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 883 records · Page 49Linked to original sources
PubMed2000

[Boy or girl? Molecular mechanisms in sex differentiation].

A growing number of factors have been recognized as crucial in sexual development, and many clinical conditions have become understandable as mutations in relevant genes have been identified. In some cases this has led to the development of DNA diagnostics, which can be of some aid in the workup of this type of patient. So far it is mainly more serious disorders which have been elucidated, thanks to the identification of extensive mutations in the key genes for sexual development. Exactly to what extent less severe damage in these genes underlies more subtle disorders of sexual development, such as disturbances in pubertal development and diminished fertility, is with few exceptions unknown. We are still aware of only a fraction of the information hidden in our genetic heritage. Developments in this field are nonetheless rapid, and molecular analyses will probably become more and more part and parcel of the workup of patients with a wide variety of disturbances in sexual development.

Animals↗
PubMed2002

Multiple functions of mfa-1, a putative pheromone precursor gene of Neurospora crassa.

A putative pheromone precursor gene of Neurospora crassa, mfa-1 (which encodes mating factor a-1), was identified as the most abundant clone in starved mycelial and perithecial cDNA libraries. Northern analysis demonstrated high mfa-1 expression in all mating type a tissues and suggested low expression levels in mat A tissues. The mfa-1 gene was expressed as an approximately 1.2-kb transcript predicted to encode a 24-residue peptide, followed by a long 3' untranslated region (3' UTR). The predicted MFA1 sequence showed 100% sequence identity to PPG2 of Sordaria macrospora and structural similarity (a carboxy-terminal CAAX motif) to many hydrophobic fungal pheromone precursors. Mutants with a disrupted open reading frame (ORF) in which the critical cysteine residue had been changed to a nonprenylatable residue, tyrosine (YAAX mutants), were isolated, as were mfa-1 mutants with intact ORFs but multiple mutations in the 3' noncoding region (CAAX mutants). The 3' UTR is required for the full range of mfa-1 gene activity. Both classes of mutants showed delayed and reduced vegetative growth (which was suppressed by supplementation with a minute amount [30 micro M] of ornithine, citrulline, or arginine), as well as aberrant sexual development. When crossed as female parents to wild-type males, the CAAX and YAAX mutants showed greatly reduced ascospore production. No ascospores were produced in homozygous mfa-1 crosses. As males, YAAX mat a mutants were unable to attract wild-type mat A trichogynes (female-specific hyphae) or to initiate sexual development, while CAAX mat a mutants were able to mate and produce sexual progeny despite their inability to attract mat A trichogynes. In the mat A background, both CAAX and YAAX mutants showed normal male fertility but defective vegetative growth and aberrant female sexual development. Thus, the mfa-1 gene appears to have multiple roles in N. crassa development: (i) it encodes a hydrophobic pheromone with a putative farnesylated and carboxymethylated C-terminal cysteine residue, required by mat a to attract trichogynes of mat A; (ii) it is involved in female sexual development and ascospore production in both mating types; and (iii) it functions in vegetative growth of both mating types.

3' Untranslated Regions↗
PubMed1989

Development of sexuality in female children and adolescents.

Female sexuality (meaning sexual desire, excitement and orgasm) has been of considerable interest in psychiatry. Women's efforts to define and legitimize their own experience of their sexuality have increased in the past 25 years. However, the integration of these new views into the body of psychiatric (especially psychoanalytic) theory has not occurred very actively or successfully. Very little is known about the development of sexuality in childhood and adolescence. This paper looks at various behaviours, interests and events in women's lives that might reveal something about the development of their sexuality. The literature on female masturbation is reviewed and some sex differences high-lighted. The literature on interest in babies, the wish to have babies, and menarche is explored for possible associations with sexuality. Rather than sexuality being a central organizer of experience, it seems quite possible that experience is an organizer of sexuality. Therefore, to better understand female sexuality we need to consider the impact of experiences during childhood and adolescence.

