Proliferation of germ cells and somatic cells in first trimester human embryonic gonads as indicated by S and S+G2+M phase fractions.

OBJECTIVES: The number of germ cells and somatic cells in human embryonic and foetal gonads has previously been estimated by stereological methods, which are time- and labour-consuming with little information concerning cell proliferation. Here, we studied whether flow cytometry could be applied as an easier method, also enabling estimation of the fraction of cells in S or S+G(2)+M (SG(2) M) cell-cycle phases as indicators of cell proliferation. METHODS: Cell suspensions from 35 human embryonic gonads at days 37 to 68 post-conception (pc) were immunomagnetically sorted into C-KIT positive (germ) cells and negative (somatic) cells. They were stained for DNA content and analysed by flow cytometry. S and SG(2) M fractions could be measured for 13 of the female and 20 of the male gonads. The number of cells was estimated using fluorescent reference beads. RESULTS: During the period from 37 to 68 days pc, female germ and somatic cells had a stable S and SG(2) M fractions indicating steady growth of both subpopulations, whereas they decreased in both male germ and somatic cells. The number of germ and somatic cells estimated by flow cytometry was significantly lower than in stereological estimates, suggesting loss of cells during preparation. CONCLUSIONS: Cell proliferation as indicated by S and SG(2) M fractions could be estimated specifically for primordial germ and somatic cells. Estimation of total number of germ and somatic cells was not feasible.

No evidence for the presence of oogonia in the human ovary after their final clearance during the first two years of life.

BACKGROUND: Conflicting results of studies on mouse and human have either verified or refuted the presence of oogonia/primordial germ cells in the post-natal ovary. The aim of this study was to trace whether oogonia recognized by immunohistochemical methods in the first trimester human ovary were present also in peri- and post-natal ovaries. METHODS: For this study, 82 human ovaries were collected: 25 from embryos from 5 to 10 weeks post conception (wpc), 2 at 18 wpc, 32 from 32 wpc to 2 years and 23 from 2 to 32 years. Of these, 80 ovaries were fixed and paraffin-embedded and 2 (8 year-old) ovaries were processed for plastic sections. Serial sections were prepared for immunohistochemical detection of markers for oogonia: tyrosine kinase receptor for stem cell factor (SCF)(C-KIT), stage-specific embryonic antigen-4 (SSEA4), homeobox gene transcription factor (NANOG), octamer binding transcription factor 4 (OCT4) and melanoma antigen-4 (Mage-A4), while noting that C-KIT also stains diplotene oocytes. RESULTS: Almost all oogonia exclusively stained for SSEA4, NANOG, OCT4 and C-KIT, whereas MAGE-A4 only stained a small fraction. At birth only a few oogonia were stained. These disappeared before 2 years, leaving only diplotene oocytes stained for C-KIT. From 18 wpc to 2 years, the medulla contained conglomerates of healthy and degenerating oogonia and small follicles, waste baskets (WBs) and oogonia enclosed in growing follicles (FWB). Medulla of older ovaries contained groups of primordial, healthy follicles. CONCLUSIONS: We found no evidence for the presence of oogonia in the human ovary after their final clearing during the first 2 years. We suggest that perinatal medullary WB and FWB give rise to the groups of small, healthy follicles in the medulla.

Germ cell numbers in human embryonic and fetal gonads during the first two trimesters of pregnancy: analysis of six published studies.

BACKGROUND: The number of germ cells in human embryonic and fetal ovaries in relation to age is currently based on volumetric estimations from one study including a total of 12 ovaries. Six recent publications present stereological estimations of the number of germ cells in ovaries and testes for the first two trimesters. METHODS: Germ cell numbers from 103 human first and second trimester gonads aged 37-133 days post-conception (p.c.), obtained after legal termination of pregnancy, were collected from six independent studies that all used similar validated stereological methods for estimating germ cell numbers as well as somatic cell numbers. RESULTS: Statistically, the six studies estimated similar number of germ cells (P > 0.05) and no interaction between the studies and age was found (P > 0.05), indicating that the increase in cell numbers in relation to age was of comparable magnitude in each study. The number of germ cells increased from a mean of 7200 to 4,933,000 in fetal ovaries and from 3700 to 1,417,000 in fetal testes, from week 5 to week 19 p.c. A higher rate of increase was found for female germ cells as compared with males (P = 0.004). During the same period, the number of somatic cells increased from a mean of 158,000 to 1,017,000 in ovaries and from 154,000 to 2,035,000 in testes, respectively. CONCLUSIONS By the use of validated stereological methods, this study provides more accurate and improved information on human germ and somatic cell numbers in ovaries and testes during the first two trimesters of pregnancy.

