Cilia and cilia-related disorders

Abstract

Extract

Among the puzzling aspects of the recently described autosomal recessive polycystic kidney disease (ARPKD) of sheep (Johnstone et al 2005 Johnstone, AC, Davidson, BI, Roe, AR, Eccles, MR and Jolly, RD. 2005. Congenital polycystic kidney disease in lambs. New Zealand Veterinary Journal, 53: 307–314. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) is the multiplicity of organ systems affected and the phenotypic variations that occur between the various animal species. It has been shown in studies of other inherited polycystic kidney disease syndromes that the normal gene products of a mutant are likely to be involved in ciliary structure and function. The studies that have led to this recognition can be expected to eventually provide the basis for a better understanding of the functioning of this organelle, and the pathogenesis of lesions in the related diseases.

It is well known that cilia are important in the perception of light, olfactory stimuli and sound and that motile cilia provide cell motility (e.g. sperm) and transport of mucus and other fluids. Recent research has indicated that the involvement of the primary cili-um/basal body complex is of central importance in the detection and cellular response to extracellular movement of fluid, critical phases of embryonic development, cell cycle regulation and maintenance of cell polarity.

Confocal microscopic studies of renal cyst epithelium in ovine ARPKD have shown that only 30% of cells have a cilium and that these are often truncated (McGlashan et al 2005 McGlashan, SR, Poole, CA, Stayner, C, Johnstone, AC, Eccles, MR and Jensen, CG. 2005. “Primary cilia in fibrosis associated with two models of polycystic kidney disease”. In Proceedings of the 45th Annual Conference of the American Society for Cell Biology December 10–14 [Google Scholar]). The observation, although preliminary, strongly supports the argument that the mutant gene in this disease of sheep normally encodes for a protein essential for primary ciliary function.     

Effects of Gonadotropins on In Vitro Maturation and of Electrical Stimulation on Parthenogenesis of Canine Oocytes

The objective of this study was to determine the effects of gonadotropins on in vitro maturation (IVM) and electrical stimulation on the parthenogenesis of canine oocytes. In experiment I, cumulus oocyte complexes were collected from ovaries at a random phase of the oestrus cycle and cultured on maturation medium treated with hCG or eCG for 48 or 72 h. There were no significant differences in the effects on the metaphase II (MII) rate between the hCG and eCG treatment groups over 48 h (5.4% vs 5.5%). The MII rate in the co-treatment group of hCG and eCG for 48 h was higher than in each hormone treated group (15.5%, p < 0.05). In experiment 2, the parthenogenetic effect on oocyte development, at various electrical field strengths (1.0, 1.5, 2.0 kV/cm DC) for 60 or 80 μs with a single DC pulse after IVM on the co-treatment of hCG and eCG, was examined. The rate of pronuclear formation (37.1%) in electrical activation at 1.5 kV/60 μs without cytochalasin B (CB) was higher than that of oocytes activated in the other groups (p < 0.05). However, we did not observe the cleavage stages. Also, CB did not influence parthenogenesis of canine oocytes. The results showed that the pronucleus formation rate, indicative of the parthenogenesis start point, could be increased by electrical stimulation. Therefore, these results can provide important data for the parthenogenesis of canine oocytes and suggest the probability of parthenogenesis in canines.     

Vaccination and challenge studies with psittacine beak and feather disease virus

SUMMARY: Psittacine beak and feather disease virus (PBFDV) was administered to adult galahs ( Eolophusroselcapillus ) by mouth or by intramuscular injection. Concentration of PBFDV antibodies in serum and excretion of PBFDV were monitored by haemagglutlnation inhibition (HI) and haemagglutination (HA) respectively. After oral administration, 17 of 18 galahs remained clinically normal and a small rise in antibody titre was detected in 3 of 18 birds. After intramuscular administration, antibody was detected in all birds. PBFDV was not detected in the feather dander of birds in either group. One bird developed diarrhoea and high faecal HA titres within 4 days of oral administration and then died. Adult and nestling cockatoos were vaccinated with an experimental inactivated double-oil emulsion vaccine. PBFDV antibody responses are comparable to those induced by a primary-oil emulsion vaccination regimen using Freund's adjuvants. Both vaccines protected nestlings. Three sibling wild-caught sulphur-crested cockatoos were vaccinated but died of PBFD before experimental challenge despite antibody responses in all birds. Unvaccinated control chicks developed acute PBFD within 4 weeks of challenge, probably from PBFDV-induced hepatitis since high concentrations of PBFDV were detected in their livers.     

