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Functional melanocytes in the epidermis are required for cutaneous pigmentation in cattle. In spotted cattle variations in the size of pigmented sectors are of interest to animal researchers, as it is believed that those with a higher proportion of white coat absorb less solar radiation. The proportion of unpigmented coat was determined from photographs of German Simmental and Holstein bulls. The receptor tyrosinase kinase (KIT) locus is associated with depigmentation phenotypes in mice, humans and pigs, and it is suggested that KIT is a candidate gene for the degree of spotting in cattle.

The analysis of 16 paternal half-sib families of the Holstein breed with 872 sons and 264 genetic markers is studied to detect QTL affecting body conformation and the behavior in dairy cattle. This study provides the first evidence for QTL involved in behavior of dairy cattle and also identifies QTL for udder conformation on chromosome 6 that could form the basis of recently reported QTL for clinical mastitis.

Copyright of Züchtungskunde is the property of Verlag Eugen Ulmer and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Züchtungskunde is the property of Verlag Eugen Ulmer and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Züchtungskunde is the property of Verlag Eugen Ulmer and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cattle temperament, which describes individual behaviour differences with regard to a stressor or environmental challenge, is known for its impact on working safety, adaptability to new housing conditions, animal productivity and for evaluation of animal welfare. However, successful use of temperament in animal breeding and husbandry to improve keeping conditions in general or animal welfare in particular, requires the availability of informative and reproducible phenotypes and knowledge about the genetic modulation of these traits. However, the knowledge about genetic influences on cattle temperament is still limited. In this review, an outline is given for the interdependence between production systems and temperament as well as for the phenotyping of cattle temperament based on both behaviour tests and observations of behaviour under production conditions. In addition, the use of temperament as a selection criterion is discussed. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) and mRNAs establish a complex regulatory network influencing diverse biological pathways including muscle development and growth. Elucidating miRNA-dependent regulatory networks involved in muscle development could provide additional insights into muscle traits largely predefined during prenatal development. The present study aimed to determine differentially expressed transcripts and functional miRNA- mRNA relationships associated with different stages of skeletal muscle development in two pig breeds, German Landrace and Pietrain, distinct in muscle characteristics. A comparative transcriptional profiling of longissimus dorsi muscle tissues from fetuses at 35, 63 and 91 days post-conception as well as adult pigs (180 days postnatum) was performed using the Affymetrix GeneChip porcine genome microarray. Differential expression patterns were identified to be associated with muscularly developmental stages and breed types. The integration of miRNA expression data and ingenuity pathways analysis (ipa) pathway analysis revealed several miRNA-dependent regulatory networks related to muscle growth and development. The present results provide insights into muscle biology for further improvement of porcine meat quality. [ABSTRACT FROM AUTHOR]

Measurements and simulations of an industrial outside vapor deposition process as used for the manufacture of optical wave guides were performed. Deposition efficiencies, flame temperatures, and gas velocities were measured. The hydrogen flame reaction was modeled by calculating the turbulent flow including a combustion model and using a computational fluid dynamics (CFD) solver to compute flow velocities, turbulence and temperatures in the flame. These results were compared with experimental data and reasonable agreement was found. The produced SiO2 particles with predefined size were tracked through the flow field and it was determined whether they hit the surface of the cylindrical target or pass it. Three flame configurations were investigated and the model could predict well the trends of the deposition efficiencies for the different flames. The differences in flame velocities and turbulence levels for the different configurations assisted the explanation of the performances of the flames. Turbulence levels were different for the three flames and it was concluded that for turbulent deposition processes the thermophoretic force that drives particles towards colder surfaces is less important than for laminar deposition processes. [ABSTRACT FROM AUTHOR]

The present study aimed at identifying bovine hepatic and intestinal DNA sequences expressed breed specifically as potential functional candidate genes for nutrient transformation. Transcript levels of 29 expressed sequence tags (ESTs) were analysed comparatively in the liver and intestine of growing Charolais and German Holstein bulls by real-time RT-PCR. In previous studies, these ESTs were characterized as differentially displayed in mRNA differential display of cows varying in metabolic type and harbouring single nucleotide polymorphisms. Breed-specific gene expression levels indicate significantly increased hepatic metabolic activity in Charolais and increased intestinal metabolic activity in German Holstein bulls. Transcript levels of six functional genes measured in liver ( NDUFB8, NACA, UAP1, SAH) and intestine ( FUS/TLS, APOC3), respectively, support this assumption. The observed coincidence of metabolic type-specific expressed ESTs with variant ESTs showing breed-specific allele distribution points to functional genetic variants located in the vicinity of the analysed sequences. In addition, location of most of the breed specifically expressed ESTs within chromosome regions known to be affecting carcass and growth traits in cattle supports the putative candidate gene character of the ESTs identified. [ABSTRACT FROM AUTHOR]

A contig of the class III region of the bovine major histocompatibility complex (MHC) was established from bacterial and yeast artificial chromosomes using PCR and BAC-end sequencing. The marker content of individual clones was determined by gene and BAC-end specific PCR, and the location of genes and BAC-ends was confirmed analyzing somatic hybrid cells. A comparative analysis indicated that the content and order of MHC class III genes is strongly conserved between cattle and other mammalian species. Fluorescence in situ hybridization localized the bovine class III region to BTA23q21→q22. The results show that the collection of sequenced BAC-ends is a powerful resource for generating high-resolution comparative chromosome maps. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]