In human granulosa cells from small antral follicles, androgen receptor mRNA and androgen levels in follicular fluid correlate with FSH receptor mRNA.

Human small antral follicles (diameter 3-9 mm) were obtained from ovaries surgically removed for fertility preservation. From the individual aspirated follicles, granulosa cells and the corresponding follicular fluid were isolated in 64 follicles, of which 55 were available for mRNA analysis (24 women). Expressions of androgen receptor (AR) mRNA levels in granulosa cells, and of androstenedione and testosterone in follicular fluid, were correlated to the expression of the FSH receptor (FSHR), LH receptor (LHR), CYP19 and anti-Müllerian Hormone-receptor II (AMHRII) mRNA in the granulosa cells and to the follicular fluid concentrations of AMH, inhibin-B, progesterone and estradiol. AR mRNA expression in granulosa cells and the follicular fluid content of androgens both showed a highly significant positive association with the expression of FSHR mRNA in granulosa cells. AR mRNA expression also correlated significantly with the expression of AMHRII, but did not correlate with any of the hormones in the follicular fluid. These data demonstrate an intimate association between AR expression in immature granulosa cells, and the expression of FSHR in normal small human antral follicles and between the follicular fluid levels of androgen and FSHR expression. This suggests that follicular sensitivity towards FSH stimulation may be augmented by stimulation of androgens via the AR.

Cigarette smoking during early pregnancy reduces the number of embryonic germ and somatic cells.

BACKGROUND: Cigarette smoking during pregnancy is associated with negative reproductive consequences for male fetuses in adult life such as reduced testicular volume and sperm concentration. The present study evaluates the number of germ and somatic cells present in human embryonic first-trimester gonads in relation to maternal smoking. METHODS: The study includes 24 human first-trimester testes, aged 37-68 days post-conception, obtained from women undergoing legal termination of pregnancy. A questionnaire was used to obtain information about smoking and drinking habits during pregnancy. Validated stereological methods were used to estimate gonadal cell numbers in histological sections. Results were also evaluated in the context of previously published data on ovaries from our laboratory. RESULTS: A significant reduction in the number of germ cells by 55% [95% confidence interval (CI) 74-21% reduction, P = 0.004] and somatic cells by 37% (95% CI 59-3%, P = 0.023) was observed in testes prenatally exposed to maternal cigarette smoking, compared with unexposed. The effect of maternal smoking was dose-dependent being higher in the heavy smokers and remained consistent after adjusting for possible confounders such as alcohol and coffee consumption (P = 0.002). The number of germ cells in embryonic gonads, irrespective of gender, was also significantly reduced by 41% (95% CI 58-19%, P = 0.001) in exposed versus non-exposed embryonic gonads. CONCLUSIONS: Prenatal exposure to maternal cigarette smoke reduces the number of germ and somatic cells in embryonic male and female gonads. This effect may have long-term consequences on the future fertility of exposed offspring. These findings may provide one potential cause of the reduced fertility observed during recent years.

Human primordial germ cells migrate along nerve fibers and Schwann cells from the dorsal hind gut mesentery to the gonadal ridge.

