FIGalpha, a germ cell-specific transcription factor required for ovarian follicle formation

Primordial follicles are formed perinatally in mammalian ovaries and at birth represent the lifetime complement of germ cells. With cyclic periodicity, cohorts enter into a growth phase that culminates in ovulation of mature eggs, but little is known about the regulatory cascades that govern these events. FIGalpha, a transcription factor implicated in postnatal oocyte-specific gene expression, is detected as early as embryonic day 13. Mouse lines lacking FIGalpha were established by targeted mutagenesis in embryonic stem cells. Although embryonic gonadogenesis appeared normal, primordial follicles were not formed at birth, and massive depletion of oocytes resulted in shrunken ovaries and female sterility. Fig(α) (the gene for FIGalpha null males have normal fertility. The additional observation that null females do not express Zp1, Zp2 or Zp3 indicates that FIGalpha plays a key regulatory role in the expression of multiple oocyte-specific genes, including those that initiate folliculogenesis and those that encode the zona pellucida required for fertilization and early embryonic survival. The persistence of FIGalpha in adult females suggests that it may regulate additional pathways that are essential for normal ovarian development.

Decline in prevalence of neural tube defects in a high-risk region of the United States

OBJECTIVES

To conduct surveillance for neural tube defects (NTDs) in a high-risk region of the United States and to prevent occurrence and recurrence of NTDs through the periconceptional use of folic acid supplements.

DESIGN

Active and passive methods were used for surveillance of NTD-affected pregnancies and births during a 6-year period (October 1992-September 1998). Individual genetic counseling was used to prevent NTD recurrences and a public awareness campaign was used to reduce NTD occurrences.

SETTING

State of South Carolina.

PATIENTS

All cases of spina bifida, anencephaly, and encephalocele identified among 278 122 live births and fetal deaths to South Carolina residents during 1992-1998 were included.

MAIN OUTCOME MEASURE

Changes in occurrence and recurrence rates during a 6-year period.

RESULTS

Over the 6 years of surveillance, the prevalence rates for NTDs decreased from 1.89 to.95 cases per 1000 live births and fetal deaths. The prevalence decrease is explained primarily by a decrease in cases of spina bifida. Isolated NTDs accounted for 297/360 (82%) NTDs and 63/360 (18%) had at least 1 other structural anomaly. Females predominated among isolated NTDs but the sex distribution was equal among NTD cases with other anomalies. Prevalence rates for whites (1.48 cases per 1000 live births and fetal deaths) were higher than rates for blacks (.87 cases per 1000 live births and fetal deaths). There were no NTD recurrences in 113 subsequent pregnancies to mothers of infants with isolated NTDs who took periconceptional folic acid. The rate of periconceptional folic acid use among women of childbearing years increased from 8% to 35% during the 6-year project period.

CONCLUSION

The prevalence of NTDs in a high-risk region has declined coincident with the increased periconceptional use of folic acid supplements among women of childbearing age.neural tube defects, high-risk region, birth defects, folic acid, spina bifida, anencephaly, encephalocele.

Evidence based medicine in practice: lessons from a Scottish clinical genetics project

OBJECTIVE

To establish national clinical guidelines and integrated care pathways for five conditions (tuberous sclerosis (TS), Huntington's disease (HD), myotonic dystrophy (MD), neurofibromatosis type 1 (NF1), and Marfan syndrome (MS)) and audit their use in Scotland.

DESIGN

Systematic review of published reports followed by consensus conferences to prepare clinical guidelines and integrated care pathways. Structured review of medical records before and after introduction of integrated care pathways to document changes in practice. Survey of staff views on procedures adopted.

SETTING

All four clinical genetics centres in Scotland.

RESULTS

Project resulted in reduced variation in practice across centres, improved data recording in medical records, and improved communication with other professional groups. A very poor evidence base for management of patients with the conditions studied was found.

CONCLUSIONS

A collaborative structure for undertaking clinical research would improve the evidence base for current practice. National discussion of the boundaries of responsibility of care for the long term management of patients with these disorders is required. The integrated care pathway approach shows promise as a means of facilitating the development of audit within clinical genetics services.