Laboratory diagnosis of psittacine beak and feather disease by haemagglutination and haemagglutination inhibition

SUMMARY Simple and sensitive haemagglutination and haemagglutination Inhibition assays were developed for psittacine beak and feather disease (PBFD) virus and serum antibody, respectively. The assays were used in the examination of samples from 73 birds clinically affected with PBFD. High antigen titres (log₂ 9 to log₂ 12) were detected In feathers, faeces and cloacal contents of PBFD-affected birds. Antigen was not detected In either faecal or feather samples from 20 normal galahs (Eolophus roselcapillus) and 9 normal sulphur crested cockatoos (Cacatua galerita). After kaolin treatment and haemadsorption of serum, haemagglutination inhibition (HI) antibody titres could not be detected in serum from 42 PBFD-affected birds, whereas serum HI titres from 64 normal psittacine birds ranged from less than log₂ 1 to log₂ 8. Serum and yolk HI antibody responses of 6 PBFD virus-inoculated layer hens were measured. Pre-inoculation chicken sera contained high concentrations of non-specific haemagglutination inhibitors (not detected in chloroform-extracted yolk), which were removed by kaolin treatment and haemadsorption.     

Comparison of the efficacy of macrocyclic lactone anthelmintics,either singly or in combination with other anthelmintic(s), in nine beef herds in southern NSW

Anthelmintic resistance (AR) is a well-recognized challenge in farmed ruminants. The use of anthelmintics in combination is one of the strategies recommended to slow the rate of AR development. Two studies were undertaken in 2017 and 2019 to assess the efficacy of single-dose macrocyclic lactone (ML) anthelmintic and ML combination drenches. In total, 11 Faecal Egg Count Reduction Trials (FECRTs) were set up in 10 different beef herds, with results available from 10 of those FECRTs (9 herds). AR to a single ML anthelmintic was detected in all 9 herds, with resistance to Cooperia and Haemonchus spp on 9 farms, and resistance to Ostertagia and Trichostrongylus spp on 2 farms. In contrast, for the ML combination anthelmintics, all FECRTs resulted in efficacies of 99%–100%. The results suggest that cattle producers should strongly consider using combination drenches in their herds in preference to single actives.     

Trichomonas gallinae in budgerigars and columbid birds in Perth, Western Australia

Objective To estimate the prevalence of infection with Trichomonas gallinae and other parasites of the alimentary tract in psittacine and columbid birds in Perth and to determine in vitro the effectiveness of drugs commonly recommended for treating trichomoniasis.
Design and procedures Samples of crop contents were collected from aviary flocks of budgerigars (Melopsittacus undulatus) and other psittacine and columbid birds in both private and commercial collections in Perth. Similar samples from wild Senegal doves (Streptopelia senegalensis) also were collected. Crop contents were examined and cultured for Trichomonas gallinae and in vitro studies were conducted on the susceptibility of isolates to several drugs used commonly. Other parasites also were detected by faecal examination and/or necropsy.
Results T gallinae was recovered from birds in 1 of 13 private collections of budgerigars (2/289 birds in total). Direct wetmount examination of crop fluid identified 36.4% of samples at four commercial bird dealers which were later determined by culture to contain T gallinae . The prevalence of T gallinae infection ranged from 0 to 11.4% in budgerigars. The prevalence of T gallinae infection in wild Senegal doves was 46% and from one flock of racing pigeons was 59%. The in vitro minimum lethal concentrations of metronidazole, dimetridazole and ronidazole ranged from 40 to 96, 30 to 80 and 40 to 92 μg/mL respectively for six isolates of T gallinae . Other alimentary parasites detected during the survey included Spironucleus sp (syn Hexamita sp), coccidia, Ascaridia platycerci and Raillietina sp.
Conclusions Thirteen budgerigar flocks belonging to members of avicultural societies in Perth had a low prevalence of trichomoniasis and other parasitic infections. The dose rate currently recommended for ronidazole may not result in complete protozoacidal activity against T gallinae infection.