The aim of this study was to investigate the spatiotemporal development of autonomic nerve fibers and primordial germ cells (PGCs) along their migratory route from the dorsal mesentery to the gonadal ridges in human embryos using immunohistochemical markers and electron microscopy. Autonomic nerve fibers in the dorsal mesentery, the pre-aortic and para-aortic plexuses and in the gonadal ridge were stained for beta III tubulin, neuron specific enolase and the glia fibrillary acidic protein. Electron microscopy demonstrated the presence of neurofilaments and neurotubules in these nerve fibers and their intimate contact with PGCs. PGCs expressed GAGE, MAGE-A4, OCT4 and c-Kit. Serial paraffin sections showed that most PGCs were located inside bundles of autonomic nerve fibers with the majority adjacent to the most peripheral fibers (close to Schwann cells). We also show that both nerve fibers and PGCs arrive at the gonadal ridge between 29 and 33 days pc. In conclusion, our data suggest that PGCs in human embryos preferentially migrate along autonomic nerve fibers from the dorsal mesentery to the developing gonad where they are delivered via a fine nerve plexus.

The number of oogonia and somatic cells in the human female embryo and fetus in relation to whether or not exposed to maternal cigarette smoking.

BACKGROUND: Prenatal exposure to maternal cigarette smoking or compounds of cigarette smoke is associated with serious reproductive hazards such as apoptotic death of oogonia in murine offspring and decreased fecundability in human offspring. The present study addresses potential effects of in utero exposure to cigarette smoking. METHODS: Twenty-nine human first-trimester ovaries from legal abortions [aged 38-64 days post-conception (p.c.)] were collected. Mothers filled out a questionnaire about their smoking habits and delivered a urine sample for cotinine analysis. The ovarian cell numbers were estimated using stereological methods. RESULTS: A non-linear correlation between the numbers of oogonia and somatic cells in relation to age of the embryo/fetus was shown in 28 ovaries, including the first estimates performed in ovaries younger than 47 days p.c. Prenatal exposure to smoke showed a significant decrease in the number of somatic cells (P < or = 0.01). The number of oogonia was not significantly associated with prenatal exposure to maternal smoking (P < or = 0.09). The ratio between the two cell types decreased considerably from 1:45 to 1:23 from 38 to 46 days p.c. and was not affected by smoking. CONCLUSIONS: Oogonia proliferate and/or invade the developing ovary at a much faster relative rate than somatic cells. In utero exposure to maternal smoking significantly reduces the number of somatic cells from Days 38 to 64 p.c. Since oocytes cannot survive without being enclosed by somatic cells in a follicle, reduction in the somatic cells number may have long-range consequences on the number of oocytes available in adult life and on the future fertility of female offspring exposed to smoking in utero.

Age determination enhanced by embryonic foot bud and foot plate measurements in relation to Carnegie stages, and the influence of maternal cigarette smoking.

BACKGROUND: Reliable age determination of first-trimester human embryos and fetuses is an important parameter for clinical use and basic science. Age determination by ultrasound or morphometric parameters of embryos 4-6 weeks post conception (p.c.) have been questioned, and more accurate methods are required. Data on whether and how maternal smoking and alcohol consumption influence embryonic and fetal foot growth is also lacking. METHODS: Embryonic tissue from 102 first-trimester legal abortions (aged 35-69 days p.c.) were collected. All women answered a questionnaire concerning smoking and drinking habits, and delivered a urine sample for cotinine analysis. Embryonic age was evaluated by vaginal ultrasound measurements and by post-termination foot length and compared with the Carnegie stages. RESULTS: Foot bud and foot plate were defined and measured as foot length in embryos aged 35-47 days p.c. (range 0.8-2.1 mm). In embryos and fetuses aged 41-69 days p.c., heel-toe length was measured (range 2.5-7.5 mm). We found a significant linear correlation between foot length and age. Morphology of the feet was compared visually with the Carnegie collection, and we found that the mean ages of the two collections correlated well. Foot length was independent of gender, Environmental Tobacco Smoke, maternal smoking and alcohol consumption. CONCLUSION: Foot length correlated linearly to embryonic and foetal age, and was unaffected by gender, ETS, maternal smoking and alcohol consumption.

Human immature oocytes grow during culture for IVM.

