Browsing by Author "Extavour, Cassandra"
Now showing items 21-35 of 35
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Long-Lost Relative Claims Orphan Gene: oskar in a Wasp
Extavour, Cassandra G. (Public Library of Science, 2011) -
The Maternal and Early Embryonic Transcriptome of the Milkweed Bug Oncopeltus fasciatus
Ewen-Campen, Benjamin Scott; Shaner, Nathan; Panfilio, Kristen A.; Suzuki, Yuichiro; Roth, Siegfried; Extavour, Cassandra G. (BioMed Central, 2011)Background. Most evolutionary developmental ("evo-devo") studies of emerging model organisms focus on small numbers of candidate genes cloned individually using degenerate PCR. However, newly available sequencing technologies ... -
Mechanisms of germ cell specification across the metazoans: Epigenesis and preformation
Extavour, Cassandra G.; Akam, Michael (The Company of Biologists, 2003)Germ cells play a unique role in gamete production, heredity and evolution. Therefore, to understand the mechanisms that specify germ cells is a central challenge in developmental and evolutionary biology. Data from model ... -
The Molecular Machinery of Germ Line Specification
Ewen-Campen, Benjamin Scott; Schwager, Evelyn E.; Extavour, Cassandra G. (Wiley-Blackwell, 2009)Germ cells occupy a unique position in animal reproduction, development, and evolution. In sexually reproducing animals, only they can produce gametes and contribute genetically to subsequent generations. Nonetheless, germ ... -
Notch/Delta signalling is not required for segment generation in the basally branching insect Gryllus bimaculatus
Kainz, F.; Ewen-Campen, B.; Akam, M.; Extavour, Cassandra G. (The Company of Biologists, 2011)Arthropods and vertebrates display a segmental body organisation along all or part of the anterior-posterior axis. Whether this reflects a shared, ancestral developmental genetic mechanism for segmentation is uncertain. ... -
De Novo Assembly and Characterization of a Maternal and Developmental Transcriptome for the Emerging Model Crustacean Parhyale hawaiensis
Zeng, Victor; Villanueva, Karina E; Ewen-Campen, Benjamin Scott; Alwes, Frederike; Browne, William E; Extavour, Cassandra G. (BioMed Central, 2011)Background: Arthropods are the most diverse animal phylum, but their genomic resources are relatively few. While the genome of the branchiopod Daphnia pulex is now available, no other large-scale crustacean genomic resources ... -
Oogenesis: Making the Mos of Meiosis
Extavour, Cassandra G. (Elsevier BV, 2009)Meiosis is an ancient type of cell division whose advent allowed the evolution of sexual reproduction. The evolutionary history of the specialization that allowed gamete production to emerge from a simple reduction division ... -
Patterns of cell lineage, movement, and migration from germ layer specification to gastrulation in the amphipod crustacean Parhyale hawaiensis
Alwes, Frederike; Hinchen, Billy; Extavour, Cassandra G. (Elsevier BV, 2011)The acquisition of specific cell fates throughout embryonic development is one of the core problems in developmental and evolutionary biology. In the amphipod Parhyale hawaiensis all three germ layers and the germ line are ... -
A premeiotic function forboulein the planarianSchmidtea mediterranea
Iyer, Harini; Issigonis, Melanie; Sharma, Prashant Pradeep; Extavour, Cassandra G.; Newmark, Phillip A. (Proceedings of the National Academy of Sciences, 2016)Mutations in Deleted in Azoospermia (DAZ), a Y chromosome gene, are an important cause of human male infertility. DAZ is found exclusively in primates, limiting functional studies of this gene to its homologs: boule, ... -
Refuting the hypothesis that the acquisition of germ plasm accelerates animal evolution
Whittle, Carrie; Extavour, Cassandra G. (Springer Nature, 2016)Primordial germ cells (PGCs) give rise to the germ line in animals. PGCs are specified during embryogenesis either by an ancestral mechanism of cell-cell signalling (induction) or by a derived mechanism of maternally ... -
The roles of cell size and cell number in determining ovariole number in Drosophila
Sarikaya, Didem Pelin; Belay, Abel A.; Ahuja, Abha; Dorta, Aisha; Green, Delbert André; Extavour, Cassandra G. (Elsevier BV, 2012)All insect ovaries are composed of functional units called ovarioles, which contain sequentially developing egg chambers. The number of ovarioles varies between and within species. Ovariole number is an important determinant ... -
The transcriptional repressor Blimp-1 acts downstream of BMP signaling to generate primordial germ cells in the cricket Gryllus bimaculatus
Nakamura, Taro; Extavour, Cassandra G. (The Company of Biologists, 2016)Germ cells are specified by one of two well-characterised modes: via maternally inherited germ plasm (as seen in the case of Drosophila, C. elegans, Xenopus and zebrafish) or via inductive signals later during embryogenesis ... -
Vasa and nanos expression patterns in a sea anemone and the evolution of bilaterian germ cell specification mechanisms
Extavour, Cassandra G.; Pang, Kevin; Matus, David Q.; Martindale, Mark Q. (Wiley-Blackwell, 2005)Most bilaterians specify primordial germ cells (PGCs) during early embryogenesis using either inherited cytoplasmic germ line determinants (preformation) or induction of germ cell fate through signaling pathways (epigenesis). ... -
vasa and piwi are required for mitotic integrity in early embryogenesis in the spider Parasteatoda tepidariorum
Schwager, Evelyn; Meng, Yue; Extavour, Cassandra G. (Elsevier BV, 2015)Studies in vertebrate and invertebrate model organisms on the molecular basis of primordial germ cell (PGC) specification have revealed that metazoans can specify their germ line either early in development by maternally ... -
Vasa Protein Expression is Restricted to the Small Micromeres of the Sea Urchin, but is Inducible in Other Lineages Early in Development
Wessel, Gary; McClay, David; Oliveri, Paola; George, Sophie; Extavour, Cassandra; Song, Jia L.; Gustafson, Eric; Juliano, Celina E.; Lopez, Manuel; Voronina, Ekaterina (Elsevier, 2008)Vasa is a DEAD-box RNA helicase that functions in translational regulation of specific mRNAs. In many animals it is essential for germ line development and may have a more general stem cell role. Here we identify vasa in ...