Acquisition of a potential marker for insect transformation: isolation of a novel alcohol dehydrogenase gene from Bactrocera oleae by functional complementation in yeast

The alcohol dehydrogenase genes make up one of the best studied gene families in Drosophila, both in terms of expression and evolution. Moreover, alcohol dehydrogenase genes constitute potential versatile markers in insect transformation experiments. However, due to their rapid evolution, these genes cannot be cloned from other insect genera by DNA hybridization or PCR-based strategies. We have therefore explored an alternative strategy: cloning by functional complementation of appropriate yeast mutants. Here we report that two alcohol dehydrogenase genes from the medfly Ceratitis capitata can functionally replace the yeast enzymes, even though the medfly and yeast genes have evolved independently, acquiring their enzymatic function convergently. Using this method, we have cloned an alcohol dehydrogenase gene from the olive pest Bactrocera oleae. We conclude that functional complementation in yeast can be used to clone alcohol dehydrogenase genes that are unrelated in sequence to those of yeast, thus providing a powerful tool for isolation of dominant insect transformation marker genes.

The crystal structures of the synthetic C-terminal octa- and dodecapeptides of trichovirin

The structures of two synthetic peptides with sequences corresponding to the C-terminal region of the naturally occurring 14-residue peptaibol trichovirin have been determined. The crystal structures of 8- and 12-residue segments are presented and are compared with the structures of the tetrapeptide and of the 9-residue segment, which have been reported earlier. A comparison between these segments leads to the hypothesis that the three-dimensional structure of trichovirin is to a large extent determined by the properties of a periodically repeating -Aib-Pro- pattern in the sequence of the peptide.

P-element insertion alleles of essential genes on the third chromosome of Drosophila melanogaster: correlation of physical and cytogenetic maps in chromosomal region 86E-87F

We have established a collection of 2460 lethal or semi-lethal mutant lines using a procedure thought to insert single P elements into vital genes on the third chromosome of Drosophila melanogaster. More than 1200 randomly selected lines were examined by in situ hybridization and 90% found to contain single insertions at sites that mark 89% of all lettered subdivisions of the Bridges' map. A set of chromosomal deficiencies that collectively uncover approximately 25% of the euchromatin of chromosome 3 reveal lethal mutations in 468 lines corresponding to 145 complementation groups. We undertook a detailed analysis of the cytogenetic interval 86E-87F and identified 87 P-element-induced mutations falling into 38 complementation groups, 16 of which correspond to previously known genes. Twenty-one of these 38 complementation groups have at least one allele that has a P-element insertion at a position consistent with the cytogenetics of the locus. We have rescued P elements and flanking chromosomal sequences from the 86E-87F region in 35 lines with either lethal or genetically silent P insertions, and used these as probes to identify cosmids and P1 clones from the Drosophila genome projects. This has tied together the physical and genetic maps and has linked 44 previously identified cosmid contigs into seven "super-contigs" that span the interval. STS data for sequences flanking one side of the P-element insertions in 49 lines has identified insertions in the alphagamma element at 87C, two known transposable elements, and the open reading frames of seven putative single copy genes. These correspond to five known genes in this interval, and two genes identified by the homology of their predicted products to known proteins from other organisms.

One-hundred and five new potential Drosophila melanogaster genes revealed through STS analysis

Complementation analysis had suggested that the Drosophila melanogaster genome contains approximately 5000 genes, but it is now generally accepted that the actual number is several times as high. We report here an analysis of 1788 anonymous sequence tagged sites (STSs) from the European Drosophila Genome Project (EDGP), totalling 463 kb. The data reveal a substantial number of previously undescribed potential genes, amounting to 6.1% of the number of Drosophila genes already in the sequence databases.

