Genetic mechanism regulating diversity in the placement of eyes on the head of animals.

Despite the conservation of genetic machinery involved in eye development, there is a strong diversity in the placement of eyes on the head of animals. Morphogen gradients of signaling molecules are vital to patterning cues. During Drosophila eye development, Wingless (Wg), a ligand of Wnt/Wg signaling, is expressed anterolaterally to form a morphogen gradient to determine the eye- versus head-specific cell fate. The underlying mechanisms that regulate this process are yet to be fully understood. We characterized defective proventriculus (dve) (Drosophila ortholog of human SATB1), a K50 homeodomain transcription factor, as a dorsal eye gene, which regulates Wg signaling to determine eye versus head fate. Across Drosophila species, Dve is expressed in the dorsal head vertex region where it regulates wg transcription. Second, Dve suppresses eye fate by down-regulating retinal determination genes. Third, the dve-expressing dorsal head vertex region is important for Wg-mediated inhibition of retinal cell fate, as eliminating the Dve-expressing cells or preventing Wg transport from these dve-expressing cells leads to a dramatic expansion of the eye field. Together, these findings suggest that Dve regulates Wg expression in the dorsal head vertex, which is critical for determining eye versus head fate. Gain-of-function of SATB1 exhibits an eye fate suppression phenotype similar to Dve. Our data demonstrate a conserved role for Dve/SATB1 in the positioning of eyes on the head and the interocular distance by regulating Wg. This study provides evidence that dysregulation of the Wg morphogen gradient results in developmental defects such as hypertelorism in humans where disproportionate interocular distance and facial anomalies are reported.

Clinical outcomes of transfer of frozen and thawed single blastocysts derived from nonpronuclear and monopronuclear zygotes.

PURPOSE: In assisted reproductive technology, normal zygotes are bipronuclear (2PN) during fertilization confirmation; however, sometimes, nonpronuclear zygotes (0PN) and monopronuclear zygotes (1PN) are found during routine observations. METHODS: To elucidate the clinical usefulness of in vitro-fertilized embryos, we investigated the rates of clinical pregnancy, live birth, miscarriage, and congenital abnormality after transfer of frozen-thawed 1PN- and 0PN-derived single blastocysts at Denentoshi Ladies Clinic, Kanagawa, Japan. RESULTS: The rates of pregnancy and live birth for 1PN-derived blastocysts obtained by conventional in vitro fertilization were 37.5% and 27.1%, respectively, which was not significantly different from those for 2PN-derived blastocysts; however, the rates for 0PN-derived blastocysts were significantly lower. The pregnancy and live birth rates for 0PN-derived embryos obtained by intracytoplasmic sperm injection (ICSI) were 45.7% and 34.8%, respectively, which was not significantly different from those for 2PN-derived blastocysts; however, the rates for 1PN-derived blastocysts were significantly lower (4.0% for both) than those for 2PN- and 0PN-derived blastocysts. No congenital abnormalities were found in infants resulting from transfer of 0PN- or 1PN-derived blastocysts. CONCLUSIONS: Both 1PN- and 0PN-derived blastocysts can be used for embryo transfer; however, care should be taken in making decisions about 1PN-derived blastocysts, especially if they are obtained by ICSI.

A vertex specific dorsal selector Dve represses the ventral appendage identity in Drosophila head.

