Paired fins in vertebrate evolution and ontogeny.

The origin of paired appendages became one of the most important adaptations of vertebrates, allowing them to lead active lifestyles and explore a wide range of ecological niches. The basic form of paired appendages in evolution is the fins of fishes. The problem of paired appendages has attracted the attention of researchers for more than 150 years.

The Molecular Mechanism of Body Axis Induction in Lampreys May Differ from That in Amphibians.

Lamprey homologues of the classic embryonic inducer Noggin are similar in expression pattern and functional properties to Noggin homologues of jawed vertebrates. All genes of vertebrates apparently originated from a single ancestral gene as a result of genome duplications. , and of lampreys, like and of gnathostomes, demonstrate the ability to induce complete secondary axes with forebrain and eye structures when overexpressed in embryos.

Loss of noggin1, a classic embryonic inducer gene, in elasmobranchs.

Secreted proteins of the Noggin family serve as pivotal regulators of early development and cell differentiation in all multicellular animals, including vertebrates. Noggin1 was identified first among all Noggins. Moreover, it was described as the first known embryonic inducer specifically secreted by the Spemann organizer and capable of inducing a secondary body axis when expressed ectopically.

Three paralogues in lampreys and gnathostomes-brothers or cousins?

is a key regulator of the early development of the vertebrate forebrain and sensory organs. In this study, we describe for the first time three paralogues in lamprey, representative of one of two basally diverged lineages of vertebrates-the agnathans. We also first describe three genes in sterlet-representative of one of the evolutionarily ancient clades of gnathostomes.

Two-Channel Indirect-Gap Photoluminescence and Competition between the Conduction Band Valleys in Few-Layer MoS.

MoS is a two-dimensional layered transition metal dichalcogenide with unique electronic and optical properties. The fabrication of ultrathin MoS is vitally important, since interlayer interactions in its ultrathin varieties will become thickness-dependent, providing thickness-governed tunability and diverse applications of those properties. Unlike with a number of studies that have reported detailed information on direct bandgap emission from MoS monolayers, reliable experimental evidence for thickness-induced evolution or transformation of the indirect bandgap remains scarce.