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Sexual Development (sexual + development)
Selected AbstractsNeuroendocrine mechanisms controlling female puberty: new approaches, new conceptsINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2006Sergio R. Ojeda Summary Sexual development and mature reproductive function are controlled by a handful of neurones that, located in the basal forebrain, produce the decapeptide luteinizing hormone releasing hormone (LHRH). LHRH is released into the portal system that connects the hypothalamus to the pituitary gland and act on the latter to stimulate the synthesis and release of gonadotrophin hormones. The pubertal activation of LHRH release requires coordinated changes in excitatory and inhibitory inputs to LHRH-secreting neurones. These inputs are provided by both transsynaptic and glia-to-neurone communication pathways. Using cellular and molecular approaches, in combination with transgenic animal models and high-throughput procedures for gene discovery, we are gaining new insight into the basic mechanisms underlying this dual control of LHRH secretion and, hence, the initiation of mammalian puberty. Our results suggest that the initiation of puberty requires reciprocal neurone-glia communication involving excitatory amino acids and growth factors, and the coordinated actions of a group of transcriptional regulators that appear to represent a higher level of control governing the pubertal process. [source] Sexual development and reproductive seasonality of hogfish (Labridae: Lachnolaimus maximus), an hermaphroditic reef fishJOURNAL OF FISH BIOLOGY, Issue 5 2007R. S. McBride The seasonality, size, age, colour phases and sexual dimorphism of 13 reproductive classes of hogfish Lachnolaimus maximus are described. Analysis of histological sections of gonads (n = 1662) confirmed earlier conclusions that L. maximus is a monandric, protogynous hermaphrodite. Sex change was initiated at the end of the spawning season and over a broad range of sizes and ages. It occurred after a functional female phase (postmaturation) and proceeded more slowly (months) than previously believed. Eventually all individuals changed sex to a terminal male phase. Females were batch spawners, spawning as often as every day during winter and spring. There was no evidence of precocious sperm crypts in active females, sperm competition or other alternative male sexual strategies. Mating has been reported elsewhere to be haremic. The sexual development of L. maximus appears to be adaptive in terms of Ghiselin's size-advantage model, which links monandric protogyny and polygyny. The slow rate of sex change, however, poses problems when fishing pressure is high because harvest of a single male has the potential to reduce the reproductive output of an entire harem. [source] Sex determination in fish: Lessons from the sex-determining gene of the teleost medaka, Oryzias latipesDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 5-6 2003Masaru Matsuda Although sex determination systems in animals are diverse, sex-determining genes have been identified only in mammals and some invertebrates. Recently, DMY (DM domain gene on the Y chromosome) has been found in the sex-determining region on the Y chromosome of the teleost medaka fish, Oryzias latipes. Functional and expression analyses of DMY show it to be the leading candidate for the male-determining master gene of the medaka. Although some work is required to define DMY as the master sex-determining gene, medaka is expected to be a good experimental animal for investigating the precise mechanisms involved in primary sex determination in non-mammalian vertebrates. In this article, the process of identification of DMY and is summarized and the origins of DMY and sexual development of the medaka's gonads are reviewed. In addition, putative functions of DMY are discussed. [source] Sexuality in children and adolescents with disabilitiesDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 9 2005Nancy Murphy MD This review presents a discussion of the sexual development of children and adolescents with disabilities, described in the framework of body structure and function, individual activities, and societal perspectives presented in the World Health Organization's International Classification of Functioning, Disability and Health. Issues of sexual development, gynecological care and contraception, sexual functioning, societal barriers, sexual victimization, and sexuality education are presented. Overall, adolescents with disabilities seem to be participating in sexual relationships without adequate knowledge and skills to keep them healthy, safe, and satisfied. Although their sexual development may be hindered both by functional limitations and by intentional or unintentional societal barriers, the formal and informal opportunities for teenagers with disabilities to develop into sexually expressive