Search

Introduction Among the animals to be domesticated, chickens are the most numerous domestic animal and the preferred source of animal protein (Wang et al. 2020). The chicken as a model [...], The chicken model organism has advanced the areas of developmental biology, virology, immunology, oncology, epigenetic regulation of gene expression, conservation biology, and genomics of domestication. Further, the chicken model organism has aided in our understanding of human disease. Through the recent advances in high-throughput sequencing and bioinformatic tools, researchers have successfully identified sequences in the chicken genome that have human orthologs, improving mammalian genome annotation. In this review, we highlight the importance of chicken as an animal model in basic and pre-clinical research. We will present the importance of chicken in poultry epigenetics and in genomic studies that trace back to their ancestor, the last link between human and chicken in the tree of life. There are still many genes of unknown function in the chicken genome yet to be characterized. By taking advantage of recent sequencing technologies, it is possible to gain further insight into the chicken epigenome. Key words: chicken, poultry, epigenetics, sequencing, histone modification, DNA methylation. Le poulet a gagne en importance en tant qu'organisme modele pour des etudes en biologie du developpement, en virologie, en immunologie, en oncologie, en regulation epigenetique de l'expression genique, en biologie de la conservation et en genomique de la domestication. De plus, le poulet en tant qu'organisme modele a contribue a la comprehension de la maladie chez l'humain. Grace aux recentes avancees en matiere de sequencage a haut debit et d'outils bioinformatiques, les chercheurs ont reussi a identifier des sequences au sein du genome du poulet qui ont des orthologues chez l'humain, ce qui a permis d'ameliorer l'annotation des genomes chez les mammiferes. Dans cette synthese, les auteurs soulignent l'importance du poulet en tant que modele animal en recherche fondamentale et preclinique. Les auteurs exposent l'importance du poulet pour l'epigenetique aviaire et pour des etudes genomiques qui remontent a leur ancetre, le dernier lien entre les humains et le poulet dans l'arbre de la vie. I1 reste de nombreux genes de fonction inconnue au sein du genome du poulet qui doivent encore etre caracterises. En profitant des recentes technologies de sequencage, il est possible d'acquerir une meilleure comprehension de l'epigenome du poulet. [Traduit par la Redaction] Mots-cles: poulet, volaille, epigenetique, sequencage, modification des histones, methylation de l'ADN.

We report a suite of key microfluidic devices for complex high-throughput whole-animal genetic and drug screens. We demonstrate a high-speed microfluidic sorter that can isolate and immobilize Caenorhabditis elegans in a well defined geometry for screening phenotypic features at subcellular resolution in physiologically active animals. We show an integrated chip containing individually addressable screening-chamber devices for incubation and exposure of individual animals to biochemical compounds and high-resolution time-lapse imaging of many animals on a single chip without the need for anesthesia. We describe a design for delivery of compound libraries in standard multiwell plates to microfluidic devices and also for rapid dispensing of screened animals into multiwell plates. When used in various combinations, these devices will facilitate a variety of high-throughput assays using whole animals, including mutagenesis and RNAi and drug screens at subcellular resolution, as well as high-throughput high-precision manipulations such as femtosecond laser microsurgery for large-scale in vivo neural degeneration and regeneration studies. Caenorhabditis elegans | femtosecond laser microsurgery | immobilization and time-lapse imaging | mutagenesis | RNAi and drug screening

Theodosius Dobzhansky's contributions to evolutionary theory are presented, from 1918 to 1973, along with a brief biography. The Ukrainian-born Dobzhansky is credited with the synthesis of evolution with genetics in describing the origin of species; he also taught genetics at several US institutions, including the California Institute of Technology, Rockefeller University and the University of California at Davis.

Fluorescent in situ hybridization, PCR-primed in situ labeling, and molecular probes have been developed and used to identify and evolve DNA sequences for cytological identification and physical mapping of soybean somatic chromosomes. Use of different cloned examples of each family allows selective labelling of unique subsets of soybean chromosomes.Double hybridization with biotin and digoxigenin determine the overlap in the chromosomes between different probes. It is essential to use different procedures for single-copy and highly repetitive DNA sequences.

