Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Corticotropin-Releasing Hormone (Crh) Expression in the Thymus Gland of the Lewis Rat: Effect of Collagen-Induced Arthritis

Thymus glands and peripheral lymphocytes are known to express CRH This study addresses 1) the distribution of ir-CRH in thymus sections, and 2) the effect of immune challenge (collagen-induced arthritis, CIA) on CRH expression. CIA was induced in 14 female Lewis rats, with 7 exposed to stress (5 hrs/day) on days 7-13 post-injection. Stress retarded, but did not prevent, progression of arthritic symptoms: at sacrifice (day 15 post-injection) there was no difference in symptom severity. Thymus weights in CIA groups were less than in uninjected rats (p\u3c0.05, non-stress; p\u3c0.005 stress). In thymus sections, most irCRH localized to discrete cell clusters. Cells with the appearance of lymphocytes were most heavily stained and immunoreactivity was frequently more dense near the plasma membrane. Vessels were seen in the center of many these clusters and extravasating cells appeared densely stained In rats with CIA (non-stressed), the ir-CRH clusters appeared larger and more diffuse. In stressed rats with CIA, ir-CRH was more intense relative to the non-stress animals with arthritis. We conclude that selected subsets of lymphocytes express CRH during maturation and that CRH expression in the thymus is regulated by immune challenge and factors associated with stress