Distribution of two forms of somatostatin in the brain, anterior intestine, and pancreas of adult lampreys (Petromyzon marinus)

Lamprey embryos were obtained by artificial fertilization to ascertain the contributions made by the neural crest to the head skeleton. Early-neurula-stage embryos of Petromyzon marinus were subjected to neural crest extirpation along the anterior half from one of seven zones, raised to a larval stage at which control larvae exhibit well-developed skeletons and analysed by light microscopy for any abnormalities to the cranial and visceral skeleton. The removal of premigratory neural crest at the level of the anterior prosencephalon (zone I) and at the level of somites 6 to 8 (zone VII) had no effect on skeletal development. However, the extirpation of neural crest from the intervening regions was positively correlated with deletions/reductions to the trabeculae (basicranial elements) and to the branchial arches (viscerocranial elements). Alterations to the trabeculae (16/27 cases, or 59%) occurred only after extirpation of zones II-V (corresponding to the posterior prosencephalon to midrhombencephalon) while alterations to the branchial arches (21/28 cases, or 75%) occurred only after removal of neural crest from zones III-VI (corresponding to the mesencephalon to the level of the fifth somite). Furthermore, the first three branchial arches were correlated in a majority of cases with neural crest from zone III, the next two arches with zones IV, V and VI and the last two arches with zone VI. Organs that develop within or adjacent to the area of neural crest extirpation such as the brain, notochord and lateral mesodermal derivatives were not affected. Parachordals were never altered by the operations nor were there any discernible changes to developing mucocartilage or to the prechondrogenic otic capsule. The contributions of the neural crest to the petromyzonid head skeleton described herein are compared with the roles of neural crest in the development of cranial and visceral skeletal elements in other vertebrates. The importance of these findings to the current hypothesis of the phylogeny of the vertebrate skeleton and the central role of the neural crest in vertebrate cephalization is discussed.

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Distribution of lamprey gonadotropin-releasing hormone in the brain and pituitary gland of larval, metamorphic, and adult sea lampreys, Petromyzon marinus

Canadian Journal of Zoology ◽

10.1139/z94-008 ◽

1994 ◽

Vol 72 (1) ◽

pp. 48-53 ◽

Cited By ~ 26

Author(s):

Glenda M. Wright ◽

Kim M. McBurney ◽

John H. Youson ◽

Stacia A. Sower

Keyword(s):

Pituitary Gland ◽

Preoptic Area ◽

Petromyzon Marinus ◽

Gonadotropin Releasing Hormone ◽

Immunoperoxidase Technique ◽

Dorsal Region ◽

Releasing Hormone ◽

Sea Lampreys ◽

The Brain

Lamprey gonadotropin-releasing hormone was demonstrated in the brains of larval, metamorphic, and adult sea lampreys, Petromyzon marinus, using an immunoperoxidase technique. Gonadotropin-releasing hormone was observed in the neurohypophysis and preoptic area of the brain of larval, metamorphic, juvenile, and prespawning adults. The occurrence of immunoreactive cells and the intensity of the immunostaining was lowest in larvae, but by stage 5 of metamorphosis there was a marked increase in the prevalence and staining of these cells, which continued into adults. In larvae and lampreys in metamorphic stages 1–4, most immunoreactive fibres were confined to the dorsal region of the neurohypophysis. During stage 5 there was an expansion of immunopositive fibres into the ventral portion of the neurohypophysis. Prominent immunoreactivity was observed throughout the neurohypophysis from stage 5 onward through the adult stages. Changes in immunoreactivity of these cells and fibres in the brain and neurohypophysis correlate well with increased concentrations of hormone in the brain during development and with the timing of presumed changes in activity of cells in the adenohypophysis during metamorphosis.

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Pheromone 3kPZS evokes context-dependent serotonin sexual dimorphism in the brain of the sea lamprey (Petromyzon marinus)

Integrative Zoology ◽

10.1111/1749-4877.12099 ◽

2015 ◽

Vol 10 (1) ◽

pp. 91-101 ◽

Cited By ~ 1

Author(s):

Yuwen CHUNG-DAVIDSON ◽

Huiyong WANG ◽

Anne M. SCOTT ◽

Weiming LI

Keyword(s):

Sexual Dimorphism ◽

Petromyzon Marinus ◽

Sea Lamprey ◽

Context Dependent ◽

The Brain

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Conserved expression of alternative splicing variants of peroxisomal acyl-CoA oxidase 1 in vertebrates and developmental and nutritional regulation in fish

Physiological Genomics ◽

10.1152/physiolgenomics.00136.2006 ◽

2007 ◽

Vol 28 (3) ◽

pp. 239-252 ◽

Cited By ~ 48

Author(s):

Sofia Morais ◽

Anja Knoll-Gellida ◽

Michèle André ◽

Christophe Barthe ◽

Patrick J. Babin

Keyword(s):

Alternative Splicing ◽

Early Stage ◽

Acyl Chain ◽

Amino Acid Sequences ◽

Fatty Acyl Chain ◽

Nutritional Regulation ◽

Vertebrate Lineage ◽

Anterior Intestine ◽

Acyl Coa Oxidase ◽

The Brain

The acyl-coenzyme A oxidase 1 (ACOX1) catalyzes the first, rate-limiting step in peroxisomal β-oxidation of medium to very long straight-chain fatty acids. Zebrafish ( Danio rerio) acox1 was characterized and compared with homologs from other sequenced genomes, revealing a remarkable conservation of structure in the vertebrate lineage. Strictly conserved regions of the deduced proteins included acyl-CoA oxidase and FAD binding domains, as well as a COOH-terminal peroxisomal targeting signal. Whole mount in situ hybridization showed that zebrafish acox1 transcripts were diffusely distributed in early-stage embryonic cells, then discreetly expressed in the brain and widely present in the liver and intestine at later stages. An evolutionarily conserved alternative splicing of the corresponding acox1 primary transcript was identified in teleosts and tetrapods including mammals, giving rise, after exon skipping, to two splice variants, ACOX1–3I and ACOX1–3II. Real-time quantitative RT-PCR on zebrafish adult tissues indicated high levels of both variants in the liver, anterior intestine, and to a lesser extent, in the brain. However, the ACOX1–3II transcript variant was expressed seven times more in zebrafish brain than the ACOX1–3I variant. These data suggest a tissue-specific modulation of ACOX1 activity by exchanging exon 3 duplicated isoforms containing amino acid sequences that are potentially implicated in fatty acyl chain specificity. In addition, a significant pretranslational up-regulation of zebrafish and rainbow trout ( Oncorhynchus mykiss) acox1 expression was observed in the anterior intestine after feeding. Taken together, these data indicate that ACOX1 alternative splicing isoforms play a key conserved role in the vertebrate fatty acid metabolism.

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