and fulfilled persons do exist. Health care providers are urged to increase their awareness of this unmet need and to implement strategies that promote the physical, emotional, social, and psychosexual independence of children, teenagers, and young adults with disabilities. [source] Reproductive effects of the endocrine disruptor fenarimol on a Baltic amphipod Monoporeia affinisENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2006Therese Jacobson Abstract An endocrine disruptor, the fungicide fenarimol, was investigated regarding its effects on reproduction and hormone (ecdysteroid) levels in the deposit-feeding amphipod Monoporeia affinis. In addition, the influence of food shortage, both by itself and in combination with fenarimol, on reproduction was examined. Field-collected amphipods were exposed in flow-through microcosms during the period of sexual maturation and mating in four treatment series: Control with low food, fenarimol with low food, control with high food, and fenarimol with high food. Fenarimol was added at a concentration of 0.3 mg/L in two pulses/week. Results show that fenarimol has a negative effect on fertilization rate and male mating ability. Results were supported by a tendency toward delayed male sexual development. Food shortage decreased weight in both sexes and retarded female oocyte development. Higher ecdysteroid levels were recorded in males than in females, and food shortage increased male ecdysteroid levels. No effect of fenarimol exposure on ecdysteroid levels was observed. No synergistic effects of fenarimol and food shortage could be distinguished in any variable examined. Thus, M. affinis was vulnerable to reproductive impairment by fenarimol, with effects on the next generation (i.e., a disturbed sexual development and fertilization ability). Food shortage has negative effects on M. affinis, but it does not enhance the effects of fenarimol. [source] Abnormalities in sexual development of the amphipod Gammarus pulex (L.) found below sewage treatment worksENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2001Melanie Yvette Gross Abstract Increasing numbers of widely used industrial, agricultural, and natural chemicals are known to elicit endocrine-disrupting effects in a wide range of vertebrate and invertebrate species. The objective of this study was to determine whether the sexual development of the freshwater crustacean Gammarus pulex (L.) was affected below sewage treatment works (STW) previously known to contain endocrine-disrupting chemicals in their effluent. The gonadal structure, external sexual characteristics, and size of gammarids from exposed sites were compared to those of gammarids from a reference site. No significant difference was found in the gonadal structure of males collected below two STW. However, a highly significant number of females collected from a site known to elicit high estrogenic responses in vertebrates displayed an abnormal structure of oocytes in vitellogenesis. Body size was significantly shorter and male/female size differential was significantly reduced below one of the STW. Analysis of gnathopod and genital papillae length data suggests that different allometric relationships of these organs to body size exist between sample sites. [source] Variation of metallothionein and metal concentrations in the digestive gland of the clam Ruditapes decussatus: Sex and seasonal effectsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2001Maria A. Serafim Abstract Metallothionein (MT) and metal (Cd, Cu, and Zn) concentrations were determined in the digestive gland of male and female Ruditapes decussatus. Clams were collected monthly during the period of sexual development, from June to September, at two different sites of a coastal lagoon, the Ria Formosa Lagoon, on the south coast of Portugal. The MT concentrations were determined in the heat-treated cytosolic fraction of the digestive gland of both male and female clams. Total metal (Cd, Cu, and Zn) concentrations in the heat-treated cytosol of the digestive gland were also determined in both sexes. The MT and metal concentrations in the digestive gland were not sex dependent in this species. Therefore, these results suggest that random samples can be used to determine MT and metal concentrations in the digestive gland of R. decussatus. Seasonal and site-specific dependency, however, were detected for MT, Cd, and Cu concentrations. The maximum concentration levels of MT, Cd, and Cu were detected in July and August for both sexes in the same area. Zinc concentrations, however, did not show marked seasonal variations, indicating that this species is able to regulate zinc concentrations. The highest MT concentrations were significantly related to the highest metal concentrations. [source] Nonylphenols in sediments and effluents associated with diverse wastewater outfalls,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2000Robert