The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

A Simple and Efficient Device for Demonstrating Cross-sectional Anatomy of the Head

Described in this article is a novel device that facilitates study of the cross-sectional anatomy of the human head. In designing our device, we aimed to protect sections of the head from the destructive action of handling during anatomy laboratory while also ensuring excellent visualization of the anatomic structures. We used an electric saw to create 15-mm sections of three cadaver heads in the three traditional anatomic planes and inserted each section into a thin, perforated display box made of transparent acrylic material. The thin display boxes with head sections are kept in anatomical order in a larger transparent acrylic storage box containing formaldehyde solution, which preserves the specimens but also permits direct observation of the structures and their anatomic relationships to each other. This box-within-box design allows students to easily view sections of a head in its anatomical position as well as to examine internal structures by manipulating individual display boxes without altering the integrity of the preparations. This methodology for demonstrating cross-section anatomy allows efficient use of cadaveric material and technician time while also giving learners the best possible handling and visualization of complex anatomic structures. Our approach to teaching cross-sectional anatomy of the head can be applied to any part of human body, and the value of our device design will only increase as more complicated understandings of cross-sectional anatomy are required by advances and proliferation of imaging technology. Anat Sci Educ 3: 141-143, 2010. (C) 2010 American Association of Anatomists.

Clinical and Fiberoptic Endoscopic Evaluation of Swallowing in Robin Sequence Treated With Nasopharyngeal lntubation: The Importance of Feeding Facilitating Techniques

Objective: To evaluate oral feeding capacity, the swallowing process, and risk for aspiration, both clinically and during fiberoptic endoscopic evaluation of swallowing, in infants with isolated Robin sequence treated exclusively with nasopharyngeal intubation and feeding facilitating techniques. Design: Longitudinal and prospective study. Setting: Hospital de Reabilitacao de Anomalies Craniofaciais, University of Sao Paulo, Bauru, Brazil. Patients: Eleven infants with isolated Robin sequence, under 2 months of age, treated with nasopharyngeal intubation. Interventions: Feeding facilitating techniques were applied in all infants throughout the study period. The infants were evaluated clinically and through fiberoptic endoscopic evaluation of swallowing at first, second, and, if necessary, third week of hospitalization (T1, T2, T3). The mean volume of ingested milk was registered during clinical evaluation, and events were registered during feeding. Results: The respiratory status of all infants was improved after nasopharyngeal intubation; 72% of them presented risk for aspiration during fiberoptic endoscopic evaluation of swallowing at T1. This risk was less frequent when thickened milk was given to the infants and at subsequent evaluations (T2 and T3). Conclusions: Nasopharyngeal intubation aids in stabilizing the airway in isolated Robin sequence, but it does not relate directly to feeding. The risk for aspiration was present in most of the infants, mainly during the first week of hospitalization, and improved within a few weeks, after the use of feeding facilitating techniques.

A simple solution of the laminar dam break wave

The sudden release of a mass of fluid in a channel generates a highly unsteady flow motion, called dam break wave. While industrial fluids exhibit sometimes non-Newtonian behaviours, the viscous fluid flow assumption remains a useful approximation for simplified analyses. In this study, new solutions of laminar dam break wave are proposed for a semi-infinite reservoir based upon the method of characteristics. The solutions yield simple explicit expressions of the wave front location, wave front celerity and instantaneous free-surface profiles that compare favourably with experimental observations. Both horizontal and sloping channel configurations are treated. The simplicity of the equations may allow future extension to more complicated fluid flows.

Characterization by restriction fragment length polymorphism and sequence analysis of field and vaccine strains of infectious laryngotracheitis virus involved in severe outbreaks

At the end of 2002 and throughout 2003, there was a severe outbreak of infectious laryngotracheitis (ILT) in an intensive production area of commercial hens in the Sao Paulo State of Brazil. ILT virus was isolated from 28 flocks, and 21 isolates were genotyped by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) using four genes and eight restriction enzymes, and by partial sequencing of the infected cell protein 4 (ICP4) and thymidine kinase (TK) genes. Three groups resulted from the combinations of PCR-RFLP patterns: 19 field isolates formed Group I, and the remaining two isolates together with the chicken embryo origin (CEO) vaccine strains formed Group II. Group III comprised the tissue-culture origin (TCO) vaccine strain by itself. The PCR-RFLP results agreed with the sequencing results of two ICP4 gene fragments. The ICP4 gene sequence analysis showed that the 19 field isolates classified into Group I by RFLP-PCR were identical among themselves, but were different to the TCO and CEO vaccines. The two Group II isolates could not be distinguished from one of the CEO vaccines. The nucleotide and amino acid sequence analyses discriminated between the Brazilian and non-Brazilian isolates, as well as between the TCO and CEO vaccines. Sequence analysis of the TK gene enabled classification of the field isolates (Group I) as virulent and non-vaccine. This work shows that the severe ILT outbreak was caused by a highly virulent, non-vaccine strain.