BACKGROUND: Oocyte competence for maturation and embryogenesis is associated with diameter in many mammals. We aimed to test whether this relationship exists in humans and to quantify its impact upon in vitro maturation (IVM). METHODS: We used computer-assisted image analysis daily to measure average diameter, zona thickness and other parameters in oocytes. Immature oocytes originated from unstimulated patients with polycystic ovaries, and from stimulated patients undergoing intracytoplasmic sperm injection (ICSI). Some were cultured with meiosis activating sterol (FF-MAS). Matured oocytes were inseminated using ICSI and embryo development was monitored. In vivo matured oocytes were also measured. RESULTS: Immature oocytes were smaller at collection than in vivo matured oocytes. Maturation was related to oocyte diameter and many oocytes grew in culture. FF-MAS stimulated growth in oocytes derived from ICSI patients, but only stimulated growth in PCO derived oocytes if they matured in vitro. Degenerating oocytes showed cytoplasmic shrinkage. Neither zona thickness, perivitelline space, nor the total diameter of the oocyte plus zona were informative regarding maturation capacity. CONCLUSIONS: Immature oocytes grow during maturation culture. FF-MAS promotes oocyte growth in vitro. Oocytes from different sources have different growth profiles in vitro. Measuring oocytes in clinical IVM may provide additional non-invasive information that could potentially avoid the use of growing oocytes.

Global gene expression analysis in fetal mouse ovaries with and without meiosis and comparison of selected genes with meiosis in the testis.

In order to identify novel genes involved in early meiosis and early ovarian development in the mouse, we used microarray technology to compare transcriptional activity in ovaries without meiotic germ cells at embryonic age 11.5 (E11.5) and E13.5 ovaries with meiosis. Overall, 182 genes were differentially expressed; 134 were known genes and 48 were functionally uncharacterized. A comparison of our data with the literature associated, for the first time, at least eight of the known genes with female meiosis/germ cell differentiation (Aldh1a1, C2pa, Tex12, Stk31, Lig3, Id4, Recql, Piwil2). These genes had previously only been described in spermatogenesis. The microarray also detected an abundance of vesicle-related genes of which four were upregulated (Syngr2, Stxbp1, Ric-8, SytIX) and one (Myo1c) was downregulated in E13.5 ovaries. Detailed analysis showed that the temporal expression of SytIX also coincided with the first meiotic wave in the pubertal testis. This is the first time that SytIX has been reported in non-neuronal tissue. Finally, we examined the expression of one of the uncharacterized genes and found it to be gonad-specific in adulthood. We named this novel transcript "Gonad-expressed transcript 1" (Get-1). In situ hybridization showed that Get-1 was expressed in meiotic germ cells in both fetal ovaries and mature testis. Get-1 is therefore a novel gene in both male and female meiosis.

Biochemical pregnancy after fertilization of an oocyte aspirated from a heterotopic autotransplant of cryopreserved ovarian tissue: case report.

Autotransplantation of frozen/thawed ovarian tissue in women undergoing cancer therapy has so far led to the birth of two healthy babies. In both cases, it can be discussed whether the fertilized oocyte originated from the transplant or from the native ovary. We now present a biochemical pregnancy achieved after heterotopical autotransplantation of cryopreserved ovarian cortical tissue and hence the unquestionable proof that pregnancy can occur after transplantation of cryopreserved ovarian tissue. A woman diagnosed with Hodgkin's lymphoma had ovarian tissue cryopreserved at the age of 28, before receiving chemotherapy and radiation therapy that rendered her amenorrhoeic. After complete remission, she had autotransplantation of ovarian tissue to the remaining ovary, to the right pelvic wall and to a midline subperitoneal pocket on the lower abdominal wall. The transplanted tissue resumed hormone secretion and follicles developed in all three locations. Three times during 8 months, when follicles could not be visualized in other locations, oocytes were aspirated from the subperitoneal autotransplanted tissue on the lower abdominal wall. Twice, an oocyte was retrieved, fertilized by intracytoplasmatic sperm injection (ICSI) and transferred to the woman's uterus. One of the treatments resulted in a positive pregnancy test 14 days after transfer. Clinical pregnancy, however, was not achieved. In conclusion, heterotopic autotransplantation of cryopreserved ovarian tissue can sustain follicle development. The oocytes of aspirated mature follicles are capable of fertilization after ICSI, and the resulting embryo is competent of producing hCG at detectable levels.