Gpbox (Psx2), a homeobox gene preferentially expressed in female germ cells at the onset of sexual dimorphism in mice

XX gonads differentiate into ovaries, a morphologic event evident by embryonic day 13.5 (E13.5) in mice. To identify early markers of oogenesis, sex-specific urogenital ridge cDNA libraries were constructed from E12-13 embryos. After mass excision and isolation of plasmid DNA, approximately 4800 expressed sequence tags were determined and compared to existing databases. Few cDNAs were specifically expressed in the urogenital ridge, but one, designated GPBOX, encodes a 227-amino-acid homeobox protein that is first expressed at E10.5 in the embryo as well as in the extraembryonic tissues. The Gpbox gene is single copy in the mouse genome and is located on the X chromosome in close proximity to two other homeobox genes, Pem and Psx1. Within the embryo, its expression is limited to the gonad, and transcripts are not detected in adult tissues. Although comparable levels are initially present in both sexes, GPBOX transcripts accumulate faster in female germ cells and peak at E12.5 when they are present in fivefold greater abundance than in males. The persistence of GPBOX transcripts in female germ cells until E15.5 and their virtual disappearance in males by E13.5 suggest that Gpbox may play a role in mammalian oogenesis.

Five cases of isolated glycerol kinase deficiency, including two families: failure to find genotype:phenotype correlation

Little is understood of the genotype/phenotype correlations in X linked glycerol kinase deficiency (GKD) where most cases are caused by extensive deletions of Xp21, which often include genes flanking the GK locus. Few cases of isolated GKD have been investigated where the phenotype is not influenced by neighbouring genes. In this paper, we present the mutation data from four confirmed and one suspected case of non-deletion, isolated, X linked GKD and therefore extend the base of patients that can allow an assessment of genotype/phenotype correlations for this disease. The mutations found were two terminations leading to premature truncation of the GK polypeptide chain, one insertion, and an amino acid substitution. Phenotypic variation was observed in two families, where there was more than one affected subject carrying the same mutation, confirming previous studies that suggest there is no correlation between disease severity and genotype. Furthermore, the nature of the mutation in different families does not appear to influence the spectrum of phenotypic variation. In addition, one coding polymorphism in exon 3 has been found. The characterisation of the gene structure has been completed and shows that instead of 19 there are 21 exons.

The mouse zona pellucida: folliculogenesis, fertility and pre-implantation development

Perinatally, oocytes within the mouse ovary become surrounded by a layer of flattened granulosa cells and form primordial follicles. The subsequent accretion of the zona pellucida between the oocytes and granulosa cells provides a biochemical marker of folliculogenesis. In mice, the zona matrix is composed of three proteins (ZP1, ZP2, ZP3). Mouse lines lacking either ZP1 or ZP3 have been established and have abnormal folliculogenesis. Without ZP1, structurally defective zonae are formed resulting in decreased fecundity due to early embryonic loss. More strikingly, without ZP3, the zona matrix is absent, no 2-cell embryos are formed and females are infertile. The structural integrity of the zona matrix can be restored by substituting human homologues for the missing mouse protein and these 'humanized' zona matrices should prove useful in investigating the molecular basis of fertilization.

The zona pellucida: using molecular genetics to study the mammalian egg coat

An extracellular matrix that mediates critical steps in fertilization and early development surrounds all vertebrate eggs. In mice and humans, this matrix is known as the zona pellucida and comprises three glycoproteins: ZP1, ZP2 and ZP3. Homologues of these proteins isolated from other vertebrates have conserved protein motifs that may be important for establishing a common fibrillar structure. However, specific but contradictory biological roles have been assigned to individual egg coat proteins based on assays in vitro in a wide range of species. Mouse lines lacking either ZP1 or ZP3 have been established with abnormal or absent zona matrices and varying degrees of infertility to examine zona structure and function in vivo. By crossing mouse lines lacking individual zona proteins with those expressing human homologues, the structural integrity of the zona matrix can be restored. Because mouse and human spermatozoa exhibit order-specific binding to the zona pellucida, mice with 'humanized' chimaeric zonae may provide an experimental system to elucidate the molecular basis of sperm-zona interaction.

Expression of receptor protein tyrosine phosphatase alpha mRNA in human prostate cancer cell lines

Receptor protein tyrosine phosphatase alpha (RPTPalpha) is a transmembrane protein phosphatase, and has been proposed to be involved in the differentiation of the neuronal system. In the present study, we demonstrated the expression of RPTPalpha mRNA in several normal human tissues. We further investigated the regulation of expression of RPTPalpha mRNA in epithelial cells utilizing three commercially available human prostate cancer cell lines LNCaP, PC-3 and DU145. This is because these cells exhibit different levels of differentiation, defined by the expression of a tissue-specific differentiation antigen, prostatic acid phosphatase (PAcP), and their androgen sensitivity. LNCaP cells express PAcP and are androgen-sensitive cells, while PC-3 and DU145 cells do not express PAcP and are androgen-insensitive cells. Northern blot analyses revealed that, in LNCaP cells, fetal bovine serum (FBS) and 5alpha-dihydrotestosterone (DHT) down-regulates RPTPalpha mRNA expression, similar to the effect on PAcP. Contrarily, FBS up-regulated the RPTPalpha mRNA level in PC-3 and DU145 cells. In LNCaP cells, sodium butyrate inhibited cell growth and up-regulated RPTPalpha as well as PAcP mRNA expression. Although, sodium butyrate also inhibited the growth of PC-3 and DU145 cells, the level of RPTPalpha mRNA was decreased in PC-3, while increased in DU145 cells. Thus, data taken together indicate that the expression of RPTPalpha is apparently regulated by a similar mechanism to that of PAcP in LNCaP cells.

Mater encodes a maternal protein in mice with a leucine-rich repeat domain homologous to porcine ribonuclease inhibitor

MATER (Maternal Antigen That Embryos Require) is an ooplasm-specific protein first identified as an antigen (OP1) associated with ovarian autoimmunity in mice. Its primary structure has been deduced from full-length cDNA that encodes a 125-kDa protein required for progression of the mouse embryo beyond two cells. Expression of the gene encoding MATER is restricted to the oocyte, which makes it one of a growing, but still limited, number of maternal-effect genes in mammals. To further investigate the function of MATER during oogenesis and early development, we have characterized the gene and resultant protein. Mater is a single-copy gene in the genome of 129/Sv mice and is located at the proximal end of Chromosome (Chr) 7. The gene, spanning approximately 32 kbp, contains 15 exons ranging in size from 48 to 1576 bp, which together encode the 111 amino acid MATER protein. The first five exons encode 26-27 amino acid hydrophilic repeats and exons 8-14 encode 14 leucine-rich repeats. The three-dimensional structure of the latter domain can be closely modeled on the previously determined X-ray crystallographic coordinates of porcine ribonuclease inhibitor. These characterizations of the gene and protein provide the basis for genetic investigations of MATER function in early mammalian development.

Global action to prevent war: a programme for government and grassroots efforts to stop war, genocide and other forms of deadly conflict

