Microglial cells, implicated in multiple sclerosis (MS), superimposed on an image of a demyelinated lesion in an animal model of MS. On page 1215, Geiger and colleagues describe T cells engineered to tackle MS-like autoimmune disease. (Microglial cells © Photo Researchers; histology image courtesy Raymond A. Sobel).

Scanning electron micrograph of murine neural stem and progenitor cells migrating in a polyglycolic acid biosynthetic scaffold in culture (image courtesy Erin Lavik and Robert Langer). On p. 1111, Snyder and colleagues apply neural stem cell—seeded scaffolds for brain repair.

Iodine-stained pollens in an anther from heterozygously (Waxy/waxy) targeted rice plant (see p. 1030).

A representation of human immunoglobulin G (center), which has now been produced in transchromosomic calves (see p. 889). FISH images in the background indicate the artificial chromosome (red). Photo courtesy Photo Researchers. FISH images courtesy Robl et al.

A transgenic, cloned zebrafish expressing green fluorescent protein. Cloning zebrafish from long-term cultured cells should allow genetic targeting in these fish (see Lee et al. p. 795).

Nuclear transplantation in process. A bovine oocyte is held by a glass pipette (left),while a glass needle (right) is used to remove the maternal nucleus. A polar body (top) is located just underneath the zona pellucida (the thick envelope surrounding the ovum). Stained with bisbenzimide (Hoeschst 33342; Sigma) dye and visualized under a fluorescence microscope. On page 689, Lanza et al. report the successful transplantation of cloned cells into a steer. Picture courtesy Advanced Cell Technology.

Canola field in western Australia. GM canola has been shown to outcross with "organically grown" varieties in Canada (see p. 537). Photo © Photo Researchers.

Colored scanning electron micrograph of T cells (green) superimposed onto firbroblasts (orange). On p. 460, Collas and colleagues use T cell extracts to reprogram fibroblasts. Images © Photo Researchers, Inc.

An etched fiber-optic bundle used to create a self-assembled bead array for the analysis of alternatively spliced mRNAs (see Fu and colleagues, p.353). A pit at the tip of each fiber holds a 3.1 micron bead bearing between 500,000 and 750,000 oligonucleotides. Binding of labeled sample oligonucleotides is detected by a camera at the other end of the fibers.

Joy, one of five cloned knockout piglets produced by Dai et.al. (p. 251). The gene inactivated in these pigs, α 1,3 galactosyl transferase, synthesizes an antigen involved in the immune rejection of pig to human transplants.

An artificial antigen-presenting cell (APC) interacting with a cytotoxic T cell in vitro. June and colleagues have constructed APCs that express ligands for the T-cell receptor, CD28, and the 4–1BB costimulatory molecules (see p. 143). © Doug Struthers.

The cover shows the airways of the bronchus of a patient suffering from cystic fibrosis. The airways are lined with hair like cilia (dark blue, purple) which normally clear bacteria and mucus (yellow) from the lungs. In cystic fibrosis, mucus accumulates and life-threatening infections develop. On p. 47, Liu and colleagues use RNA trans-splicing to attempt to correct one of the underlying genetic mutations. Scanning electron micrograph by Jergen Burger, Max Planck Institute, Science Photo Library.