Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sexual Development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed2002

Stage-specific gene expression during sexual development in Phytophthora infestans.

Eight genes that are upregulated during sexual development in the heterothallic oomycete, Phytophthora infestans, were identified by suppression subtractive hybridization. Two genes showed very low but detectable expression in vegetative hyphae and became induced about 40- to >100-fold early in mating, before gametangial initials appeared. The remaining six loci were not induced until later in mating, coincident with the formation of gametangia and oospores, with induction levels ranging from 60- to >100-fold. Five genes were single copy, and three were members of families. Sequence analysis revealed that the predicted products of three of the genes had similarity to proteins that influence RNA stability, namely a ribonuclease activator, the pumilio family of RNA-binding proteins and RNase H. The products of two other mating-induced genes resembled two types of Phytophthora proteins previously shown to elicit plant defence responses. Each mating-induced gene was also expressed in a self-fertile strain, which was shown to be a heterokaryon. However, quantitative and qualitative differences existed in their expression in normal matings and in the self-fertile heterokaryon. Besides the mating-induced genes, two extrachromosomal RNA elements were identified.

Amino Acid Sequence↗
PubMed2003

Regulation of the rate of asexual growth and commitment to sexual development by diffusible factors from in vitro cultures of Plasmodium falciparum.

The mechanism of switching to sexual differentiation (gametocytogenesis) of Plasmodium falciparum appears to be controlled by stochastic mechanisms that are sensitive to environmental conditions. In any given conditions, only a proportion of genetically identical parasites will become committed to sexual development. We used an experimental co-culture system to detect the presence of diffusible molecules from asexually replicating bloodstream stages of P. falciparum that were capable of influencing the growth and differentiation of the parasite. We cultured two populations of P. falciparum in a shared environment separated by a membrane that allowed free diffusion of molecules. The data presented show that P. falciparum parasites in culture stimulate their own growth and replication, and constitutively inhibit sexual conversion via diffusible molecules. These observations support the model that for P. falciparum, the sexual pathway of development is the default, and that constitutive repression of the sexual pathway permits asexual multiplication to occur in the bloodstream of the human host.

Analysis of Variance↗
PubMed1989

Frequency of acrocentric association in abnormal sexual development in males and females.

A significant difference (P less than 0.05) was observed in a chi 2 comparison of DD, GG and DG-DI associations between male hypogonads and females with primary amenorrhea. This difference increased still further (P less than 0.01) when only DD and GG associations were compared between males and females with abnormal sexual development (ASD). Similarly, when normal males and females were compared for DI, TRI, TETRA, DD vs GG and DG vs GG acrocentric chromosome associations, a significant difference (P less than 0.05) was again observed. The sex difference was also apparent in TRI and TETRA acrocentric associations both in abnormal and normal sexual development males and females. These results suggested that probably sex difference (may be hormonal) influences the number and/or type of acrocentric chromosomes involved in association between males and females with ASD and also between normal males and females.

Amenorrhea↗
PubMed1990

Abnormal sexual development in transgenic mice chronically expressing müllerian inhibiting substance.

Müllerian inhibiting substance (MIS), also known as anti-Müllerian hormone, is a glycoprotein normally secreted by the Sertoli cells of the fetal and adult testis and by granulosa cells of the postnatal ovary. The production of MIS in the male fetus brings about the regression of the Müllerian ducts, the anlagen of the uterus, oviducts, and upper vagina. In addition, purified MIS induces the formation of seminiferous cord-like structures in fetal rat ovaries cultured in vitro, suggesting that MIS may influence testicular differentiation. We have produced transgenic mice chronically expressing human MIS under the control of the mouse metallothionein-1 promoter to investigate its role during sexual development. In females, chronic expression led to the inhibition of Müllerian duct differentiation, resulting in a blind vagina and no uterus or oviducts. At birth the ovaries had fewer germ cells than normal; during the next two weeks germ cells were lost and the somatic cells became organized into structures resembling seminiferous tubules. Apparently, these structures degenerate as they are undetectable in adult females. The majority of transgenic males developed normally. But in two lines with the highest levels of MIS expression, some males showed feminization of the external genitalia, impairment of Wolffian duct development, and undescended testes. These results suggest that MIS has several distinct roles in mammalian sexual development.

