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PubMed1992

The genetics of personality disorder.

Most measurable aspects of normal personality appear to be at least moderately heritable, with direct evidence coming from family, twin and adoption studies and indirect support deriving from psychophysiological research and breeding experiments on animals. Interestingly, genetic studies also shed light on the environmental sources of variation in personality and suggest that shared family environment rarely, if ever, has any positive effect on similarity between relatives. Despite problems of classification, and variations in the use of terms, a survey of the literature provides reasonably consistent evidence of a genetic contribution to several categories of abnormal personality, which we here divide into three groups, antisocial, anxious/avoidant, and schizoid-schizotypal personalities. However, personality disorders are complex traits that do not show simple mendelian patterns of inheritance and so far molecular genetics has been of no help in understanding their aetiology. Fortunately, techniques are now becoming available that enable the detection and potential localisation of genes of small effect and which may help elucidate the molecular basis even of (probably) polygenic traits such as abnormal personality.

Animals↗
PubMed2002

Ploidy Determination in Agrostis Using Flow Cytometry and Morphological Traits.

The taxonomic classification of the genus Agrostis is one of the most complicated of the grass genera. Classification based upon morphological and anatomical characters is difficult and complicated by the presence of intermediate forms and the misapplication of names. Determining ploidy levels of new germplasm can assist in species determination and is necessary before initiating breeding or genetics studies. The objectives of this study were to (i) evaluate the use of laser flow cytometry as a quick, reliable tool to determine ploidy level and aid in Agrostis species determination, and (ii) identify morphological characters associated with DNA content or ploidy level. The six Agrostis species evaluated were A. canina L. subsp. canina, A. canina L. subsp. montana (Hartm.) Hartm., A. palustris Huds. [= A. stolonifera var. palustris (Huds.) Farw.], A. tenuis Sibth. (= A. capillaris L.), A. castellana Boiss. & Reut., and A. alba L. Ploidy level was determined by flow cytometry and root tip chromosome counts. Plant height, panicle height, flag leaf length, flag leaf width, and highest internode length of mature field-grown spaced plants were measured. Significant differences in 2C DNA content were found between species (P < 0.01) differing in ploidy level. Flow cytometry was effective in differentiating between diploid, tetraploid, and hexaploid species. Chromosome numbers previously reported and those observed in this study were positively correlated with 2C nuclear DNA content (r = 0.98, P < 0.01). Flag leaf length was the only morphological measurement taken that was significantly positively correlated to DNA content (r = 0.98, P < 0.001). The results of this study indicate that laser flow cytometry is a quick, reliable tool to determine ploidy levels and infer certain species of AGROSTIS: This technique will aid breeders to quickly and accurately determine ploidy levels of new germplasm collections.

Journal Article↗
PubMed1995

[Seizure disorders in the dog. 1. Clinical features and differential diagnosis].

For differential diagnosis, therapy, and prognosis of seizures in dogs it is recommended to distinguish between two groups of diseases: 1. Epilepsy is diagnosed if seizures occur repeatedly without an active, underlying disorder. Idiopathic epilepsy occurs most commonly. A hereditary component has been demonstrated in several breeds. Symptomatic epilepsy results from previous resolved forebrain disorders, which cause epileptic seizures through scar formation. 2. Seizures are caused by active structural forebrain disease or metabolic-toxic imbalances. Upon initial presentation of the dog, a preliminary classification may be achieved with the seizure history, clinical and neurological examination, and routine laboratory evaluation. The diagnosis of idiopathic epilepsy is based on typical seizure history and exclusion of structural forebrain disease and metabolic-toxic imbalances with special laboratory testing, CSF examination, and brain scanning procedures.

Animals↗
PubMed1991

Effects of stage of gestation and breed on bovine responses to vaccination with Brucella abortus strain 19.