Developmental fields are subdivided into lineage-restricted cell populations, known as compartments. In the eye imaginal disc of Drosophila, dorso-ventral (DV) lineage restriction is the primary event, whereas antero-posterior compartment boundary is the first lineage restriction in other imaginal discs. The Iroquois complex (Iro-C) genes function as dorsal selectors and repress the default, ventral, identity in the eye-head primordium. In Iro-C mutant clones, change of the dorsal identity to default ventral fate leads to generation of ectopic DV boundary, which results in dorsal eye enlargement, and duplication of ventral appendages like antenna and maxillary palp. Similar phenotypes were observed in heads with defective proventriculus (dve) mutant clones. Here, we show that the homeobox gene dve is a downstream effector of Iro-C in the dorsal head capsule (vertex) specification and represses the ventral (antennal) identity. Two homeodomain proteins Distal-less (Dll) and Homothorax (Hth) are known to be determinants of the antennal identity. Ectopic antenna formation in heads with dve mutant clones was associated with ectopic Dll expression and endogenous Hth expression in the vertex region. Interestingly, dve Dll double mutant clones could also induce ectopic antennae lacking the distal structures, suggesting that the Dve activity is crucial for repressing inappropriate antenna-forming potential in the vertex region. Our results clearly indicate that not only the activation of effector genes to execute developmental program but also the repression of inappropriate program is crucial for establishment of the organ identity.

The significance of serum anti-Müllerian hormone (AMH) levels in patients over age 40 in first IVF treatment.

PURPOSE: Although studies of serum anti-Müllerian hormone (AMH) in predicting ovarian reserve are numerous, many studies utilized patients under age 40. However, the assessment of ovarian reserve is especially critical in older infertile women. This study evaluates the significance of AMH level in patients over age 40 at the time of their first in vitro fertilization (IVF) treatment. METHODS: Forty-nine women over age 40 were studied. Although serum samples were taken prior to their IVF treatments, the data of serum AMH of patients were not taken into consideration to determine the therapy strategy, including follicle induction in which clomiphene citrate and human menopausal gonadotropin were used. RESULT(S): Twelve out of 49 patients achieved a clinical pregnancy (24.4 %). There was a positive correlation between serum AMH levels and the number of oocytes retrieved (P < 0.0001). The ROC curve analysis for prediction of poor ovarian response, ≤3 retrieved oocytes, showed that the optimum cut-off level was < 1.0 ng/mL for AMH. The lower AMH group (AMH < 1.0 ng/ml) showed less chance of undergoing embryo transfer than the higher AMH group (AMH ≥1.0 ng/ml). There was no difference in pregnancy rate between the two groups. Five out of 12 pregnant women exhibited AMH levels of less than 0.4 ng/ml. CONCLUSION(S): Assessment of serum AMH concentration in older patients is useful for the prediction of oocytes numbers which may be obtained in IVF. A cut-off level of 1.0 ng/ml AMH can be used to predict poor ovarian response. This cut-off level of AMH of 1.0 ng/ml might be useful to predict whether patients could have an embryo transfer, but had no power to predict achieving pregnancy. On the other hand, our data also showed that patients over age 40 with extreme low levels of AMH still had a chance of pregnancy.

Defective proventriculus specifies the ocellar region in the Drosophila head.

A pair of the Drosophila eye-antennal disc gives rise to four distinct organs (eyes, antennae, maxillary palps, and ocelli) and surrounding head cuticle. Developmental processes of this imaginal disc provide an excellent model system to study the mechanism of regional specification and subsequent organogenesis. The dorsal head capsule (vertex) of adult Drosophila is divided into three morphologically distinct subdomains: ocellar, frons, and orbital. The homeobox gene orthodenticle (otd) is required for head vertex development, and mutations that reduce or abolish otd expression in the vertex primordium lead to ocelliless flies. The homeodomain-containing transcriptional repressor Engrailed (En) is also involved in ocellar specification, and the En expression is completely lost in otd mutants. However, the molecular mechanism of ocellar specification remains elusive. Here, we provide evidence that the homeobox gene defective proventriculus (dve) is a downstream effector of Otd, and also that the repressor activity of Dve is required for en activation through a relief-of-repression mechanism. Furthermore, the Dve activity is involved in repression of the frons identity in an incoherent feedforward loop of Otd and Dve.

Spatial and temporal requirement of defective proventriculus activity during Drosophila midgut development.

The Drosophila middle midgut cells derived from the endoderm develop into four distinct types of cell. Of these cells, copper cells have invaginated microvillar membranes on their apical surface, and they are involved in two distinct functions, i.e., copper absorption and acid secretion. The homeobox gene defective proventriculus (dve) is expressed in the midgut, and two transcripts, type A (∼4.9kb) and type B (∼3.5kb), have been identified. We isolated the deletion allele dve(E181) that completely removes the first exon for type-A (dve-A) transcript. Dve expression pattern in dve-A mutant background indicates that isoform switching is dynamically regulated in a cell-type specific manner. Using RNAi for dve-A, we examined spatial and temporal requirement of the Dve-A activity. Early Dve-A activity is required to repress isoform switching in copper cells, and for establishment of two gut functions. Late Dve-A activity in copper cells, but not in adjacent interstitial cells, is required for acid secretion, while the activity is redundantly required in both cells for the copper absorptive function. Furthermore, ectopic type-B expression in larval copper cells specifically impaired the copper absorptive function. These results provide insight into molecular mechanisms to establish functional specificity.

Clinical outcome of frozen blastocyst transfer; single vs. double transfer.

PURPOSE: Frozen embryo transfer has been established as an indispensable ART procedure for both the effective use of surplus embryos and the prevention of ovarian hyperstimulation syndrome. The frequency of frozen embryo transfer is increasing in our clinic, and we report that frozen embryo transfer is effective for patients with repeat failures. We present our clinical outcome of frozen blastocyst transfer (FBT). METHODS: In 2006, 470 patients received FBT (562 cycles (IVF: 354 cycles; ICSI: 208 cycles)). One frozen blastocyst was transferred in 412 cycles (335 patients) and two blastocysts were transferred in 150 cycles (135 patients). Assisted hatching was performed in all cases. RESULTS: In 412 cycles (average age: 34.6 years) who received a single FBT, the rate of clinical pregnancy per cycle was 40.7%, the live birth rate was 29.1%, the abortion rate was 21.6%, the ectopic pregnancy rate was 1.2%, the frequency of monochorionic twins was 2.3%, and the cesarean section rate was 38.3%. In 150 cycles (average patient age 34.8 years) who received two FBTs, the clinical pregnancy rate was 46%, the live birth rate was 35.3%, the abortion rate was 16.3%, the ectopic pregnancy rate was 4.4%, the frequency of twins was 15.9% and the cesarean section rate was 39.6%. A significant difference in the ectopic pregnancy rate and the twinning rate was found between single transfers and double transfers (P < 0.05). When IVF and ICSI were compared, there was no statistically significant difference in the abortion rate, the ectopic pregnancy rate, and the cesarean section rate. CONCLUSIONS: The clinical pregnancy rate was similar for the transfer of one and two blastocysts. Single FBT decreases obstetrical risk without reducing the pregnancy rate.

The decrease of serum luteinizing hormone level by a gonadotropin-releasing hormone antagonist following the mild IVF stimulation protocol for IVF and its clinical outcome.

PURPOSE: While performing the mild ovarian stimulation protocol with a GnRH antagonist, the pregnancy rate was compared between the groups, which were divided by the degree that the luteinizing hormone (LH) level decreased. MATERIALS AND METHODS: Patients aged 27 to 42years (36.1 +/- 3.79) underwent 308 IVF cycles who opted for IVF via the mild ovarian stimulation protocol began clomiphene citrate on day 3 and recombinant FSH on day 5. A GnRH antagonist was administered when the dominant follicle reached 14mm. Serum LH was measured at the time of GnRH antagonist administration and at the time of hCG injection. The pregnancy rate and implantation rate were compared between 50 cycles in which the LH level dropped less than one-third and the control (LH level within 1/3). RESULT(S): The pregnancy rate for the group in which the LH level fell less than one third was 18%. Conversely, the pregnancy rate for the control group was 39%. The implantation rate was 18% for the less than one-third group and 26% for the control group. Both the pregnancy rate and the implantation rate for the group in which the LH level fell less than one-third were significantly lower than that of control (p < 0.02). CONCLUSION(S): When performing the mild ovarian stimulation protocol, serum LH should be followed. If the serum LH level is less than one-third at the time of hCG injection, both the pregnancy rate and implantation rate are significantly lower.

Location of endometrial polyp and pregnancy rate in infertility patients.

OBJECTIVE: To assess endometrial polyp location and abnormal endometrial findings and their impact on pregnancy rate. DESIGN: Retrospective study. SETTING: Reproductive clinic in Kanagawa, Japan. PATIENT(S): A retrospective study was conducted on 230 infertility patients who had an endometrial polyp, as suspected on the basis of ultrasound and as diagnosed by hysteroscopy. INTERVENTION(S): Polyps were excised by either polypectomy or curettage. All samples were examined for pathology. The endometrial cavity was subdivided into five area categories: uterotubal junction, anterior uterine wall, posterior uterine wall, lateral uterine wall, and multiple. The patients received < or =6 months of follow-up; pregnancy rates were compared between the five subdivisions. MAIN OUTCOME MEASURE(S): Pregnancy rates. RESULT(S): The incidence of endometrial polyps was as follows, by location: uterotubal junction, 8.0%; posterior uterine wall, 32.0%; anterior uterine wall, 15.4%; lateral uterine wall, 9.2%; and multiple, 35.4%. The pregnancy rate after surgery was as follows, by location: uterotubal junction, 57.4%; posterior uterine wall, 28.5%; anterior uterine wall, 14.8%; lateral uterine wall, 18.8%; and multiple, 40.3%. Endometrial hyperplasia was found in 6.9% of the cases. The pregnancy rate after surgery at the uterotubal junction was significantly higher than that of other locations. CONCLUSION(S): Endometrial polyps are commonly found on the posterior wall of the uterus; however, excision of polyps that were located at the uterotubal junction significantly improved the pregnancy rate. Endometrial polyps should be categorized by both size and location.

Mild stimulation with clomiphene citrate in combination with recombinant follicle-stimulating hormone and gonadotropin-releasing hormone antagonist and its influence on serum estradiol level and pregnancy rate.

Aim: The mild ovarian stimulation protocol for in vitro fertilization (IVF) is carried out to minimize adverse side-effects as well as cost. While performing mild ovarian stimulation with a gonadotropin-releasing hormone (GnRH) antagonist, the pregnancy rate was examined in cases that exhibited a serum estradiol (E2) drop down. Methods: In this study, 174 patients who requested mild ovarian stimulation for IVF began clomiphene citrate on day 3 and recombinant follicle-stimulating hormone (FSH) on day 5 of their menstrual cycles. A GnRH antagonist was administered when the dominant follicle reached a diameter of 14 mm. Serum luteinizing hormone and estradiol were measured at the time of GnRH antagonist administration and at the time of human chorionic gonadotropin (hCG) injection. Pregnancy rates and implantation rates were compared between 24 cycles in which the E2 level fell at the time of hCG injection and 150 cycles in which it did not fall. Results: The pregnancy rate in the cases in which the E2 level fell (25% decrease) at the time of hCG injection was significantly lower than it was in the cases in which it did not fall (16.7 vs 41.0%). The implantation rate for the cases in which the E2 level fell was also lower than that of the control group (7.0 vs 31.0%). There was no significant difference in the number of good-quality embryos between the two groups. Conclusion: When performing the mild ovarian stimulation protocol, serum E2 should be followed. It is prudent to avoid embryo transfer in the same cycle in cases that exhibit E2 drop down. (Reprod Med Biol 2008; 7: 85-89).

Notch signaling relieves the joint-suppressive activity of Defective proventriculus in the Drosophila leg.

Segmentation plays crucial roles during morphogenesis. Drosophila legs are divided into segments along the proximal-distal axis by flexible structures called joints. Notch signaling is necessary and sufficient to promote leg growth and joint formation, and is activated in distal cells of each segment in everting prepupal leg discs. The homeobox gene defective proventriculus (dve) is expressed in regions both proximal and distal to the intersegmental folds at 4 h after puparium formation (APF). Dve-expressing region partly overlaps with the Notch-activated region, and they become a complementary pattern at 6 h APF. Interestingly, dve mutant legs resulted in extra joint formation at the center of each tarsal segment, and the forced expression of dve caused a jointless phenotype. We present evidence that Dve suppresses the potential joint-forming activity, and that Notch signaling represses Dve expression to form joints.

