Prospects for sexing mammalian sperm edited by Rupert P. Amman and George E. Seidel, Jr.; 288 pages; Cloth - $32.50, Paper - $22.50. Available from Colorado Associated University Press, 1338 Grandview Avenue, Box 480, University of Colorado, Boulder, Colorado, 80309

Progress has been made toward developing conditions to enable bull sperm to penetrate and fertilize ova in vitro. Efforts toward understanding oocyte maturation also hold promise. A procedure for bovine in vitro fertilization (IVF) involving recovery of oocytes near the time of ovulation, fertilization with in vitro capacitated sperm, embryo culture and transfer has led to development of normal offspring. Additional research is needed to facilitate recovery of mature oocytes and to improve in vitro conditions to insure development of viable embryos that can continue normal development following non-surgical uterine transfer.Bovine IVF promises a means to overcome certain types of infertility, to produce large numbers of half-siblings simultaneously, to greatly extend valuable semen, a better way to assess functional performance of male and female gametes, to provide synchronously developing pronuclear stage ova for nuclear transfer and/or gene injection, and many possibilities in research and for future applications.