How flowering plants discriminate between self and non-self pollen to prevent inbreeding.

Flowering plants have evolved various genetic mechanisms to circumvent the tendency for self-fertilization created by the close proximity of male and female reproductive organs in a bisexual flower. One such mechanism is gametophytic self-incompatibility, which allows the female reproductive organ, the pistil, to distinguish between self pollen and non-self pollen; self pollen is rejected, whereas non-self pollen is accepted for fertilization. The Solanaceae family has been used as a model to study the molecular and biochemical basis of self/non-self-recognition and self-rejection. Discrimination of self and non-self pollen by the pistil is controlled by a single polymorphic locus, the S locus. The protein products of S alleles in the pistil, S proteins, were initially identified based on their cosegregation with S alleles. S proteins have recently been shown to indeed control the ability of the pistil to recognize and reject self pollen. S proteins are also RNases, and the RNase activity has been shown to be essential for rejection of self pollen, suggesting that the biochemical mechanism of self-rejection involves the cytotoxic action of the RNase activity. S proteins contain various numbers of N-linked glycans, but the carbohydrate moiety has been shown not to be required for the function of S proteins, suggesting that the S allele specificity determinant of S proteins lies in the amino acid sequence. The male component in self-incompatibility interactions, the pollen S gene, has not yet been identified. The possible nature of the pollen S gene product and the possible mechanism by which allele-specific rejection of pollen is accomplished are discussed.

Thyroid hormone and estrogen interact to regulate behavior.

Environmental perturbations that increase plasma thyroid hormone (T3) concentrations also profoundly affect female reproductive behavior and physiology. We explored whether these effects were mediated by interactions between T3 receptor (TR) and estrogen receptor (ER). This hypothesis was of interest because the half-site of a consensus T3 response element DNA sequence is identical to an ER response element (ERE), and TRs bind to a consensus ERE. Molecular data presented in the accompanying paper [Zhu, Y.-S., Yen, P.M., Chin, W.W.& Pfaff, D.W. (1996) Proc. Natl. Acad. Sci. USA 93, 12587-12592] demonstrate that TRs and ERs are both present in rat hypothalamic nuclear extracts and that both can bind to the promoter the hypothalamic gene preproenkephalin and that interations between liganded TRs and ERs affect preproenkephalin transcription. In this paper, we show that molecular interactions between TRs and ERs are sufficient to mediate environmental effects on estrogen-controlled reproductive behavior. Ovariectomized (OVX) rats treated with high doses of T3 showed significantly lower levels of lordosis behavior in response to estradiol benzoate (EB) compared with OVX females treated with EB alone. Conversely, thyroidectomized/OVX females treated with EB showed significantly greater levels of lordosis behavior compared with OVX females treated with EB, showing the effect of endogenous T3. Thyroid hormone interference with EB-induced behavior could not be explained by a reduction in plasma E2 concentrations or by a general reduction in responsiveness of EB-sensitive tissues. Moreover, numbers of hypothalamic ER-immunoreactive cells increased dramatically following T3 treatment. These data suggest that T3 may reduce EB-dependent sexual behavior through interactions between TR and ER in the nuclei of behaviorally relevant hypothalamic neurons, envisioning for the first time a functional consequence of interactions between two nuclear hormone receptors in brain. These results also open up the possibility of molecular interactions on DNA encoding environmental signals, a new field for the study of neuronal integration.

Physiological coupling of growth factor and steroid receptor signaling pathways: estrogen receptor knockout mice lack estrogen-like response to epidermal growth factor.

Past studies have shown that epidermal growth factor (EGF) is able to mimic the uterotropic effects of estrogen in the rodent. These studies have suggested a "cross-talk" model in which EGF receptor (EGF-R) signaling results in activation of nuclear estrogen receptor (ER) and its target genes in an estrogen-independent manner. Furthermore, in vitro studies have indicated the requirement for ER in this mechanism. To verify the requirement for ER in an in vivo system, EGF effects were studied in the uteri of ER knockout (ERKO) mice, which lack functional ER. The EGF-R levels, autophosphorylation, and c-fos induction were observed at equivalent levels in both genotypes indicating that removal of ER did not disrupt the EGF responses. Induction of DNA synthesis and the progesterone receptor gene in the uterus were measured after EGF treatment of both ERKO and wild-type animals. Wild-type mice showed increases of 4.3-fold in DNA synthesis, as well as an increase in PR mRNA after EGF treatment. However, these responses were absent in ERKO mice, confirming that the estrogen-like effects of EGF in the mouse uterus do indeed require the ER. These data conclusively demonstrate the coupling of EGF and ER signaling pathways in the rodent reproductive tract.