Monozygotic multiple gestation following in vitro fertilization: analysis of seven cases from Japan.

We present a series of monozygous multiple gestations achieved following in vitro fertilization (IVF): one case of monochorionic triplet pregnancy and six cases of dizygotic triplet pregnancy. From September 2000 to December 2006, all patients achieving clinical pregnancy by ART were reviewed (n = 2433). A 37 year-old woman who delivered a healthy singleton after IVF returned two years later for FET, and a single blastocyst was transferred. This also resulted in pregnancy, but TV-USG revealed a single gestational sac with three distinct amniotic sacs, each containing a distinct fetal pole with cardiac activity. This pregnancy was electively terminated at nine weeks' gestation. An additional six cases of dizygotic triplets established after fresh embryo transfer (no ICSI or assisted hatching) are also described. Of these, one resulted in a miscarriage at eight weeks' gestation and five patients have an ongoing pregnancy. This case series suggests the incidence of dizygotic/monochorionic triplets following IVF is approximately 10 times higher than the expected rate in unassisted conceptions, and underscores the importance of a conservative approach to lower the number of embryos at transfer. The role of embryo transfer technique and in vitro culture media in the twinning process requires further study.

Clinical outcomes of two different endometrial preparation methods for cryopreserved-thawed embryo transfer in patients with a normal menstrual cycle.

Aim: To compare the clinical outcomes of cryopreserved-thawed embryo transfer among patients with a normal menstrual cycle who had natural or hormone-replacement cycles. Methods: From January 2004 to June 2006, cryopreserved embryos following conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) were thawed and transferred in a total of 720 natural cycles and 136 hormone-replacement cycles. Results: Cryopreserved-thawed embryo transfer in patients who had a natural or hormone-replacement cycle resulted in clinical pregnancy in 43.1% and 40.4%, respectively; a rate of miscarriage of 14.5% and 23.6%, respectively; and a rate of ongoing pregnancy and delivery of 36.5% and 30.9%, respectively. None of these differences were statistically significant. Conclusions: Patients with a normal menstrual cycle who have natural or hormone-replacement cycles can be expected to have comparable clinical outcomes with cryopreserved-thawed embryo transfer. (Reprod Med Biol 2007; 6: 53-57).

Sperm retention site and its influence on pronucleus stage evaluation following intracytoplasmic sperm injection.

Aim: It has been suggested that the position of the sperm after intracytoplasmic sperm injection (ICSI) has an effect on the development and quality of the embryo. In this study, we retrospectively examined whether pronucleus stage evaluation used through clinical studies in recent years has relevance with regard to sperm location. Methods: From 2003 to 2005, 1285 oocytes from 459 patients (average age: 36 years) were retrospectively analyzed. The 459 patients underwent ICSI because of fertilization disorders and oligozoospermia. Follicle stimulation was via either Clomid or the long protocol. Human chorionic gonadotropin was administered to induce ovulation and oocyte retrieval was conducted 35 h later. After confirming the presence of a polar body, we immobilized the ovum at the 6 o'clock position, introduced the injection pipette at the 3 o'clock position and carried out ICSI. Results: When a sperm was located at a position that was opposite to the polar body, both classifications of Scott and Tesarik regarding embryo quality were distinctly low. Furthermore, a good embryo classification ensued when the sperm was located adjacent to the polar body. Conclusion: The zone in which the sperm was located did not always correlate with embryo quality; however, our study suggested that sperm location affects the synchronization of the nucleolus. When carrying out ICSI, it is important to take into consideration the insertion point of the sperm. (Reprod Med Biol 2007; 6: 171-174).