Number of germ cells and somatic cells in human fetal ovaries during the first weeks after sex differentiation.

BACKGROUND: This study presents the number of germ cells and somatic cells in human fetal ovaries during week 6 to week 9 post conception, i.e. the first weeks following sex differentiation of the gonads. METHODS: One ovary with attached mesonephros from each of 11 individual legal abortions was used for estimation of cell numbers. After recovery of the fetus, the ovary-mesonephric complexes were immediately isolated, fixed and processed for histology. A stereological method was utilized to estimate the total number of oogonia in all ovaries and somatic cells in seven of them. RESULTS: The number of oogonia per ovary increased from approximately 26,000 in week 6 to approximately 250,000 in week 9 and somatic cells from approximately 240,000 to approximately 1.4 x 10(6). The ratio of oogonia to somatic cells tended to increase throughout the period. The concentration of oogonia was similar in the cranial (mesonephric connected) part and the caudal part of the ovaries. CONCLUSIONS: This is the first stereological estimation of the number of oogonia and somatic cells in human fetal ovaries, and the first estimation of germ cells and somatic cells in ovaries aged <9 weeks. The number of oogonia in week 9 is comparable to the numbers previously published based on non-stereological estimations. We found early stages of meiosis in fetal ovaries from week 9.

Cryopreservation of intact testicular tissue from boys with cryptorchidism.

BACKGROUND: Boys with cryptorchidism often face fertility problems in adult life despite having orchiopexy performed at a very young age. During this operation, a biopsy of the testis is normally taken in order to evaluate their infertility potential and the presence of malignant cells. This study evaluated the morphology and functional capacity of cryopreserved testes biopsies and their possible use in fertility preservation. METHODS: Biopsies from 11 testes (eight boys) were obtained. Each biopsy was subdivided into six pieces and two pieces were frozen in each of two different cryoprotectants. One fresh and two cryopreserved pieces were cultured for 2 weeks. All pieces were prepared for histology. Used culture media were analysed for testosterone and inhibin B concentrations. RESULTS: The morphology of the fresh and frozen-thawed samples was similar, with well-preserved seminiferous tubules and interstitial cells. A similar picture appeared after 2 weeks of culture, but a few of the cultured biopsies contained small necrotic areas. The presence of spermatogonia was verified by c-kit-positive immunostaining. Production of testosterone and inhibin B (ng/mm(3) testis tissue) in the frozen-thawed pieces was on average similar to that of the fresh samples. CONCLUSIONS: Intact testicular tissue from young boys with non-descended testes tolerates cryopreservation with surviving spermatogonia and without significant loss of the ability to produce testis-specific hormones in vitro. It may be an option to freeze part of the testis biopsy, which is routinely removed during the operation for cryptorchidism, for fertility preservation in adult life.

Follow-up of ovarian function post-chemotherapy following ovarian cryopreservation and transplantation.

BACKGROUND: The purpose of this study was to assess the ovarian function after treatment of a malignant disease in women who previously had cortical tissue from an entire ovary cryopreserved prior to chemotherapy, and to assess ovarian function after autotransplantation of cryopreserved ovarian tissue. All were treated with chemotherapeutic drugs with an estimated high risk of inducing ovarian failure. METHODS: Twenty-two women with breast cancer (n = 8), Hodgkin's disease (n = 6), non-Hodgkin's (n = 2), leukaemia (n = 5) or brain tumour (n = 1) underwent a clinical examination >18 months after cryopreservation. Three patients with premature ovarian failure had ovarian tissue autotransplanted orthotopically and heterotopically. Ovarian function was assessed by ultrasonography of the remaining ovary and hormone measurements. RESULTS: Nine of 22 women (41%) had sonographic and hormonal signs of ovarian failure with ovarian volumes <1.3 cm3, no antral follicles and high FSH levels (median 57.1 IU/l). Thirteen of the 22 women (59%) still menstruated and 10 had a seemingly normal ovarian function, with a median ovarian volume of 6.8 cm3, a median number of antral follicles of six, FSH <15 IU/l and normal estradiol levels. All three patients with autotransplanted ovarian tissue regained ovarian function as confirmed by return of menses, follicles on ultrasonography and normalized hormone levels. Two embryos were created from the crypreserved tissue after IVF. CONCLUSIONS: Treatment with bone-marrow transplantation and/or high doses of alkylating agents led to ovarian failure in all patients. Autotransplantation of ovarian tissue led to return of ovarian function.

Anti-Müllerian hormone initiates growth of human primordial follicles in vitro.

Survival and growth of follicles in human ovarian tissue is presently only performed with limited success. We evaluated the effect of anti-Müllerian hormone (AMH) and/or testosterone on follicular growth during a 4-week culture period using ovarian cortical tissue from six women in their reproductive years. The cortex of each biopsy was isolated and immediately cryopreserved upon collection and stored in liquid nitrogen. After thawing the tissue was placed in culture. After the culture period all follicles were counted on histological sections and classified for viability and stage of development. Based on evaluation of 6603 follicles it was found that the number of growing follicles significantly increased during the culture period as compared to the uncultured control, irrespective of the composition of the culture medium. Furthermore, significantly more follicles advanced to the primary and secondary stage (p<0.05) in tissue cultured with AMH (54%) as compared to tissue cultured in control medium (41%). The mean diameter of follicles classified as primary follicles was significantly enhanced in tissue cultured in the presence of AMH (p=0.002) and AMH plus testosterone (p<0.001) as compared to that observed in tissue cultured with control medium and medium containing testosterone alone. In contrast the mean diameter of the oocyte and its nucleus remained similar irrespective of culture medium. In conclusion, AMH seems to affect early stages of human follicular development by enhancing recruitment, survival and/or growth during a 4-week culture period.

Survival of primordial follicles following prolonged transportation of ovarian tissue prior to cryopreservation.

BACKGROUND: Cryopreservation of ovarian tissue for fertility preservation is becoming increasingly common. Treatment of diseases that may deprive the ovaries of follicles is often performed at local hospitals that are without the necessary facilities and expertise to cryopreserve ovarian tissue. The aim of the present study was to evaluate whether primordial follicles of ovarian cortex survive transport for up to 4 h prior to cryopreservation. METHODS: Immediately after recovery of one ovary from each of four patients, the cortex was roughly isolated, placed in IVF culture medium, kept on ice and transported for 3-4 h to the centre where final dissection and cryopreservation took place. Transplantation of pieces of thawed ovarian cortex under the skin of ovariectomized immunodeficient mice for a period of 4 weeks was used to assess the survival of primordial follicles. RESULTS: After transplantation, ovarian tissue from each of the four patients contained surviving follicles. CONCLUSIONS: Transport of roughly isolated ovarian cortex cooled on ice for a period of up to 4 h allows survival of primordial follicles following cryopreservation and transplantation to immunodeficient mice.

Erroneous genetic sex determination of a newborn twin girl due to chimerism caused by foetal blood transfusion. A case report.

OBJECTIVE: We present a case of erroneous sex determination in a newborn twin girl (twin A) due to chimerism. CASE REPORT: Amniocentesis and ultrasound examination had pointed towards male sex of both twins. At birth, twin A presented as a phenotypically normal female with 46,XY karyotype, and 46,XY gonadal dysgenesis was suspected. Twin B was a normal male. RESULTS: In our department, further examinations of twin A included undetectable testosterone and inhibin-B and elevated FSH. Ultrasound suspected an infantile uterus, and sequencing of the SRY gene was normal. After gonadectomy, a 46,XX karyotype was demonstrated in both normal infantile ovaries and in the fibroblasts from a skin biopsy. Analysis of X-linked markers in DNA from blood lymphocytes in both twins was identical, consistent with 46,XY karyotypes. CONCLUSION: Twin A is a 46,XX female with a chimeric 46,XY blood cell line due to intrauterine transfusion from her twin brother.

Density and distribution of primordial follicles in single pieces of cortex from 21 patients and in individual pieces of cortex from three entire human ovaries.

