Phenotyping of Aggressive Behavior in Golden Retriever Dogs with a Questionnaire

Reliable and valid phenotyping is crucial for our study of genetic factors underlying aggression in Golden Retriever dogs. A mail questionnaire based on the Canine Behavioral Assessment and Research Questionnaire (CBARQ; Hsu and Serpell, 2003, JAVMA 223(9):1293–1300) was used to assess behavioral phenotypes. Owners of 228 Golden Retrievers completed the questionnaire. These dogs had been referred to our clinic for aggression problems several years earlier or they were related to aggressive dogs. In this paper, three sets of results are presented, which indicate that behavior scores from the CBARQ can be applied to genetic studies. First, factor analysis demonstrated that CBARQ items can be grouped into 10 behavioral traits, including three types of aggression: stranger-directed aggression, owner-directed aggression, and dog-directed aggression. The results were remarkably similar to those reported by Hsu and Serpell. The aggression scores showed considerable variation in our dog families, which is a prerequisite for genetic studies. Second, retrospective questions enabled us to study changes in the aggressive behavior of the dogs in the course of time. After an average time interval of 4.3 years, over 50% of the dogs had become less aggressive. Third, we analyzed data obtained with an aggression test of 83 dogs. Two out of the three CBARQ aggression factors were also found in the aggression test data.Electronic supplementary material to this article is available at and is accessible for authorized users.     

Allelic diversity at the DLA-88 locus in Golden Retriever and Boxer breeds is limited

In the dog, previous analyses of major histocompatibility complex class I genes suggest a single polymorphic locus, dog leukocyte antigen (DLA)-88. While 51 alleles have been reported, estimates of prevalence have not been made. We hypothesized that, within a breed, DLA-88 diversity would be restricted, and one or more dominant alleles could be identified. Accordingly, we determined allele usage in 47 Golden Retrievers and 39 Boxers. In each population, 10 alleles were found; 4 were shared. Seven novel alleles were identified. DLA-88*05101 and *50801 predominated in Golden Retrievers, while most Boxers carried *03401. In these breeds, DLA-88 polymorphisms are limited and largely non-overlapping. The finding of highly prevalent alleles fulfills an important prerequisite for studying canine CD8+ T-cell responses.     

Dynamic histomorphometry of alveolar bone remodeling in the adult rat

Alveolar bone normally undergoes remodeling on one side of the socket and modeling on the opposite side as the tooth migrates at a rate of 6.7 μm per day. Periodontal ligament width, however, remains constant. Because of this very high turnover rate, this bone is a good model to study bone modeling and remodeling activities. This study was undertaken in order to measure the different cellular events occurring during tooth migration along the alveolar bone of the rat. The histomorphometric measurements performed on this model permitted us to calculate the duration of each phase of the remodeling cycle, i.e., resorption lasts about 1.5 days and reversal about 3.5 days. Since the duration of the forming phase is about 1 day (Guyomard and Baron, ′74), the total duration of each remodeling cycle is about 6 days. This time is very short compared to 60–120 days in adult human trabecular bone. Additionally, in this model each osteoclast resorbs 2–4 times its own volume of bone per day. Based on this knowledge, it will be possible to measure accurately the effects of experimental conditions on bone cells and bone remodeling in this rat alveolar bone model.     

Differences in intermediary energy metabolism between juvenile and adult Fasciola hepatica

A comparison of glucose catabolism by juvenile and adult liver flukes, Fasciola hepatica, showed that in the adult the cytosolic degradation of glucose via phosphoenolpyruvate carboxykinase (PEPCK) was the most important route, whereas in the freshly excysted juvenile a large part was degraded via pyruvate kinase (PK). However, it was also shown that the adult did not exclusively use the PEPCK pathway, nor did the juvenile exclusively use the PK pathway. When the juvenile was forced to anaerobic functioning it produced propionate and acetate just like the adult, but this did not imply that it switched to the pathways of the adult: the pathway via PK remained important. Malic enzyme (NADP(H)-dependent) was demonstrated to be present in the cytosol and in the mitochondria of both juveniles and adults. These enzyme activities enable the parasite to use a mixture of malate and pyruvate in any ratio as substrate for the mitochondrial production of propionate and acetate. Pyruvate dismutation was important in the anaerobically functioning juvenile, whereas in the adult malate was the major, but not the only mitochondrial substrate. The pH profiles of PK and PEPCK showed that the pathway of PEP metabolism at the PK/PEPCK branchpoint can be regulated by the pH. However, the end products of glucose breakdown were not dependent on the pH. During its development, the liver fluke will gradually be forced to anaerobic functioning. At first, the acidic end product will favour a partitioning of PEP at the PK/PEPCK branchpoint towards malate formation. Later, a lasting predominance of the PEPCK pathway occurs as PK activity almost completely disappears.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endocrine profile and testicular histomorphometry in adult rat offspring of diabetic mothers

