irrespective of the definition used by the authors. Mating (copulation) was defined as positive mating (typically determined as sperm in the vagina (vaginal smear) or a vaginal plug) and mating index (%) as positive matings/cohabitated females. Fecundity (conception) was defined as a pregnant female and fecundity index (%) as pregnant females/successfully mated females. Fertility was defined as the number of live offspring and fertility (gestation) index (%) as the number of live offspring/litter.
Biochemical, hematological, and hormonal profile of rats orally administered methanol stem bark extract of Napoleona vogelii Hook and Planch (Lecythidaceae)
Published in Drug and Chemical Toxicology, 2019
Victor Olabowale Ikumawoyi, Esther Oluwatoyin Agbaje, Olufunsho Awodele, Akinwumi Akinyinka Akinyede
Hormonal assessment showed that administration of the extract resulted in significant reduction in TT levels at all doses. The extract may act via the hypothalamic-pituitary axis (Hadley 1988, Frias et al. 2002, Ren et al. 2005) to bring about this effect. It might reduce the secretion of releasing hormones by a pertubatory effect on the hypothalamic-pituitary axis (Sinha and Mathur 1990, Mali et al. 2002, Yakubu 2012) hence resulting in infertility in males. However, there was an increase in the level of EST at 200 and 400 mg/kg which suggest the pro-fertility effect of the extract in females. Adequate levels of EST and PROG are required for stimulation of growth and maturation of follicles. It is also required for female estrous behavior that enhances mating, and prepares the external genitalia for copulation, also creates suitable conditions for the development of fertilized egg cells and maintains pregnancy (Oladimeji et al. 2014). The effect of the extract on EST could enhance these functions hence promoting female fertility.
The effect of repeated light-dark shifts on uterine receptivity and early gestation in mice undergoing embryo transfer
Published in Systems Biology in Reproductive Medicine, 2018
Cathy A. Goldstein, Louise M. O’Brien, Ingrid L. Bergin, Thomas L. Saunders
After residing in their assigned light-dark conditions (described below) for 2 weeks, control (normal light-dark condition) and experimental (altered light-dark condition) female mice naturally cycling through estrus were mated in parallel with vasectomized male mice (2 female mice placed with 1 vasectomized male) to produce pseudopregnant females. Vasectomized male mice were maintained on the same light-dark schedule as the female mice they were mated with. Females were checked for copulation plugs on days 1-5 following the introduction of the vasectomized males. Females with copulation plugs received embryo transfer surgery on the day copulation plugs were identified. Embryos were thawed as described [Renard and Babinet 1984], washed through M2 medium, and placed in KSOMaa medium in an incubator until surgical transfer. Female egg recipients were anesthetized with Rompun/Ketamine [Zeller et al. 1998] and Caprofen was used for analgesia. A small incision was made in the skin and body wall and the reproductive tract was exteriorized. The bursa covering the ovary and oviduct was slit and the eggs were placed into the infundibulum of the oviduct in a small volume of sterile media with a transfer pipet and the reproductive tract returned to the peritoneal cavity. The procedure was then repeated on the opposite uterine horn so that 8 embryos were transferred to each uterine horn.
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