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PubMed1992

Sexual development and free-running period in quail kept in constant darkness.

In Japanese quail (Coturnix coturnix japonica) sexual development may occur in total darkness (DD). Linked to sexual maturation, variations of the rhythm of feeding activity were observed: in DD, the amount of activity increased and the period of the free-running rhythm lengthened. During the first weeks in DD all the quails presented a free-running period less than 24 hr (22.3 +/- 0.5 hr; N = 50). At the end of the experiment, the more a bird was mature, the greater the lengthening of its period. In DD, testosterone implants in castrated male quails can mimic these modifications but we failed to find any correlation between the number of implants (i.e., the level of testosterone) and the extent of the lengthening.

Activity Cycles↗
PubMed1990

[Sexual development in obese women].

By means of an interview and the questionnaire "Heterosexual Development of Women" [HDW] the authors subjected to sexuological examination 129 obese women aged 20-50 years with a body mass index above 25. As regards the time when overweight developed 29 women developed obesity during the prepubertal period and in 100 of the women obesity developed during adolescence and later. It was revealed that the sexual development of obese women was normal. The mean values in the HDW questionnaire in both subgroups with a different period of development of overweight were all within the normal range.

Adult↗
PubMed1986

[Sexual development and levels of plasma testosterone in the light type of cockerel].

The concentration of testosterone in blood plasma during the ontogenetic development of cockerels was studied in relation to the development of spermatogenic part of gonads. On the basis of the results, sexual development of cockerels can be divided into three stages. The first stage (from hatching to the age of eight to nine weeks) was characterized by a slow increase in gonad weight, by low concentration of plasma testosterone (0.4-2.0 nmol/l) and by the occurrence of spermatogonia in testes. In the course of the second stage (from the age of nine to 16 weeks) a rapid increase in the weight of testes and testosterone concentration was observed. At the end of this stage all phases of spermatogenic cycle were observed in gonads; the testosterone levels averaged to 10 nmol/l. In the course of this stage all cockerels reached sexual maturity; large individual differences in spermatogenesis development were observed. The third stage (16 weeks of age and more) was characterized by an intensive spermatogenesis, further increase in gonad weight and by typical variations of the plasma testosterone levels. The concentration of the circulating testosterone increased before the onset of the final stages of the spermatogenic cycle.

Animals↗
PubMed1991

[Abnormalities of sexual development in Puerto Rico: status report].

Puerto Rico presents the highest incidence in the world of anomalous sexual development. The authors have collected over 3100 cases in the past 19 years. Clinical and laboratory studies suggest possible estrogenic contamination of meats and poultry products. Variation in diet provides protection to a significant number of patients. The possibility of mycotic contamination of food employed in animal husbandry by Fusarium sp., and mycotoxins capable of estrogenic effects have been suggested in a preliminary study. Private and government investigators are active in the study of the condition, but more fiscalizing action is needed. A detailed study of food components for possible contaminants determination is considered mandatory.

Adolescent↗
PubMed1979

Cytogenetic and endocrine studies in a 45,X female subject with spontaneous sexual development.

Cytogenetic and endocrine evaluation of a postpubertal 45,X female subject with Turner's stigmas and spontaneous sexual development was performed. A 45,X chromosomal complement was found in the peripheral blood lymphocytes, bone marrow, and fibroblasts derived from skin and ovaries. Menarche, pubarche, and thelarche occurred at age 12; at age 16 she developed menstrual irregularities, with endometrial bleeding occurring every 60 to 90 days. The ovaries were normal in size, and histologic examination revealed a marked paucity of primordial follicles, increased collagenization, and absence of corpora albicans. Anovulatory cycles with moderately elevated levels of luteinizing hormone (LH) and low follicle-stimulating hormone (FSH) levels were observed. LH-releasing hormone pituitary stimulation induced a normal LH release with a very slight FSH increase. Administration of clomiphene citrate successfully induced a normal-length ovulatory cycle. Similarities in the hormonal situation of this patient and that seen in the Stein-Leventhal syndrome are pointed out.

Adolescent↗
PubMed1979

Aggregation during sexual development in Dictyostelium discoideum.

