Implementation of two high through-put techniques in a novel application: detecting point mutations in large EMS mutated plant populations

Background  

The establishment of mutant populations together with the strategies for targeted mutation detection has been applied successfully to a large number of organisms including many species in the plant kingdom. Considerable efforts have been invested into research on tomato as a model for berry-fruit plants. With the progress of the tomato sequencing project, reverse genetics becomes an obvious and achievable goal.     

Mitochondrial Activity, Distribution and Segregation in Bovine Oocytes and in Embryos Produced in Vitro

Contents Bovine oocytes and embryos produced in vitro were studied to determine the mitochondrial pattern of distribution, segregation and activity using DIOC 6 and Jc-1 fluorescence. The highest fluorescence level observed in mature oocytes was taken as 100% activity and six activity levels were estimated as follows: (1) 0%, (2) 1-15%, (3) 16-30%, (4) 31-50%, (5) 51-75% and (6) 76-100%. Three patterns of mitochondrial distribution were found: (1) diffused throughout the cytoplasm in oocytes and embryos, (2) pericytoplasmic in oocytes and embryos, and (3) perinuclear only in embryos. The segregation of mitochondria in blastomeres showed two distinct patterns: (1) symmetrical with an even mitochondrial population, and (2) asymmetrical with different numbers of mitochondria in each blastomere. In immature oocytes, mitochondrial activity was very low and the distribution was diffuse or negligible, while in mature oocytes the activity was high and the distribution was diffuse or pericytoplasmic. Competent embryos up to the 16-cell stage showed intermediate levels of activity (16-50%) but activity decreased thereafter up to the blastocyst stage. Non-competent embryos showed low levels of activity (1-15%) at all stages. These results suggest that mitochondria might play an important role during early development and that a minimum threshold of activity regulates the potential competence for reaching the blastocyst stage.     

Surgical treatment of uterine torsion using a ventral midline laparotomy in 19 mares

OBJECTIVE: To report on the outcome of surgical treatment of uterine torsion in preterm mares. DESIGN: Retrospective case series of pregnant mares with uterine torsion presented to the Clinic for Obstetrics, Gynaecology and Andrology of Large and Small Animals. METHODS: Hospital records of all pregnant mares that underwent ventral midline laparotomy for uterine torsion between 1998 and 2004 were reviewed. The signalment, history, clinical signs, results of diagnostic procedures, direction and degree of the uterine twist, treatment and outcome were retrieved from each case record. RESULTS: This study comprised 19 mares between months 5 and 11 of pregnancy (8.7 +/- 1.9) and suffering from uterine torsion. In all cases ventromedian laparotomy was carried out under general anaesthesia. Gastrointestinal disorders were also present in 52.6% of horses. Postoperative complications included subcutaneous seromas (five mares), peritonitis (one mare) and abortion (two mares). In four mares (21%) the operation was unsuccessful (i.e. these mares had to be euthanased intra- or postoperatively). Of the surviving 15 mares, 13 (86.6%) gave birth to viable foals at full term. The foals developed normally. Only two mares aborted. CONCLUSIONS: Because of its versatility the ventral midline approach should be considered for correction of uterine torsion. The approach has many advantages, including rapid and clear access to the abdominal cavity, safety, visual assessment of uterine wall viability, correction of concomitant gastrointestinal tract problems, and performance of hysterotomy or hysterectomy, if indicated. In this study, managing uterine torsion in this way resulted in a high percentage of cases (86.6%) in which pregnancy was maintained, with the birth of a viable, mature foal.