C. Hale Abstract Nonylphenols (NPs) have been reported to disrupt endocrine function and sexual development in aquatic organisms at low concentrations. Environmental NP burdens are predominantly derived from degradation of nonylphenol polyethoxylate surfactants. We detected NPs in discharge-associated riverine sediments adjacent to 11 of 20 active sewage treatment plants (STPs) at concentrations up to 12,400 ,g/kg. While most previous studies have focused on STPs, nonylphenols were observed in association with a variety of outfall types. The highest sediment burden, 14,100 ,g/kg, was detected near a federal facility's stormwater discharge. Of 75 sediments examined from 67 sites, 45% contained NP concentrations >5 ,g/kg; median concentration in these NP-positive sediments was 369 ,g/kg. Other surfactant-derived alkylphenolic compounds, specifically 4- tert -octylphenol and 4-cumylphenol, were observed in two sediments at 8,220 and 70,000 ,g/kg, respectively. The maximum NP concentration detected in an effluent, 6,300 ,g/L, was from a shipyard oil/water separator. Nonylphenols were detected (> 1.0 ,g/L) in 20% of the 59 effluents examined; 10% exceeded 10 ,g/L. Sediments sampled near a STP that had ceased treatment operations 20 years prior contained 54,000 ,g/kg, indicative of long-term NP residence. Results indicate that NPs may be released from diverse sources, concentrate in associated sediments, and persist therein for extended periods. [source] Extra terminal residues have a profound effect on the folding and solubility of a Plasmodium falciparum sexual stage-specific protein over-expressed in Escherichia coliFEBS JOURNAL, Issue 21 2002Sushil Prasad Sati The presence of extra N- and C- terminal residues can play a major role in the stability, solubility and yield of recombinant proteins. Pfg27 is a 27K soluble protein that is essential for sexual development in Plasmodium falciparum. It was over-expressed using the pMAL-p2 vector as a fusion protein with the maltose binding protein. Six different constructs were made and each of the fusion proteins were expressed and purified. Our results show that the fusion proteins were labile and only partially soluble in five of the constructs resulting in very poor yields. Intriguingly, in the sixth construct, the yield of soluble fusion protein with an extended carboxyl terminus of 17 residues was several fold higher. Various constructs with either N-terminal or smaller C-terminal extensions failed to produce any soluble fusion protein. Furthermore, all five constructs produced Pfg27 that precipitated after protease cleavage from its fusion partner. The sixth construct, which produced soluble protein in high yields, also gave highly stable and soluble Pfg27 after cleavage of the fusion. These results indicate that extra amino acid residues at the termini of over-expressed proteins can have a significant effect on the folding of proteins expressed in E. coli. Our data suggest the potential for development of a novel methodology, which will entail construction of fusion proteins with maltose binding protein as a chaperone on the N-terminus and a C-terminal ,solubilization tag'. This system may allow large-scale production of those proteins that have a tendency to misfold during expression. [source] The delicate balance between male and female sex determining pathways: potential for disruption of early steps in sexual developmentINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2010P. Koopman Summary Testes and ovaries develop from the same primordial structures, the genital ridges, in the mammalian foetus. Male development depends critically on the correct functioning of the Y-linked testis-determining gene, Sry. However, Sry is highly vulnerable to mutation, and so does not provide a very robust sex-determining mechanism. Both in testes and in ovaries, proper gonadal development involves co-ordinated regulation of the bipotential fates of a number of different cell lineages, and is dependent on intercellular signalling mechanisms. If either the testicular or ovarian pathway stalls in the early stages, mechanisms operate to engage the alternative pathway. For these reasons, the early steps in mammalian sexual development are vulnerable to genetic and environmental perturbation, and represent possible points of action of endocrine disrupting compounds. [source] Age, growth and sexual development of solenette, Buglossidium luteum (Risso, 1810), in the central Aegean SeaJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2010A. T., lkyaz Summary Age, growth, spawning period and maturity of the solenette (Buglossidium luteum Risso, 1810) were studied in the central Aegean Sea to provide fisheries managers with essential data for science-based management. A total of 1220 samples were collected by trawl hauls from July 2004 to June 2007 in ,zmir Bay (Turkey). Sample sizes ranging from 5.3 to 11.6 cm total length were