Androgens↗
PubMed1991

S. pombe pac1+, whose overexpression inhibits sexual development, encodes a ribonuclease III-like RNase.

The Schizosaccharomyces pombe pac1 gene is a multicopy suppressor of the pat1 temperature-sensitive mutation, which directs uncontrolled meiosis at the restrictive temperature. Overexpression of the pac1 gene had no apparent effect on vegetative growth but inhibited mating and sporulation in wild type S. pombe cells. In such cells, expression of certain genes required for mating or meiosis was inhibited. The pac1 gene is essential for vegetative cell growth. The deduced pac1 gene product has 363 amino acids. Its C-terminal 230 residues revealed 25% amino acid identity with ribonuclease III, an enzyme that digests double-stranded RNA and is involved in processing ribosomal RNA precursors and certain mRNAs in Escherichia coli. The pac1 gene product could degrade double-stranded RNA in vitro. These observations establish the presence of a RNase III homolog in eukaryotic cells. The pac1 gene product probably inhibits mating and meiosis by degrading a specific mRNA(s) required for sexual development. It is likely that mRNA processing is involved in the regulation of sexual development in fission yeast.

Amino Acid Sequence↗
PubMed2002

Normal sexual development of two strains of rat exposed in utero to low doses of bisphenol A.

Pregnant Sprague-Dawley (SD) and Alderley Park (Wistar derived) rats were exposed by gavage during gestation days 6-21 to 20 microg/kg, 100 microg/kg, or 50 mg/kg body weight of BPA with ethinylestradiol (EE; 200 microg/kg) acting as a positive control agent. The sexual development of the derived pups was monitored until termination at postnatal day 90-98. The endpoints evaluated were litter size and weight, anogenital distance at birth, days of vaginal opening, first estrus and prepuce separation, weights of the liver, seminal vesicles, epididimydes, testes, ventral prostate, uterus, vagina, cervix and ovaries, and daily sperm production. Males were terminated at postnatal day 90 and females at postnatal day 98. The only statistically significant effects observed for any dose of BPA were a decrease in daily sperm production and an increase in the age of vaginal opening for the Alderley Park animals at the highest dose evaluated (50 mg/kg). The dose of EE evaluated proved to be maternally toxic in our laboratory, but provided gross evidence of endocrine disruption in the treated dams. These results diverge from those of Chahoud and his colleagues who indicated disturbances to the sexual development of both male and female SD rat pups administered the same 3 doses of BPA. This failure to confirm low dose endocrine effects for BPA is discussed within the context of similar divergent conclusions derived from other assessments of the endocrine toxicity of this agent to rats.

Animals↗
PubMed1992

Neurotrophic factors and female sexual development.

The concept is proposed that polypeptide neurotrophic factors contribute to the developmental regulation of ovarian and hypothalamic function in mammals. Nerve growth factor (NGF) and neurotrophin-3, two members of the neurotrophin family, have been identified in the rat ovary and one of its receptors has been localized to the innervation and thecal cells of developing follicles. Although NGF supports the sympathetic innervation of the gland, the extent to which follicles are innervated appears to be defined by the differential expression of NGF receptors in the theca of developing follicles. The presence of NGF receptors in steroid-producing cells suggests a direct involvement of neurotrophins in the regulation of gonadal endocrine function. Evidence is beginning to emerge suggesting that development of the reproductive hypothalamus is affected by insulin-like growth factor 1 secreted by peripheral tissues, and transforming growth factor alpha (TGF alpha) produced locally. In the rat hypothalamus, TGF alpha appears to be synthesized in both neurons and glial cells. In glial cells it may interact with epidermal growth factor (EGF) receptors to further enhance TGF alpha synthesis and to, perhaps, stimulate eicosanoid formation. In turn, one of these eicosanoids, prostaglandin E2, may act on luteinizing hormone-releasing hormone (LHRH) neurons to stimulate the release of LHRH in a genomic-independent manner. This provides the basis for the notion that during development LHRH secretion is regulated by a dual mechanism, one that involves transsynaptic effects exerted by neurotransmitters, the other that requires a glial-neuronal interaction and that may predominantly regulate release of the neuropeptide. An increased expression of the TGF alpha and EGF receptor genes in reactive astrocytes is postulated to contribute to the process by which hypothalamic injury causes sexual precocity. Morphological maturation of the reproductive hypothalamus is thought to occur during sexual development. The process is accelerated by estradiol, which exerts its neurotrophic effects by enhancing the expression of genes encoding cytoskeletal proteins involved in neuronal development and regeneration. It is suggested that acquisition of functional competence by both the ovaries and the reproductive hypothalamus requires the participation of specific, but not similar, neurotrophic factors. The relevance of these concepts to the process of sexual development in other species, particularly primates, remains to be defined.