Eighty-eight cattle were injected SC with 2.5 x 10(8) viable cells of Brucella abortus strain 19. All but 1 heifer became seropositive on the basis of the results of 7 brucellosis tests, and the proportion positive decreased with time. The proportion of cattle that were seropositive during a 20- to 67-week period after vaccination was as follows, in decreasing order: hemolysis-in-gel, 59%; buffered-acid plate antigen, 39%; ELISA, 16%; card, 10%; rivanol, 8%; cold complement-fixation, 7%; and automated complement-fixation, 5%. Using the serologic classification in Uniform Methods and Rules for brucellosis eradication, 7 cattle tested brucellosis-positive (2 suspects and 5 reactors). None of the 27 nonpregnant heifers tested positive. Of 18 heifers that were 84 to 135 days in gestation when vaccinated, 6 (33%) tested positive for brucellosis, compared with 0 of 13 and 1 (3%) of 30 heifers that were 11 to 78 and 145 to 253 days in gestation at vaccination, respectively (X2 = 12.07; 2 df; P less than 0.01). Neither breed (Angus, Hereford, Jersey, and Brahman) nor calf survival was related to brucellosis-positive results. Postpartum milk samples from 61 heifers and 24 tissues from 2 reactor cattle were culture-negative for B abortus.

Animals↗
PubMed1998

Comparison of two classification protocols in the evaluation of elbow dysplasia in the dog.

The incidence of elbow disease based solely on arthrosis (ARTH) score was compared with a protocol using a combination of ARTH score plus a score for primary lesions (ED score). The population of dogs studied included 425 Bernese mountain dogs and 22 dogs of other breeds. The overall agreement between the two systems was high. However, 12 per cent of ARTH-score negative cases were positive using the ED score. This difference was statistically significant (P < 0.005). The female:male ratio of the dogs missed using the ARTH score was 2:1. The proportion of dogs affected with arthrosis increased with age, male dogs being affected more frequently. The development of arthrosis depends not only on age and breed, but probably also on gender. Thus, screening for elbow dysplasia should be based on at least two radiographic projections, including arthrosis and primary lesions. As the vast majority of dogs in this study were Bernese mountain dogs, conclusions are valid only for this breed.

Age Factors↗
PubMed1989

Influence of gender, breed and age on maturity characteristics of sheep.

Fifty-one ewes, 50 wethers and 51 rams of Finn x whiteface or Suffolk x whiteface breeding were slaughtered at an average age of 271, 361, 459, 557 or 652 d to study changes in maturity characteristics with changes in age. When metacarpal epiphyseal cartilage (growth plates) ossifies with age, break joints on the distal end of the metacarpals fuse and the end of the bone then appears as a spool joint rather than as a break joint. This fusion occurs earlier chronologically in ewes than in rams or wethers. Most Finn x whiteface-cross ewes, which normally reach reproductive maturity earlier than Suffolk x whiteface-cross ewes, exhibited ossified metacarpal growth plates by 459 d of age; break joints of Suffolk x whiteface crosses were not fused until 557 d of age. Both breed groups of rams exhibited fused joints by 557 d of age, but only 3 of 10 wethers exhibited spool joints at 652 d of age. Microscopic examination showed that even in these three wethers the epiphyseal growth plate could still be detected. Yearling 2-yr-old classifications of sheep from teeth were not gender-dependent within the discrete age classes of this study. About half the sheep in each gender group were classified as yearlings at 459 d of age and about half in each group were classified as 2-yr-olds by 652 d of age. Stepwise multiple regression equations to estimate age of sheep in days were developed. Overall maturity, lean color and texture and rib bone maturity were the best carcass measures of maturity. Maturity scores for characteristics of the break joint did not enter any of the equations studied. When eye lens weight was included in equations with the best measures of carcass maturity, accuracy of estimates for age of sheep was improved.

Age Determination by Teeth↗
PubMed1999

Centric fusion differences among Oryx dammah, O. gazella, and O. leucoryx (Artiodactyla, Bovidae)

G- and C-banded karyotypes of the genus Oryx were compared using the standard karyotype of Bos taurus. Chromosomal complements were 2n = 56 in O. gazella gazella, 2n = 58 in O. g. beisa and O. g. callotis, 2n = 56-58 in O. dammah, and 2n = 57-58 in O. leucoryx. The number of autosomal arms in all karyotypes was 58. Nearly all variation in diploid number was the result of three independent centric fusions, but one 2n = 57 specimen of O. g. gazella deviated from the normal complement of 2n = 56 due to XXY aneuploidy. A 2;17 centric fusion was fixed in O. g. gazella, whereas O. g. beisa and O. g. callotis lacked this fusion and had indistinguishable karyotypes. Oryx dammah was polymorphic for a 2;15 centric fusion, and O. leucoryx was polymorphic for an 18;19 centric fusion. The five Oryx taxa shared a fixed 1;25 centric fusion; the small acrocentric element involved in the 1;25 fusion was identified by fluorescence in situ hybridization using a cosmid specific to Bos chromosome 25. The X and Y chromosomes were also conserved among the five taxa. Oryx g. gazella differed from the other Oryx species because of the fixed 2;17 centric fusion. This difference reflects an apparently longer period of geographic isolation between O. g. gazella and other populations of Oryx, and it is consistent with the classification of O. gazella and O. beisa as distinct species (see Kingdon, 1997). The lack of monobrachial relationships among the Oryx taxa indicates that sterility barriers between species have not developed. Viability of hybrid offspring constitutes a threat to captive breeding programs designed for endangered species conservation; in the case of Oryx, the 2;15, 2;17, and 18;19 metacentrics could serve as marker chromosomes for assessing hybridization between certain Oryx taxa.

