Assignment of 64 genes expressed in 28-day-old pig embryo to radiation hybrid map

A swine resource family was constructed at the National Institute of Animal Industry, Japan, in order to determine the genetic regions responsible for economically important traits, including fetus development. To identify genes expressed in the early stage of embryo development, we cataloged and mapped genes expressed in a 28-day-old normal pig embryo. In this effort, we have mapped 64 genes, which have map information in human genome onto a swine radiation hybrid (RH) map, IMpRH. These mappings provided additional chromosomal homologies between swine and human to improve the comparative map between the two species. The distribution of the genes assigned to swine chromosomes are as follows: 9 genes were assigned on SSC6; 6 genes each assigned on SSC5 and SSC14; 5 genes each assigned on SSC3, SSC4, and SSC8; 4 genes each assigned on SSC1, SSC7, SSC9, and SSC15; 3 genes each assigned on SSC2, SSC13 and SSCX; and 1 gene each assigned on SSC10, SSC11, and SSC16. Moreover, the present findings revealed 18 new chromosomal homologies between pig and human. Briefly, SSC3 regions were indicated to correspond with HSA1 and HSA10; SSC4 with HSA6; SSC5 with HSA2, HSA15, and HSA16; SSC6 with HSA3, HSA6, and HSA20; SSC7 with HSA11; SSC8 with HSA3, HSA6, and HSA7; SSC9 with HSA8; SSC13 with HSA1; SSC14 with HSA13; SSC15 with HSA19; SSC16 with HSA9. Received: 19 December 2000 / Accepted: 13 March 2001     

The effect of chronically ingested inorganic lead on brain levels of Fe,Zn, Cu,and Mn of 25 day old rat

Lead poisoning was produced in suckling rats by lead fed to lactating mother rats being transmitted to newborns $\text{via}$ maternal milk. The brain of 25 day old lead poisoned rats contained 6.0 to 12.5 ppm lead. Zinc was depressed 56% (cerebral cortex), 45% in cerebellum and 43% (caudate nucleus) whereas copper was depressed 52% in the cerebellum. Inhibition of monoamine oxidase (pargyline) or partial depletion of serotonin and norepinephrine did not alter the concentration of Fe, Cu, Zn, or Mn in brain.     

Mass isolation and culture of sea urchin micromeres

Summary A procedure is described for large-scale isolation of micromeres from 16-cell stage sea urchin embryos. One to two grams of >99% pure, viable micromeres (2.3 to 4.6 × 10⁸ cells) are routinely isolated in a single preparation. In culture, these cells uniformly proceed through their normal development, in synchrony with micromeres in whole embryos, ultimately differentiating typical larval skeletal structures. The attributes of this procedure are: (a) the very early time of isolation of the cells, directly after the division that establishes the cell line; (b) the large yield of cells; (c) the purity of the preparation of cell; and (d) their synchronous development in culture through skeletogenesis. The procedure greatly aids in making sea urchin micromeres a favorable material for molecular analysis of development. This work was supported in part by the following grants from the National Institutes of Health: Grant HL-10312 to A.H.W., Grant GM-20784 to Helen R. Whiteley, Grant ES-02190 to N. Karle Mottet, M.D., and Training Grants ES-07032 and HD-00266.