Sex chromosome abnormalities after intracytoplasmic sperm injection.

Comment

Will ICSI overthrow IVF in all cases of male infertility ?

info:eu-repo/semantics/nonPublished

Colony sex ratios vary with breeding structure but not relatedness asymmetry in the facultatively polygynous ant Pheidole pallidula

We investigated sex allocation in a Mediterranean population of the facultatively polygynous (multiple queen per colony) ant Pheidole pallidula. This species shows a strong split sex ratio, with most colonies producing almost exclusively a single-sex brood. Our genetic (microsatellite) analyses reveal that P. pallidula has an unusual breeding system, with colonies being headed by a single or a few unrelated queens. As expected in such a breeding system, our results show no variation in relatedness asymmetry between monogynous (single queen per colony) and polygynous colonies. Nevertheless, sex allocation was tightly associated with the breeding structure, with monogynous colonies producing a male-biased brood and polygynous colonies almost only females. In addition, sex allocation was closely correlated with colony total sexual productivity. Overall, our data show that when colonies become more productive (and presumably larger) they shift from monogyny to polygyny and from male production to female production, a pattern that has never been reported in social insects.

Investigation of population genetic structure and mating system in the ant Pheidole pallidula

The origin of eusociality in haplo-diploid organisms such as Hymenoptera has been mostly explained by kin selection. However, several studies have uncovered decreased relatedness values within colonies, resulting primarily from multiple queen matings (polyandry) and/or from the presence of more than one functional queen (polygyny). Here, we report on the use of microsatellite data for the investigation of sociogenetic parameters, such as relatedness, and levels of polygyny and polyandry, in the ant Pheidole pallidula. We demonstrate, through analysis of mother-offspring combinations and the use of direct sperm typing, that each queen is inseminated by a single male. The inbreeding coefficient within colonies and the levels of relatedness between the queens and their mate are not significantly different from zero, indicating that matings occur between unrelated individuals. Analyses of worker genotypes demonstrate that 38% of the colonies are polygynous with 2-4 functional queens, and suggest the existence of reproductive skew, i.e. unequal respective contribution of queens to reproduction. Finally, our analyses indicate that colonies are genetically differentiated and form a population exhibiting significant isolation-by-distance, suggesting that some colonies originate through budding.

Significant reproductive skew in the facultatively polygynous ant Pheidole pallidula

Reproductive skew - the extent to which reproduction is unevenly shared between individuals in a social group - varies greatly between and within animal species. In this study, we investigated how queens share parentage in polygynous (multiple queen) colonies of the Mediterranean ant Pheidole pallidula. We used highly polymorphic microsatellites markers to determine parentage of gynes (new queens), males and workers in P. pallidula field colonies. The comparison of the genotypes of young and adult workers revealed a very low queen turnover (less than 2%). The first main finding of the study of reproductive skew in these colonies was that there was a significant departure from equal contribution of queens to gyne, male and worker production. Reproductive skew was greater for male production than for queen and worker production. There was no relationship between the magnitude of the reproductive skew and the number of reproductive queens per colony, their relatedness and the overall colony productivity, some of the factors predicted to influence the extent of reproductive skew. Finally, our study revealed for the first time a trade-off in the relative contribution of nestmate queens to gyne and worker production. The queens contributing more to gyne production contributed significantly less to worker production.

Premature ovarian aging in mice deficient for Gpr3

After becoming competent for resuming meiosis, fully developed mammalian oocytes are maintained arrested in prophase I until ovulation is triggered by the luteotropin surge. Meiotic pause has been shown to depend critically on maintenance of cAMP level in the oocyte and was recently attributed to the constitutive Gs (the heterotrimeric GTP-binding protein that activates adenylyl cyclase) signaling activity of the G protein-coupled receptor GPR3. Here we show that mice deficient for Gpr3 are unexpectedly fertile but display progressive reduction in litter size despite stable age-independent alteration of meiotic pause. Detailed analysis of the phenotype confirms premature resumption of meiosis, in vivo, in about one-third of antral follicles from Gpr3-/- females, independently of their age. In contrast, in aging mice, absence of GPR3 leads to severe reduction of fertility, which manifests by production of an increasing number of nondeveloping early embryos upon spontaneous ovulation and massive amounts of fragmented oocytes after superovulation. Severe worsening of the phenotype in older animals points to an additional role of GPR3 related to protection (or rescue) of oocytes from aging. Gpr3-defective mice may constitute a relevant model of premature ovarian failure due to early oocyte aging.

Differential inducibility of HLA class I and II antigens by r-IFN gamma in type III bare lymphocyte syndrome.

Case Reports

Molecular basis of complete C4 deficiency. A study of three patients.

