نتایج جستجو برای: caspian lamprey

تعداد نتایج: 5247  

2009
Gayle K. McEwen Debbie K. Goode Hugo J. Parker Adam Woolfe Heather Callaway Greg Elgar

Comparisons between diverse vertebrate genomes have uncovered thousands of highly conserved non-coding sequences, an increasing number of which have been shown to function as enhancers during early development. Despite their extreme conservation over 500 million years from humans to cartilaginous fish, these elements appear to be largely absent in invertebrates, and, to date, there has been lit...

Journal: :Endocrinology 1994
C J Knox S K Boyd S A Sower

Quantitative in vitro autoradiography was used to characterize and localize putative GnRH receptors in the anterior pituitary of the adult female sea lamprey, Petromyzon marinus. Pituitaries were sectioned at 20 microns and incubated for 3 h at 4 C with DAla6,Pro9 NEt mammalian GnRH as both the labeled and unlabeled ligand. Scatchard analysis revealed two classes of high affinity binding sites ...

1998
Auke Jan Ijspeert John Hallam David Willshaw

This paper presents how neural swimming controllers for a lamprey can be adapted for controlling both the swimming and the walking of a salamander like an imat Using a Genetic Algorithm GA we extend a connectionist model of the biological Central Pat tern Generator CPG controlling the swimming of a lamprey Ekeberg to control the locomotion of a D mechanical simulation of a salamander We rst sum...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Robert Cerny Maria Cattell Tatjana Sauka-Spengler Marianne Bronner-Fraser Feiqiao Yu Daniel Meulemans Medeiros

The appearance of jaws was a turning point in vertebrate evolution because it allowed primitive vertebrates to capture and process large, motile prey. The vertebrate jaw consists of separate dorsal and ventral skeletal elements connected by a joint. How this structure evolved from the unjointed gill bar of a jawless ancestor is an unresolved question in vertebrate evolution. To understand the d...

2013
Ke Li Cory O. Brant Michael J. Siefkes Hanna G. Kruckman Weiming Li

A sulphate-conjugated bile alcohol, 3,12-diketo-4,6-petromyzonene-24-sulfate (DKPES), was identified using bioassay-guided fractionation from water conditioned with sexually mature male sea lamprey (Petromyzon marinus). The structure and relative stereochemistry of DKPES was established using spectroscopic data. The electro-olfactogram (EOG) response threshold of DKPES was 10(-7) Molar (M) and ...

2012
Stacia A. Sower Wayne A. Decatur Nerine T. Joseph Mihael Freamat

This minireview provides the current status on gonadotropin-releasing hormone receptors (GnRH-R) in vertebrates, from the perspective of a basal vertebrate, the sea lamprey, and provides an evolutionary scheme based on the recent advance of whole genome sequencing. In addition, we provide a perspective on the functional divergence and evolution of the receptors. In this review we use the phylog...

2009
Tatyana V. Piterkina

The spatial and temporal structure of spider communities was studied in the clay semi-desert of the north-western Caspian Lowland, western Kazakhstan (49°23' N, 46°47' E). The soils and vegetation are complex, being composed of a mosaic of desert and steppe plant communities. Besides the native associations, there are plantations of different tree species. The ground-dwelling spider assemblages...

Journal: :General and comparative endocrinology 2006
Hiroshi Kawauchi Stacia A Sower

The adenohypophysial hormones have been believed to have evolved from several ancestral genes by duplication followed by evolutionary divergence. To understand the origin and evolution of the endocrine systems in vertebrates, we have characterized adenohypophysial hormones in an agnathan, the sea lamprey Petromyzon marinus. In gnathostomes, adrenocorticotropin (ACTH) and melanotropin (MSH) toge...

Journal: :Frontiers of Biogeography 2013

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