Adolescent↗
PubMed1994

Analysis of the Schizosaccharomyces pombe cyclin puc1: evidence for a role in cell cycle exit.

The puc1+ gene, encoding a G1-type cyclin from the fission yeast Schizosaccharomyces pombe, was originally isolated by complementation in the budding yeast Saccharomyces cerevisiae. Here, we report the molecular characterization of this gene and analyse its role in S. pombe. We fail to identify any function of this cyclin at the mitotic G1/S transition in S. pombe, but demonstrate that it does function in exit from the mitotic cycle. Expression of the puc1+ gene is increased during nitrogen starvation, and puc1 affects the timing of sexual development in response to starvation. Overexpression of the puc1 protein blocks sexual development, and rescues pat1ts cells, which would otherwise undergo a lethal meiosis. We conclude that puc1 contributes to negative regulation of the timing of sexual development in fission yeast, and functions at the transition between cycling and non-cycling cells.

Alleles↗
PubMed1994

Differential distribution of the alpha 6 subunit of integrins in the development and sexual differentiation of the mouse testis.

The distribution of the alpha 6 subunit of integrins in the development and sexual differentiation of mouse testis was analyzed by light and electron microscopy during the embryonic, fetal and early postnatal periods. At the pregonadal phase only the epithelial cells of the mesonephric duct and of the distal mesonephric tubules showed a reaction to alpha 6, whereas the surface epithelium and the mesenchyme of the mesonephros were negative or contained only a rudimentary amount of the alpha 6 subunit. With the formation of the gonadal ridge and the testicular blastema, the gonadal cells became positive for the alpha 6 subunit. This expression remained in embryonic cord cells and in the vascular endothelial cells, whereas the differentiating cells of the surface epithelium, tunica albuginea, the Leydig cells, and the interstitial mesenchymal cells were negative. With the fetal and postnatal differentiation, the expression of the alpha 6 subunit gradually diminished in the cord cells, and by the prepubertal phase, alpha 6 was found only at adhesion sites between some Sertoli cells. Similar changes were seen in the mesonephric duct and tubules, and in the rete cords. The presence of alpha 6 in regions undergoing developmental cell aggregation processes and their disappearance during tissue maturation, suggest that alpha 6 plays a specific but transient role in gonadal cell adhesion necessary for the histogenetic organization of the testis. In addition to its role in developing and organizing cells, alpha 6 integrin was also a prominent component in degenerating cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Only one of the paired Schizophyllum commune A alpha mating-type, putative homeobox genes encodes a homeodomain essential for A alpha-regulated development.

The A alpha mating-type locus is one of four master regulatory loci controlling sexual development in Schizophyllum commune. The A alpha locus contains two homeobox genes, Y and Z, encoding two homeodomain-related proteins, Y and Z. Y and Z are each multiallelic genes. When haploid strains form fusion cells, only particular combinations of Y and Z alleles activate A alpha-regulated sexual development. The role of the putative homeodomain was examined in several Y and Z alleles by site-directed mutagenesis of regions critical to secondary structure and function of homeodomains. Mutations of the Z homeobox do not affect the function of Z proteins in A alpha-activated development, but mutations of Y homeoboxes destroy the ability of Y proteins to activate development. We conclude that only one of two A alpha homeodomain-related regulators relies upon the homeodomain motif to effect gene expression in sexual development. This conclusion affords a refinement of our working hypothesis for the mechanism by which A alpha proteins may regulate target gene expression. On the basis of our results with the Z protein, we speculate that the DNA-binding motifs of some transcriptional regulators may be lost or modified during evolution once these regulators have been recruited to participate in complexes with other DNA-binding proteins.

Amino Acid Sequence↗
PubMed1995

The development of sexual dimorphism in natural killer cell activity and resistance to tumor metastasis in the Fischer 344 rat.

