Karyology of Lower Teleost Fishes (Clupeiformes, Taxonomy, Elopiformes, Phylogeny).

Karyotypes of nine species (Megalops atlanticus, Elops saurus, Brevoortia patronus, B. smithi, B. tyrannus, Dorosoma cepedianum, D. petenense, Harengula clupeola, and Anchoa mitchilli) and one hybrid (B. smithi x B. tyrannus) of teleost fishes revealed diploid complements ranging from 28 to 50 chromosomes and comprised of uniarmed elements or combinations of uniarmed and small and large biarmed elements. The occurance of large metacentric-submetacentric chromosomes was usually associated with a reduction in total chromosome number suggesting fusion events in the evolution of karyotypes from ancestral complements with 48 to 52 acrocentrics. Information from karyotypes is used to characterize species, genera, and families and, where possible, these data are used in combination with published reports to reinterpret previously proposed phylogenetic classifications

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