composed of 46% females, 32% males and 22% immature individuals, with a female to male ratio of 1 : 0.7. Age composition stages of the females were from I to IV, and males between I and III. The length,weight relationship was calculated as W = 0.0101L3.008 for all samples. Estimated von Bertalanffy growth parameters were L = 13.30 cm, to = ,0.440 year and k = 0.481 year,1, with a growth performance index of 1.93 (,'). The spawning period began in April and continued until July. Lengths at first maturity of females and males were 8.1 and 7.9 cm total length, respectively. Both sexes matured at the age of 2 years. [source] Differential expression of the two distinct replication protein A subunits from Cryptosporidium parvumJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2008Stanley Dean Rider Jr. Abstract Apicomplexan parasites differ from their host by possessing at least two distinct types (long and short) of replication protein A large subunits (RPA1). Different roles for the long and short types of RPA1 proteins have been implied in early biochemical studies, but certain details remained to be elucidated. In the present study, we have found that the Cryptosporidium parvum short-type RPA1 (CpRPA1A) was highly expressed at S-phase in parasites during the early stage of merogony (a cell multiplication process unique to this group of parasites), but otherwise present in the cytosol at a much lower level in other cell-cycle stages. This observation indicates that CpRPA1A is probably responsible for the general DNA replication of the parasite. On the other hand, the long-type CpRPA1B protein was present in a much lower level in the early life cycle stages, but elevated at later stages involved in sexual development, indicating that CpRPA1B may play a role in DNA recombination. Additionally, CpRPA1B could be up-regulated by UV exposure, indicating that this long-type RPA1 is probably involved in DNA repair. Collectively, our data implies that the two RPA1 proteins in C. parvum are performing different roles during DNA replication, repair and recombination in this parasite. J. Cell. Biochem. 104: 2207,2216, 2008. © 2008 Wiley-Liss, Inc. [source] Caregiver Understanding of Adolescent Development in Residential TreatmentJOURNAL OF CHILD AND ADOLESCENT PSYCHIATRIC NURSING, Issue 4 2002Susan Kools PhD PROBLEM Caretaker knowledge and understanding of adolescent development and its application to clinical practice with severely emotionally disturbed adolescents in residential treatment. METHODS Twenty child-care workers and registered nurses participated in semistructured interviews analyzed using dimensional analysis, a grounded theory method. FINDINGS Three distinct categories of caregivers were identified based on level of expertise and engagement in developmentally appropriate treatment practices: inexperienced, party-liners, and transcenders. Developmental issues identified included lack of resident preparation for puberty and staff discomfort with adolescent sexuality. CONCLUSIONS Caregiver, institutional, and social barriers to developmentally sensitive practice were identified. Practice recommendations include direct preparation of children and adolescents in residential treatment for pubertal changes and sexual development, and carefkl discernment of age-appropriate and psycho-pathological adolescent behaviors. [source] The genetic basis of early-life morphological traits and their relation to alternative male reproductive tactics in Atlantic salmonJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2010D. J. PáEZ Abstract Although heritability estimates for traits potentially under natural selection are increasingly being reported, their estimation remains a challenge if we are to understand the patterns of adaptive phenotypic change in nature. Given the potentially important role of selection on the early life phenotype, and thereby on future life history events in many fish species, we conducted a common garden experiment, using the Atlantic salmon (Salmo salar L.), with two major aims. The first objective is to determine how the site of origin, the paternal sexual tactic and additive genetic effects influence phenotypic variation of several morphological traits at hatching and emergence. The second aim is to test whether a link exists between phenotypic characteristics early in life and the incidence of male alternative tactics later in life. We found no evidence of a site or paternal effect on any morphological trait at hatching or emergence, suggesting that the spatial phenotypic differences observed in the natural river system from which these fish originated are mainly environmentally driven. However, we do find significant heritabilities and maternal effects for several traits, including body size. No direct evidence was found correlating the incidence of precocious maturation with early life characteristics. We suggest that under good growing