A microcinematographic analysis of the behaviour and movements of cells and cell masses in mated cultures (NC4 X VI2) of Dictyostelium discoideum indicates that a chemotactic process directs cell aggregation during macrocyst development. Zygote giant cells form before aggregation begins and act as the aggregation centres. Young multicellular macrocyst stages are sources of cyclic AMP, and amoebae from macrocyst cultures orient chemotactically to cyclic AMP. The data, coupled with other characteristics such as pulsatile streaming, suggest that the aggregation process leading to macrycyst development is the same as that occurring during fruit construction. Other aspects of sexual development are also discussed. Based upon these data, we propose a model for the sequence of events leading to macrocyst development in D. discoideum.

Chemotaxis↗
PubMed1989

The control of sexual development in Drosophila melanogaster: genetic and molecular analysis of a genetic regulatory hierarchy--a minireview.

Genetic analyses of mutants affecting the sexual development of the fruitfly, Drosophila melanogaster, have led to a genetic model that describes how the wild-type genes interact with one another as parts of a single regulatory pathway. More recent molecular studies on some of these sex differentiation regulatory genes have lent support to this genetic model, and have defined the molecular nature of some of these genetic interactions. One surprising feature of the regulatory hierarchy to emerge from these molecular studies is that many of the sex-specific genetic switches in this pathway are not transcriptional regulation events but, rather, are based on sex-specific alternative RNA processing events (pre-mRNA splicing and/or polyadenylation site selection).

Animals↗
PubMedDate not supplied

[Pathogenesis of functional retardation of physical and sexual development in adolescents. Status of somatotropic and gonadotropic function].

A study of somatotropic and gonadotropic functions in male adolescents with functional retardation of physical and sexual development has shown an important role of the deficiency of gonadotropins, especially FSH, in the pathogenesis of this condition. LH secretion in retarded physical development (RPD) is lowered to a lesser degree and positively correlates with testosterone deficiency. The feedback in the hypothalamohypophyseogonadal function in RPD is less frequently affected and to a lesser degree than gonadotropic functions. Of the tested methods (tests with TRH, L-DOPA and bromocriptine) STH reserves are better revealed with L-DOPA and TRH tests, gonadotropic reserves, especially LH,--with TRH and bromocriptine tests. The stimulating TRH effect on the growth hormone is indicative of the versatility and nonspecificity of its action on the pituitary gland in functional developmental disorders.

Adolescent↗
PubMed1989

Effect of zeranol on sexual development of crossbred bulls.

Three groups of 1/2 Simmental X 1/4 Brahman X 1/4 Hereford bull calves were used during two different years to study effects of zeranol on sexual development. At 154 d of age, half the calves were implanted with 36 mg zeranol and half, not implanted, served as controls. Implanted calves were reimplanted at 90-d intervals throughout the trial (9 mo) each year. Trial 1 was conducted with 24 calves and Trial 2 was conducted the following year with 10 bulls. Twenty-four days after weaning (200 d of age) and at 28-d intervals thereafter, bulls in drylot in Trial 1 were weighted, scrotal circumference (SC) was measured and an ejaculate of semen was collected by electroejaculation to determine puberty. At these times, bulls were given 200 micrograms of GnRH i.m. and blood was collected at 0, 1, 2, 3, 4 and 5 h after GnRH. Serum concentrations of LH and testosterone (TEST) were determined. At slaughter, testis weight, length and circumference and pubertal status were recorded. Bulls implanted with zeranol had smaller SC than control bulls during the entire 9-mo period (P less than .0001). More control bulls reached puberty than did implanted bulls (82.4 vs 23.5%, respectively; P less than .001). Control bulls had larger testis measurements at slaughter (P less than .0001). Implants did not alter total weight gain or ADG (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Pharmacologic stimulation in delayed female sexual development (response of androstenedione vs. 17 beta-estradiol). Presentation of 2 cases].

Two girls of 13 and 18 years of age, XX chromosomic pattern, complaining of delay in sexual development (Stage 1) and primary amenorrhea, were studied. Height, weight and surface area in the 13 years subject were three standard deviations below the anthropometric characteristics of already menstruating girls of the same age. Presence of uterus and ovarian tissue was demonstrated by laparoscopy in both, and afterwards, simultaneous measurements of androstenedione (delta 4) and 17 beta-estradiol (E2) were performed in peripheral blood, before and after: placebo, clomiphene (25 and 50 mg), LH-RH, FSH/LH. Under this trials the gonadal structures produced delta 4 and E2, being the former in many instances a good index of ovarian steroid production and associated to growth of pubic and axillary hair. In the patient whose menstruation began after the pharmacologic stimuli, the steroid production was higher as compared to the one, with initiation of no menstrual bleeding. Critical aspects of the various phases of the study are revised to better understand the physiology of some biological processes.