Aneuploidy↗
PubMed1981

Histopathologic observations on Sertoli cell tumors in dog.

Thirty-three cases of Sertoli cell tumor, occurring in dogs of different breeds and ages, were studied histologically. Ectopic testes showed a particularly high tendency to develop the tumor. Metastases were not detected in regularly autopsied dogs nor reported or later ascertained for the bioptic consignments. According to Nielsen and Lein's classification (1974) our findings were divided as follows: 27 intratubular Sertoli cell tumors, 19 with stromal invasion and 8 without invasion; 2 diffuse tumors; 4 multiple primary tumors (3 Sertoli-seminoma cell tumor and 1 Sertoli-Leydig cell tumor). The above classification is discussed and proposed tentatively for revision.

Animals↗
PubMedDate not supplied

Dystrophin-deficient muscular dystrophy in a Labrador retriever.

Sex-linked muscular dystrophy associated with dystrophin deficiency has been reported in several breeds of dogs and is best characterized in the golden retriever. In this case report, a young, male Labrador retriever with dystrophin-deficient muscular dystrophy is presented. Clinical signs included generalized weakness, lingual hypertrophy, and dysphagia. Electromyographic abnormalities including complex repetitive discharges were present. Serum creatine kinase concentration was dramatically elevated. Histopathological changes within a muscle biopsy specimen confirmed a dystrophic myopathy, and dystrophin deficiency was demonstrated by immunohistochemical staining. While X-linked muscular dystrophy has not previously been reported in the Labrador retriever, a hereditary myopathy with an autosomal recessive mode of inheritance has been characterized. A correct diagnosis and classification of these two disorders are critical for breeders and owners since both the mode of inheritance and the prognosis differ.

Animals↗
PubMed1989

Breeding soundness, libido and performance of beef bulls mated to estrus synchronized females.

Ninety-three beef bulls and 2316 females were used to determine the relationships between breeding assessments of bulls and subsequent mating performance. Each bull was given a breeding soundness examination (BSE) and two 10-min libido/serving capacity (L/SC) tests. Breeding potential of each bull was classified as satisfactory (BSE score = 60 to 100) or questionable (BSE score = 30 to 59); libido was classified as either high (mean score = 9.0 to 10) or medium (mean score = 6.0 to 8.5). Bulls were then joined, single-sire, with groups of females which had received one of two treatments to synchronize estrus. Bull-to-female ratios ranged from 1:7 to 1:51. Continuous observations were conducted on the mating activity of each group. One bull was removed from the experiment due to a severe breeding problem. Bulls of satisfactory breeding potential (n = 80) did not differ (P > 0.10) from bulls of questionable breeding potential (n = 12) in measurements of mating activity. However, by the end of the synchronized breeding period, bulls classified as satisfactory breeders achieved approximately a 9% higher (P < 0.10) pregnancy rate than did bulls of questionable breeding status (45.6 +/- 2.1% vx 36.5 +/- 5.3%). Bulls with a high libido (n = 69) serviced more (P < 0.01) estrous females (81.3 +/- 3.1% vs 63.5 +/- 4.2%) than bulls with a medium libido (n = 23). However, pregnancy rates achieved by bulls of either libido classification did not differ significantly. Individual components of the BSE as well as mean libido score were poorly correlated with pregnancy rates (r = -0.22 to 0.18). It was concluded that classification of bulls by mean libido score can aid in identifying groups of bulls that service more estrus synchronized females, whereas classification by BSE score aids in identifying groups of bulls that impregnate more females.

