Search results for "Serial homology"
showing 4 items of 4 documents
Progressive derivation of serially homologous neuroblast lineages in the gnathal CNS of Drosophila
2018
Along the anterior-posterior axis the central nervous system is subdivided into segmental units (neuromeres) the composition of which is adapted to their region-specific functional requirements. In Drosophila melanogaster each neuromere is formed by a specific set of identified neural stem cells (neuroblasts, NBs). In the thoracic and anterior abdominal region of the embryonic ventral nerve cord segmental sets of NBs resemble the ground state (2nd thoracic segment, which does not require input of homeotic genes), and serial (segmental) homologs generate similar types of lineages. The three gnathal head segments form a transitional zone between the brain and the ventral nerve cord. It has be…
Gene expression profiles uncover individual identities of gnathal neuroblasts and serial homologies in the embryonic CNS of Drosophila.
2015
The numbers and types of progeny cells generated by neural stem cells in the developing CNS are adapted to its region-specific functional requirements. In Drosophila, segmental units of the CNS develop from well-defined patterns of neuroblasts. Here we constructed comprehensive neuroblast maps for the three gnathal head segments. Based on the spatiotemporal pattern of neuroblast formation and the expression profiles of 46 marker genes (41 transcription factors), each neuroblast can be uniquely identified. Compared with the thoracic ground state, neuroblast numbers are progressively reduced in labial, maxillary and mandibular segments due to smaller sizes of neuroectodermal anlagen and, part…
Neuroblast pattern and identity in the Drosophila tail region and role of doublesex in the survival of sex-specific precursors.
2013
The central nervous system is composed of segmental units (neuromeres), the size and complexity of which evolved in correspondence to their functional requirements. In Drosophila, neuromeres develop from populations of neural stem cells (neuroblasts) that delaminate from the early embryonic neuroectoderm in a stereotyped spatial and temporal pattern. Pattern units closely resemble the ground state and are rather invariant in thoracic (T1-T3) and anterior abdominal (A1-A7) segments of the embryonic ventral nerve cord. Here, we provide a comprehensive neuroblast map of the terminal abdominal neuromeres A8-A10, which exhibit a progressively derived character. Compared with thoracic and anterio…
Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Li…
2015
How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual’s survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerf…