Inheritance of Hypodontia in Kerry Blue Terrier Dogs

Complex segregation analysis, which earlier proved efficient in studying complex hereditary diseases in humans and have been introduced in animal genetics for several years, was used to analyze the inheritance of hypodontia by premolars in Kerry Blue Terrier dogs. Dental formulas have been determined in 598 out of 911 animals united into a single large, extended pedigree. The results of integrated segregation analysis indicated heterogeneous genetic control of different forms of hypodontia. The absence of different premolars in dogs has been demonstrated to be described by different models of inheritance: the absence of the second premolars can be described by the recessive major-gene model, whereas the agenesis of the fourth premolars have a more complex genetic mechanism and cannot be described by the model of a simple major-gene control.     

Inheritance of hypodontia in Kerry Blue Terrier dogs

Integral segregation analysis, which earlier proved efficient in studying complex hereditary diseases in humans and have been introduced in animal genetics for several years, was used to analyze the inheritance of hypodontia by premolars in Kerry Blue Terrier dogs. Dental formulas have been determined in 598 out of 911 animals united into a single large, complex pedigree. The results of integrated segregation analysis indicated heterogeneous genetic control of different forms of hypodontia. The geneses of different premolars in dogs have been demonstrated to be described by different models of inheritance: the absence of the second premolars can be described by the recessive major-gene model, whereas the agenesis of the fourth premolars have a more complex genetic mechanism and cannot be described by the model of a simple major-gene control.     

Changes in litter size in Kerry Blue Terrier dogs with abnormal dentition

The pleiotropic effects of mutations resulting in abnormal dentition were analyzed in Kerry Blue Terrier. A decrease in litter size was demonstrated for dogs with dentition anomalies. The mean litter size was 5.72 puppies when both parents had normal dentition and 3.64 puppies when the parents had hypodontia. Analysis showed that the decrease in litter size cannot be fully explained by the effect of inbreeding and is most probably associated with the pleiotropic effect of the genes controlling teeth development on the embryonic viability.     

Oligodontia and its inheritance in Kerry blue terrier

Defects of the premolar tooth formula (oligodontia, tooth number reduction) were studied in dogs of the Kerry blue terrier breed. For this purpose, a database including 480 individuals of 96 litters was constructed. The occurrence of oligodontia was investigated in pedigree groups with inbred and outbred crosses. No selective mating choice for the anomaly under study was found in the sample. The results indicate that oligodontia is inherited, which requires comprehensive study of its genetic control and search for corresponding genes.     

Polymorphism of dental formula and segregation of its variants in a pedigree of Kerry Blue Terrier dogs

Polymorphism of the dental formula was analyzed in a complex pedigree of Kerry Blue Terrier. A lack of one or more lower premolars was observed in some dogs. Two different patterns of missing teeth were identified. One pattern consisted in agenesis of a second premolar, often in combination with agenesis of neighbor teeth, including the fourth premolar. In the second pattern, agenesis of a fourth premolar was expressed as an isolated abnormality. It was shown previously that the first pattern is inherited as a recessive trait with near complete penetrance. In this work, the major-gene control was demonstrated for the second pattern. This abnormality develops in 70–80% of mutant homozygotes and in no more than 20% of heterozygotes and wild-type homozygotes. It was shown that the two dentition abnormalities are controlled by different genes, which were designated LPA2 and LPA4 (Lower Premolar Agenesis).     

Loss-of-Function Mutations in the WNT Co-receptor LRP6 Cause Autosomal-Dominant Oligodontia

Tooth agenesis is one of the most common developmental anomalies in man. Oligodontia, a severe form of tooth agenesis, occurs both as an isolated anomaly and as a syndromal feature. We performed exome sequencing on 20 unrelated individuals with apparent non-syndromic oligodontia and failed to detect mutations in genes previously associated with oligodontia. In three of the probands, we detected heterozygous variants in LRP6, and sequencing of additional oligodontia-affected individuals yielded one additional mutation in LRP6. Three mutations (c.1144_1145dupAG [p.Ala383Glyfs^∗8], c.1779dupT [p.Glu594^∗], and c.2224_2225dupTT [p.Leu742Phefs^∗7]) are predicted to truncate the protein, whereas the fourth (c.56C>T [p.Ala19Val]) is a missense variant of a conserved residue located at the cleavage site of the protein’s signal peptide. All four affected individuals harboring a LRP6 mutation had a family history of tooth agenesis. LRP6 encodes a transmembrane cell-surface protein that functions as a co-receptor with members from the Frizzled protein family in the canonical Wnt/β-catenin signaling cascade. In this same pathway, WNT10A was recently identified as a major contributor in the etiology of non-syndromic oligodontia. We show that the LRP6 missense variant (c.56C>T) results in altered glycosylation and improper subcellular localization of the protein, resulting in abrogated activation of the Wnt pathway. Our results identify LRP6 variants as contributing to the etiology of non-syndromic autosomal-dominant oligodontia and suggest that this gene is a candidate for screening in DNA diagnostics.     