At the end of history's bloodiest century and the outset of a new millennium, we have an opportunity to fulfil one of humanity's oldest dreams: making the world largely free of war. Global changes make this goal achievable. Nuclear weapons have shown the folly of war. For the first time, there is no war and no immediate prospect of war among the main military powers. For the first time, many proven measures to prevent armed conflict, distilled in the crucible of this century's wars, are available. If systematically applied, these measures can sharply decrease the frequency and violence of war, genocide, and other forms of deadly conflict. To seize the opportunity, nations should adopt a comprehensive programme to reduce conventional armaments and armed conflict. This programme will complement and strengthen efforts to eliminate nuclear arms. To assure its ongoing worldwide implementation, the conventional reduction programme should be placed in a treaty framework. We propose a four-phased process, with three treaties, each lasting five to ten years, to lay the groundwork for the fourth treaty, which will establish a permanent international security system. The main objectives of the treaties are to achieve: 1. A verified commitment to provide full transparency on conventional armed forces and military spending, not to increase forces during negotiations on arms reductions, and to increase the resources allocated to multilateral conflict prevention and peacekeeping. 2. Substantial worldwide cuts in national armed forces and military spending and further strengthening of United Nations and regional peacekeeping and peace-enforcement capabilities. 3. A trial of a watershed commitment by participating nations, including the major powers, not to deploy their armed forces beyond national borders except in a multilateral action under UN or regional auspices. 4. A permanent transfer to the UN and regional security organizations of the authority and capability for armed intervention to prevent or end war, accompanied by further substantial cuts in national armed forces and increases in UN and regional forces. This programme offers many valuable features: a global framework for conventional forces that parallels the nuclear Non-Proliferation Treaty; a verified no-increase commitment for national armed forces based on full data exchange; a commitment to undertake prescribed confidence-building measures, including limits on force activities and deployments; a commitment to a specified plan for increased funding of UN and regional peacekeeping capabilities; a commitment to strengthen international legal institutions; and after a trial period, a lasting commitment by each participant not to unilaterally deploy its armed forces beyond its borders, but instead to give the responsibility for peacekeeping and peace enforcement to international institutions. This programme of phased steps to reduce armed forces and strengthen peacekeeping institutions will make war rare. It will foster the spread of zones of peace like those in North America and Western Europe where, after centuries of violence, international and civil war have given way to the peaceful settlement of disputes.

Abnormal zonae pellucidae in mice lacking ZP1 result in early embryonic loss

All vertebrates have an egg shell that surrounds ovulated eggs and plays critical roles in gamete recognition. This extracellular matrix is known as the zona pellucida in eutherian mammals and consists of three glycoproteins, ZP1, ZP2 and ZP3 in the mouse. To investigate the role of ZP1 in fertilization and early development, we have used targeted mutagenesis in embryonic stem cells to create mouse lines (Zp1(tm/tm)) lacking ZP1. Although a zona pellucida composed of ZP2 and ZP3 was formed around growing Zp1(tm/tm) oocytes, the matrix was more loosely organized than zonae around normal oocytes. In some Zp1 null follicles, this structural abnormality resulted in ectopic clusters of granulosa cells, lodged between the zona matrix and the oolemma, that perturbed normal folliculogenesis. Comparable numbers of eggs were ovulated from Zp1 null females and normal females following hormonal stimulation. However, after mating with males, fewer two-cell embryos were recovered from Zp1 null females, and their litters were significantly smaller than those produced by normal mice. Therefore, although mouse ZP1 is not essential for sperm binding or fertilization, it is required for the structural integrity of the zona pellucida to minimize precocious hatching and reduced fecundity.

A systematic approach to erectile dysfunction in the cardiovascular patient: a consensus statement

Sexual activity is no more stressful to the heart when compared with a number of other natural daily activities, e.g. walking one mile on the level in 20 minutes. The cardiac risk of sexual activity in patients diagnosed with cardiovascular disease is minimal in properly assessed and advised patients. Erectile dysfunction (ED) is common, affecting 10% of men aged 40-70 years and increases in frequency with age. ED and cardiovascular disease share many of the same risk factors and often coexist. ED in the diagnosed cardiovascular patient should be identified by routine questioning in general practice. Modern therapies can restore a sexual relationship in the majority of patients with ED and can lead to a substantial improvement in quality of life. The majority of patients assessed to be at low or intermediate cardiac risk, as defined later in this paper (Table 4), can be effectively managed in primary care. Primary care treatment for ED in patients defined as high risk can be initiated following a specialist opinion and/or confirmation that the patient's cardiovascular condition is stabilised. There is no evidence that currently licensed treatments for ED add to the overall cardiovascular risk in patients with or without diagnosed cardiovascular disease.

Haemochromatosis mutations in North-East Scotland

The HFE gene and its mutations C282Y and H63D cause hereditary haemochromatosis (HH). Among 54 affected individuals from North-East Scotland, 91% were homozygous for C282Y and 5.5% were compound heterozygotes for C282Y and H63D. The general population allele frequencies were high (8% and 15.7% for C282Y and H63D respectively). Although it is likely that HH is under diagnosed, these figures suggest that disease expression is variable, and many of those with the genetic predisposition HH will never develop the clinical consequences of iron overload. This has implications for diagnosis and predictive testing.