Sequence variation of the alpha-lactalbumin gene in Holstein and Nellore cows

The alpha-lactalbumin is a subunit of lactose-synthase, an enzyme responsible for lactose production, a disaccharide that influences milk production. Sequence variations of bovine alpha-lactalbumin have been associated with differences in milk yield. This study aimed to analyze allelic frequency differences at position-1689 (g. AG) and+15 (g. AG) of the alpha-lactalbumin gene in Holstein (Bos taurus) and Nellore (Bos indicus) cows. Blood samples were analyzed from 34 Holstein, 104 Nellore, and 99 Dairy Nellore cows using PCR-RFLP. The different RFLP patterns were sequenced and a novel sequence variation on nucleotide-46 was identified. An adenine at this position was designated as the A allele and a guanine was designated B allele. The frequencies of alleles A-1689, A-46, and A+15 differed between Holstein and both Nellore breeds. The results show that differences in alpha-lactalbumin allelic variants in the 5`-flanking and the 5`-UTR region might be associated with differences in milk production between Holstein cows and cows from Nellore breeds. However, the lack of difference between Nellore and Dairy Nellore suggests that other sequence variantions that regulate milk production might be responsible for the selection of Dairy Nellore cows with superior milk production.

A simple, inexpensive and easily reproducible model of spinal cord injury in mice: Morphological and functional assessment

Spinal cord injury (SCI) causes motor and sensory deficits that impair functional performance, and significantly impacts life expectancy and quality. Animal models provide a good opportunity to test therapeutic strategies in vivo. C57BL/6 mice were subjected to laminectomy at T9 and compression with a vascular clip (30 g force, 1 min). Two groups were analyzed: injured group (SCI, n = 33) and laminectomy only (Sham, n = 15). Locomotor behavior (Basso mouse scale-BMS and global mobility) was assessed weekly. Morphological analyses were performed by LM and EM. The Sham group did not show any morphofunctional alteration. All SCI animals showed flaccid paralysis 24 h after injury. with subsequent improvement. The BMS score of the SCI group improved until the intermediate phase (2.037 +/- 1.198): the Sham animals maintained the highest BMS score (8.981 +/- 0.056). p < 0.001 during the entire time. The locomotor speed was slower in the SCI animals (5.581 +/- 0.871) than in the Sham animals (15.80 +/- 1.166), p < 0.001. Morphological analysis of the SCI group showed, in the acute phase, edema, hemorrhage, multiple cavities, fiber degeneration, cell death and demyelination. In the chronic phase we observed glial scarring, neuron death, and remyelination of spared axons by oligodendrocytes and Schwann cells. In conclusion, we established a simple, reliable, and inexpensive clip compression model in mice, with functional and morphological reproducibility and good validity. The availability of producing reliable injuries with appropriate outcome measures represents great potential for studies involving cellular mechanisms of primary injury and repair after traumatic SCI. (C) 2008 Elsevier B.V. All rights reserved.

Essential role of the N-terminal autoregulatory sequence in the regulation of phenylalanine hydroxylase

Phenylalanine hydroxylase (PAH) is activated by its substrate phenylalanine and inhibited by its cofactor tetrahydrobiopterin (BH4). The crystal structure of PAH revealed that the N-terminal sequence of the enzyme (residues 19-29) partially covered the enzyme active site, and suggested its involvement in regulation. We show that the protein lacking this N-terminal sequence does not require activation by phenylalanine, shows an altered structural response to phenylalanine, and is not inhibited by BH4. Our data support the model where the N-terminal sequence of PAH acts as an intrasteric autoregulatory sequence, responsible for transmitting the effect of phenylalanine activation to the active site, (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

The leucine-rich repeat as a protein recognition motif

Leucine-rich repeats (LRRs) are 20-29-residue sequence motifs present in a number of proteins with diverse functions. The primary function of these motifs appears to be to provide a versatile structural framework for the formation of protein-protein interactions. The past two years have seen an explosion of new structural information on proteins with LRRs. The new structures represent different LRR subfamilies and proteins with diverse functions, including GTPase-activating protein rna 1 p from the ribonuclease-inhibitor-like subfamily; spliceosomal protein U2A', Rab geranylgeranyltransferase, internalin B, dynein light chain 1 and nuclear export protein TAP from the SDS22-like subfamily; Skp2 from the cysteine-containing subfamily; and YopM from the bacterial subfamily. The new structural information has increased our understanding of the structural determinants of LRR proteins and our ability to model such proteins with unknown structures, and has shed new light on how these proteins participate in protein-protein interactions.