Journal Article↗
PubMed1992

Sexual performance of rams in serving capacity tests predicts success in pen breeding.

The purpose of this study was to determine the extent to which sexual performance (serving capacity) tests can be used to predict the sexual behavior and reproductive success of rams in the context of pen mating. Standard serving capacity tests were used to select four low (LP) and four high-performing (HP) rams from a population of 94 yearling males. Each selected ram was then exposed to approximately 30 estrus-synchronized ewes for a 9-d period. Ejaculations observed and mounting marks left on ewes confirmed the greater (P less than .001) sexual activity of the HP rams in the field. In addition, ewes exposed to HP rams had a higher lambing percentage, more lambs born, and more live lambs born per ewe. Ram classification was not related (P greater than .60) to the number of lambs born per ewe lambing (prolificacy). It was concluded that serving capacity tests, properly conducted, can be used to predict ram mating performance and thus aid in establishing more efficient ram-to-ewe stocking rates.

Animals↗
PubMed2006

Gliadin, glutenin or both? The search for the Holy Grail in coeliac disease.

Wheat gluten was traditionally classified into gliadin and glutenin based upon solubility in aqueous alcohol. Gliadins were thought to be responsible for precipitating coeliac disease; glutenins were thought probably to be nontoxic. More recent classification, according to primary amino acid structure, reveals not only great heterogeneity but also similarities between different gliadin and glutenin proteins. Peptides derived from both groups are immunostimulatory in coeliac disease and it is highly probable that glutenin proteins are therefore toxic. Attempts to breed wheat with satisfactory baking properties tolerated by coeliac patients will be very difficult.

Celiac Disease↗
PubMed1991

C. R. Henderson, the statistician; and his contributions to variance components estimation.

C. R. Henderson's 1953 Biometrics paper "Estimation of Variance and Covariance Components" is an outstanding landmark in the discipline of statistics. It sets out the very first ideas of how to estimate variance components from unbalanced (unequal subclass numbers) data in situations more complicated than the one-way classification (completely randomized design). As such it had three important, long-lasting impacts. First, it provided methods for actually using unbalanced data, even in large quantity, for estimating variance components. And this has played a tremendous role in population genetics and in animal breeding where the use of estimated variance components is vital to the application of selection theory and selection index techniques. Second, that 1953 paper stimulated numerous statisticians to become interested in random effects, mixed models, and variance components estimation, with such statistical greats as H. O. Hartley and C. R. Rao making contributions in the late 1960s and early 1970s. By then, improved methods of estimating variance components from unbalanced data had been developed, namely maximum likelihood (ML) and restricted maximum likelihood (REML). Once computing power had expanded to the point where these methods became feasible, Henderson made notable contributions to these methods, allied to his two great interests: animal breeding and feasible computing procedures. For both of these, his mixed model equations were a salient feature. Third, these methods reached a wide audience of geneticists and statisticians.

Analysis of Variance↗
PubMed1983

Genetic analysis of the BB/W diabetic rat.

A large colony of BB/W diabetic rats has been developed as a research model for insulin dependent, type 1 diabetes mellitus. The foundation stock had 8% diabetics which appeared in a sporadic manner. The Worcester (W) colony was inbred by brother X sister matings for 11 generations and the proportion of diabetics increased to over 50%. The age of detection varies from 46 to 250 days. For selection purposes, classification was made at 120 days, which means that 15 to 20% potential diabetics were classified as normal. Evidence from different analyses indicates that the inheritance of diabetes is by a recessive gene or gene cluster with 50% penetrance at 120 days. The selection of breeding stock from diabetic parents raised the proportion of diabetics produced by two normal parents from 12 to 43%. Diallel tests show that diabetic and normal offspring of two diabetic parents have the same diabetic genotype. Outcrosses to other strains of rat indicate that the trait is transferred as a recessive with only 3% diabetics recovered in the F2 where noninbred BB stock was used as the diabetic source, and 36% where partially inbred BB/W was used as the diabetic parent. Since the proportion of diabetics produced by all types of crosses has changed, and may continue to change with changes in the genetic background, we have used the operational term penetrance to describe the frequency of diabetes in individuals homozygous for the diabetes gene cluster. At present the penetrance at 120 days is 59% in the BB/W colony.