The development of sexual dimorphism in the number and activity level of natural killer (NK) cells was studied in the inbred Fischer 344 rat from prepubescence to maturity. Additionally, in view of the biological significance of NK cells in controlling cancer, especially the metastatic process, we used a syngeneic mammary tumor (MADB106) to assess the host anti-metastatic activity. This tumor model was used because NK cells control the lung clearance of i.v.-injected MADB106 tumor cells, a process that critically affects the metastatic colonization of these tumor cells in the lungs. The results indicated that although prepubescent (36 days of age) males and females exhibited greater NK cytotoxicity (assessed in vitro) and higher anti-metastatic activity, evidenced by fewer tumor cells retained in the lungs. On the other hand, the mature males (140-170 days of age) displayed greater LGL/NK number and activity per ml blood, retained fewer tumor cells, and developed fewer lung tumor colonies compared to the females. During early postpubescence (63 days of age), a transitional stage between prepubescence and maturity, females and males exhibited equivalent numbers of circulating LGL/NK cells, and females displayed slightly greater NK cytotoxicity per ml blood yet retained somewhat greater numbers of tumor cells compared to the males. Overall, whereas the males exhibited increasing levels of NK number and activity throughout the age span tested, the females, despite displaying greater NK function compared to the males at prepubescence and slight improvement at postpubescence, fell behind the males in these indices of NK function at maturity.

Animals↗
PubMed2005

A psychodynamic (NonOedipal) and brain function hypothesis regarding a type of male sexual masochism.

A clinical observation suggests a hypothesis that differs from classical analytic oedipal theory as to the origin and psychodynamics of a type of male sexual masochism. This type of masochism may occur when a painful childhood life experience regarding severely forbidden sexual pleasure is associated and amalgamated with shame, humiliation, and feared physical and psychological punishment resulting in sexual pleasure. If this takes place with sufficient frequency during the critical phases of childhood sexual development, possibly including early adolescent sexual development, it becomes recorded as long-term memory in brain neural networks. The phenomenon of its recording includes, at least in part, the commonly accepted theory of Donald Hebb. In later years, the man feels compelled to reproduce in a masochistic ritual the former childhood psychological and physical conditions, to bring about the most intense sexual pleasure. Humiliation, shame, discomfort, helplessness, and even possible pain are simulated or actually instigated. By voluntarily placing himself in charge of the type of sadistic treatment he receives in acts of masochism, a patient may unconciously place himself in charge of his plight, in an attempt to master it, in contrast to his childhood helpless state. This formulation does not require an Oedipal explanation.

Adult↗
PubMed2026

Transcriptome sequencing provides novel insights into larval development and sexual dimorphism in the firefly Aquatica leii (Coleoptera: Lampyridae).

Fireflies are regarded as one of the most charismatic beetles due to their bioluminescence and ecological importance as bioindicators of freshwater quality. However, molecular mechanisms of larval development and sexual dimorphism in aquatic species remain poorly understood. Here, we performed multi-stage transcriptomic analysis of the aquatic firefly Aquatica leii across larval instars from L2 to L6, together with adult females and males, with three biological replicates per stage. Using time-series expression clustering, differential expression analysis, and weighted gene co-expression network analysis (WGCNA), we characterized the transcriptional dynamics of continuous larval development and the onset of sex-biased gene expression. We identified a critical transcriptional transition occurred at L5-L6, marked by downregulation of early morphogenetic genes and upregulation of juvenile hormone metabolism, oxidoreductase activity, and muscle contraction genes, indicating a shift from growth to metamorphic preparation. WGCNA identified a module strongly correlated with L6 (R = 0.97) enriched for the same functions, confirming a coordinated late-larval program. Notably, genes exhibiting sex-biased expression in adults were already expressed during late larval stages (L5 and L6), and 123 genes progressively upregulated from L2 to L6 showed enrichment in chitin biosynthesis, heart contraction, and ion transport; among these, six genes maintained high expression in adults with clear male-biased (Alei052192, Alei006658, and Alei087054) or female-biased (Alei003725, Alei096818, and Alei074026) patterns. These findings establish that transcriptional foundations for sexual dimorphism and adult tissue formation are laid during late larval stages, providing the first multi-stage transcriptomic resource for aquatic firefly conservation and breeding.