conditions, body size and other traits at early developmental stages are not reliable cues for the surpassing of the threshold values associated with male sexual development. [source] Age and size compositions, growth and reproductive biology of the breaksea cod Epinephelides armatus, a gonochoristic serranidJOURNAL OF FISH BIOLOGY, Issue 5 2007S. E Moore Details of the reproductive biology, size and age compositions and growth of the breaksea cod Epinephelides armatus, the sole representative of Epinephelides, were obtained by collecting monthly samples of a wide total length (LT) range of individuals from coastal marine waters at 31,32° S on the lower west coast of Australia. Although the modal LT class of females (250,299 mm) was markedly less than that of males (400,449 mm), the modal ages of the two sexes were similar, i.e. 4 v. 5 years, respectively. The similarity in the age compositions and the histological demonstration that the gonads of all E. armatus consist solely of either ovarian or testicular tissues demonstrate that this species is gonochoristic, which is highly unusual for an anthiinine serranid. The absence of a central, membrane-lined ,ovarian' lumen in the testes of juveniles would account for adult testes containing neither this ovarian remnant nor the peripherally located sperm sinuses that are found in the mature testes of almost all other serranids. The results demonstrate that E. armatus exhibits a very unusual pattern of sexual development for a serranid. The spawning period of E. armatus lasts for c. 9 months, which is long for a species in temperate Western Australian waters, but comparable with that of many other relatively small serranids elsewhere. Females grow slower than males, attaining LT at 3, 5 and 10 years of c. 200, 285 and 420 mm, respectively, compared with c. 215, 315 and 450 mm, respectively. Females, however, attain maturity at a greater LT and older age than males. [source] Characterization and Functionality of Frozen Muscle Protein in Volador (Illexcoindetii), Pota (Todaropsis eblanae), and Octopus (Eledone cirrhosa)JOURNAL OF FOOD SCIENCE, Issue 7 2003C. Ruiz-Capillas ABSTRACT: Three species of cephalopods: volador (Illex coindetii), pota (Todaropsis eblanae), and octopus (Eledone cirrhosa) were classified according to sex, stage of sexual development, and anatomical zone for characterization and functionality of their muscle proteins. The 3 species exhibited very similar levels of total protein. Octopus mantles and arms contained the least proline and the most hydroxyproline. The highest solubility values in immature pota coincided with the lowest apparent viscosity and emulsifying capacity values. The highest insolubility values observed in octopus coincided with the highest viscosity and emulsifying capacity values. However, in volador which exhibited an intermediate solubility, viscosity was very high and emulsifying capacity was very low. [source] Cybersex and the E-teen: What Marriage and Family Therapists Should KnowJOURNAL OF MARITAL AND FAMILY THERAPY, Issue 4 2008David L. Delmonico Adolescents who use the Internet regularly (the "e-teen") present a new set of challenges for marriage and family therapists. This article introduces marriage and family therapists to (a) the basic technological concepts and unique psychological characteristics of the Internet important in understanding and addressing adolescent online sexual behavior, (b) the appropriate developmental expectations for teens online, including risk-taking behaviors and critical decision-making skills, and (c) suggested strategies for assessment, prevention, and intervention when dealing with problematic online sexual behavior in adolescents. Marriage and family therapists cannot ignore the role the Internet plays in adolescent sexual development and its implication for the family. This article will serve as a primer for the marriage and family therapist when presented with adolescents who engage in online sexual behaviors. [source] Expression of Three Gene Families Encoding Cell,Cell Communication Molecules in the Prepubertal Nonhuman Primate HypothalamusJOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2005A. E. Mungenast Abstract Transsynaptic and glial,neuronal communication are important components of the mechanism underlying the pubertal activation of luteinizing hormone-releasing hormone (LHRH) secretion. The molecules required for the architectural organization of these cell,cell interactions have not been identified. We now show that the hypothalamus of the prepubertal female rhesus monkey expresses a multiplicity of genes encoding three families of adhesion/signalling proteins involved in the structural definition of both neurone-to-neurone and bi-directional neurone,glia communication. These include the neurexin/neuroligin (NRX/NRL) and protocadherin-, (PCDH,) families of synaptic specifiers/adhesion molecules, and key components of the