CYTOGENETIC EVIDENCE OF INVOLVEMENT OF CHROMOSOME REGION-15Q12 AND REGION-12Q15 IN CONDITIONS WITH ASSOCIATED OVERGROWTH

Syndromes with associated overgrowth are poorly understood. Besides their mode of inheritance, nothing is known regarding the basic genetic alterations that lead to their abnormal phenotypic manifestations. The chromosome localization of the genes involved remains unknown for this group of syndromes, with the only exception being the Wiedemann-Beckwith syndrome.

The frequency of 844ins68 mutation in the cystathionine beta-synthase gene is not increased in patients with venous thrombosis

Background and Objectives. A frequent mutation in the cystathionine beta-synthase (CBS) gene (844ins68, a 68-bp insertion in the coding region of exon 8) was recently discovered. In the present study we Investigated this mutation as a candidate risk factor for venous thrombosis.Design and Methods. The prevalence of the 844ins68 CBS mutation was determined in 101 patients with objectively diagnosed deep venous thrombosis and in 101 healthy controls matched for age, sex and race. PCR amplification of a DNA fragment containing exon 8 of the CBS gene was employed to determine the genotypes, Additionally, Bsrl restriction enzyme digestion of the PCR products was performed in all samples from carriers of the insertion, to test for concurrent presence of a second mutation (T833C) in the CBS gene.Results. The insertion was found in 21 out of 101 patients (20.8%; allele frequency 0.109) and in 20 out of 101 controls (19.8%; allele frequency 0.114), yielding a relative risk for venous thrombosis related to the 844ins68 CBS mutation close to 1.0. In addition, the T833C GBS mutation was detected in all alleles carrying the 844ins68 CBS insertion, confirming the co-inheritance of the two mutations.Interpretation and Conclusions. Our findings do not support the hypothesis that the 844ins68 mutation in the CBS gene is a genetic risk factor for venous thrombosis. (C)1998, Ferrata Storti Foundation.

NEWLY RECOGNIZED AUTOSOMAL RECESSIVE FACIOTHORACOSKELETAL SYNDROME

We report on 2 brothers, born to consanguineous parents presenting thin/long face, small ears, blepharophimosis, malar hypoplasia, long neck, pectus excavatum, brachy-camptodactyly, and sacral dimple. We suspect that these patients represent a previously undescribed autosomal recessive syndrome. (C) 1994 Wiley-Liss, Inc.

Hereditary equine regional dermal asthenia in three related Quarter horses in Brazil

Hereditary equine regional dermal asthenia belongs to a group of inherited, congenital connective tissue dysplasias usually described as hyperelastosis cutis, cutaneous asthenia, dermatosparaxis, or Ehlers-Danlos-like syndrome. This report presents the clinical and histological features of three related Quarter horses affected with regional dermal asthenia. These horses had bilateral asymmetric lesions of the trunk and lumbar regions, where the skin was hyperextensible. Handling of the skin elicited a painful response and superficial trauma led to skin wounds. The skin was thinner than normal in the affected areas, with thickened borders and harder fibrotic masses (pseudotumours). The histopathological findings included thinner and smaller collagen fibrils, and a loose arrangement of collagen fibres in the middle, adventitial and deep dermis. Masson's trichrome and Calleja stains did not reveal any abnormality of collagen and elastic fibres. Electron microscopy showed no abnormalities. As in human patients, pseudotumour histopathological findings included fibroplasia and neovascularization. The pedigree chart of these animals supports an autosomal recessive type of inheritance, which has been suggested by other studies. This is the first report of this disease in Brazil. Its clinical and histological features resemble those described in horses affected with this condition in the United States.

Immotile Short-Tail Sperm Defect in Nelore (Bos taurus indicus) Breed Bulls

ContentThis case study reported the presence of short tail sperm defect in the semen of three Nelore breed bulls. The sperm presented 0% of motility in the three animals evaluated and a total of 70%, 61% and 34% of pathologies of the intermediate piece of the tail respectively for animals 1, 2 and 3. It was identified that animals 2 and 3 had high degree of inbreeding, although no relationship was found with animal 1. Animal 2 was the only one that presented inbreeding coefficient (6.25%). His half-sib (animal 3) and animal 1, from the same herd, had shown no inbreeding, showing that inheritance is not the only determinant factor for its incidence on Nelore males.