Adolescent↗
PubMed1992

Physical characteristics and factors related to sexual development and behaviour and the risk for prostatic cancer.

A case-control study of prostatic cancer was carried out to examine the association between selected physical characteristics and factors related to sexual development and behaviour and the risk for this disease. In consideration of an endocrinologic mechanism for these putative risk factors, the association between selected factors and serum hormone level in a comparison group, free of prostate cancer, was also examined. One-hundred cases and 113 controls were included for study. An elevated risk for prostatic cancer was found for those currently married (odds ratio (OR) = 4.0), those who had been married once (OR = 2.8), and those who were currently practising a religion (OR = 2.0). Compared to subjects with one child, those with more than one child and those with no children were more common among cases than controls. Prostatic cancer risk was associated with large body size and, in particular, with greater weight (p < 0.01). Early age at attainment of adult height was also associated with prostatic cancer risk (p < 0.01). Only moderate associations were found between increased frequency of sexual intercourse and prostatic cancer risk. The levels of testosterone (T), dihydrotestosterone, salivary testosterone and T/SHBG (sex hormone binding globulin) did not vary with age. Older men had higher oestradiol levels. Further, little association between hormone levels and risk factors was found, except for married subjects having increased serum androgens (p < 0.05) and heavy subjects having decreased serum androgens (not significant).

Age Factors↗
PubMed1977

Attitudes, opinions, and sexual development of 205 homosexual women.

Two hundred and five homosexual women, aged 15 to 50, were surveyed as to their attitudes and experiences in the areas of education, religion, family experiences, marriage, friendship, personal happiness, sexual development and satisfaction, psychological adjustment, and occupational status. The investigation discovered a high rate of only-child status among lesbian women, a tendency toward ambivalence of opinion on many issues, and a general lack of insight into self and others. Comparisons with other research on female homosexuality were made.

Adaptation, Psychological↗
PubMed1988

The role of sterility genes (ste and aff) in the initiation of sexual development in Schizosaccharomyces pombe.

Haploid homothallic strains of Schizosaccharomyces pombe with mutations in any of nine "sterility genes" (ste) do not mate with wild-type fertile strains. Those defective in genes ste1 to ste4 and ste7 to ste9 are also deficient in meiosis and sporulation. I found that the ste1, ste3 and ste8 genes act very early in the sexual development, presumably before the pat1-controlled conjugation-specific event. ste5 and ste6 exert their function downstream of pat1 in the initiation of conjugation and do not play any role in the meiotic pathway. ste2, ste4, ste7 and ste9 are involved in both sexual pathways: they seem to act downstream of pat1 in conjugation but upstream of pat1 in the initiation of meiosis. A new gene, aff1, whose defective allele suppresses the pat1-114-provoked haploid sporulation and arrest of vegetative growth is also described. It is supposed that the aff1+ gene product participates in a cascade of regulatory events, as a factor antagonistic to pat1.

Alleles↗
PubMed1992

Effects of neonatal exposure to the antiprogestin mifepristone, RU 486, on the sexual development of the rat.

RU 38486 (RU 486, mifepristone) is a potent progesterone receptor antagonist that has been used in humans in the pharmacologic induction of abortion. The effects of exposure to RU 486 during the neonatal period of the rat has not been previously reported. We examined the consequences of such exposure in the context of sexual development. Long-Evans rat pups were subcutaneously injected with either 100 micrograms RU 486, 300 micrograms RU 486, 500 micrograms progesterone (P), or 50 micrograms testosterone propionate (TP) in 0.05 ml sesame oil, or oil vehicle alone within 8 hours of birth, and 24 and 48 hours later. Treatment with either dose of RU 486 significantly advanced the onset of vaginal opening in females and attenuated defeminization of the lordosis response measured in males castrated as adults. As expected, TP-treated subjects were masculinized and defeminized, with females displaying fused vaginas and neither males nor females demonstrating lordosis behavior. Treatment with P caused no significant alterations in either the timing of vaginal opening or sexual behavior. These results indicate that RU 486 has clear developmental effects in the rat. Since this may well be a result of progesterone receptor blockade, further research is needed to clarify the processes involved.