This investigation was conducted to evaluate the effect of maternal diabetes on fetal testicular structure and function, and reproductive hormones levels. Sixteen female rats were divided into two groups. Diabetes was induced in one group by alloxan. Blood was collected from 90-day-old male offspring of both groups, and the level of blood glucose, testosterone, FSH and LH in their serum was measured. Weight, volume and various histological parameters of testes were determined. A significant increase in blood glucose and decrease in LH, FSH and testosterone in sera of offspring of diabetic mothers (ODM) were observed. The weight and volume of testes in the ODM were 22.7 and 22.9% higher, respectively, than those of the control group (P < 0.05), while the ratio of testes to body weight did not change significantly. The number of seminiferous tubules increased (+21%) significantly (P < 0.05), while thickness of the testicular capsule (−25%), number of Leydig cells (−15.6%), number of Sertoli cells (−14.9%), number of spermatogonia (−26.3%) and diameter of seminiferous tubules (−11%) showed significantly reduced values in the ODM compare to the control. In conclusion, maternal hyperglycemia has a deleterious effect on testicular parameters during fetal life, which will affect reproductive endocrine during postpuberty.     

Differences between ethnic groups in sex dimorphism of adult height

An analysis has been made of sex dimorphism in adult height using data from 58 Negroid, 76 European, and 67 Amerindian populations. Regression analyses were carried out on the sex difference and sex average of male and female stature means. The greatest sex dimorphism was found in Amerindians and the least in Negroid populations. Data from 36 Asiatic and 27 New Guinea populations have also been considered. It seems that sex dimorphism in adult height has a strong genetic component, making it inappropriate as a measure by which to judge the health and nutritional status of a population.     

Correlations between microcomputed tomography and bone histomorphometry in Korean young females

The bone mass and microarchitecture are important determinants of bone strength, with microarchitectural deterioration being one of the specific changes associated with osteoporosis. The purpose of this study was to evaluate and compare the results of microcomputed tomography (micro-CT) and histomorphometry of biopsied specimens. A bone biopsy was performed on the iliac crest of 10 normal premenopausal Korean women. Measurements of the bone mineral density (BMD), micro-CT, and bone histomorphometry were performed. The bone volume, as determined by both micro-CT and histomorphometry, was significantly correlated (r=0.88, p < 0.01). The osteoid surface was correlated with both the bone volume (r=0.84, p < 0.01) and the structure model index (SMI) (r= -0.89, p < 0.01) measured by micro-CT. The SMI was correlated with both the bone volume (r=-0.85, p < 0.01) and the total hip BMD (r=-0.65, p < 0.05). In conclusion, some, but not all of the parameters of the micro-CT, were well correlated with the bone histomorphometric results. Micro-CT and histomorphometry appear to be complementary techniques in the study of bone microarchitecture.     

Secondary osteon variants and remodeling in human bone

Histomorphometric analysis of human cortical bone has documented the occurrence of secondary osteon variants. These include drifting osteons which form tails as they move erratically through the cortex and Type II osteons which show partial resorption and redeposition within the cement line of the osteon. Little is known about the biological significance of these variants. Prior studies suggested correlations with age, biomechanics, diet, and mineral homeostasis. No study has yet tested for osteon variant associations with static measures of bone remodeling. In this study, thin sections (n = 112) of the posterior femur representing a late English Medieval adult human osteological collection, subdivided by age, sex, and socio-economic status, were examined to determine whether remodeling indicators reconstructed from osteon parameters (area, diameter, area ratios) and densities differed between categories of presence or absence of Type II and drifting osteon variants. Of the 112 sections, 33 presented with Type II osteons, and 38 had drifting osteons. Sporadic statistically significant results were identified. Haversian canal:osteon area ratio differed (p = 0.017) with Type II osteon presence, Type II osteons were more prevalent in males than females (p = 0.048), and drifting osteons were associated with smaller osteon (p = 0.049) and Haversian canal area (p = 0.05). These results may be explained through some biological (sex) and social (status) processes such as a period of physiological recovery (e.g., following lactation, malnutrition). However, the general lack of consistent relationships between osteon variants and remodeling indicators suggests they occur as a result of natural variation.     