On the Origin of Cattle: How Aurochs Became Cattle and Colonized the World

Since their domestication in the Neolithic, cattle have belonged to our cultural heritage. The reconstruction of their history is an active field of research 1 that contributes to our understanding of human history. Archeological data are now supplemented by analyses of modern and ancient samples of cattle with DNA markers of maternal, paternal, or autosomal inheritance. The most recent genetic data suggest that maternal lineages of taurine cattle originated in the Fertile Crescent with a possible contribution of South-European wild cattle populations, while zebu cattle originate from the Indus Valley. Subsequently, cattle accompanied human migrations, which led to the dispersal of domestic cattle of taurine, indicine, or mixed origin over Asia, Africa, Europe, and the New World. This has resulted in their adaptation to different environments and considerable variation in appearance and performance. More recently, rational management of breeding led to international movements of sires, which again changed the global patterns of genetic diversity.

Spondylothoracic dysplasia in two siblings

The spondylothoracic dysplasia syndrome is characterized by congenital malformations of vertebrae and ribs. As a consequence of the anomalous development of the vertebral column, the neck and thorax are short, and the normal head looks as if emerging from the shoulders. The thorax is short and asymmetric with an increased anteroposterior diameter. Dorsolumbar lordosis and a protuberant abdomen are present. The extremities though normal in length appear long relative to the shortened trunk. Short stature results from the vertebral abnormalities. The syndrome was seen in 2 siblings of nonconsanguineous parents.

Epidemiology and genetics of endemic goiter. II. Genetic aspects

Complex genetic models and segregation analysis were applied to family data obtained in a hyperendemic goiter area in Brazil. The single locus and Falconer's models did not fit the data. Edward's model showed convergency, but statistical concordance has not been obtained. Although the genetic load model explains statistically the family data, it would be hard to imagine that endemic goiter could be explained by a model where synergism among genetic and environmental factors is not assumed.

Increased B chromosome frequency and absence of drive in the fish Prochilodus lineatus

The neotropical freshwater fish species Prochilodus lineatus (Pisces, Prochilodontidae) shows 2n = 54 chromosomes plus supernumerary microchromosomes ranging in number from zero to seven among different animals. The transmission rates of B chromosomes were studied by the analysis of the parental and F1 generations in 10 controlled crosses performed with specimens from a natural population. The mean transmission rate observed for B chromosomes (k(B) = 0.511) was consistent with that expected from a regular meiotic behaviour orbs in both sexes and with the theoretical value under a Mendelian mode of transmission (0.5). Possible explanations for the dramatic increase in B frequency observed in this population during the last 10 years are discussed, bearing in mind the current absence of drive.

The frequency of 844ins68 mutation in the cystathionine β-synthase gene is not increased in patients with venous thrombosis

Background and Objectives. A frequent mutation in the cystathionine β- synthase (CBS) gene (844ins68, a 68-bp insertion in the coding region of exon 8) was recently discovered. In the present study we investigated this mutation as a candidate risk factor for venous thrombosis. Design and Methods. The prevalence of the 844ins68 CBS mutation was determined in 101 patients with objectively diagnosed deep venous thrombosis and in 101 healthy controls matched for age, sex and race. PCR amplification of a DNA fragment containing exon 8 of the CBS gene was employed to determine the genotypes. Additionally, Bsrl restriction enzyme digestion of the PCR products was performed in all samples from carriers of the insertion, to test for concurrent presence of a second mutation (T833C) in the CBS gene. Results. The insertion was found in 21 out of 101 patients (20.8%; allele frequency 0.109) and in 20 out of 101 controls (19.8%; allele frequency 0.114), yielding a relative risk for venous thrombosis related to the 844ins68 CBS mutation close to 1.0. In addition, the T833C CBS mutation was detected in all alleles carrying the 844ins68 CBS insertion, confirming the co- inheritance of the two mutations. Interpretation and Conclusions. Our findings do not support the hypothesis that the 844ins68 mutation in the CBS gene is a genetic risk factor for venous thrombosis.

Extended Hierarchical Censored Production Rules (EHCPRs) system: An approach toward generalized knowledge representation

