caa a22 4500 477095585 CHVBK 20180405111526.0 cr unu---uuuuu 170330e19960501xx s 000 0 eng 10.1007/BF00185875 doi (NATIONALLICENCE)springer-10.1007/BF00185875 Early organization of the pituitary gland in Sparus aurata L. (Teleostei) An ultrastructural study [Elektronische Daten] [M. Villaplana, A. Ayala, M. Hernández, B. Agulleiro] The cell organization of the pituitary gland and the relationship between neurohypophysis and adenohypophysis in the early developmental stages of the gilthead sea bream, Sparus aurata, were studied by electron microscopy. In newly hatched larvae, the pituitary gland was embedded in the ventral floor of the diencephalon and separated from the hypothalamus by a continuous basal lamina. Elongated mesenchymal cells next to the ventral surface were observed. At this stage, there was no neurohypophysis and the adenohypophysis consisted of undifferentiated endocrine cells with small scarce secretory granules and a few stellate cells, with no distinctive zonation. An incipient neurohypophysis was present in 1-day-old larvae. The first evagination of the neurohypophysis into the adenohypophysis were observed in 2-day-old larvae and developed progressively with age, being deeper in the caudal zone. Two regions in the adenohypophysis, one anterior — the presumptive pars distalis — and one posterior — the presumptive pars intermedia — were found in 2-day-old larvae. Three regions (rostral and proximal pars distalis and pars intermedia) were clearly distinguishable in 4-day-old larvae. The ultrastructural features of the pituitary endocrine cells varied during gland differentiation, with the secretory granules gradually increasing in number and size, accompanying organelle development. Nevertheless, even in the oldest larvae studied (65 days), undifferentiated cells similar to those in the earliest stages were observed. The first blood vessels appeared in the neurohypophysis around 16 days after hatching. During early development, the pituitary gland progressively emerged from the ventral floor of the brain. By 16 days, the principal pattern of the pituitary gland architecture appeared to be established. Springer-Verlag, 1996 Pituitary gland nationallicence Development nationallicence Ultrastructure nationallicence Sparus aurata (Teleostei) nationallicence Villaplana M. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut Ayala A. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut Hernández M. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut Agulleiro B. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut Anatomy and Embryology Springer-Verlag 193/5(1996-05-01), 441-452 0340-2061 193:5<441 1996 193 429 https://doi.org/10.1007/BF00185875 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00185875 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Villaplana M. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut NATIONALLICENCE 700 1- Ayala A. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut NATIONALLICENCE 700 1- Hernández M. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut NATIONALLICENCE 700 1- Agulleiro B. Department of Cell Biology, Faculty of Biology, University of Murcia, E-30100, Murcia, Spain aut NATIONALLICENCE 773 0- Anatomy and Embryology Springer-Verlag 193/5(1996-05-01), 441-452 0340-2061 193:5<441 1996 193 429 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer