ca puccino, a Droso hila maternal P ef ect gene required P or polarity of the egg and embryo, is related to the vertebrate limb deformity locus Steven Emmons, Huy Phan, John Calley, Wenliang Chen, Brian James, and Lynn ~anseau' Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721 USA We report the molecular isolation of cappuccino (capu), a gene required for localization of molecular determinants within the developing Drosophila oocyte. The carboxy-terminal half of the capu protein is closely related to that of the vertebrate limb defo-ty locus, which is known to function in polarity determination in the developing vertebrate limb. In addition, capu shares both a proline-rich region and a 70-amino-acid domain with a number of other genes, two of which also function in pattern formation, the Saccharomyes cerevisiae BNIl gene and the Aspergillus FigA gene. We also show that capu mutant oocytes have abnormal microtubule distributions and premature microtubule-based cytoplasmic streaming within the oocyte, but that neither the speed nor the timing of the cytoplasmic streaming correlates with the strength of the mutant allele. This suggests that the premature cytoplasmic streaming in capu mutant oocytes does not suffice to explain the patterning defects. By inducing cytoplasmic streaming in wild-type oocytes during mid-oogenesis, we show that premature cytoplasmic streaming can displace staufen protein from the posterior pole, but not gurken mRNA from around the oocyte nucleus.[Key Words: Drosophila; cappuccino; pattern formation; cytoplasmic streaming; maternal effect; oogenesis; f ormins] Received July 5, 1995; revised version accepted August 25, 1995. The developing Drosophila oocyte is an excellent model system for studying the establishment of polarity within a single cell because the embryonic anterior-posterior and dorsal-ventral axes are initially organized within the oocyte. Anterior-posterior axis formation of the larva involves three pathways within the oocyte: one that establishes the anterior end, one at the posterior end to establish the abdomen and pole cells, and one at both termini of the oocyte to establish the ends (for reviews, see Manseau andSchupbach 1989a andNusslein-Volhard et al. 1987). The larval anterior is established during oogenesis through localization of the bicoid mRNA to the anterior end of the oocyte (Berleth et al. 1988; Driever and Niisslein-Volhard 1988a,b). Formation of the abdomen and pole cells requires localization of a large number of molecular determinants to the posterior pole of the developing oocyte (vasa protein, Hay et al. 1988;Lasko and Ashburner 1990; oskar mRNA and protein, Ephrusso et al. 1991;Kim-Ha et al. 1991;Smith et al. 1992; staufen protein, St. Johnston et al. 1991; tudor protein, Bardsley et al. 1993, nanos mRNA and protein, Wang and Lehmann 199 1 ; Ephrussi and Lehmann 1992j 'Corresponding author. Smith et al. 1992; germ cell-less mRNA, Jongens et al. 1994). The termini of the larva are marked during oogenesis b...

We have screened a collection of approximately 400 GAL4 enhancer trap lines for useful patterns of expression in the embryo, larval brain, imaginal discs, and ovary using a UAS‐lacZ reporter construct. Although similar patterns of expression have previously been reported in the original P[lacZ] enhancer trap screens, these lines are useful for directing ectopic expression of genes in discrete patterns during these stages. In addition, we have identified some unique patterns of expression that have not been previously reported. Dev. Dyn. 209:310–322, 1997. © 1997 Wiley‐Liss, Inc.

Histone acetyltransferases (HATs) are important to gene activation, altering chromatin structures to facilitate association of transcription proteins with gene promoters. The functions of individual HATs in mammalian developmental are not well defined. Our previous studies demonstrated that Gcn5, a prototypical HAT, is required for mesodermal maintenance in early embryos. Homozygous Gcn5 null embryos die soon after gastrulation, preventing determination of Gcn5 functions later during development. We report here the creation of a Gcn5 flox(neo) allele, which is only partially functional and gives rise to a hypomorphic phenotype. Mice homozygous for this allele had an increased risk of cranial neural tube closure defects (NTDs) and exencephaly. These defects were found at an even greater penetrance in

Gcn5 is a prototypical histone acetyltransferase (HAT) that serves as a coactivator for multiple DNA-bound transcription factors. We previously determined that deletion of Gcn512 (hereafter referred to as Gcn5) causes embryonic lethality in mice. Gcn5 null embryos undergo gastrulation but exhibit high levels of apoptosis, leading to loss of mesodermal lineages. To further define the functions of Gcn5 during development, we created Gcn5 ؊/؊ mouse embryonic stem (ES) cells. These cells survived in vitro and formed embryoid bodies (EBs) that expressed markers for ectodermal, mesodermal, and endodermal lineages.

External TPPMs are safe and effective in patients requiring long-term pacing after infected CIED removal.