Functional anatomy of the female reproductive system of the American lobster (Homarus americanus).

Light microscopy studies of the female American lobster Homarus americanus reproductive system are essentially nonexistent or outdated. Based on samples taken in the spring, summer, and autumn from the southern Gulf of St. Lawrence between 1994 and 2014, and using a combination of histological and scanning electron microscope techniques, we propose an ovarian cycle with 10 stages, identifying for the first time a recovery stage. Also, an atypical resorption stage, characterized by massive reabsorption of mature oocytes, is occasionally observed during summer months. The oviducts are composed of connective tissue (elastic and collagen fibers) with no muscle or secretory activities. Their epithelium shows a cyclic pattern and phagocytosis activities linked to spawning. Although the role of the seminal receptacle is to store and protect semen, free spermatozoa (i.e., without the spermatophoric wall and the acellular gelatinous substance that constitute the semen) were also observed in its posteriolateral grooves immediately prior to spawning, which is consistent with an external fertilization mechanism at the seminal receptacle. Unexpectedly, free spermatozoa were observed externally near two pore-like structures located on the gonopore's operculum, not at the seminal receptacle, after spawning; hence, more work is needed to fully understand the fertilization mechanism for the American lobster.

Shift in egg-laying strategy to avoid plant defense leads to reproductive isolation in mutualistic and cheating yucca moths.

Through the process of ecological speciation, insect populations that adapt to new host plant species or to different plant tissues could speciate if such adaptations cause reproductive isolation. One of the key issues in this process is identifying the mechanisms by which adaptation in ecological traits leads directly to reproductive isolation. Here I show that within a radiation of specialist moths that pollinate and feed on yuccas, shifts in egg placement resulted in changes in female moth egg-laying structures that led to concomitant changes in male reproductive morphology. As pollinator moths evolved to circumvent the ability of yuccas to selectively abscise flowers that contain pollinator eggs, ovipositor length became shorter. Because mating occurs through the ovipositor, shortening of the ovipositor also led to significantly shorter and wider male intromittent organs. In instances where two pollinator moth species occur in sympatry and on the same host plant species, there is one short and one long ovipositor species that are reproductively isolated. Given that many plant-feeding insects lay eggs into plant tissues, changes in ovipositor morphology that lead to correlated changes in reproductive morphology may be a mechanism that maintains reproductive isolation among closely related species using the same host plant species.

Neonatal diethylstilbestrol exposure disrupts female reproductive tract structure/function via both direct and indirect mechanisms in the hamster.

We assessed neonatal diethylstilbestrol (DES)-induced disruption at various endocrine levels in the hamster. In particular, we used organ transplantation into the hamster cheek pouch to determine whether abnormalities observed in the post-pubertal ovary are due to: (a) a direct (early) mechanism or (b) an indirect (late) mechanism that involves altered development and function of the hypothalamus and/or pituitary. Of the various disruption endpoints and attributes assessed: (1) some were consistent with the direct mechanism (altered uterine and cervical dimensions/organization, ovarian polyovular follicles, vaginal hypospadius, endometrial hyperplasia/dysplasia); (2) some were consistent with the indirect mechanism (ovarian/oviductal salpingitis, cystic ovarian follicles); (3) some were consistent with a combination of the direct and indirect mechanisms (altered endocrine status); and (4) the mechanism(s) for one (lack of corpora lutea) was uncertain. This study also generated some surprising observations regarding vaginal estrous assessments as a means to monitor periodicity of ovarian function in the hamster.

Low phytoestrogen levels in feed increase fetal serum estradiol resulting in the "fetal estrogenization syndrome" and obesity in CD-1 mice.

BACKGROUND: Although estrogenic chemicals can disrupt development of the reproductive system, there is debate about whether phytoestrogens in soy are beneficial, benign, or harmful. OBJECTIVES: We compared reproductive and metabolic characteristics in male and female mice reared and maintained on non-soy low-phytoestrogen feed or soy-based high-phytoestrogen feed. METHODS: The low-phytoestrogen diet was non-soy PMI 5K96 (verified casein diet), and the high-phytoestrogen diet consisted of soy-based PMI 5008 during pregnancy and lactation and soy-based PMI 5001 maintenance feed after weaning. RESULTS: In fetuses whose mothers consumed the low-phytoestrogen PMI 5K96 feed, we found a paradoxical significant elevation in endogenous serum estradiol, which was associated postnatally with adverse reproductive outcomes referred to as the "fetal estrogenization syndrome (FES)". In females, this syndrome included early puberty and increased uterine responsiveness to estrogen, and in males, it included reduced testis, epididymis, and seminal vesicle size, but an enlarged prostate. The low-phytoestrogen-fed males and females were lighter at birth, but, between weaning and adulthood, they became obese and developed abnormally high serum leptin levels; these males, but not females, showed impaired glucose regulation. CONCLUSIONS: Removing phytoestrogens from mouse feed produces an obese phenotype consistent with metabolic syndrome, and the associated reproductive system abnormalities are consistent with FES due to elevated endogenous fetal estradiol. Laboratory rodents may have become adapted to high-phytoestrogen intake over many generations of being fed soy-based commercial feed; removing all phytoestrogens from feed leads to alterations that could disrupt many types of biomedical research.

The onset of puberty in female mice as reflected in urinary steroids and uterine/ovarian mass: interactions of exposure to males, phyto-oestrogen content of diet, and ano-genital distance.

Development of puberty in female mice was examined in relationship with the ano-genital distance index (AGDI), phyto-oestrogen content of diet and exposure to males post weaning. Throughout gestation and post-natal development, females were exposed to a regular diet or a nutritionally similar diet deficient in phyto-oestrogens. After segregation at weaning on the basis of short or long AGDI, an indirect measure of in utero androgen exposure, females were housed alone or underneath two outbred adult males for 2 weeks. Female urinary samples were collected non-invasively throughout this exposure, then assayed for oestradiol, progesterone and creatinine. Females were then killed and uterine and ovarian mass was determined. Urinary oestradiol was substantially reduced in females raised on the phyto-oestrogen-free diet. Oestradiol levels were more dynamic over days in urine of male-exposed females, especially among those on the regular diet. Urinary progesterone was not strongly influenced by diet. Progesterone was more dynamic in urine of male-exposed females, and was generally elevated compared with levels in isolated females, the size of this effect dependent on AGDI, diet and whether the measure was adjusted for creatinine. Urinary creatinine was elevated by the phyto-oestrogen-free diet and reduced by male exposure, tending to decline over days in females exposed to males. Male exposure increased uterine and ovarian mass and was influenced by AGDI in interaction with diet and male exposure.

Onset of sexual maturation in female mice as measured in behavior and fertility: Interactions of exposure to males, phytoestrogen content of diet, and ano-genital distance.

Age of puberty was examined in female mice through non-invasive behavioral and fertility measures, in relationship to ano-genital distance, phytoestrogen content of diet, and exposure to males post-weaning. Throughout gestation and post-natal development, females were exposed to a regular diet or one that was nutritionally similar but deficient in phytoestrogens. After segregation at weaning on the basis of a short or long ano-genital distance index (AGDI), an indirect measure of in utero androgen exposure, females were housed alone or underneath two outbred adult males for two weeks. Subsequently, an outbred male was placed in the cage of each developing female, and mating behavior, escape attempts, biting gestures, and boxing postures were recorded. Next, females were monitored for the occurrence of a copulatory plug and allowed to bear young, with pregnancy and litters monitored up to weaning. Male-exposed females fed a regular diet were immediately sexually receptive when housed directly with males, and their conceptions occurred earlier than did those of other females. Subjects fed a diet deficient in phytoestrogens were least likely to show sexual receptivity. Male-exposed females with longer AGDI displayed more escape attempts in the presence of males, regardless of diet. Once inseminated, most females carried to term and the majority of pups survived until weaning. These data suggest that phytoestrogens and AGDI interact with exposure to males in determining age at onset of puberty.

Distribution of vasopressin in the forebrain of spotted hyenas.

The extreme virilization of the female spotted hyena raises interesting questions with respect to sexual differentiation of the brain and behavior. Females are larger and more aggressive than adult, non-natal males and dominate them in social encounters; their external genitalia also are highly masculinized. In many vertebrates, the arginine vasopressin (VP) innervation of the forebrain, particularly that of the lateral septum, is associated with social behaviors such as aggression and dominance. Here, we used immunohistochemistry to examine the distribution of VP cells and fibers in the forebrains of adult spotted hyenas. We find the expected densely staining VP immunoreactive (VP-ir) neurons in the paraventricular and supraoptic nuclei, as well as an unusually extensive distribution of magnocelluar VP-ir neurons in accessory regions. A small number of VP-ir cell bodies are present in the suprachiasmatic nucleus and bed nucleus of the stria terminalis; however, there are extensive VP-ir fiber networks in presumed projection areas of these nuclei, for example, the subparaventricular zone and lateral septum, respectively. No significant sex differences were detected in the density of VP-ir fibers in any area examined. In the lateral septum, however, marked variability was observed. Intact females exhibited a dense fiber network, as did two of the four males examined; the two other males had almost no VP-ir septal fibers. This contrasts with findings in many other vertebrate species, in which VP innervation of the lateral septum is consistently greater in males than in females.

Multigeneration reproductive and developmental toxicity study of bar gene inserted into genetically modified potato on rats.

Each specific protein has an individual gene encoding it, and a foreign gene introduced to a plant can be used to synthesize a new protein. The identification of potential reproductive and developmental toxicity from novel proteins produced by genetically modified (GM) crops is a difficult task. A science-based risk assessment is needed in order to use GM crops as a conventional foodstuff. In this study, the specific characteristics of GM food and low-level chronic exposure were examined using a five-generation animal study. In each generation, rats were fed a solid pellet containing 5% GM potato and non-GM potato for 10 wk prior to mating in order to assess the potential reproductive and developmental toxic effects. In the multigeneration animal study, there were no GM potato-related changes in body weight, food consumption, reproductive performance, and organ weight. Polymerase chain reaction (PCR) was carried out using extracted genomic DNA to examine the possibility of gene persistence in the organ tissues after a long-term exposure to low levels of GM feed. In each generation, the gene responsible for bar was not found in any of the reproductive organs of the GM potato-treated male and female rats, and the litter-related indexes did not show any genetically modified organism (GMO)-related changes. The results suggest that genetically modified crops have no adverse effects on the multigeneration reproductive-developmental ability.

Phytoestrogens alter the reproductive organ development in the mink (Mustela vison).

The aim of the present study was to examine the reproductive effects of two perorally applied phytoestrogens, genistein (8 mg/kg/day) and beta-sitosterol (50 mg/kg/day), on the mink (Mustela vison) at human dietary exposure levels. Parental generations were exposed over 9 months to these phytoestrogens and their offspring were exposed via gestation and lactation. Parents and their offspring were sampled 21 days after the birth of the kits. Sex hormone levels, sperm quality, organ weights, and development of the kits were examined. The exposed females were heavier than the control females at the 1st postnatal day (PND). The control kits were heavier than the exposed kits from the 1st to the 21st PND. Phytoestrogens did not affect the organ weights of the adult minks, but the relative testicular weight of the exposed kits was higher than in the control kits. The relative prostate weight was higher and the relative uterine weight lower in the beta-sitosterol-exposed kits than in the control kits. Moreover, the plasma dihydrotestosterone levels were lower in the genistein-exposed male kits compared to the control male kits. This study could not explain the mechanisms behind these alterations. The results indicate that perinatal phytoestrogen exposures cause alterations in the weight of the reproductive organs of the mink kits.

Effects of p-nonylphenol and resveratrol on body and organ weight and in vivo fertility of outbred CD-1 mice.

The aim of this study was to analyse the multigenerational effects of para-nonylphenol (NP) and resveratrol (RES) on the body weight, organ weight and reproductive fitness of outbred CD-1 mice. The data indicate that in male mice, NP had an effect on the weight of selected reproductive organs and the kidneys in the parental (P) generation males. Effects on selected reproductive organs, the liver and kidneys in the F1-generation males were also seen. In females, effects of NP on body weight and kidney weight were seen in the P generation, but no effects on any measured parameter were seen in the F1 generation. RES had no effect on body weight but did have some effect on selected male and female reproductive organs in the P generation. RES altered the spleen and liver weights of P-generation males and the kidney weight of F1-generation males. Acrosomal integrity (using a monoclonal antibody against intra-acrosomal sperm proteins) was assessed for both generations of NP- and RES-treated mice. A significant reduction in acrosomal integrity was seen in both generations of NP-treated, but not in RES-treated, mice. Fewer offspring were observed in the second litter of the F2 generation of mice treated with NP; no similar effect was seen in RES-treated mice. The litter sex ratio was not different from controls. Unlike RES, NP had a negative effect on spermatogenesis and sperm quality with a resultant impact on in vivo fertility.

[Vesalius and the anatomy of the female genital tract]. / Vesalius en de anatomie van de tractus genitalis femininus.

Some of Vesalius' books allow us to clarify his knowledge of the anatomy of the female genital tract. We distinguish chronologically his Tabulae anatomicae sex (1538), the Fabrica (1543), the Letter on Chynaroot (1546), the Fabrica II (1555) and his letter to Falloppio (1564). The whole of these writings gives us an overview of the evolution of the insight concerning this important chapter of human anatomy. Anno 1538, Vesalius is in several matters Galen's pupil. Let us consider his pictures of the tractus genitalis of man and woman, which unmistakably follow the galenic theory of sexual isomorphism, a delusion to which our Brussels anatomist adhered during all his life. On other points he outdid the "Master" from the very beginning, e.g. as to the structure of the uterus. In this matter he followed da Carpi (1470-1550), his immediate predecessor and the man who pictured a woman's womb as "Uterus simplex". But even in this matter, Vesalius could not separate himself completely from the antique scheme: near the fundus uteri he draws two "ears" or cornua wherein he lets the oviducts discharge themselves, mythical structures that will disappear from his pictures, from 1543 on. The epididymis-like structure of the oviducts will nevertheless be maintained. The chapters 15 to 17 of the fifth book of the Fabrica stand centrally because herein it is the first time that these parts are systematically and thoroughly described; moreover, the pictoral aspect means a great renovation. Before Vesalius, no anatomist had ever published such detailed and artistic pictures of the female organs. But knowing that text and illustration were made at the dissection table, we should consider the author's mistakes as more conspicuous. Thus for instance, the oviduct as vas semen efferens, the structure of which he "saw" in line with Galen's propagation theory. For Vesalius the uterine tube has remained the homologue of the complex canals through which the male seed leaves the body. Another example of an erroneous "observation", inspired by the functional theories of his predecessors, is the imagined connection of blood-vessels between the female internal organs and the breasts. The needlessly complicated terminology and Vesalius' describing and paraphrasing anatomical nomenclature are not very favourable to an easy reading of this works. His classification of the parts of the genital tract is confusing, the more as it is not consistent. We already said that Vesalius attributes but one cavity to woman's uterus.(ABSTRACT TRUNCATED AT 400 WORDS)

Fertility of young mares after long-term anabolic steroid treatment.

The effect of prior treatment with anabolic steroids was studied in 46 three-year-old mares. In the preceding year, these mares had been assigned to 1 of 4 treatment groups and had received the manufacturer's recommended dosage of 1.1 mg of boldenone undecylenate (BU)/kg of body weight, 4.4 mg of boldenone undecylenate (4 BU)/kg, 1.1 mg of nandrolone decanoate (ND)/kg, or 0.04 ml of sesame oil/kg (control, C). Mares had received an injection every 3 weeks for 54 weeks for a total of 19 injections, with the final injection in December. In the following breeding season, fewer (P less than 0.05) mares in all groups previously administered anabolic steroids displayed estrous behavior than did mares in the control group. Duration of estrus was shortened (P less than 0.05) in mares that had received steroids. Abnormal sexual behavior that was observed during steroid treatment continued (P less than 0.05) for up to 6 months after treatment ceased. However, observations of abnormal behavior declined with time (P less than 0.05). All mares in each treatment group ovulated by the end of the trial, and the interval to first ovulation was similar (P greater than 0.05). Ovarian size, follicular development, and conditions of the tubular genitalia was adversely (P less than 0.05) affected in mares in all steroid-treatment groups until approximately the middle of March. After that time, no difference was noted among groups. First-cycle pregnancy rates were 83%, 67%, 50%, and 42% for mares in the untreated, BU, 4 BU, and ND groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Foeniculum vulgare Mill. seed extract on the genital organs of male and female rats.

Following the oral administration of acetone extract of Foeniculum vulgare (fennel) seeds for 15 days is male rats, total protein concentration was found to be significantly decreased in testes and vas deferens and increased in seminal vesicles and prostate gland. There was a decrease in activities of acid and alkaline phosphatase in all these regions, except that alkaline phosphatase was unchanged in vasa. In female rats, oral administration of the extract for 10 days led to vaginal cornification and oestrus cycle. While moderate doses caused increase in weight of mammary glands, higher doses increased the weight of oviduct, endometrium, myometrium, cervix and vagina also. The results confirm the oestrogenic activity of the seed extract.