Cardiac involvement in Emery Dreifuss muscular dystrophy: a case series

Three patients with Emery Dreifuss muscular dystrophy are reported. Emery Dreifuss muscular dystrophy is an X linked muscular dystrophy, in which locomotor involvement is characteristically mild and slowly progressive. The effect on the heart becomes apparent in the teenage years and is characterised by cardiac conduction defects and infiltration of the myocardium by fibrous and adipose tissue. It first affects the atria, which results in atrial paralysis; treatment with ventricular pacing is usually needed. Female carriers can develop heart problems and are at risk of sudden death. Relatives of affected patients should be offered screening with electrocardiography and echocardiography.

Toolbox: How to do a sexual physical exam

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Incorporation of mouse zona pellucida proteins into the envelope of Xenopus laevis oocytes

All vertebrate eggs have extracellular matrices, referred to as the zona pellucida in Mus musculus and the vitelline envelope in Xenopus laevis. The mouse zona, composed of three sulfated glycoproteins (ZP1, ZP2, ZP3), is critical for fertilization and early development, and mice lacking a zona pellucida produce no live offspring. The primary structures of mouse ZP1 (623 amino acids), ZP2 (713 amino acids) and ZP3 (424 amino acids) have been deduced from full-length cDNAs, but posttranslational modifications result in mature zona proteins with molecular masses of 200-180 kDa, 140-120 kDa, and 83 kDa, respectively. The vitelline envelope forms a similar structure around Xenopus eggs and contains three glycoproteins that are structurally related (39-48% amino acid similarity) to the three mouse zona proteins. To investigate whether the structural semblances are sufficient to allow incorporation of the mouse zona proteins into the Xenopus vitelline envelope, capped synthetic mRNAs encoding ZP1, ZP2, and ZP3 proteins were injected into the cytoplasm of stage VI Xenopus oocytes. After 20 h of incubation the oocytes were harvested, and posttranslationally modified zona proteins were detected with monoclonal antibodies specific to mouse ZP1, ZP2, and ZP3. The oocytes were imaged with confocal microscopy to detect individual zona proteins in the extracellular matrix of the oocytes, and this localization was confirmed biochemically. Thus the mouse zona proteins appear to have been sufficiently conserved through 350 million years of evolution to be incorporated into the extracellular envelope surrounding Xenopus eggs.

Protein kinase cascades in intracellular signalling by interleukin-I and tumour necrosis factor

Interleukin 1 (IL-1) and tumour necrosis factor (TNF) are major mediators of inflammation, with similar actions. Their receptor mechanisms and downstream pathways are reviewed. They activate several protein kinases in fibroblasts, including the three types of mitogen-activated protein kinase (MAPK), the kinase of the inhibitor of nuclear factor-kappa B (I kappa BK), and the TNF-/IL-1-activated beta-casein kinase. Cultured cells show a broader spectrum of kinase activation by IL-1 than tissues in vivo, suggesting that the receptors connect to more pathways in proliferating cells than in resting differentiated cells. The c-Jun N-terminal kinase (JNK) is strongly activated by IL-1 in tissues. In rabbit liver this is mediated by MAPK kinase 7; the upstream kinase is unidentified. Little is known of downstream MAPK targets in inflammation. Inhibitor experiments suggest that p38MAPK mediates induction of cyclo-oxygenase-2 and metalloproteinases by IL-1, and of TNF, IL-1 and cyclo-oxygenase-2 by endotoxin (in monocytes). p38MAPK is needed for induction of the mRNAs (except IL-1 mRNA).

