Characterization of gap junction proteins in the bladder of Cx43 mutant mouse models of oculodentodigital dysplasia.

Oculodentodigital dysplasia (ODDD) is a rare developmental disease resulting from germline mutations in the GJA1 gene that encodes the gap junction protein connexin43 (Cx43). In addition to the classical ODDD symptoms that affect the eyes, teeth, bone and digits, in some cases ODDD patients have reported bladder impairments. Thus, we chose to characterize the bladder in mutant mouse models of ODDD that harbor two distinct Cx43 mutations, G60S and I130T. Histological assessment revealed no difference in bladder detrusor wall thickness in mutant compared to littermate control mice. The overall localization of Cx43 in the lamina propria and detrusor also appeared to be similar in the bladders of mutant mice with the exception that the G60S mice had more instances of intracellular Cx43. However, both mutant mouse lines exhibited a significant reduction in the phosphorylated P1 and P2 isoforms of Cx43, while only the I130T mice exhibited a reduction in total Cx43 levels. Interestingly, Cx26 levels and distribution were not altered in mutant mice as it was localized to intracellular compartments and restricted to the basal cell layers of the urothelium. Our studies suggest that these two distinct genetically modified mouse models of ODDD probably mimic patients who lack bladder defects or other factors, such as aging or co-morbidities, are necessary to reveal a bladder phenotype.

Decreased levels of Cx43 gap junctions result in ameloblast dysregulation and enamel hypoplasia in Gja1Jrt/+ mice.

Coordinated differentiation of the ameloblast cell layer is essential to enamel matrix protein deposition and subsequent mineralization. It has been hypothesized that this process is governed by Cx43-based gap junctional intercellular communication as oculodentodigital dysplasia (ODDD) patients harboring autosomal-dominant mutations in Cx43 exhibit enamel defects typically resulting in early adulthood tooth loss. To assess the role of Cx43 in tooth development we employ a mouse model of ODDD that harbors a G60S Cx43 mutant, Gja1(Jrt)/+, and appears to exhibit tooth abnormalities that mimic the human disease. We found that total Cx43 plaques at all stages of ameloblast differentiation, as well as within the supporting cell layers, were greatly reduced in Gja1(Jrt)/+ incisors compared to wild-type littermate controls. To characterize the Gja1(Jrt)/+ mouse tooth phenotype, mice were sacrificed prior to tooth eruption (postnatal day 7), weaning (postnatal day 21), and adulthood (2 months postnatal). A severely disorganized Gja1(Jrt)/+ mouse ameloblast layer and abnormal accumulation of amelogenin were observed at stages when the cells were active in secretion and mineralization. Differences in enamel thickness became more apparent after tooth eruption and incisor exposure to the oral cavity suggesting that enamel integrity is compromised, leading to rapid erosion. Additional analysis of incisors from mutant mice revealed that they were longer with a thicker dentin layer than their wild-type littermates, which may reflect a mechanical stress response to the depleted enamel layer. Together, these data show that reduced levels of Cx43 gap junctions result in ameloblast dysregulation, enamel hypoplasia, and secondary tissue responses.

Evaluation of antimicrobial activity in Paenibacillus spp. strains isolated from natural environment.

AIMS: Paenibacillus isolates were selected to test antimicrobial activity against bacteria, filamentous fungi and yeasts isolates, with the purpose of finding new bacterium species for microbiological control. METHODS AND RESULTS: Fifty-five strains belonging to 15 species of Paenibacillus were inoculated on trypticase soya agar, potato dextrose agar and sabouraud agar plates in order to evaluate their antimicrobial activity against 16 indicator bacteria, 14 filamentous fungi and six yeasts isolates, both reference and field strains. After these screening, culture supernatant of 17 isolates was prepared. Twenty-five Paenibacillus isolates presented antimicrobial activity, where seven species (Paenibacillus chibensis; P. koreensis; P. illinoiensis; P. validu; P. pabuli; P. brasilensis and P. peoriae) stood out inhibiting at least 13 of the 16 indicator bacteria. Only 14 of the 55 isolates exhibited antifungal activity. P. peoriae inhibited 13 among the 14 filamentous fungi and all yeasts indicator strains. Fourteen isolates produced culture supernatant with antimicrobial activity. CONCLUSIONS: Among the 55 isolates analysed, 25 exhibited a broad inhibition spectrum against bacteria and pathogenic fungi. P. validus, P. chibensis, P. koreensis and P. peoriae isolates proved to be the subject matter for studies on the production of antimicrobial agents. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study revealed other two species with antimicrobial activity: P. validus and P. chibensis, and it contributed to enhance Paenibacillus biocontrolling potential, proving that it exhibit a broad action spectrum.

Survival of ovine embryos stored at 4 degrees C for 24 hours.

This study was conducted to ascertain if sheep embryos collected for transfer can be stored for short periods without freezing to allow for international transport. Of twelve Finnish Landrace ewes treated with equine follicle stimulating hormone (FSH), eleven ewes ovulated with a mean of 9.1 +/- 4.3 (SD) corpora lutea. Recovery rate from the nine ewes with normal corpora lutea was 68 +/- 27%, providing 61 morulae which were then cooled to 4 C and stored for 24 h while transporting them from Scotland to France. Romanov recipients received either 4 (n = 14) or 5 (n = 1) of these morulae. Fourteen of the recipients lambed, with a mean lambing rate of 2.1 +/- 0.8, representing 48.3% of embryos transferred. Cooling of embryos to 4 C and storing them in ovum culture medium for 24 h at 4 C may be a valuable technique for the handling and short-term storage of embryos.