Differences in significance of drug resistance mechanisms between adult and childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is now curable in 60-80% of children. In adults, in spite of adopting treatment protocols based on therapy for childhood ALL, the disease is still curable in 30-40% of patients only. These worse results of therapy may be due to the induction of various cell defence mechanisms, such as activation of P-glycoprotein, which protects man against xenobiotics. Among a number of various multi-drug resistance mechanisms, differences between adults and children with ALL have been found only for higher P-glycoprotein expression and possibly more often p53 gene mutations in adults. Induction of expression of drug resistance proteins during chemotherapy and co-existence of various mechanisms are common phenomena in adult ALL. Differences in resistance to different drugs might contribute to the impact of age on the outcome of ALL. The underlying mechanisms for these differences are still largely unknown; however, knowledge about drug resistance mechanisms can lead to new therapeutic options.     

Adaptation of cancellous bone to overloading in the adult rat: a single photon absorptiometry and histomorphometry study

Nine-month-old female rats were subjected to right hindlimb immobilization or served as controls for 0, 2, 10, 18, and 26 weeks and were double-labeled with bone markers. The right limb was immobilized against the abdomen and considered unloaded, while the left limb was overloaded during ambulation. Single-photon absorptiometry was performed on intact femur; static and dynamic histomorphometry were performed on 20 microns thick undecalcified frontal sections of the proximal tibial metaphysis. Changes in the continuously overloaded limb was compared to that in both limbs of age-matched control animals. Single-photon absorptiometry detected increases of bone mineral density of +6%, +6%, and +5% in the proximal and +9%, +7%, and +10% in the distal femoral metaphyses after 10, 18, and 26 weeks of continuous overloading. Morphometrically, significant changes occurred in proximal tibial metaphyses compared to age-matched controls: trabecular area increased +41% and +45%, trabecular number increased +31% and +32%, and trabecular separation decreased -30% and -31% after 18 and 26 weeks of overloading. A significant increase in mineral apposition rate (+38%) was found only at 26 weeks of overloading. Insignificant decreases in both eroded and labeled bone surfaces occurred at all time periods. The histomorphometric changes indicated that increased cancellous bone mass was caused by an increase in bone formation activity (i.e., increases in mineral apposition and bone formation rates) and a decrease in remodeling space (i.e., decrease in bone eroded surface). These findings indicate that the adult skeleton can quickly adapt to the increased biomechanical needs by increasing its cancellous bone mass with an adequate structural pattern.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ontogenetic relationships between in vivo strain environment, bone histomorphometry and growth in the goat radius

Vertebrate long bone form, at both the gross and the microstructural level, is the result of many interrelated influences. One factor that is considered to have a significant effect on bone form is the mechanical environment experienced by the bone during growth. The work presented here examines the possible relationships between in vivo bone strains, bone geometry and histomorphology in the radii of three age/size groups of domestic goats. In vivo bone strain data were collected from the radii of galloping goats, and the regional cortical distribution of peak axial strain magnitudes, radial and circumferential strain gradients, and longitudinal strain rates related to regional patterns in cortical growth, porosity, remodelling and collagen fibre orientation. Although porosity and remodelling decreased and increased with age, respectively, these features showed no significant regional differences and did not correspond to regional patterns in the mechanical environment. Thicker regions of the radius's cortex were significantly related to high strain levels and higher rates of periosteal, but not endosteal, growth. However, cortical growth and strain environment were not significantly related. Collagen fibre orientation varied regionally, with a higher percentage of transverse fibres in the caudal region of the radius and primarily longitudinal fibres elsewhere, and, although consistent through growth, also did not generally correspond to regional strain patterns. Although strain magnitudes increased during ontogeny and regional strain patterns were variable over the course of a stride, mean regional strain patterns were generally consistent with growth, suggesting that regional growth patterns and histomorphology, in combination with external loads, may play some role in producing a relatively 'predictable' strain environment within the radius. It is further hypothesized that the absence of correlation between regional histomorphometric patterns and the measured strain environments is the result of the variable mechanical environment. However, the potential effects of other physiological and mechanical factors, such as skeletal metabolism and adjacent muscle insertions, that can influence the gross and microstructural morphology of the radius during ontogeny, cannot be ignored.     