Identification of the regulatory subunit of Arabidopsis thaliana acetohydroxyacid synthase and reconstitution with its catalytic subunit

Acetohydroxyacid synthase (EC 4.1.3.18; AHAS) catalyzes the initial step in the formation of the branched-chain amino acids. The enzyme from most bacteria is composed of a catalytic subunit, and a smaller regulatory subunit that is required for full activity and for sensitivity to feedback regulation by valine. A similar arrangement was demonstrated recently for yeast AHAS, and a putative regulatory subunit of tobacco AHAS has also been reported. In this latter case, the enzyme reconstituted from its purified subunits remained insensitive to feedback inhibition, unlike the enzyme extracted from native plant sources. Here we have cloned, expressed in Escherichia coil, and purified the AHAS regulatory subunit of Ambidopsis thaliana. Combining the protein with the purified A. thaliana catalytic subunit results in an activity stimulation that is sensitive to inhibition by valine, leucine, and isoleucine. Moreover, there is a strong synergy between the effects of leucine and valine, which closely mimics the properties of the native enzyme. The regulatory subunit contains a sequence repeat of approximately 180 residues, and we suggest that one repeat binds leucine while the second binds valine or isoleucine. This proposal is supported by reconstitution studies of the individual repeats, which were also cloned, expressed, and purified. The structure and properties of the regulatory subunit are reminiscent of the regulatory domain of threonine deaminase (EC 4.2.1.16), and it is suggested that the two proteins are evolutionarily related.

Ultrastructure and small-subunit ribosomal DNA sequence of Henneguya lesteri n. sp (Myxosporea), a parasite of sand whiting Sillago analis (Sillaginidae) from the coast of Queensland, Australia

Henneguya lesteri n. sp, (Myxosporea) is described from sand whiting, Sillago analis, from the southern Queensland coast of Australia. H. lesteri displays a preference for the pseudobranchs and is typically positioned along the afferent blood vessels, displacing the adjoining lamellae and disrupting their normal array, The plasmodia appeared as whitish-hyaline, elliptical cysts (mean dimensions 230 x 410 mum) attached to the oral mucosa lining of the hyoid arch on the inner surface of the operculum. Infections of the gills were also found, in which the plasmodia were spherical, averaged 240 x 240 mum in size and were located on the inner hemibranch margin. The parasites lodged in the gill filament crypts and generated a mild hyperplastic response of the branchial epithelium, In histological sections, the plasmodium wall and adjoining ectoplasm appeared as a finely granulated, weakly eosinophilic layer, Ultrastructurally, this section of the host-parasite interface contained an intricate complex of pinocytotic channels. H. lesteri is polysporic, disporoblastic and pansporoblast forming. Sporogenesis is asynchronous, with the earliest developmental stages aligned predominantly along the plasmodium periphery, and maturing sporoblasts and spores toward the center. Ultrastructural details of sporoblast and spore development are in agreement with previously described myxosporeans. The mature spore is drop-shaped, length (mean) 9.1 mum, width 4.7 mum, thickness 2.5 mum, and comprises 2 polar capsules positioned closely together, a binucleated sporoplasm and a caudal process of 12.6 mum. The polar capsules are elongated, 3.2 x 1.6 mum, with 4 turns of the polar filament. Mean length of the everted filament is 23.2 mum, Few studies have analyzed the 18S gene-of marine Myxosporea. In fact, H. lesteri is the first marine species of Henneguya to be characterized at the molecular level: we determined 1966 bp of the small-subunit (18S) rDNA, The results indicated that differences between this and the hitherto studied freshwater Henneguya species are greater than differences among the freshwater Henneguya species.

A novel variant genotype C of hepatitis B virus identified in isolates from Australian Aborigines: complete genome sequence and phylogenetic relatedness

There have been no reports of DNA sequences of hepatitis B virus (HBV) strains from Australian Aborigines, although the hepatitis B surface antigen (HBsAg) was discovered among them. To investigate the characteristics of DNA sequences of HBV strains from Australian Aborigines, the complete nucleotide sequences of HBV strains were determined and subjected to molecular evolutionary analysis. Serum samples positive for HBsAg were collected from five Australian Aborigines. Phylogenetic analysis of the five complete nucleotide sequences compared with DNA sequences of 54 global HBV isolates from international databases revealed that three of the five were classified into genotype D and were most closely related in terms of evolutionary distance to a strain isolated from a healthy blood donor in Papua New Guinea. Two of the five were classified into a novel variant genotype C, which has not been reported previously, and were closely related to a strain isolated from Polynesians, particularly in the X and Core genes. These two strains of variant genotype C differed from known genotype C strains by 5.9-7.4% over the complete nucleotide sequence and 4.0-5.6 % in the small-S gene, and had residues Arg(122), Thr(127) and Lys(160) characteristic of serotype ayw3, which have not been reported previously in genotype C. In conclusion, this is the first report of the characteristics of complete nucleotide sequences of HBV from Australian Aborigines. These results contribute to the investigation of the worldwide spread of HBV, the relationship between serotype and genotype and the ancient common origin of Australian Aborigines.