The highly polymorphic fourth component of human complement (C4) is usually encoded by two genes, C4A and C4B, adjacent to the 21-hydroxylase (21-OH) genes and is also remarkable by the high frequency of the null alleles, C4A*Q0 and C4B*Q0. Complete C4 deficiency is exceptional because this condition appears only in homozygotes for the very rare double-null haplotype C4AQ0,BQ0. This condition in most cases gives rise to systemic lupus erythematosus and an increased susceptibility to infections. The molecular basis for complete C4 deficiency has not yet been established. Therefore we studied the DNA of three previously described C4 deficient patients belonging to unrelated families by restriction fragment length polymorphism analysis using C4 and 21-OH probes. These studies revealed a deletion of the C4B and 21-OHA genes in two patients and no deletion at all in the third patient. Therefore, complete C4 deficiency as a result of homozygosity for the C4AQ0, BQ0 haplotype is not a consequence of a deletion of the C4 genes. The molecular basis of this genetic abnormality is certainly very complex and may vary also from one case to another.

Safety and efficacy of drisapersen for the treatment of Duchenne muscular dystrophy (DEMAND II): an exploratory, randomised, placebo-controlled phase 2 study.

Duchenne muscular dystrophy is caused by dystrophin deficiency and muscle deterioration and preferentially affects boys. Antisense-oligonucleotide-induced exon skipping allows synthesis of partially functional dystrophin. We investigated the efficacy and safety of drisapersen, a 2'-O-methyl-phosphorothioate antisense oligonucleotide, given for 48 weeks.

Rôle de la molécule CD81 dans le fonctionnement des lymphocytes B chez l'homme.

News

Echovirus meningoencephalitis in X-linked hypogammaglobulinemia.

Echovirus meningoencephalitis and polymyositis are classical complications of X-linked agammaglobulinemia (1). The treatment of meningoencephalitis is troublesome since intravenous (2), intrathecal (3) and intraventricular (4) administration of gammaglobulins have been reported successful, but failure also occurred in some cases (5). We report our experience of high dose intravenous treatment.

Expression of liver-specific member of the 3β-hydroxysteroid dehydrogenase family, an isoform possessing an almost exclusive 3-ketosteroid reductase activity

We have recently characterized two types of rat 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) isoenzymes expressed in adrenals and gonads. In addition, we have cloned a third type of cDNA encoding a predicted type III 3β-HSD protein specifically expressed in the male rat liver which shares 80% similarity with the two other isoenzymes. Transient expression in human HeLa cells of the cDNAs reveals that the type III 3β-HSD protein does not display oxidative activity for the classical substrates of 3β-HSD, in contrast to the type I 3β-HSD isoenzyme. However, in the presence of NADH, type III isoenzyme, in common with the type I isoform, converts 5α-androstane-3,17-dione (A-dione) and 5α-dihydrotestosterone (DHT) to the corresponding 3β-hydroxysteroids. In fact, the type I and the type III isoenzymes have the same affinity for DHT with K(m) values of 5.05 and 6.16 μM, respectively. When NADPH is used as cofactor, the affinity for DHT of the type III isoform becomes higher than that of the type I isoform with K(m) values of 0.12 and 1.18 μM, respectively. The type III isoform is thus a 3-ketoreductase using NADPH as preferred cofactor which is responsible for the conversion of 3-keto-saturated steroids such as DHT and A-dione into less active steroids.

A phase 1-2 clinical trial of gene therapy for recurrent glioblastoma multiforme by tumor transduction with the herpes simplex thymidine kinase gene followed by ganciclovir.

This study has investigated the effects of herpes simplex thymidine kinase gene (HSV-tk) transfer followed by ganciclovir treatment as adjuvant gene therapy to surgical resection in patients with recurrent glioblastoma multiforme (GBM). The study was open and single-arm, and aimed at assessing the feasibility and safety of the technique and indications of antitumor activity. In 48 patients a suspension of retroviral vector-producing cells (VPCs) was administered by intracerebral injection immediately after tumor resection. Intravenous ganciclovir was infused daily 14 to 27 days after surgery. Patients were monitored for adverse events and for life by regular biosafety assaying. Tumor changes were monitored by magnetic resonance imaging (MRI). Reflux during injection was a frequent occurrence but serious adverse events during the treatment period (days 1-27) were few and of a nature not unexpected in this population. One patient experienced transient neurological disorders associated with postganciclovir MRI enhancement. There was no evidence of replication-competent retrovirus in peripheral blood leukocytes or in tissue samples of reresection or autopsy. Vector DNA was shown in the leukocytes of some patients but not in autopsy gonadal samples. The median survival time was 8.6 months, and the 12-month survival rate was 13 of 48 (27%). On MRI studies, tumor recurrence was absent in seven patients for at least 6 months and for at least 12 months in two patients, one of whom remains recurrence free at more than 24 months. Treatment-characteristic images of injection tracks and intracavity hemoglobin were apparent. In conclusion, the gene therapy is feasible and appears to be satisfactorily safe as an adjuvant to the surgical resection of recurrent GBM, but any benefit appears to be marginal. Investigation of the precise effectiveness of this gene therapy requires prospective, controlled studies.