Estradiol stimulates tyrosine phosphorylation of the insulin-like growth factor-1 receptor and insulin receptor substrate-1 in the uterus.

The signaling pathways associated with estrogen-induced proliferation of epithelial cells in the reproductive tract have not been defined. To identify receptor tyrosine kinases that are activated in vivo by 17 beta-estradiol (E2), uteri from ovariectomized mice were examined for enhanced tyrosine phosphorylation of various receptors and a receptor substrate following treatment with this hormone. Within 4 hr after hormone exposure, extracts showed increased phosphotyrosine (P-Tyr) immunoreactivity at several bands, including 170- and 180-kDa; these bands were still apparent at 24 hr after E2. Analysis of immunoprecipitates from uterine extracts revealed that E2 enhanced tyrosine phosphorylation of the insulin-like growth factor-1 receptor (IGF-1R) and insulin receptor substrate-1 (IRS-1) by 6 hr. Comparison of supernatants from IRS-1 and control rabbit IgG immunoprecipitates indicated that the 170-kDa P-Tyr band in extracts was equivalent to IRS-1. The receptors for epidermal growth factor, platelet-derived growth factor, and basic fibroblast growth factor did not exhibit an E2-induced increase in P-Tyr content. The nonestrogenic steroid hormones examined did not stimulate the P-Tyr content of IGF-1R or IRS-1. Immunolocalization of P-Tyr and IRS-1 revealed strong reactivity in the epithelial layer of the uterus from E2-treated mice, suggesting that the majority of P-Tyr bands observed in immunoblots originate in the epithelium. Since hormonal activation of IRS-1 is epithelial, estrogen-specific, and initiated before maximal DNA synthesis occurs following treatment with hormone, this protein, as part of the IGF-1R pathway, may be important in mediating estrogen-stimulated proliferation in the uterus.

A mutation that allows endosperm development without fertilization.

The mechanisms that initiate reproductive development after fertilization are not understood. Reproduction in higher plants is unique because it is initiated by two fertilization events in the haploid female gametophyte. One sperm nucleus fertilizes the egg to form the embryo. A second sperm nucleus fertilizes the central cell to form the endosperm, a unique tissue that supports the growth of the embryo. Fertilization also activates maternal tissue differentiation, the ovule integuments form the seed coat, and the ovary forms the fruit. To investigate mechanisms that initiate reproductive development, a female-gametophytic mutation termed fie (fertilization-independent endosperm) has been isolated in Arabidopsis. The fie mutation specifically affects the central cell, allowing for replication of the central cell nucleus and endosperm development without fertilization. The fie mutation does not appear to affect the egg cell, suggesting that the processes that control the initiation of embryogenesis and endosperm development are different. FIE/fie seed coat and fruit undergo fertilization-independent differentiation, which shows that the fie female gametophyte is the source of signals that activates sporophytic fruit and seed coat development. The mutant fie allele is not transmitted by the female gametophyte. Inheritance of the mutant fie allele by the female gametophyte results in embryo abortion, even when the pollen bears the wild-type FIE allele. Thus, FIE carries out a novel, essential function for female reproductive development.

Interactions of maize bushy stunt phytoplasma with the leafhopper vector, Dalbulus maidis (Delong and Wolcott) (Hemiptera: Cicadellidae) and associated microbiota

Phytoplasmas are bacteria with a persistent propagative transmission by insect vectors that generates direct and indirect interactions among them. In order to understand these interactions for maize bushy stunt phytoplasma (MBSP) and the leafhopper vector Dalbulus maidis (Hemiptera: Cicadellidae), two research lines were addressed. The first one aimed to determine the indirect effects of maize infection by MBSP on some biological and behavioral parameters of the vector, whereas a second line investigated direct interactions of the phytoplasma with D. maidis during its movement through the vector body following acquisition from plants, and associated microbiota. Indirect effects were investigated in choice experiments in which alighting and oviposition preferences by D. maidis were compared on healthy vs. MBSP-infected plants with variable incubation time (diseased plants with early and advanced symptoms, or still asymptomatic). Likewise, indirect effect of MBSP on the D. maidis biology was determined in two life table experiments in which the vector was reared on healthy vs. MBSP-infected plants expressing advanced disease symptoms or still asymptomatic. Choice experiments showed that alighting and oviposition preferences of D. maidis on MBSP-infected plants compared to healthy plants depend on the pathogen incubation period in the plant. The leafhopper preferred MBSP-infected plants over healthy ones during the asymptomatic phase of the disease, but rejected infected plants with advanced symptoms. The vector was able to acquire MBSP from asymptomatic infected plants shortly (3 days) after inoculation, but transmission efficiency increased when acquisition occurred at later stages of the pathogen incubation period (≥14 days) in the source plants and the test plants showed disease symptoms faster. These results suggest that MBSP modulates D. maidis preference for asymptomatic infected plants in the early stages of the crop, allowing rapid spread of this pathogen. Maize infection by the phytoplasma had a neutral effect on most life table parameters of D. maidis; a lower net reproductivity rate (Ro) was observed in the cohort reared on MBSP-infected plants with advanced symptoms, which was compensated to some extent by a higher sexual ratio. MBSP acquisition by all vector nymphal stadia was confirmed by PCR, and the pathogen as detected in both male and female reproductive organs. Concerning direct MBSP-vector interactions, transmission electron microscopy analyses showed phytoplasma-like cells in the midgut lumen, microvilli and epithelial cells, suggesting that MBSP enters the epithelium midgut through the microvilli wall. Within the epithelial cells, mitochondria and bacteria-like cells (possibly endosymbionts) were observed together with masses of phythoplasma-like cells. In the hemocoel, phytoplasma-like cells grouped into a matrix were also observed in association with bacteria-like cells similar to those observed in the midgut epithelium. Similar associations were found in the salivary gland. Interestingly, in-situ hybridization (FISH) technique revealed a variation in diversity and abundance of the microbiota in intestine and salivary glands of D. maidis adults over time after MBSP acquisition from plants. Sulcia sp., Cardinium sp. and eubacteria increased their abundance over time, whereas Rickettsia sp. decreased. The frequent association of the vector microbiota with the phytoplasma in some tissues of D. maidis suggests that endosymbiotic bacteria may play some role in MBSP-vector interactions.

Endocrine-disrupting compounds: A review of their challenge to sustainable and safe water supply and water reuse

The relevance of endocrine-disrupting compounds as potential contaminants of drinking water is reviewed, particularly in the reuse of wastewater. Growing populations and increasing intensification of land and water use for industry and agriculture have increased the need to reclaim wastewater for reuse, including to supplement the drinking water supply. The variety of anthropogenic chemicals that have been identified as potential endocrine disruptors in the environment and the problems arising from their use as human and livestock pharmaceuticals, as agricultural chemicals and in industry are discussed. The potentially adverse impact of these chemicals on human health and the ecology of the natural environment are reviewed. Data for the removal of estrogenic compounds from wastewater treatment are presented, together with the comparative potencies of estrogenic compounds. The relative exposure to estrogens of women on oral contraceptives, hormone replacement therapy, and through food consumption is estimated. A brief overview of some methods available or under development for the assessment of estrogenic activity in environmental samples is provided. The review concludes with a discussion of the directions for further investigation, which include human epidemiology, methodology development, and wastewater monitoring. (C) 2006 Wiley Periodicals, Inc.

New Thelastomatoidea (Nematoda : Oxyurida) from Australian burrowing cockroaches (Blaberidae : Geoscapheinae, Panesthiinae)

Four new species and two new genera of thelastomatoid are described from several species of Australian burrowing cockroaches (Blattodea: Panesthiinae; Geoscapheinae). Corpicracens munozae n. g., n. sp., Pseudodesmicola botti n. g., n. sp. and Cephalobellus nolani n. sp. are described from Geoscapheus dilatatus (Blattodea: Geoscapheinae) from Mendooran, New South Wales; one new thelastomatid, Blattophila praelongicauda n. sp., is described from Panesthia cribrata from Lamington National Park, Queensland. Corpicracens munozae n. g., n. sp. is long and slender, with a monodelphic female reproductive system, a clavate corpus with a slight posterior pseudobulb, oval eggs flattened at the poles, and a relatively robust, subulate tail. Pseudodesmicola botti n. g., n. sp. is slightly more robust in body, also has a monodelphic reproductive system, a cylindrical corpus with a posterior pseudobulb, ovoid eggs and a very long, subulate tail. Cephalobellus nolani n. sp. is distinguished from other members of the genus by its relatively short and broad body and egg shape. Lastly, Blattophila praelongicauda n. sp. is distinguished from other members of the genus by having eggs with a single, polar operculum, tail length, and position of the vulva, nerve ring and excretory pore. An additional species, known by a single specimen from Panesthia tryoni tryoni from the same locality is characterised but not named. The species found are all relatively rare parasites of Australian burrowing cockroaches, each having a prevalence of less than 10%.

KRAS variation and risk of endometriosis

Endometriosis is a common gynaecological disease with symptoms of pelvic pain and infertility which affects 7-10% of women in their reproductive years. Activation of an oncogenic allele of Kirsten rat sarcoma viral oncogene homologue (KRAS) in the reproductive tract of mice resulted in the development of endometriosis. We hypothesized that variation in KRAS may influence risk of endometriosis in humans. Thirty tagSNPs spanning a region of 60.7 kb across the KRAS locus were genotyped using iPLEX chemistry on a MALDI-TOF MassARRAY platform in 959 endometriosis cases and 959 unrelated controls, and data were analysed for association with endometriosis. Genotypes were obtained for most individuals with a mean completion rate of 99.1%. We identified six haplotype blocks across the KRAS locus in our sample. There were no significant differences between cases and controls in the frequencies of individual single-nucleotide polymorphisms (SNPs) or haplotypes. We also developed a rapid method to screen for 11 common KRAS and BRAF mutations on the Sequenom MassARRAY system. The assay detected all mutations previously identified by direct sequencing in a panel of positive controls. No germline variants for KRAS or BRAF were detected. Our results demonstrate that any risk of endometriosis in women because of common variation in KRAS must be very small.

Sugar Feeding Affects the Male Contribution in Reproduction in Aedes Aegypti

Juvenile hormone (JH) is crucial for the stimulation and progression of oogenesis from emergence to the previtellogenic resting stage in female Aedes aegypti mosquitoes. Juvenile hormone has been suggested to be among the many substances transferred form the male accessory glands to the female during copulation but no evidence for this has previously been provided. Quantification of JH III in the accessory glands of males and in the bursae copulatrix and spermathecae of mated females was performed using HPLC-FD. These amounts were measured in relation to the quality of adult sugar feeding in the male. The effect of this variable transfer was measured on two fecundity markers that occur during the previtellogenic stage of oogenesis, specifically follicular resorption and ovarian lipids. Male mosquitoes provided with 20% sucrose contained ~ 60% greater amount of JH in the accessory glands and transferred 4 fmol more JH during copulation than males provided with 3% sucrose. These differences resulted in a nearly 40% reduction in follicular resorption and an approximate 3-fold increase in lipid content in the ovaries of mated females during the previtellogenic stage. These results suggest that the contribution of JH from the male is dependent on the quality of nutrition obtained during adult sugar feeding. Female fecundity is likely responsive to these variable previtellogenic effects, possibly resulting in a difference in the number of eggs laid. Improvements in female reproductive output may have wider implications in the transmission of diseases attributed to this important arbovirus vector.

History of Premenstrual Mood Change and Postpartum Episodes are Associated with Perimenopausal Episodes in Women with Bipolar Disorder

Background and Aims: Reproductive life events are potential triggers of mood episodes in women with bipolar disorder. We aimed to establish whether a history of premenstrual mood change and postpartum episodes are associated with perimenopausal episodes in women who have bipolar disorder. Methods: Participants were 339 post-menopausal women with DSM-IV bipolar disorder recruited into the Bipolar Disorder Research Network (www.bdrn.org). Women self-reported presence (N = 200) or absence (N = 139) of an illness episode during the perimenopausal period. History of premenstrual mood change was measured using the self-report Premenstrual Symptoms Screening Tool (PSST), and history of postpartum episodes was measured via semi-structured interview (Schedules for Clinical Assessment in Neuropsychiatry, SCAN) and inspection of case-notes. Results: History of a postpartum episode within 6 months of delivery (OR = 2.13, p = 0.03) and history of moderate/severe premenstrual syndrome (OR = 6.33, p < 0.001) were significant predictors of the presence of a perimenopausal episode, even after controlling for demographic factors. When we narrowed the definition of premenstrual mood change to premenstrual dysphoric disorder, it remained significant (OR = 2.68, p = 0.007). Conclusions: Some women who have bipolar disorder may be particularly sensitive to reproductive life events. Previous mood episodes in relation to the female reproductive lifecycle may help clinicians predict individual risk for women with bipolar disorder approaching the menopause. There is a need for prospective longitudinal studies of women with bipolar disorder providing frequent contemporaneous ratings of their mood to overcome the limitations of retrospective self-report data.

