392 research outputs found
Expression Pattern of nos1 in the Developing Nervous System of Ray-Finned Fish
No full textFish have colonized nearly all aquatic niches, making them an invaluable resource to understand vertebrate adaptation and gene family evolution, including the evolution of complex neural networks and modulatory neurotransmitter pathways. Among ancient regulatory molecules, the gaseous messenger nitric oxide (NO) is involved in a wide range of biological processes. Because of its short half-life, the modulatory capability of NO is strictly related to the local activity of nitric oxide synthases (Nos), enzymes that synthesize NO from L-arginine, making the localization of Nos mRNAs a reliable indirect proxy for the location of NO action domains, targets, and effectors. Within the diversified actinopterygian nos paralogs, nos1 (alias nnos) is ubiquitously present as a single copy gene across the gnathostome lineage, making it an ideal candidate for comparative studies. To investigate variations in the NO system across ray-finned fish phylogeny, we compared nos1 expression patterns during the development of two well-established experimental teleosts (zebrafish and medaka) with an early branching holostean (spotted gar), an important evolutionary bridge between teleosts and tetrapods. Data reported here highlight both conserved expression domains and species-specific nos1 territories, confirming the ancestry of this signaling system and expanding the number of biological processes implicated in NO activities
What Controls Sex Development in Fish?
No full text12 pages. Translations available in English, Spanish, Chinese, French, Portuguese, Japanese, German, Italian, Danish, and Norwegian.In mammals and in birds, the sex of an individual is determined by its genes. A sex determining gene on a sex chromosome influence the development of ovaries or testes. But sex in fishes is much more diverse! What controls sex development in fish? Sex genes like in mammals and birds? Or do other types of sex determination systems exist in fish?
In this short scientific graphic novel, Sophia Breslin, John Postlethwait, and Thomas Desvignes introduce you to the control of sex determination in fish: from the genetic regulation by sex determining genes and sex chromosomes to various cases of hermaphrodism and the influence of the environment, revealing the myriad of different sex determination systems found in fishes
A Mysterious Disease in Antarctic Fish
No full textWhile conducting research in Antarctica in 2018, scientists were surprised to capture many specimens of two species of fish that had massive skin tumors.
In this short graphic novel, “A mysterious disease in Antarctic fish“, Chloe DaMommio, John Postlethwait, and Thomas Desvignes take us on a scientific expedition to Antarctica aboard the US Antarctic Research Vessel Laurence M. Gould to capture those diseased fish, set sail to the isolated Palmer Station to sample them, then back to their laboratory in the States to identify the origin of this mysterious disease and its effects on the fish.
The graphic novel is available in English, Spanish, French, German, and Danish!
And to know more about the science behind the graphic novel, the research results are now published in open-access.This material is based upon work supported by the Office of Polar Programs at the National Science Foundation under NSF grant number OPP-1947040. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation
Supplemental Material for Wilson and Postlethwait, 2024
No full textZebrafish sex chromosomes have a region, unique in the genome, that contains protein-coding genes silenced in ovaries but expressed in testes and then transiently expressed in embryos as they begin to express their own genes. This region also contains maternal-specific genes encoding the protein-synthesis machinery used specifically by developing embryos, and is adjacent to mir-430, which targets maternal transcripts for degradation. This region defines a distinct maternal-to-zygotic-transisition block of genes.</p
Animal Nutrition and Digestion
No full textA "Animal Nutrition and Digestion" (Forrás: Biology! Bringing Science to Life; John H. Postlethwait, Janet L. Hopson, Ruth C. Veres) című fejezet magyar nyelvre történő lefordítása.gjangol-magyar természettudományi szakfordító, biológiaMSc/M
Molecular pedomorphism underlies craniofacial skeletal evolution in Antarctic notothenioid fishes
No full textAbstract Background Pedomorphism is the retention of ancestrally juvenile traits by adults in a descendant taxon. Despite its importance for evolutionary change, there are few examples of a molecular basis for this phenomenon. Notothenioids represent one of the best described species flocks among marine fishes, but their diversity is currently threatened by the rapidly changing Antarctic climate. Notothenioid evolutionary history is characterized by parallel radiations from a benthic ancestor to pelagic predators, which was accompanied by the appearance of several pedomorphic traits, including the reduction of skeletal mineralization that resulted in increased buoyancy. Results We compared craniofacial skeletal development in two pelagic notothenioids, Chaenocephalus aceratus and Pleuragramma antarcticum, to that in a benthic species, Notothenia coriiceps, and two outgroups, the threespine stickleback and the zebrafish. Relative to these other species, pelagic notothenioids exhibited a delay in pharyngeal bone development, which was associated with discrete heterochronic shifts in skeletal gene expression that were consistent with persistence of the chondrogenic program and a delay in the osteogenic program during larval development. Morphological analysis also revealed a bias toward the development of anterior and ventral elements of the notothenioid pharyngeal skeleton relative to dorsal and posterior elements. Conclusions Our data support the hypothesis that early shifts in the relative timing of craniofacial skeletal gene expression may have had a significant impact on the adaptive radiation of Antarctic notothenioids into pelagic habitats.</p
JUVENILE HORMONE AND THE ADULT DEVELOPMENT OF DROSOPHILA
No full textVolume: 147Start Page: 119End Page: 13
- …