Animals↗
PubMed1998

Epidermal growth factor tyrosine kinase receptors and the neuroendocrine control of mammalian puberty.

In recent years evidence has begun to accumulate indicating that the central control of mammalian puberty requires not only changes in transsynaptic communication, but also the participation of glial cells. Neurons and astrocytes control the pubertal process by regulating the secretory activity of those neurons that produce luteinizing hormone-releasing hormone (LHRH), the neuropeptide that governs sexual development. LHRH, in turn, directs sexual development by stimulating the secretion of pituitary gonadotropins. Astrocytes affect LHRH neuronal function via cell-cell signaling mechanisms involving several growth factors acting via receptors endowed with tyrosine kinase activity. We have identified two members of the epidermal growth factor/transforming growth factor alpha (EGF/TGFalpha) family and their respective receptors as key players in the glial-neuronal interactive process that regulates LHRH secretion. Our results indicate that TGFalpha and its distant congener neuregulin (NRG) are produced in hypothalamic astrocytes and stimulate LHRH release indirectly via activation of their respective receptors, located--surprisingly--not on LHRH neurons, but on astrocytes. Activation of EGF receptors by TGFalpha, and/or the erbB2/erbB4 receptor complex by NRG, leads to glial release of prostaglandin (PG) E2, which then acts directly on LHRH neurons to stimulate LHRH release. That a central blockade of TGFalpha or NRG action delays puberty, and focal overexpression of TGFalpha advances it, leads to the conclusion that both TGFalpha and NRG are physiological components of the central mechanism controlling the initiation of female puberty.

Animals↗
PubMed1999

Practice parameters for the assessment and treatment of children and adolescents who are sexually abusive of others. American Academy of Child and Adolescent Psychiatry Working Group on Quality Issues.

The assessment and treatment of children and adolescents with sexually abusive behavior requires an understanding of normal sexual development. A multiplicity of biological and psychosocial factors determines the child's sexual development, gender role, sexual orientation, patterns of sexual arousal, sexual cognitions, sexual socialization, and the integration of sexual and aggressive patterns of behavior. The individual's sexuality evolves in concert and as a result of interaction with family, ethnic, social, and cultural influences. These parameters summarize what we know about the epidemiology and phenomenology of sexually abusive youths and provide guidelines for the assessment and the selection of treatment interventions for these youths. Essential considerations in the assessment and treatment of sexually abusive youths, as well as the different categories of sexually abusive youths which should be recognized and which influence treatment decisions, are presented. The spectrum of currently available psychosocial and biological treatments will be summarized.

Adolescent↗
PubMed1995

Cloning and functional analysis of the ndk1 gene encoding nucleoside-diphosphate kinase in Schizosaccharomyces pombe.

We cloned the ndk1 gene encoding a subunit of nucleoside-diphosphate kinase (NDK) from Schizosaccharomyces pombe, by using polymerase chain reaction. The deduced ndk1 gene product has 151 amino acid residues and is approximately 60% identical with both Saccharomyces cerevisiae and mammalian NDKs. The gene product exhibited NDK activity and cross-reacted with antibodies raised against rat NDK. Disruption of ndk1 greatly reduced the cellular NDK activity but caused no obvious phenotype in cell growth and sexual development of the organism. However, a mutated allele of ndk1 could inhibit sexual development in a dominant-negative manner. This allele carried a point mutation in cysteine 116, which locates next to the putative active center histidine 117, and the mutant gene product showed no NDK activity. Gene expression inducible in response to mating pheromone signaling was decreased in cells carrying the dominant-negative allele. Cases have been reported in higher eukaryotes in which NDK appears to play a more sophisticated role than a simple catalyst in cell physiology, and the results of this study suggest that S. pombe NDK may also perform such a role in regulation of sexual development in the fission yeast.