Animals↗
PubMed1988

Prospective study on the sexual development of male and female rats perinatally exposed to maternally administered cimetidine.

Cimetidine, a widely prescribed, potent histamine H2-receptor antagonist, is unrelatedly a mild antiandrogen. Since perinatal androgens are essential for normal masculine imprinting, we wanted to determine if maternally administered cimetidine interfered with the offspring's reproductive development. Cimetidine was administered in the mothers' drinking water at several levels reflecting both human and rat therapeutic-like doses from day 17 of gestation through day 7 of lactation. Except for the highest dose of cimetidine (4.0 mg/ml drinking water) the drug had no effect on the dams' food and water consumption or body weight gain. In general, feminine sexual development as measured by pubertal onset, reproductive organ weights and adult estrous cyclicity, was unaffected by perinatal exposure to cimetidine. Similarly, early exposure to the drug had little effect on masculine sexual development. The developmental profile of serum dehydroepiandrosterone, androstenedione, testosterone and 5 alpha-dihydrotestosterone when measured at 1, 4 and 18 weeks of age, was unaffected by perinatal exposure to cimetidine. Furthermore, serum androgen concentrations and seminal vesicle weights following orchiectomy and androgen replacement were the same in control and cimetidine-exposed rats. In contrast, pituitary weights of adult males exposed to maternally administered cimetidine appeared to be insensitive to androgen regulation. However, taken in totality, our results do not support the concept that cimetidine is a reproductive teratogen.

Androgens↗
PubMed2002

The veA gene activates sexual development in Aspergillus nidulans.

The previously isolated gene complementing the veA1 mutation was confirmed to be the veA gene. The determined nucleotide sequence of the gene demonstrated that there is an open reading frame (ORF) of a 573 amino acid polypeptide. The nucleotide sequence matched some clones of which functions were not assigned yet and the amino acid sequence matched that of Neurospora crassa VeA-related protein with 61% similarity. The nucleotide sequence of the veA1 mutant gene differed from that of the wild type gene by only one nucleotide and the nucleotide G in the initiation codon ATG of the VeA ORF was mutated to the nucleotide T. Then, the mutant ORF may use the 37th methionine codon of the wild type one as a new initiation codon. The veA transcript was present in the conidia and in mycelia cultured for up to 14h and expressed almost constitutively at an increased level throughout the asexual and sexual developmental processes, suggesting that it may act from a relatively early developmental stage. Null mutants of the gene never formed sexual structures, even under conditions where sexual development preferentially occurs in wild types. Over-expressors of the gene formed larger numbers of sexual structures with a much reduced number of conidial heads than a control strain (a veA1 mutant), even under conditions where wild type strains form little sexual structure but form conidial heads very well, such as in the presence of a salt at high concentration. Furthermore, over-expressors could form Hülle cells and cleistothecia, even in a liquid culture. These results indicated that the veA gene is a positive regulator in sexual development and simultaneously a negative one in asexual development.

Amino Acid Sequence↗
PubMed2002

Leptin and thyroxine during sexual development in male monkeys: effect of neonatal gonadotropin-releasing hormone antagonist treatment and delayed puberty on the developmental pattern of leptin and thyroxine secretion.

OBJECTIVE: Neonatal treatment of male monkeys with a gonadotropin-releasing hormone antagonist (Ant) increased the incidence of delayed puberty. Using blood samples that had been collected from monkeys with normal or delayed puberty, we assessed the potential involvement of leptin and thyroxine (T4) in sexual development. DESIGN AND METHODS: Monkeys were treated from birth until 4 months of age with vehicle, Ant or Ant/androgen and blood samples were drawn from 10 to 62 months of age. RESULTS: Serum leptin and total T4 concentrations declined in parallel throughout adolescence in all treatment groups. There was no transient rise in leptin before or in association with the onset of puberty. Also, leptin did not differ during the peripubertal period between animals experiencing puberty at that time versus those in which puberty was being delayed. Neonates treated with Ant either alone or with androgen replacement had higher leptin levels than controls throughout development. While leptin exhibited no significant changes during the peripubertal period, T4 values increased and declined in parallel with the peripubertal changes in hypothalamic-pituitary-testicular activity. CONCLUSIONS: These data do not support the concept that a transient rise in leptin triggers the onset of puberty in male monkeys. However, the disruption of neonatal activity of the pituitary-testicular axis alters the developmental pattern of leptin. The changes in T4 levels during the peripubertal period suggest that thyroid status may be a significant contributor to the process of sexual development in the male monkey and that peripubertal changes in secretion of this hormone may serve as an effective physiological response during a critical period of elevated energy expenditure.