Author Affiliations:Prospective parents should be prepared for a surge in genetic data More prenatal tests are on the way -- but are we ready? [see PDF for image]Credit: Tim Hale/GettyPregnant [...], The growing capabilities of prenatal diagnostics are expanding the need for counselling.The growing capabilities of prenatal diagnostics are expanding the need for counselling.

The wealth of nucleotide sequence data brought about by various genome projects has given birth to another science, the science of functional genomics. This is the science that will try to determine how the blueprint becomes a functioning organism. To do this, functional genomics must bring together innovative technologies that can investigate and evaluate gene expression on a large scale. The development of these technologies are discussed.

Studies of gene function in mice often involve the analysis of embryonic stem (ES) cell-derived gene-targeted mice. Such mice carry a predesigned mutation in their germ line and are devoid [...], A method of gene targeting that allows the inducible inactivation of a target gene in mice is presented. The method uses an interferon-responsive promoter to control the expression of Cre recombinase. Here, Cre was used to delete a segment of the DNA polymerase β gene flanked by loxP recombinase recognition sites. Deletion was complete in liver and nearly complete in lymphocytes within a few days, whereas partial deletion was obtained in other tissues. This method can be used for the inducible inactivation of any other gene in vivo.

The comparative genetic maps obtained from the Mammalian Comparative Database enables the prediction of linkages, investigation of genome structure and generation of animals models. The Mammalian Comparative Database is an information resource consisting detailed information about homologous genes and the chromosomal location of these genes. The Database will enable the development of new methods and techniques for treating diseases and abnormalities in human beings.

Biochips are currently one of the key technologies in biology. To develop them, scientists and engineers borrowed miniaturization, integration, and parallel-processing techniques from the computer industry to develop laboratory devices [...]

Splicing of short introns by the nuclear pre-mRNA splicing machinery is thought to proceed via an 'intron definition' mechanism, in which the 5' and 3' splice sites (5'ss, 3'ss, respectively) are initially recognized and paired across the intron. Here, we describe a computational analysis of sequence features involved in recognition of short introns by using available transcript data from five eukaryotes with complete or nearly complete genomic sequences. The information content of five different transcript features was measured by using methods from information theory, and Monte Carlo simulations were used to determine the amount of information required for accurate recognition of short introns in each organism. We conclude: (i) that short introns in Drosophila melanogaster and Caenorhabditis elegans contain essentially all of the information for their recognition by the splicing machinery, and computer programs that simulate splicing specificity can predict the exact boundaries of [approximately equals] 95% of short introns in both organisms; (ii) that in yeast, the 5'ss, branch signal, and 3'ss can accurately identify intron locations but do not precisely determine the location of 3' cleavage in every intron; and (iii) that the 5'ss, branch signal, and 3'ss are not sufficient to accurately identify short introns in plant and human transcripts, but that specific subsets of candidate intronic enhancer motifs can be identified in both human and Arabidopsis that contribute dramatically to the accuracy of splicing simulators.

The development of tools for the manipulation of single cells is of major importance for the rapidly growing area of genomics and proteomics, particularly in massively parallel single-cell manipulation and [...], Conducting polymers are excellent materials for actuators that are operated in aqueous media. Microactuators based on polypyrrole-gold bilayers enable large movement of structures attached to these actuators and are of particular interest for the manipulation of biological objects, such as single cells. A fabrication method for creating individually addressabie and controllable polypyrrole-gold microactuators was developed. With these individually controlled microactuators, a micrometer-size manipulator, or microrobotic arm, was fabricated. This microrobotic arm can pick up, lift, move, and place micrometer-size objects within an area of about 250 micrometers by 100 micrometers, making the microrobot an excellent tool for single-cell manipulation.

In the 'Evolution' special issue, Virginia Morell's News article (25 June, p. 2106) seems to perpetuate a common misconception, that no one has actually witnessed the birth of a species [...]

'It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.' Charles Dickens had it about right [...]

A Novel Human Gene Closely Related to the abl Proto-Oncogene PROTO-ONCOGENES ARE THE NORmal counterparts of the concogenes of acute transforming retroviruses (1). The normal functions of some of these [...]

CNS and Hypoderm Regulatory Elements of the Drosophila melanogaster Dopa Decarboxylase Gene MANY GENES FOUND IN HIGHER organisms encode products used in metabolic pathways that are required in more than [...]