BACKGROUND: At the time of cryopreservation of ovarian tissue for fertility preservation a small biopsy of ovarian cortex is usually taken for histological evaluation of the follicular reserve. The purpose of this study was to evaluate the distribution and density of primordial follicles in single pieces of cortex from individual patients and in pieces of cortex comprising entire ovaries, all prepared for cryopreservation. METHODS: Cortical biopsies from 21 patients and the whole cortex of one ovary were evaluated histologically prior to cryopreservation. In addition, the cortex of two whole ovaries was cryopreserved before histological evaluation. The volume of each cortical fragment was measured, all follicles counted and the follicular density calculated. RESULTS: In individual pieces of cortex follicular density showed a significant inverse linear correlation with age. The follicular density per cortical fragment prepared from each of the three entire ovaries varied from 1.8 to 166, 0.007 to 140 and 0.04 to 4.48 follicles/mm(3) cortical tissue. CONCLUSION: The density of primordial follicles varied more than two orders of magnitude in cortical fragments from each of the three ovaries. Primordial follicles were very unevenly distributed throughout the cortex of these ovaries, although a significant linear correlation between age and follicular density was found.

Characteristics of human ovulation in natural cycles correlated with age and achievement of pregnancy.

BACKGROUND: The aim of this study was to evaluate whether characteristics of human ovulation correlate with age and pregnancy potential. METHODS: Two groups of women with regular menstrual cycles were included (i.e. one fertile and one infertile group), which were divided into four age groups (< or =29, 30-34, 35-39, > or = 40 years). Monitoring included observations of follicular phase length, whether ovulations occurred from the left or right ovary, the pattern of ovulations in succeeding natural cycles and, in a subset of women, early follicular phase FSH concentrations. RESULTS: Ovulation moving from one ovary to the other in two consecutive cycles (i.e. contralateral ovulation) was inversely correlated with age, showing a ratio of contralateral ovulation per contra plus ipsilateral ovulations (C/C+I) of 62% in women <29 years, gradually decreasing to 42% in women >40 years. The ratio of right-sided ovulation per right plus left-sided ovulations (R/R+L) was unrelated to age and remained almost constant at a level of approximately 55%. The follicular phase length was inversely correlated with age, being 16.2 +/- 2.9, 15.4 +/- 2.9, 14.8 +/- 2.8 and 13.7 +/- 1.3 days in women < 29, 30-34, 35-39 and >40 years of age respectively. The follicular phase length was similar when comparing ovulations occurring from the right and left ovary, but comparing two successive cycles, the length of the follicular phase of the second cycle, showing contralateral ovulation, was shorter than ipsilateral ovulation with two consecutive ovulations in the same ovary. The pregnancy rate of the four groups decreased with age, being 14, 12, 5 and 3% respectively. The C/C+I ratio correlates with pregnancy rate and follicular phase length, and inversely correlates with basal FSH, whereas R/R+L is unrelated to age and pregnancy rate. CONCLUSIONS: Human ovulation shows characteristics related to age. The interaction between the two ovaries seems to be most pronounced in the younger years, where ovulations jump from one ovary to the other more frequently than later on in life. The C/C+I ratio shows a clear correlation with age and pregnancy rate.

Human FATE is a novel X-linked gene expressed in fetal and adult testis.

Previously, we identified a partial cDNA sequence of a novel human transcript, designated fetal and adult testis expressed transcript (FATE). FATE is testis-specific in fetal life and co-expressed with SRY in a 7 weeks old fetal testis, suggesting a function in early testicular differentiation. Herein, full-length cDNA clones of human and porcine FATE were isolated and the gene structure and promoter region of the human FATE gene was characterized. The human FATE gene, which maps to Xq28, consists of five exons spanning approximately 7 kb of genomic DNA. Examination of 1 kb of the FATE promoter region revealed the presence of a putative steroidogenic factor 1 (SF-1) binding site at position -79 to -71 upstream of the transcription start site. We propose that FATE might represent a novel target gene of SF-1 in human testicular differentiation and/or germ cell development.