Amino Acid Sequence↗
PubMed1994

Postnatal development and sexual differentiation of pig hypothalamic nuclei.

The postnatal development of some nuclei in the hypothalamus of the pig is described in relation to sexual differentiation. The vasopressin and oxytocin containing nucleus (VON), a nucleus that has only been described in the pig to date, showed a twofold increase in neuron number and volume during puberty in both sexes. After puberty, this increase in neuron number continued in the females, resulting in a VON that is twice as large in females as in males. The supraoptic nucleus (SON) does not show an increase in neuron number during puberty but in females an increase after puberty is seen, resulting in a sexual dimorphism of the SON in adulthood. Experiments showed that the number of neurons of the VON can be influenced by gonadal steroids. This study confirms that sexual differentiation of the hypothalamus occurs much later in the pig than reported in any other mammalian species so far.

Animals↗
PubMed1995

The development of sexually dimorphic sensitivity to growth hormone (GH) feedback of the clonidine-induced GH surge in the rat.

This study investigates the development of sexually dimorphic sensitivity of the GH system to alpha 2-adrenergic stimulation and GH feedback in the rat. Sensitivity to alpha 2-adrenergic stimulation was tested with clonidine (CLN, an alpha 2-adrenergic agonist) which stimulates GH release in the adult male rat. Feedback was examined by testing whether human (h)GH suppressed the CLN-induced GH surge as previously demonstrated in adult male rats. The integrity of the pituitary and its capacity to respond to stimulation was tested at the end of the experiment by perifusing with GRF. Studies were conducted using a hypothalamic-pituitary coperifusion system which allows incubation of these tissues without the confounding influences of peripheral hormonal and extrahypothalamic neural factors. Tissue from prepubertal rats of 10, 20, 25 and 30 days of age, 50-day-old and adult rats (90-100 days) were evaluated. Results indicate that tissue from both male and female rats is sensitive to alpha 2-adrenergic stimulation at 10 days of age. In male tissue, there is an increase in GH release in response to CLN until 30 days of age, after which a slight decline in sensitivity occurs by 50 days of age and is maintained in adulthood. In regard to GH release from female tissue, a GH surge occurs in response to CLN until 30 days of age. At 50 days and in adulthood, this response is substantially diminished. Additionally, there is a profound sexual dimorphism in the capacity of hGH to suppress the CLN induced GH surge. In tissue from male rats, by 20 days of age there is an apparent GH-associated inhibition of the CLN-induced GH surge which is significant by 25 days, is more pronounced by 30 days of age, and is maintained after puberty at 50 days of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1991

Concanavalin A and wheat germ agglutinin binding glycoproteins associated with cell fusion and zygote differentiation in Dictyostelium discoideum: effects of calcium ions and tunicamycin on glycoprotein profiles.

To determine which glycoproteins may be critical to sexual development in Dictyostelium discoideum, cell samples from different developmental stages were separated by sodium dodecyl sulfate - polyacrylamide gel electrophoresis and blotted to nitrocellulose. Concanavalin A (ConA) and wheat germ agglutinin (WGA) binding proteins were visualized on the blots using an immunochemical procedure employing peroxidase-antiperoxidase. ConA labelled at least 28 proteins, but only one band showed calcium-dependent changes in its expression. WGA bound at least 30 proteins and changes in several bands were observed that did not occur in calcium-deficient controls. Two WGA-binding glycoproteins which migrated at 200 and 166 kilodaltons (kDa), respectively, showed developmental changes associated with the time of cell fusion. One WGA-binding and one ConA-binding glycoprotein migrating at 130 and 126 kDa, respectively, appeared later during sexual development, in association with the phase of zygote differentiation. Several WGA- and ConA-binding glycoproteins decreased during sexual development, but were not affected by the absence of calcium ions. Tunicamycin (1 microgram/mL) inhibited cell fusion when added to sexual cultures prior to the appearance of the 166-kDa glycoprotein gp166. The effects of this inhibitor on development support the importance of glycoproteins to cell fusion during sexual development in D. discoideum.

