Twelve years of chiari-like malformation and syringomyelia scanning in Cavalier King Charles Spaniels in the Netherlands: Towards a more precise phenotype

Chiari-like malformation (CM), syringomyelia (SM) and middle ear effusion (also called PSOM) are three conditions that frequently occur in Cavalier King Charles Spaniels (CKCS). Both CM and SM are currently screened in the Netherlands prior to breeding and are graded according to the British Veterinary Association's Kennel Club (BVA/KC) scheme. This study evaluated the prevalence and estimated genetic parameter of CM, SM and middle ear effusion from 12 years of screening results. For SM, the classical method using the BVA/KC scheme, was compared with exact measuring of the central canal dilation. For CM, the BVA/KC scheme was compared with a more detailed scheme. Next to this the presence of microchip artifacts was assessed. 1249 screening of 1020 dogs were re-evaluated. Results indicated the presence of CM in all dogs, suggesting it has become a breed-specific characteristic. And although different grades of CM were observed, the condition did not deteriorate over time. SM was present in 39% of the dogs and a clear age effect was demonstrated, with SM increasing with age. This emphasizes the importance of screening at appropriate age, since SM can worsen with increasing age. One alternative is to promote repeated measures. The presence of middle ear effusion in this study was 19%-21% for dogs younger than 3 years, and 32%-38% for dogs older than 3 years. In as much as 60%, microchip artifacts were noticed, leading to the recommendation to place microchips in another location in breeds that are susceptible to developing SM. Finally, this study estimated the heritability of CM in this population, due to the lack of phenotypic variance, to be very low at 0.02-0.03. The heritability for SM central canal dilatation to be 0.30, compared to 0.13 for the classical BVA/KC method, using a model including the age effect and the combined effect of veterinary clinic and year of the evaluation. Genetic correlations were rather small, ranging from 0.16-0.33. As a conclusion, screening for SM and CM in the entire population should be maintained, and a selection scheme against SM should be based on estimated breeding values for the exact measurement of the central canal dilatation.status: publishe

Woodiness within the Spermacoceae–Knoxieae alliance (Rubiaceae): retention of the basal woody condition in Rubiaceae or recent innovation?

† Background and Aims The tribe Spermacoceae is essentially a herbaceous Rubiaceae lineage, except for some species that can be described as ‘woody’ herbs, small shrubs to treelets, or lianas. Its sister tribe Knoxieae contains a large number of herbaceous taxa, but the number of woody taxa is higher compared to Spermacoceae. The occurrence of herbaceous and woody species within the same group raises the question whether the woody taxa are derived from herbaceous taxa (i.e. secondary woodiness), or whether woodiness represents the ancestral state (i.e. primary woodiness). Microscopic observations of wood anatomy are combined with an independent molecular phylogeny to answer this question. † Methods Observations of wood anatomy of 21 woody Spermacoceae and eight woody Knoxieae species, most of them included in a multi-gene molecular phylogeny, are carried out using light microscopy. † Key Results Observations of wood anatomy in Spermacoceae support the molecular hypothesis that all the woody species examined are secondary derived. Well-known wood anatomical characters that demonstrate this shift from the herbaceous to the woody habit are the typically flat or decreasing length vs. age curves for vessel elements, the abundance of square and upright ray cells, or even the (near-) absence of rays. These socalled paedomorphic wood features are also present in the Knoxieae genera Otiophora, Otomeria, Pentas, Pentanisia and Phyllopentas. However, the wood structure of the other Knoxieae genera observed (Carphalea, Dirichletia and Triainolepis) is typical of primarily woody taxa. † Conclusions In Spermacoceae, secondary woodiness has evolved numerous times in strikingly different habitats. In Knoxieae, there is a general trend from primary woodiness towards herbaceousness and back to (secondary) woodiness

‘Unknown yellow’: Pibiria, a new genus of Passifloraceae with a mixture of features found in Passifloroideae and Turneroideae

In 1993, a shrub with yellow flowers reminiscent of but obviously distinct from Turnera was found near Mabura Hill in central Guyana, which was recollected in 2000. This paper offers a morphological description including leaf and wood anatomy and pollen morphology in addition to a phylogenetic analysis based on plastid DNA. Thanks to these studies, the mysterious species can now be assigned a position within the larger context of Passifloraceae. Our molecular results also show that the ‘unknown yellow’, as the plant became informally known, belongs to Passifloraceae, in which it is well supported as sister to Turneroideae. It is here described as the new genus and species, Pibiria flava, and because it lacks several floral characters typically (but not universally) found in this subfamily (heterostylous, fused sepals/petals, adnation of the stamens to the calyx, presence of a corolla and clawed petals), we also propose a new subfamily, Pibirioideae, to accommodate it

Average estimated breeding values according to the classical evaluation method (BVA/KC scheme) (EBV) and according to the newly developed method (CCD) (Mms) by birth year.

<p>Average estimated breeding values according to the classical evaluation method (BVA/KC scheme) (EBV) and according to the newly developed method (CCD) (Mms) by birth year.</p

Distribution of EBVs over the phenotypic scores.

<p>The different graphs represent the BVA/KC score 0, 1 or 2 respectively. Blue lines divide the distribution into quartiles. Only dogs with their own phenotypic score are represented.</p

Overview of the CM status of the different scans according to the BVA/KC scheme and the adapted scheme, and the division over the different age classes.

<p>Age class an equals dogs older than 5 years, b between 3 and 5 years and c younger than 3 years.</p

Variance components and heritabilities for the width of the syrinx (CDD) and SM according to the BVA/KC scheme.

<p>Comparison of a model with only an age effect and a model with both age and veterinary clinic*year effect (VCY). AIC = Akaike Information Criterion.</p

Overview of the SM status of the different scans according to the BVA/KC scheme, and the division over the different age classes.

<p>Age class a equals dogs older than 5 years, b between 3 and 5 years and c younger than 3 years.</p