Embryogenesis, Histology, and Organology of the Ovary of Brevoortia patronus

One hundred ninety-one large scale menhaden, Brevoortia patronus, ranging in age from larvae to sexually mature females were used in this study. Collections were made in the littoral and shallow off shore waters of the Gulf of Mexico from Dauphin Island, Alabama, westward to West Bay, Louisiana, at intervals throughout a five year period. Using standard paraffin techniques a number of staining methods were employed. Cytological and histological accounts are presented of the tissue elements of the gonads beginning with inception in the larvae, sexual differentiation to the sexes, and the cyclic changes associated with oogenesis and spawning in the mature fish. The microscopic developments occurring during these periods are correlated with gross features of the organ, the ages of specimens, and with seasonal periods. An account of the morphology and physiology of atretic oocytes and ovulated follicles is presented. Using the ovarian components as an index, the time and duration of the spawning season is established as occurring from late October to February or early March with some variance due to environmental factors. From the study it is possible to postulate that this species exhibits intermittent total spawning in the Gulf

Embryogenesis, Histology, and Organology of the Ovary of Brevoortia patronus

One hundred ninety-one large scale menhaden, Brevoortia patronus, ranging in age from larvae to sexually mature females were used in this study. Collections were made in the littoral and shallow off shore waters of the Gulf of Mexico from Dauphin Island, Alabama, westward to West Bay, Louisiana, at intervals throughout a five year period. Using standard paraffin techniques a number of staining methods were employed. Cytological and histological accounts are presented of the tissue elements of the gonads beginning with inception in the larvae, sexual differentiation to the sexes, and the cyclic changes associated with oogenesis and spawning in the mature fish. The microscopic developments occurring during these periods are correlated with gross features of the organ, the ages of specimens, and with seasonal periods. An account of the morphology and physiology of atretic oocytes and ovulated follicles is presented. Using the ovarian components as an index, the time and duration of the spawning season is established as occurring from late October to February or early March with some variance due to environmental factors. From the study it is possible to postulate that this species exhibits intermittent total spawning in the Gulf

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