Seasonal changes in circadian grazing patterns of Kerry cows (Bos Taurus) in semi-feral conditions in Killarney National Park, Co. Kerry, Ireland

Domestic cattle generally graze during the day although some night-time grazing also occurs. However, questions remain as to the effect of management on circadian grazing patterns. This study provides for the first time a quantification of seasonal, circadian and animal variation in grazing behaviour and grazing time in cattle in semi-wild conditions.The objectives of the study were to examine how daily grazing times and the temporal distribution of grazing activity changed with season and to examine the extent to which grazing patterns were influenced by day-length. A group of 12 heifers of the Kerry breed continuously grazed a lowland field of 4.7ha. The old permanent pasture sward was dominated by Holcus spp. and Agrostis spp. Feed availability was never limiting. Length and periodicity of grazing were recorded using vibracorders attached to the necks of seven animals.Results showed that daily grazing times remained constant over most of the grazing season (circa 10-11h per day), however, some variation occurred late in the season. The temporal distribution of grazing activity changed as the season advanced so that by October grazing patterns became significantly different to those of July. The time interval between grazing bouts at dawn and dusk decreased with decreasing day-length. An increased percentage of night-time grazing occurred at shorter day-lengths.It is concluded that there is a significant seasonal effect of day-length on temporal distribution of grazing activity with night-time grazing featuring more as day-length decreases. The maintenance of similar total daily grazing times in the face of changing day-length (with the exception of late in the season) suggests that daily grazing times are a function of the attainment of a relatively constant nutritional requirement by the animal.     

Genotyping of Enterocytozoon bieneusi in Farmed Blue Foxes (Alopex lagopus) and Raccoon Dogs (Nyctereutes procyonoides) in China

Enterocytozoon bieneusi is the most common species of microsporidia found both in humans and animals. Farmed animals, particularly closely associated to humans, may play an important role of zoonotic reservoir in transmitting this disease to humans. The fur industry is a major economic component in some parts of China. To understand the prevalence, genotype variety and zoonotic risk of E. bieneusi in farmed foxes and raccoon dogs, two species of fur animals, fecal specimens of 110 blue foxes and 49 raccoon dogs from Heilongjiang and Jilin provinces in China were examined by internal transcribed spacer (ITS)-based PCR. E. bieneusi was detected in 16.4% (18/110) blue foxes and 4.1% (2/49) raccoon dogs. Altogether, four genotypes of E. bieneusi were identified, including two known genotypes D (n = 13) and EbpC (n = 5), and two novel genotypes named as CHN-F1 (n = 1) in a fox and CHN-R1 (n = 1) in a raccoon dog. Phylogenetic analysis revealed that all the four genotypes were the members of zoonotic group 1. Genotypes D and EbpC were found in humans previously. The findings of zoonotic genotypes of E. bieneusi in the foxes and raccoon dogs suggest these animals infected with E. bieneusi may pose a threat to human health.     

The Effects of Natural Hybridization on the Regulation of Doubly Uniparental Mtdna Inheritance in Blue Mussels (Mytilus Spp.)

Blue mussels in the Mytilus edulis species complex have a doubly uniparental mode of mtDNA inheritance with separate maternal and paternal mtDNA lineages. Female mussels inherit their mtDNA solely from their mother, while males inherit mtDNA from both parents. In the male gonad the paternal mtDNA is preferentially replicated so that only paternal mtDNA is transmitted from fathers to sons. Hybridization is common among differentiated blue mussel taxa; whenever it involves M. trossulus, doubly uniparental mtDNA inheritance is disrupted. We have found high frequencies of males without and females with paternal mtDNA among hybrid mussels produced by interspecific matings between M. galloprovincialis and M. trossulus. In contrast, hybridization between M. galloprovincialis and M. edulis does not affect doubly uniparental inheritance, indicating a difference in the divergence of the mechanisms regulating mtDNA inheritance among the three blue mussel taxa. Our data indicate a high frequency of disrupted mtDNA transmission in F(1) hybrids and suggest that two separate mechanisms, one regulating the transmission of paternal mtDNA to males and another inhibiting the establishment of paternal mtDNA in females, act to regulate doubly uniparental inheritance. We propose a model for the regulation of doubly uniparental inheritance that is consistent with these observations.     