Animals↗
PubMed1975

Altered sexual development in male rats after oestrogen administration during the neonatal period.

Male rats given 250 mug oestradiol benzoate by subcutaneous injection on Day 4 of postnatal life showed a marked delay in the onset of the pubertal increase in the weight of the testes and seminal vesicles and in spermatogenesis but not a complete failure of sexual development. The increase in plasma testosterone concentration at puberty was also delayed in oestrogen-treated males but the eventual increase in seminal vesicle weight was closely related in time to the delayed increase in plasma testosterone concentration. Both plasma LH and FSH concentrations were reduced for about 10 days after oestrogen administration as compared to control values. After 22 days of age, plasma LH concentration did not differ significantly from the control values. The plasma FSH concentration of the oestrogen-treated males showed a delayed rise to values equal to or higher than those of controls of the same age. The delayed rise in plasma FSH concentration in the oestrogen treated males preceded the delayed rise in plasma testosterone in these animals. The decrease in plasma FSH concentration from the high prepubertal values to the lower values in adults occurred at different ages in the control and in oestrogen-treated rats but in both groups the decrease occurred as plasma testosterone levels were increasing and the first wave of spermatogenesis was reaching completion. The increase in plasma FSH concentration after castration was reduced in oestrogen-treated males during the period throughout which FSH levels in the intact animals were subnormal but the levels in oestrogen-treated males castrated after the delayed rise in FSH had occurred did not differ from control values. It is suggested that the delayed sexual maturation of male rats treated with high doses of oestrogen in the neonatal period is related principally to abnormalities in the secretion of FSH.

Animals↗
PubMed1987

Deleterious effects of adrenocorticotrophic hormone administration during late pregnancy upon offspring somatic, neurological, and sexual development in mice.

The influence of administration of adrenocorticotrophic hormone (ACTH) during days 12-17 of pregnancy upon somatic, neurological, and neuromuscular development of offspring in mice was studied. The effects upon the onset of puberty in female offspring was also examined. Litters from mice given the higher of two doses of ACTH (1 IU/day or 8 IU/day) showed lower body weights at birth and weaning than controls. This treatment also increased pre- and postnatal mortality rates, although not significantly. Litters from mice treated with either dose of ACTH showed retarded development of the forelimb and hindlimb grasp reflexes, the body righting reflex, the auditory startle response, and eye opening. Although ear opening was delayed in litters from ACTH-treated mice, results did not achieve statistical significance. Study of female offspring housed in small groups revealed that one indicator of puberty, vaginal opening, was delayed in female offspring of ACTH-treated mice. Experiments were conducted to identify factors mediating this syndrome: ACTH did not depress maternal food intake or alter the length of pregnancy, therefore fetal undernutrition or premature birth can be excluded as mediating factors. All litters were fostered to untreated mice to control for postnatal factors influencing development. As ACTH cannot cross the placenta, the syndrome is likely to result from in utero exposure to abnormally high concentrations of glucocorticosteroids of maternal origin. It is concluded that such alterations to the fetal environment can exert a deleterious influence upon somatic, neurological, and sexual development, and that hormones of the maternal pituitary-adrenocortical axis may naturally act to regulate general development of the fetus.

Adrenocorticotropic Hormone↗
PubMed1991

The tubB alpha-tubulin gene is essential for sexual development in Aspergillus nidulans.

The filamentous fungus Aspergillus nidulans has two genes encoding alpha-tubulin, tubA and tubB. Mutational analysis of tubA has demonstrated that the tubA gene is essential for mitosis and nuclear migration. In this study we have deleted the tubB gene by replacing it with a selectable marker and have named this new allele tubB delta. The results demonstrate that the tubB gene is not required for vegetative growth or asexual reproduction, nor is it required for the initiation or early stages of sexual differentiation. Deletion of tubB, however, completely prevents ascosporogenesis, because tubB delta strains produce no sexual spores when self-crossed. These strains produce viable ascospores when outcrossed to tubB+ strains, indicating that the tubB delta mutation is recessive. We have studied the cytology of sexual development in wild-type strains and in the tubB mutant and have observed that tubB delta. strains develop normally to the stage of ascus formation. However, only a single nuclear mass is observed in the tubB delta ascus, indicating that either the two zygotic haploid nuclei are blocked in karyogamy or that karyogamy occurs but the resulting diploid nucleus is subsequently blocked in meiosis I.

Aspergillus nidulans↗