Serous cystadenofibroma of the Fallopian tube. Case report and literature review

Introduction. Cystadenofibromas of the Fallopian tube are very rare benign tumors of the female genital tract. These tumours are usually asymptomatic and are found incidentally. Case report. We describe a Fallopian serous cystadenofibroma in a 50 year-old woman operated for uterine leiomyoma. The histopathologic finding revealed a cystic lesion connected to the salpinx. The cyst was composed of connective stroma lined by epithelial cuboidal cells, without pleomorfism or detectable mitoses. Pseudopapillary structures were observed in the lumen of the cyst. The patient is well on follow-up. Conclusion. The origin of serous cystadenofibroma of the Fallopian tube is not clear. The tumor is considered an embryologic remnant rather than a proliferating neoplastic process. These tumours seem to have a benign course and a malignant potential has not been described.

Protocolo para a realização de uma ecografia ginecológica

A ecografia ginecológica deve englobar a abordagem supra-púbica e a transvaginal, pois ambas são complementares e permitem um estudo completo do aparelho reprodutor. Antes de começar o exame, é necessário fazer uma breve história clínica, a doente deve começar o exame com a bexiga cheia, para uma abordagem supra-púbica e esvaziar a bexiga para a abordagem transvaginal. O relatório deve incluir uma descrição detalhada do útero, ovários, incluindo as suas dimensões, posição, contornos, lesões, etc. O objectivo deste artigo é fazer um protocolo para a realização deste exame de modo a minimizar o erro médico.

Diagnostico de endometritis subclínica en vacas lecheras

Las enfermedades uterinas en el período posparto comprometen seriamente la eficiencia reproductiva. La clasificación hecha hace pocos años por Sheldon et al. (2006) permite diagnosticarlas con mayor facilidad de acuerdo al tiempo transcurrido desde el parto a su detección y diagnóstico. De acuerdo con esta clasificación ha sido posible utilizar las denominaciones de metritis puerperal a la que transcurre entre los días 4 a 10 posparto; a la endometritis clínica y la piómetra, que se observan a partir del día 14 posparto y la endometritis subclínica que ocurre en cualquier momento posterior a la culminación histológica de la involución uterina (en general más allá de las 5 a 6 semanas del posparto). En esta revisión se realiza un análisis de cada una de estas presentaciones y sus características. Finalmente se describen los tratamientos posibles que en su conjunto aún no han permitido una solución total quedando claro que es un control precoz y sobre todo durante el período de transición lo que permite disminuir el impacto de estas patologías sobre el tracto reproductivo y así mejorar la eficiencia reproductiva de la vaca lechera.

Spermathecae of the mangrove crab Ucides cordatus: a histological and histochemical view

Ucides cordatus is the most commercially, important mangrove crab in Brazil. In spite of its economic importance, there are few studies of its reproduction, in particular the female reproductive system. The present study describes the histology and histochemistry of the spermathecae of U. cordatus. Adult females were can lit monthly from July 2004 through June 2005, at Iguape, State of São Paulo. The crabs were anaesthetized, and their spermathecae removed and fixed in Davidson's fluid, following the histological routine for paraffin. The slides were stained with HE, xylidine Ponceau, PAS, alcian blue (pH 1.0 and 2.5), Sudan black B and picrosirius-haematoxylin. Histologically, the spermathecae possesses a capsule of conjunctive tissue, rich in collalgen fibres, which surrounds the secretory columnar epithelium. In the lumen, individual sperm packets are not observed; the spermatophores are intermixed with the seminal fluid and secretions of the spermathecae itself. A large proportion of the free spermatozoids and spermatophores are arranged in homogeneous masses in the proximal part of the spermathecae. The secretion produced by the columnar epithelium appears to promote the movement of the gametes to the fertilization chamber, in a ventral position, allowing fertilization of the oocytes. Histochemically, the secretion produced by the columnar epithelium was strongly positive for neutral polysaccharides, positive for acid polysaccharides, and weakly positive for proteins and lipids. Tills secretion forms a glycoprotein matrix which is associated with maintenance of the spermatophores, which can remain stored for long periods.