One common problem in all basic techniques of knowledge representation is the handling of the trade-off between precision of inferences and resource constraints, such as time and memory. Michalski and Winston (1986) suggested the Censored Production Rule (CPR) as an underlying representation and computational mechanism to enable logic based systems to exhibit variable precision in which certainty varies while specificity stays constant. As an extension of CPR, the Hierarchical Censored Production Rules (HCPRs) system of knowledge representation, proposed by Bharadwaj & Jain (1992), exhibits both variable certainty as well as variable specificity and offers mechanisms for handling the trade-off between the two. An HCPR has the form: Decision If(preconditions) Unless(censor) Generality(general_information) Specificity(specific_information). As an attempt towards evolving a generalized knowledge representation, an Extended Hierarchical Censored Production Rules (EHCPRs) system is suggested in this paper. With the inclusion of new operators, an Extended Hierarchical Censored Production Rule (EHCPR) takes the general form: Concept If (Preconditions) Unless (Exceptions) Generality (General-Concept) Specificity (Specific Concepts) Has_part (default: structural-parts) Has_property (default:characteristic-properties) Has_instance (instances). How semantic networks and frames are represented in terms of an EHCPRs is shown. Multiple inheritance, inheritance with and without cancellation, recognition with partial match, and a few default logic problems are shown to be tackled efficiently in the proposed system.

Hemoglobinas anormais e dificuldade diagnóstica

The human hemoglobins, with genetically defined inheritance patterns, have shown characteristic polymorphic variation within the Brazilian population, depending on the racial groups of each region. They have appeared under the form of hemoglobin variants or thalassemias, the variant types S and C and the alpha and beta thalassemias being more common, all of them in heterozygote form. During the year of 1999, blood samples from 506 individuals, with suspected anemia or that had already passed through hemoglobinopathies screening, were sent to the Hemoglobin Reference Center - UNESP for diagnostic confirmation and submitted to electrophoresis proceedings, biochemical and cytological analyses in order to characterize the type of abnormal hemoglobins. The goal of the present study was to verify which abnormal hemoglobin types show greater diagnostic difficulty. The samples came from 24 cities in twelve states. The results showed that 354 (69.96%) individuals presented abnormal hemoglobins, 30 (5.93%) being Hb AS, 5 (0.98%) being Hb AC, 76 (15.02%) suggestive of heterozygote alpha thalassemia, 134 (26.48%) suggestive of heterozygote beta thalassemia and 109 (21.54%) with other forms of abnormal hemoglobin, including rare variants and different forms of thalassemias and variant hemoglobin interactions. It has been concluded that, despite the improved techniques currently available and a constant influx of capacitated personnel, the heterozygote form of thalassemias (210 individuals -41.50%) is challenging to diagnose, followed in difficulty by rare variant characterization and interactive forms of hemoglobinopathies (109 individuals-21,54%), suggesting that the capacity for production of qualified professionals and information about these genetic changes in our population should be increased.

Complete replacement of the mitochondrial genotype in a Bos indicus calf reconstructed by nuclear transfer to a bos taurus oocyte

Due to the exclusively maternal inheritance of mitochondria, mitochondrial genotypes can be coupled to a particular nuclear genotype by continuous mating of founder females and their female offspring to males of the desired nuclear genotype. However, backcrossing is a gradual procedure that, apart from being lengthy, cannot ascertain that genetic and epigenetic changes will modify the original nuclear genotype. Animal cloning by nuclear transfer using host ooplasm carrying polymorphic mitochondrial genomes allows, among other biotechnology applications, the coupling of nuclear and mitochondrial genotypes of diverse origin within a single generation. Previous attempts to use Bos taurus oocytes as hosts to transfer nuclei from unrelated species led to the development to the blastocyst stage but none supported gestation to term. Our aim in this study was to determine whether B. taurus oocytes support development of nuclei from the closely related B. indicus cattle and to examine the fate of their mitochondrial genotypes throughout development. We show that indicus:taurus reconstructed oocytes develop to the blastocyst stage and produce live offspring after transfer to surrogate cows. We also demonstrate that, in reconstructed embryos, donor cell-derived mitochondria undergo a stringent genetic drift during early development leading, in most cases, to a reduction or complete elimination of B. indicus mtDNA. These results demonstrate that cross-subspecies animal cloning is a viable approach both for matching diverse nuclear and cytoplasmic genes to create novel breeds of cattle and for rescuing closely related endangered cattle.

A Bayesian approach for constructing genetic maps when markers are miscoded

The advent of molecular markers has created opportunities for a better understanding of quantitative inheritance and for developing novel strategies for genetic improvement of agricultural species, using information on quantitative trait loci (QTL). A QTL analysis relies on accurate genetic marker maps. At present, most statistical methods used for map construction ignore the fact that molecular data may be read with error. Often, however, there is ambiguity about some marker genotypes. A Bayesian MCMC approach for inferences about a genetic marker map when random miscoding of genotypes occurs is presented, and simulated and real data sets are analyzed. The results suggest that unless there is strong reason to believe that genotypes are ascertained without error, the proposed approach provides more reliable inference on the genetic map.