contactin-dependent neuronal,glial adhesiveness complex, including contactin/F3 itself, the contactin-associated protein-1 (CASPR1), and the glial receptor protein tyrosine phosphatase ,. Prominently expressed among members of the NRX family is the neurexin isoform involved in the specification of glutamatergic synapses. Although NRXs, PCDH,s and CASPR1 transcripts are mostly detected in neurones, the topography of expression appears different. NRX1 mRNA-containing neurones are scattered throughout the hypothalamus, PCDH, mRNA transcripts appear more abundant in neurones of the arcuate nucleus and periventricular region, and neurones positive for CASPR1 mRNA exhibit a particularly striking distribution pattern that delineates the hypothalamus. Examination of LHRH neurones, using the LHRH-secreting cell line GT1-7, showed that these cells contain transcripts encoding NRXs and one of their ligands (NRL1), at least one PCDH, (CNR-8/PCDH,10), and the CASPR1/contactin complex. The results indicate that the prepubertal female monkey hypothalamus contains a plethora of adhesion/signalling molecules with different but complementary functions, and that an LHRH neuronal cell line expresses key components of this structural complex. The presence of such cell,cell communication machinery in the neuroendocrine brain suggests an integrated participation of their individual components in the central control of female sexual development. [source] Glial,Neuronal,Endothelial Interactions are Involved in the Control of GnRH SecretionJOURNAL OF NEUROENDOCRINOLOGY, Issue 3 2002Vincent PrevotArticle first published online: 8 APR 200 Abstract In recent years compelling evidence has been provided that cell,cell interactions involving non-neuronal cells, such as glial and endothelial cells, are important in regulating the secretion of GnRH, the neuropeptide that controls both sexual development and adult reproductive function. Modification of the anatomical relationship that exist between GnRH nerve endings and glial cell processes in the external zone of the median eminence modulates the access of GnRH nerve terminals to the portal vasculature during the oestrous cycle. The establishment of direct neuro-haemal junctions between GnRH neuroendocrine terminals and the portal vasculature on the day of pro-oestrus may be critical for the transfer of GnRH upon its release into the fenestrated capillaries of the median eminence. Notwithstanding the importance of these plastic rearrangements, glial and endothelial cells also regulate GnRH neuronal function via specific cell,cell signalling molecules. While endothelial cells of the median eminence use nitric oxide to effect this regulatory control, astrocytes employ several growth factors, and in particular those of the EGF family and their erbB receptors to facilitate GnRH release during sexual development. Loss of function of each of these erbB receptors involved in the astroglial control of GnRH secretion leads to delayed sexual development. It is clear that regulation of GnRH secretion by cell,cell communication mechanisms other than transsynaptic inputs is an important component of the central neuroendocrine process controlling mammalian reproduction. [source] Disruption of a Plasmodium falciparum cyclic nucleotide phosphodiesterase gene causes aberrant gametogenesisMOLECULAR MICROBIOLOGY, Issue 1 2008Cathy J. Taylor Summary Phosphodiesterase (PDE) and guanylyl cyclase (GC) enzymes are key components of the cGMP signalling pathway and are encoded in the genome of Plasmodium falciparum. Here we investigate the role of specific GC and PDE isoforms in gamete formation , a process that is essential for malaria transmission and occurs in the Anopheles mosquito midgut following feeding on an infected individual. Details of the intracellular signalling events controlling development of the male and female gametes from their precursors (gametocytes) remain sparse in P. falciparum. Previous work involving the addition of pharmacological agents to gametocytes implicated cGMP in exflagellation , the emergence of highly motile, flagellated male gametes from the host red blood cell. In this study we show that decreased GC activity in parasites having undergone disruption of the PfGC, gene had no significant effect on gametogenesis. By contrast, decreased cGMP-PDE activity during gametocyte development owing to disruption of the PfPDE, gene, led to a severely reduced ability to undergo gametogenesis. This suggests that the concentration of cGMP must be maintained below a threshold in the developing gametocyte to allow subsequent differentiation to proceed normally. The data indicate that PfPDE, plays a crucial role in regulating cGMP levels during sexual development. [source] The Ustilago maydis Cys2His2 -type zinc finger transcription factor Mzr1 regulates fungal gene expression during the biotrophic growth stageMOLECULAR MICROBIOLOGY, Issue 6 2008Yan