Age Factors↗
PubMed2001

The forensic application of allozyme electrophoresis to the identification of blowfly larvae (Diptera: Calliphoridae) in southern Australia.

Most known carrion-breeding species of blowflies in southern Australia are of the genus Calliphora. The morphological similarity of the immatures of these species means that correctly identifying them poses a challenge for forensic entomologists. This study investigates the potential of allozyme analysis to assist with this task. Molecular profiles of third-instar larvae and adults representing four of these carrion-breeding species, Calliphora stygia, C. dubia, C. hilli hilli, and C. vicina, were compared at 42 allozyme loci. The two life stages were found to display almost identical allozyme profiles in each species (93% of loci were expressed in both life history stages), enabling the reliable identification of larvae in these four species. Integration of these results with data from a previous study indicates that allozyme analysis would also be suitable for rapid, species-level identification of the larvae of six other carrion-breeding Calliphora species occurring in southern Australia. This is the first report of the application of allozyme data to the identification of forensically important blowflies.

Animals↗
PubMed2003

Equine melanoma in a population of 296 grey Lipizzaner horses.

REASONS FOR PERFORMING STUDY: Equine melanomas occur most commonly in grey horses at age 5 years or more. Generally, benign and malignant melanomas are distinguished by microscopy, but a more distinct classification would be helpful. OBJECTIVES: The objectives of this study were to gain further evidence concerning the occurrence of melanotic tumours, and to evaluate the impact of heredity on melanoma development. METHODS: A clinical study was conducted on a defined population of 296 grey horses of Lipizzaner breed. Individuals were classified according to their stage of disease using a 0-5 scale. Heritability was estimated on a sample of 296 grey horses with pedigrees traced back as far as 32 generations. RESULTS: Of the 296 horses, dermal melanomas were present in 148 horses (50%), 68 of which were more than age 15 years; 51 of these were melanoma-bearing. In 75.6% of cases, melanotic tumours were detected underneath the tail. Although melanoma-bearing grey horses were encountered up to stage 4, none of the affected individuals suffered any severe clinical effect or was handicapped in performance. Statistical analysis revealed highly significant effects of stud and age (P < 0.0001), explaining 28% of the total variability. CONCLUSIONS: In contrast to melanomas in solid-coloured horses characterised by early metastases, melanomas in grey horses showed less malignancy. Affected individuals often had encapsulated nodules or structures similar to human blue nevi. Grey horse-specific genetic factors inhibiting metastatic processes may be responsible for this phenomenon. POTENTIAL CLINICAL RELEVANCE: Although the obtained heritability estimate of 0.36 with a standard error of 0.11 indicates a strong genetic impact on the development of melanoma in ageing grey horses, a possible influence of the genes with large effects was also suggested. Therefore, further analysis is required of melanoma development in the ageing grey horse.

Age Distribution↗
PubMed2006

Differential parental nutrient allocation in two congeneric pipefish species (Syngnathidae: Syngnathus spp.).

Male seahorses and pipefishes of the family Syngnathidae are heralded for their unique brood pouch structures for incubating embryos. There are three general types of brood pouch with increasing complexity: simple ventral gluing, two pouch flaps and a completely sealed sac. The diversity of functional roles within a type in providing nutrition, aeration and protection to offspring is unknown. Here we reveal significant differences in parental nutrient allocation to embryos for two closely related, sympatric pipefishes with similar brood pouch structure. We document differences in embryo attachment, depletion of pouch fluid nutrients over development and egg nutrient partitioning between Syngnathus floridae and Syngnathus fuscus. In S. fuscus, females produce nutritionally poor eggs and the males implant developing embryos in the brood pouch adjacent to blood vessels. A female-biased breeding population was observed, supporting the hypothesis that the cost of male parental care is high in this species. The loose connection between eggs and brood pouch tissues and the appearance of undeveloped eggs and lipid droplets in the pouch of S. floridae males suggest this species utilizes nutrient-rich eggs produced by females as nurse eggs to supplement embryonic development. A balanced sex-ratio for S. floridae further supports more equal parental contribution. This comparison provides evidence of a decline in female gametic investment and reveals the rapid diversification of syngnathid brood pouch function. Our results indicate gross classification of brooding structures into one of the three general pouch types does not predict the energetic investment of males in parental care. But rather, physiological characterization of the relative investment by each sex to offspring is essential to understanding the functional significance of the brood pouch.

Animal Feed↗