Blotting, Western↗
PubMedDate not supplied

[Acceleration of pubertal development].

Sexual precocity is defined as the appearance of physical signs of puberty at a time -3 SD before the mean age for the population, that is before 8 years for girls and 8.5-9.0 years for boys. The Authors discuss about etiology, therapeutic approach, indications for treatment, results and still open problems in this condition. From the pathogenetic point of view disorders that induce sexual precocity can be classified as gonadotropin-releasing hormone (Gn-RH) dependent or Gn-RH independent. Premature activation of the hypothalamic Gn-RH pulse generator may be induced by malformations, tumours and other neurogenic lesions of the CNS, while in more than 70% of patients the primary factor is not identifiable (idiopathic form). Idiopathic true precocious puberty is more frequent in females, whereas in males CNS lesions, especially neoplasms, are more prevalent. The main aims of therapy in precocious puberty are to inhibit puberty, to stop and possibly reverse the progression of secondary sex characteristics and particularly menses, to slow down skeletal maturation, to delay epiphyseas closure and consequently to improve final height, to preserve fertility, to improve psycho social well-being and naturally to treat the underlying cause, when known. Gonadotropin-releasing hormone agonists (Gn-RHa) are now the therapy of choice when the disease is Gn-RH dependent. They are effective both in arresting pubertal development and in improving final adult height. In selected cases with a great reduction of growth velocity an association with hGH therapy is possible. We must pay special attention to bone mineralization with this kind of treatment at this very delicate age.

Adolescent↗
PubMed1981

[Intersexuality. Development of sexual behavior pattern and the legal position of the hermaphrodite (author's transl)].

We are nowadays in a position to describe some factors which influence the development of sexual behavior patterns. The importance of such factors will vary from case to case but especially the assignment of a particular sex to the neonate and education to a particular sex behavior may be helpful in acquiring psychosexual identity. An attempt is made to assess the importance of various biological and sociopsychological factors on the development of psychosexual identity in a "girl" with intersexual sex characteristics. The need for a careful analysis of such cases is particularly essential if an operation - as for example change of sex - is under consideration. The legal consequences of operations for change of sex must be taken into consideration, but therapeutic measures should be guided by medical and psychological aspects.

Adolescent↗
PubMed2001

Fission yeast tor1 functions in response to various stresses including nitrogen starvation, high osmolarity, and high temperature.

A target of rapamycin (TOR) protein is a protein kinase that exerts cellular signal transduction to regulate cell growth in response to extracellular nutrient conditions. In the Schizosaccharomyces pombe genome database, there are two genes encoding TOR-related proteins, but their functions have not been analyzed. Here we report that one of the genes, referred to as tor1+, is required for sexual development induced by nitrogen starvation. Ste11 is a key transcription factor for the initiation of sexual development. The expression of ste11+ is normally regulated in tor1- cells; and overexpression of ste11+ hardly rescues the defect in fertility in tor1-. Upon nitrogen starvation, tor1+ cells promote two rounds of the cell cycle to become arrested at the G1 phase before initiation of sexual development. The tor1- cells do not promote such a cell cycle, suggesting that Tor1 is necessary for the response to nitrogen starvation. The tor1- cells show no growth or very slow growth under various stress conditions, including external high pH, high concentrations of salts or sorbitol, and high temperature. These results suggest that Tor1 is necessary for any response to a wide range of stresses. The vegetative growth of tor1- cells is inhibited by rapamycin, although tor1+ cells are resistant to the drug. The tor1- cells are hypersensitive to fluphenazine and cyclosporin A, which specifically inhibit calmodulin and calcineurin, respectively.

Amino Acid Sequence↗