Zheng§ Summary The smut fungus Ustilago maydis establishes a biotrophic relationship with its host plant maize to progress through sexual development. Here, we report the identification and characterization of the Cys2His2 -type zinc finger protein Mzr1 that functions as a transcriptional activator during host colonization. Expression of the U. maydis mig2 cluster genes is tightly linked to this phase. Upon conditional overexpression, Mzr1 confers induction of a subset of mig2 genes during vegetative growth and this requires the same promoter elements that confer inducible expression in planta. Furthermore, expression of the mig2-4 and mig2-5 genes during biotrophic growth is strongly reduced in cells deleted in mzr1. DNA-array analysis led to the identification of additional Mzr1-induced genes. Some of these genes show a mig2 -like plant-specific expression pattern and Mzr1 is responsible for their high-level expression during pathogenesis. Mzr1 function requires the b -dependently regulated Cys2His2 -type cell cycle regulator Biz1, indicating that two stage-specific regulators mediate gene expression during host colonization. In spite of a role as transcriptional activator during biotrophic growth, mzr1 is not essential for pathogenesis; however, conditional overexpression interfered with proliferation during vegetative growth and mating ability, caused a cell separation defect, and triggered filamentous growth. We discuss the implications of these findings. [source] Parents' Perspectives on Talking to Preteenage Children About SexPERSPECTIVES ON SEXUAL AND REPRODUCTIVE HEALTH, Issue 1 2010Ellen K. Wilson CONTEXT:Although parent-child communication about sex can significantly affect children's sexual behavior, many parents do not talk to their children about sex. Qualitative research can elucidate parents' attitudes toward and experiences with communicating with their children about sex. METHODS:In 2007, 16 focus groups were conducted with 131 mothers and fathers of children aged 10,12 in three cities in different regions of the United States. Separate groups were conducted for mothers and fathers, and for black, white and Hispanic parents. Content analysis was used to identify core themes and patterns. RESULTS:Parents believed it is important to talk to their children about sex and believed that doing so can be effective, but many had not done so. Primary barriers were parents' perception that their children are too young and not knowing how to talk to their children about the subject. Parents found it easiest to talk to their children about sex if they had a good parent-child relationship, took advantage of opportunities to talk and began having the discussions when their children were very young. Some differences were noted by parents' race, ethnicity, gender and location. CONCLUSIONS:Interventions aimed at encouraging parents to talk to their children about sex should enhance parents' understanding of the stages of children's sexual development and focus on the parents of young children. In addition, interventions should support parents in a range of strategies that complement discussions about sex. [source] CHARGE syndrome as unusual cause of hypogonadism: endocrine and molecular evaluationANDROLOGIA, Issue 5 2010L. Foppiani Summary Coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies (CHARGE) syndrome is a genetic syndrome in which hypogonadism is a frequent feature. A causative mutation within the chromodomain helicase DNA-binding protein-7 gene, which plays an important role in the embryonic development, is present in 2/3 of affected patients. We describe the clinical, hormonal and molecular characteristics of a young man from Ecuador who was diagnosed as having CHARGE syndrome at an adult age. The patient showed several phenotypic features of the syndrome, associated with a prepubertal state and cryptorchidism; hypogonadotrophic hypogonadism with undetectable testosterone levels not responsive to hCG testing and severe osteoporosis were ascertained. Molecular evaluation of the CHD7 gene showed the novel frameshift truncating heterozygous mutation p.Tyr1046Glyfs*23 in exon 12. Magnetic resonance imaging revealed mild hypoplasia of the pituitary gland and hypoplasia of the posterior cranial fossa. Parenteral testosterone therapy led to sexual development over time and, in combination with diphophonate therapy and calcium,vitamin D supplementation, significantly improved bone mineralisation. Early proper hormonal treatment of hypogonadism in patients with complex genetic syndromes is important to achieve normal sexual maturation, improve quality of life and avoid significant comorbidities, such as osteoporosis. [source] Genetic covariation in production traits of sub-adult black bream Acanthopagrus butcheri after grow-outAQUACULTURE RESEARCH, Issue 11 2005Robert G Doupé Abstract Predicting the suitability and reliability of traits associated with