Changes in litter size in Kerry blue terrier dogs with abnormal dentition

The pleiotropic effects of mutations resulting in abnormal dentition were analyzed in Kerry Blue Terrier. A decrease in litter size was demonstrated for dogs with dentition anomalies. The mean litter size was 5.72 puppies when both parents had normal dentition and 3.64 puppies when the parents had hypodontia. Analysis showed that the decrease in litter size cannot be fully explained by the effect of inbreeding and is most probably associated with the pleiotropic effect of the genes controlling teeth development on the embryonic viability.     

Jealousy in Dogs

It is commonly assumed that jealousy is unique to humans, partially because of the complex cognitions often involved in this emotion. However, from a functional perspective, one might expect that an emotion that evolved to protect social bonds from interlopers might exist in other social species, particularly one as cognitively sophisticated as the dog. The current experiment adapted a paradigm from human infant studies to examine jealousy in domestic dogs. We found that dogs exhibited significantly more jealous behaviors (e.g., snapping, getting between the owner and object, pushing/touching the object/owner) when their owners displayed affectionate behaviors towards what appeared to be another dog as compared to nonsocial objects. These results lend support to the hypothesis that jealousy has some “primordial” form that exists in human infants and in at least one other social species besides humans.     

Glomerulopathy and mutations in NPHS1 and KIRREL2 in soft-coated Wheaten Terrier dogs

Dogs of the soft-coated wheaten terrier breed (SCWT) are predisposed to adult-onset, genetically complex, protein-losing nephropathy (average onset age = 6.3 ± 2.0 years). A genome-wide association study using 62 dogs revealed a chromosomal region containing three statistically significant SNPs (p _raw ≤ 4.13 × 10^?8; p _genome ≤ 0.005) when comparing DNA samples from affected and geriatric (≥14 years) unaffected SCWTs. Sequencing of candidate genes in the region revealed single nucleotide changes in each of two closely linked genes, NPHS1 and KIRREL2, which encode the slit diaphragm proteins nephrin and Neph3/filtrin, respectively. In humans, mutations in nephrin and decreased expression of Neph3 are associated with podocytopathy and protein-losing nephropathy. The base substitutions change a glycine to arginine in the fibronectin type 3 domain of nephrin and a proline to arginine in a conserved proline-rich region in Neph3. These novel mutations are not described in other species, nor were they found in 550 dogs of 105 other breeds, except in 3 dogs, including an affected Airedale terrier, homozygous for both substitutions. Risk for nephropathy is highest in dogs homozygous for the mutations (OR = 9.06; 95 % CI = 4.24–19.35). This is the first molecular characterization of an inherited podocytopathy in dogs and may serve as a model for continued studies of complex genetic and environmental interactions in glomerular disease.     

Human Perception of Fear in Dogs Varies According to Experience with Dogs

To investigate the role of experience in humans’ perception of emotion using canine visual signals, we asked adults with various levels of dog experience to interpret the emotions of dogs displayed in videos. The video stimuli had been pre-categorized by an expert panel of dog behavior professionals as showing examples of happy or fearful dog behavior. In a sample of 2,163 participants, the level of dog experience strongly predicted identification of fearful, but not of happy, emotional examples. The probability of selecting the “fearful” category to describe fearful examples increased with experience and ranged from.30 among those who had never lived with a dog to greater than.70 among dog professionals. In contrast, the probability of selecting the “happy” category to describe happy emotional examples varied little by experience, ranging from.90 to.93. In addition, the number of physical features of the dog that participants reported using for emotional interpretations increased with experience, and in particular, more-experienced respondents were more likely to attend to the ears. Lastly, more-experienced respondents provided lower difficulty and higher accuracy self-ratings than less-experienced respondents when interpreting both happy and fearful emotional examples. The human perception of emotion in other humans has previously been shown to be sensitive to individual differences in social experience, and the results of the current study extend the notion of experience-dependent processes from the intraspecific to the interspecific domain.