Representation of unique sequences in libraries of randomized nucleic acids

From a library of nucleic acid molecules, which are randomized in parts of their sequence, unique sequence variants can be selected for specific properties. The planning of such an in vitro selection experiment requires some consideration regarding how much DNA template or RNA transcript should be used initially. The amount applied depends on the number of randomized nucleotides and on the expectations of how often each conceivable and unique sequence combination should be represented in the experimental pool. We display graphs describing the probability for the representation of unique nucleic acid molecules in a randomized pool as a function of the mean representation k, defined by the ratio of sampled nucleic acid molecules to conceivable sequence combinations and we summarize the amounts required to represent unique sequences with 99% likelihood. The probability of representation, P = 1-e-k, can be applied also to 'sub-saturated' pools (k < 1) of nucleic acids with long randomized domains, where it is impossible to provide sufficient material for full sequence representation.

High-dose chemotherapy with autologous bone marrow transplantation for refractory metastatic gestational trophoblastic disease

A patient with gestational trophoblastic disease failed to respond to all standard multiple-agent chemotherapy and had progressive uterine disease. Total hysterectomy also proved ineffective. We therefore administered high-dose cyclophosphamide, etoposide, and melphalan with autologous bone marrow support. Severe marrow suppression followed but a complete remission was achieved and the patient remains free of disease 3 years after the completion of therapy. This result seems to confirm the value of using high-dose multiagent therapy to optimize the dose-effect of therapy regimens on drug-refractory gestational trophoblastic disease.

Therapeutic strategies in tubal infertility with distal pathology

Since 1980, various treatments have been proposed for patients suffering from distal tubal infertility. Difficult choices between surgical (microsurgery/laparoscopy) treatments and in-vitro fertilization (IVF) still confront many workers. In this study, we evaluated the cumulative results of both therapeutic methods for this group of patients. From 1979 to 1990, 266 patients with distal tubal infertility were operated in our programme (group M: microsurgery, n = 211; group L: laparoscopy, n = 55). In group M, pathological findings were hydrosalpinges (n = 135) and incomplete distal tubal occlusion, (n = 76) and in group L hydrosalpinges (n = 31) and incomplete distal tubal occlusion (n = 24). After differing time intervals, IVF was proposed for these patients when no pregnancy occurred. The results were as follows: in group M, 35.5% intra-uterine pregnancy (IUP) and 6.6% ectopic pregnancy (EP) after fimbrioplasties versus 28.1% IUP and 11.9% EP after salpingostomy; in group L, 16.6% IUP and 4.2% EP after fimbrioplasty versus 12.9% IUP and 6.5% EP after salpingostomy. Following IVF, 55.7% of patients in group M and 14.5% in group L became pregnant. The cumulative results including both treatment techniques (surgery and IVF) show an average of 70% and 65% pregnancy rates in groups M and L respectively. The best results after surgery and throughout IVF were obtained during the first year. It is concluded that a short delay after surgery, averaging 6 months to 1 year, before involving patients in IVF, is very important.

[The use of LHRH analogs in ovulation induction]

The use of LH-RH agonists is appropriate for the stimulation of ovulation. In contrast, in the case of induction of ovulation in a patient with deficient ovulation, suppression of influences of the hypothalamo-pituitary axis does not modify the pathological condition responsible for the ovulatory anomaly.

Obstetrical results after embryonic reductions performed on 34 multiple pregnancies

Thirty-four women with multiple pregnancies (three or more fetuses) underwent embryonic reduction in order to reduce abortions, premature births or fetal growth-retardation by obtention of twins. Four early abortions occurred. Thirty pregnancies reached term and out of 60 fetuses, 58 infants were born alive. Fetal death in utero of one twin occurred in two pregnancies. The mean term until delivery was 36 +/- 2.8 weeks gestation and the prematurity rate was 51.7%. Of 55 neonates, 25 were underweight within the 10th percentile and 10 out of 55 neonates were underweight below the 3rd percentile. There were three deaths in the early neonatal period. The rate of perinatal mortality was 8.3%. Fifty-four children are currently healthy and one child has a mild axial hypotonia. A reduction in prematurity was observed with a gain of 2 weeks on reported data concerning triplet pregnancies. The rate of low-birth-weight infants was high, 63.5% being underweight at birth.