Aging↗
PubMed2002

The roles and rules of law in sexual development.

This article provides an overview of the diverse sources of law that regulate sexual development and its resulting behaviors, dispositions, and outcomes. After exploring how the law influences sexuality by regulating families, schools, media, and social service delivery, the article examines the role of criminal and civil law in regulating partners influences on sexual relationships. The article then briefly analyses how the law influences the manner individuals themselves influence their intimate relationships and social environments. The article emphasizes that the necessary brevity of the overview masks many complexities but that existing laws and trends highlight how the law plays a dominant role in our lives, how the law seeks to promote certain dispositions, that the law must be harnessed to foster healthy relationships, and that contending with the law s dictates provides social scientists with important opportunities to foster social reform and structure healthy, supportive social environments conducive to responsible behaviors, attitudes, and dispositions.

Civil Rights↗
PubMed2005

The Aspergillus nidulans phytochrome FphA represses sexual development in red light.

Phytochrome photoreceptors sense red and far-red light through photointerconversion between two stable conformations, a process mediated by a linear tetrapyrrole chromophore. Originally, phytochromes were thought to be confined to photosynthetic organisms including cyanobacteria, but they have been recently discovered in heterotrophic bacteria and fungi, where little is known about their functions. It was shown previously in the ascomycetous fungus Aspergillus nidulans that asexual sporulation is stimulated and sexual development repressed by red light. The effect was reminiscent of a phytochrome response, and indeed phytochrome-like proteins were detected in several fungal genomes. All fungal homologs are more similar to bacterial than plant phytochromes and have multifunctional domains where the phytochrome region and histidine kinase domain are combined in a single protein with a C-terminal response-regulator domain. Here, we show that the A. nidulans phytochrome FphA binds a biliverdin chromophore, acts as a red-light sensor, and represses sexual development under red-light conditions. FphA-GFP is cytoplasmic and excluded from the nuclei, suggesting that red-light photoperception occurs in the cytoplasm. This is the first phytochrome experimentally characterized outside the plant and bacterial kingdoms and the second type of fungal protein identified that functions in photoperception.

Amino Acid Sequence↗
PubMed2001

Differential expression of house-keeping genes of Aspergillus nidulans during sexual development.

The rpl3 gene and the rpl37 gene for Aspergillus nidulans ribosomal protein L3 (RPL3) and RPL37, which were identified as located on chromosome I and chromosome III, respectively, were isolated from chromosome-specific cosmid libraries. The nucleotide sequences of both of the rpl3 gene and the rpl37 gene identified the ORFs of 392 amino acids and 92 amino acids, respectively. Both of the two genes were present in a single copy. The expression of both genes together with two other house-keeping genes, the rps16 gene for RPS16 and the gene for gamma-actin, was analyzed during sexual development. All four genes showed nearly identical expression patterns in that each gene expression reached its maximum after 2 h, decreased thereafter, and increased again after 30-40 h of induction of sexual development.

Actins↗
PubMed2005

The gene for a lectin-like protein is transcriptionally activated during sexual development, but is not essential for fruiting body formation in the filamentous fungus Sordaria macrospora.

BACKGROUND: The filamentous fungus Sordaria macrospora forms complex three-dimensional fruiting bodies called perithecia that protect the developing ascospores and ensure their proper discharge. In previous microarray analyses, several genes have been identified that are downregulated in sterile mutants compared to the wild type. Among these genes was tap1 (transcript associated with perithecial development), a gene encoding a putative lectin homolog. RESULTS: Analysis of tap1 transcript levels in the wild type under conditions allowing only vegetative growth compared to conditions that lead to fruiting body development showed that tap1 is not only downregulated in developmental mutants but is also upregulated in the wild type during fruiting body development. We have cloned and sequenced a 3.2 kb fragment of genomic DNA containing the tap1 open reading frame and adjoining sequences. The genomic region comprising tap1 is syntenic to its homologous region in the closely related filamentous fungus Neurospora crassa. To determine whether tap1 is involved in fruiting body development in S. macrospora, a knockout construct was generated in which the tap1 open reading frame was replaced by the hygromycin B resistance gene hph under the control of fungal regulatory regions. Transformation of the S. macrospora wild type with this construct resulted in a tap1 deletion strain where tap1 had been replaced by the hph cassette. The knockout strain displayed no phenotypic differences under conditions of vegetative growth and sexual development when compared to the wild type. Double mutants carrying the Deltatap1 allele in several developmental mutant backgrounds were phenotypically similar to the corresponding developmental mutant strains. CONCLUSION: The tap1 transcript is strongly upregulated during sexual development in S. macrospora; however, analysis of a tap1 knockout strain shows that tap1 is not essential for fruiting body formation in S. macrospora.