Differences in crop bacterial community structure between hoatzins from different geographical locations

The hoatzin is the only known folivorous bird with foregut fermentation, and is distributed in Venezuela in rivers of the central savannas to the eastern Orinoco River. Differences in diet are expected to affect the digestive microbiota and we hypothesized that hoatzins from different habitats might have a different crop microbiota. We thus characterized the microbiota of six birds from the Cojedes and Orinoco Rivers using the G2 PhyloChip and, in parallel, we compared plant availability and foraging behavior of the hoatzins from the two locations. Plant composition differed between the 2 locations, which shared 5 out of 18 plant families and 1 plant genus--Coccoloba--that was highly consumed in both locations. The PhyloChip detected ～1600 phylotypes from 42 phyla. There was a core microbiota with ~50% of the OTUs shared by at least 4 of the 6 individuals, but there were also differences in the crop microbiota of animals from the two regions. There existed a higher relative abundance of Alphaproteobacteria and Actinobacteria in the crops of birds from the Cojedes River and of Clostridia and Deltaproteobacteria in the crops of birds from the Orinoco River. The results showed both a core crop microbiota and also the bacterial taxa responsible for geographical differences among individuals from the two locations with different vegetation, suggesting an effect of both diet and geography in shaping the crop bacterial community of the hoatzin.     

DNA value and prognosis of renal tumors. Differences between childhood and adult tumors.

In an attempt to reveal characteristic DNA ploidy patterns in primary renal tumors in children and adults, the nuclear DNA contents of 71 tumors were investigated. Nuclear DNA contents were measured by epifluorescence microscopy. The ploidy patterns of renal cell carcinomas (RCCs) and Wilm's tumors (WTs) were different. In RCCs there was no predominant DNA value, and aneuploidy indicated a poorer prognosis than diploidy. In contrast, a diploid pattern was predominant in WTs regardless of the prognosis. These results appear to reflect differences between adults and children in the mechanisms of tumorigenesis of renal tumors.     

The fibrillar organisation of the osteon and cellular aspects of its development

The collagen architecture of secondary osteons was studied with scanning electron microscopy (SEM) employing the fractured cortex technique and osmic maceration. Fibrillar orientation and the change in their direction in sequential lamellae was documented where lamellar formation was ongoing, as well as in resorption pits where osteoclasts had exposed the collagen organisation of the underlying layers. Applying an adaptive stereo matching technique, the mean thickness of matrix layers removed by osteoclasts was 1.36 ± 0.45 μm. It was also documented that osteoclasts do not attack the cellular membrane of the exposed osteocytes. The mean linear osteoblast density in fractured hemicanals was assessed with SEM and no significant differences were observed comparing larger with smaller central canal osteons. These findings suggested a balance between the differentiated osteoblasts that have aligned on the surface of the cutting cone and those that are transformed into osteocytes, because the canal surface is progressively reduced as the lamellar apposition advances.     

The structure of the mouse heart in late fetal stages

Because of the opportunities for genetic manipulation, the mouse has become the major species for models of human disease. Recently, targeted and insertional mutations have induced many novel models of developmental abnormality, including several of congenital heart defects. Interpretation and use of such models requires a precise understanding of the similarities and differences between mouse and human in terms of cardiac development and structure. To this end, we have characterised the late fetal mouse heart using scanning electron microscopy and serial histological sections. Right atrial anatomy is dominated by the venous valves, which separate the orifices of the caval veins from the musculature of the primary atrium. Their structure and location suggest that the pulmonary vein is unlikely to develop from the venous sinus. The pectinated wall of the appendage serves to distinguish the morphologically right atrium, in that it runs around the atrioventricular junction, from the left atrium in which this vestibular region is smooth-walled. The persistence of the left superior caval vein draining to the right atrium, along with a solitary opening for the pulmonary vein in the left atrium, distinguishes the atrial anatomy of the mouse from that of the human. The flap valve of the oval foramen is extensive and represents the embryonic primary atrial septum. The superior rim of the foramen is an infolding of the atrial roof, as has been described in the human, showing that, contrary to orthodox opinion, there is no extensive formation of a secondary atrial septum. The region of the membranous septum seen in the human heart is a relatively thick structure in the late fetal mouse, and is located exclusively in an atrioventricular position. Unlike the human, there is little distinction between the apical trabeculations of the left and right ventricles of the mouse heart.