Identification and characterisation of side population cells in the canine pituitary gland

To date, stem/progenitor cells have not been identified in the canine pituitary gland. Cells that efficiently exclude the vital dye Hoechst 33342 can be visualised and identified using fluorescence activated cell sorting (FACS) as a 'side population' (SP), distinct from the main population (MP). Such SPs have been identified in several tissues and display stem/progenitor cell characteristics. In this study, a small SP (1.3%, n=6) was detected in the anterior pituitary glands of healthy dogs. Quantitative PCR indicated significantly higher expression of CD34 and Thy1 in this SP, but no differences in the expression of CD133, Bmi-1, Axin2 or Shh. Pro-opiomelanocortin (POMC) and Lhx3 expression were significantly higher in the MP than in the SP, but no differences in the expression of Tpit, GH or PRL were found. The study demonstrated the existence of an SP of cells in the normal canine pituitary gland, encompassing cells with stem cell characteristics and without POMC expression

Prevalence and co-occurrence of hip dysplasia and elbow dysplasia in Dutch pure-bred dogs

tHip as well as elbow dysplasia (HD, ED) are developmental disorders leading to malforma-tion of their respective joints. For a long time both disorders have been scored and targetedfor improvement using selective breeding in several Dutch dog populations. In this paperall scores for both HD and ED, given to pure bred dogs in the Netherlands from 2002 to2010, were analyzed. Heritabilities and correlations between HD and ED were calculatedfor the 4 most frequently scored breeds. Heritabilities ranged from 0.0 to 0.37 for HD relatedtraits (FCI-score, osteoarthritis, congruity, shape and laxity (Norberg angle); FCI: Fédéra-tion Cynologique Internationale) and from 0.0 to 0.39 for ED related traits (IEWG score,osteoarthritis, sclerosis and indentation; IEWG: International Elbow Working Group). HDrelated traits showed high genetic and residual correlations among each other but were onlyto a minor extent correlated with ED related traits, which also showed high correlationsamong each other. Genetic correlations were higher than residual correlations. Phenotypicand genetic trends since 2001 for the four most scored breeds were slightly positive butdecreasing over time, indicating that selection over the past decade has not been effective