Fungal Proteins↗
PubMed2000

[Sexual development of the child and the onset of gender identity].

In view of the numerous questions raised by the recently disclosed pedophilia, sexual abuses and prostitution of children, it appeared worthwhile to review the recent studies dealing with the child sexual development and the onset of the gender identity. These studies consist partly in retrospective analysis of pathological situations and partly in the analysis of normal development. It appears that the social and emotional surroundings of the child, provided that they were continuous and devoid of ambiguity, play a prominent role in this process. At present, numerous authors consider that gender identity is achieved at about 2 years of age when the child has a harmonious general development. The family physician and the paediatrician are on the first line to detect potential problems provided that they were aware of the main determinants and symptoms involved.

Child↗
PubMed1988

Sister-chromatid exchange (SCE) rate in normal and abnormal sexual development in males and females.

Thirty-three patients with abnormal sexual development (9 male hypogonads, 20 females with primary amenorrhea and 4 cases of ambiguous genitalia), 10 normal males and 8 normal females (below the age of 30 years) were evaluated for SCE/cell and for SCE distribution according to chromosome groups (A to G). Smokers and alcoholics and subjects under medication were excluded from the study. The average rates of SCE/cell in male hypogonads, primary amenorrhea and ambiguous genitalia were 4.23 +/- 1.51, 4.02 +/- 0.90 and 4.33 +/- 1.34, respectively, whereas in normal males and females the average rates were 4.27 +/- 0.69 and 4.49 +/- 0.87, respectively. The SCE data followed a Poisson distribution. Chi-square testing showed a statistically significant difference only in B-group chromosomes when male hypogonads were compared with normal males (p less than 0.02) and females with primary amenorrhea were compared with normal females (p less than 0.02), suggesting the importance of the study of SCE frequency distribution at chromosome group level to bring out the differences otherwise concealed in average rates.

Adult↗
PubMed2001

Rapamycin blocks sexual development in fission yeast through inhibition of the cellular function of an FKBP12 homolog.

FKBP12 is a ubiquitous and a highly conserved prolyl isomerase that binds the immunosuppressive drugs FK506 and rapamycin. Members of the FKBP12 family have been implicated in many processes that include intracellular protein folding, transport, and assembly. In the budding yeast Saccharomyces cerevisiae and in human T cells, rapamycin forms a complex with FKBP12 that inhibits cell cycle progression by inhibition of the TOR kinases. We reported previously that rapamycin does not inhibit the vegetative growth of the fission yeast Schizosaccharomyces pombe; however, it specifically inhibits its sexual development. Here we show that disruption of the S. pombe FKBP12 homolog, fkh1(+), at its chromosomal locus results in a mating-deficient phenotype that is highly similar to that obtained by treatment of wild type cells with rapamycin. A screen for fkh1 mutants that can confer rapamycin resistance identified five amino acids in Fkh1 that are critical for the effect of rapamycin in S. pombe. All five amino acids are located in the putative rapamycin binding pocket. Together, our findings indicate that Fkh1 has an important role in sexual development and serves as the target for rapamycin action in S. pombe.

Amino Acid Sequence↗
PubMed1997

[The influence of obesity on sexual development in pubertal children].

Serum testosterone and dehydroepiandrosterone sulfate (DHEAS) were measured in obesity and control groups using radioimmunoassay method (RIA). The sexual sign and sexual maturity were measured, too. The results showed that the contents of serum testosterone were 10.36 +/- 5.72 and (8.65 +/- 4.21) nmol/L in males of obesity and control groups respectively (P < 0.01). The levels of serum DHEAS were 8.25 +/- 6.47 and (5.63 +/- 4.98) pmol/L in femals of obesity and control groups, respectively. The length and beadth diameter of testis and length and surround of penis in males in obesity group were significantly higher than in control one (P < 0.01). The first spermatorrhea age of males in obesity group was significantly younger than that in control one (P < 0.01). Menarche age in females of obesity group and the second sexual sign development were earlier than that of control one (P < 0.01). It showed that sexual hormone, sexual development and sexual maturity were significantly higher and earlier in obesity group than those in control one.

Adolescent↗