A contraceptive peptide vaccine targeting sulfated glycoprotein ZP2 of the mouse zona pellucida

In this study, we have mapped and characterized a B cell epitope of sulfated glycoprotein ZP2 (ZP2) as a step toward the development of a multi-epitope zona pellucida (ZP) vaccine. Recombinant polypeptides expressed by random deoxyribonuclease-digested fragments of ZP2 cDNA were screened for binding to IE-3, a monoclonal antibody to murine ZP2. Positive clones contained cDNA inserts encoding polypeptide corresponding to ZP2(103-134). When normal or ovariectomized female mice were immunized with three overlapping peptides that span this region of ZP2 (101-120, 111-130, 121-140), only ZP2(121-140) elicited IgG antibodies that reacted with mouse ovarian ZP, indicative of the presence of native B epitope and helper T cell epitope in ZP2(121-140). To more finely map the ZP2 B cell epitope, a random peptide display library was screened with the IE-3 antibody, and a consensus tetramer sequence VxYK that matched the ZP2(123-126) sequence VRYK was located. Competitive immunofluorescence analysis with single alanine-substituted VxYK peptides ranked the relative contribution of the three critical B cell epitope residues as Y > V > K. A chimeric peptide was constructed that contained the YRYK motif of ZP2 and a bovine RNase T cell epitope. Although (C57BL/6xA/J) F1 (B6AF1) female mice immunized with the chimeric peptide developed ZP antibody response, this peptide elicited antibody only in mice of the histocompatibility complex (MHC) H-2(k or b) haplotype. In contrast, ZP2(121-140) peptide elicited antibody in inbred mice with three additional mouse MHC haplotypes. Moreover, although ZP2(121-140) contained a T cell epitope, no oophoritis was observed after immunization of B6AF1 mice with ZP2(121-140) in complete Freund's adjuvant (CFA). In a preliminary trial, female B6AF1 mice immunized with ZP2(121-140) in CFA had reduced litter sizes as compared with mice injected with CFA alone.

A double blind, placebo controlled study of intracavernosal vasoactive intestinal polypeptide and phenotolamine mesylate in a novel auto-injector for the treatment of non-psychogenic erectile dysfunction

Three hundred and four patients with non-psychogenic erectile dysfunction (ED) completed a dose assessment phase with intracavernosal injection utilizing 25 micrograms vasoactive intestinal polypeptide (VIP) combined with phentolamine mesylate 1.0 mg (VIP/P-1) or 2.0 mg (VIP/P-2) in an auto-injector for a response rate of 83.9%. In a sub-group of 183 patients who withdrew from one or more previous ED therapies, 82% responded with an erection suitable for intercourse. One hundred and ninety-five patients were subsequently treated in a placebo controlled phase. 75.1% responded to VIP/P-1, 12% to placebo (P < 0.001); 66.5% responded to VIP/P-2, 10.3% to placebo (P < 0.001), with the median duration of erection of 54 min. The principal adverse event was transient facial flushing in 2770 injections (33.9%). There was no pain post injection and two episodes of priapism (0.05%). Only nine patients withdrew because of adverse events. Over 85% and 95% of patients were satisfied with the drug and auto-injector, respectively. Over 81% of patients and 76% of partners reported an improved quality of life.

Antibodies to human ZP3 induce reversible contraception in transgenic mice with 'humanized' zonae pellucidae

The initial spermatozoon-egg interaction of mammalian fertilization is mediated by the zona pellucida, an extracellular matrix composed of three glycoproteins (ZP1, ZP2, ZP3). These proteins are sufficiently conserved between human and mouse to form chimeric zonae pellucidae, and genetically engineered mice in which the endogenous mouse ZP3 has been replaced by human ZP3 have 'humanized' zonae, but normal fertility. Administration of monoclonal antibodies to mouse ZP3 does not affect fertility in these animals, but administration of antibodies to human ZP3 results in long-term, reversible contraception. The antibodies coat the zonae pellucidae surrounding growing oocytes within the ovary and their presence in the zona matrix inhibits, but does not eliminate, sperm binding. The contraceptive effect is attributed to steric hindrance that decreases sperm binding and prevents penetration through the zona pellucida. The resumption of fertility is associated with the disappearance of antibodies from the zona matrix. No adverse effect on mating behaviour, ovarian histology or fetal development (if administered after fertilization) is detected in treated females. These results suggest that transgenic mice expressing human proteins will prove useful in assessing contraceptive efficacy of zona epitopes in the rational design of immunocontraception directed at the human zona pellucida.