juvenile growth as indirect selection criteria for choosing future broodstock requires accurate and repeatable estimates of genetic (co)variation for growth traits at different ages. We compared juvenile wet weight of black bream Acanthopagrus butcheri (Munro) at 6 months of age with wet weight, dressed weight, fillet yield and gonad weight in tagged individuals at 18 months of age, following 12 months of farm grow-out. Fish survival and tag retention was high, and there was significant among-family variation for all traits. The phenotypic correlations among wet weight, dressed weight and fillet yield at 18 months of age were very high (0.93,0.97) and similar to their genetic correlations (0.96). Importantly, the phenotypic correlations between wet weight at 6 months and wet weight, dressed weight and fillet yield at 18 months were high (0.63,0.65), and so too were their genetic correlations (0.66,0.73), indicating the potential for using wet weight in the hatchery as a selection criterion for improved weight and meat yield of fish at harvest. Gonad weight shared little or no phenotypic or genetic correlation with these other traits, suggesting that selection for faster growing fish will not affect fecundity or sexual maturation rate. It appears, however, that cultured black bream do become sexually mature more rapidly than wild fish, as 78% of all fish harvested in this study had developing or mature gonads, whereas less than 50% of fish in wild populations are reproductively mature by the same age. Precocious sexual development may lead to uncontrolled spawning in grow-out ponds and a potential loss of selection gains. [source] The dice of fate: the csd gene and how its allelic composition regulates sexual development in the honey bee, Apis melliferaBIOESSAYS, Issue 10 2004Martin Beye Perhaps 20% of known animal species are haplodiploid: unfertilized haploid eggs developinto males and fertilized diploid eggs into females. Sex determination in such haplodiploid species does not rely on a difference in heteromorphic sex chromosome composition but the genetic basis has been elucidated in some hymenopteran insects (wasps, sawflies, ants, bees). In these species, the development into one sex or the others depends on an initial signal whether there is only one allele or two different alleles of a single gene, the complementary sex determiner (csd), in the zygotic genome. The gene has been most-recently identified in the honey bee and has been found to encode an arginine serine-rich (SR) type protein. Heterozygosity generates an active protein that initiates female development while hemizygosity/homozygosity results in a non-active CSD protein and default male development. I will discuss plausible models of how the molecular decision of male and female is made and implemented. Comparison to hierarchies of dipteran insects suggests that SR-type protein has facilitated the differentiation of sex-determining systems and hierarchies. BioEssays 26:1131,1139, 2004. © 2004 Wiley Periodicals, Inc. [source] Poor uterine development in Turner syndrome with oral oestrogen therapyCLINICAL ENDOCRINOLOGY, Issue 3 2002Wendy F. Paterson Summary OBJECTIVE To evaluate uterine development in Turner syndrome (TS) patients in relation to treatment with oral ethinyl oestradiol (E2) for pubertal induction. DESIGN AND PATIENTS Pelvic ultrasound data for 96 TS patients scanned since 1989 were analysed. Patients were classified into three groups: (1) untreated (n = 48); (2) complete spontaneous puberty (n = 10); and (3) treated with ethinyl oestradiol (n = 38). Uterine development was described in the three groups and compared with the normal data. MEASUREMENTS Uterine length, fundal-cervical ratio (FCR) and shape were recorded, and presence or absence of ovaries noted. In the treated group, cross-sectional and longitudinal data were combined to compare uterine development with Tanner breast stage. RESULTS In untreated girls up to age 10 years there was a variable distribution of uterine length and FCR about the mean. Thereafter, the uterus failed to grow and mature normally. Girls with complete spontaneous puberty had morphologically normal ovaries and uteri, but of 7 girls who attained menarche, 3 subsequently developed secondary oligomenorrhoea or amenorrhoea. In the treated group, in general, breast development and uterine length progressed with increasing E2 dose. However, only 50% of girls with complete secondary sexual development had a mature heart-shaped uterine configuration. CONCLUSIONS Our current E2 treatment regimen for TS girls gives rise to satisfactory pubertal induction and maintenance, but failed to induce a fully mature uterus in half the cohort. In view of the high risk of miscarriage in TS in both spontaneous and assisted pregnancies, the effect of more physiological methods of E2 replacement on uterine development should be investigated. [source] | |||||||||||||||||||