scholarly journals A gonad-expressed opsin mediates light-induced spawning in the jellyfish Clytia

2017 ◽  
Author(s):  
Gonzalo Quiroga Artigas ◽  
Pascal Lapébie ◽  
Lucas Leclère ◽  
Noriyo Takeda ◽  
Ryusaku Deguchi ◽  
...  
Keyword(s):  
Gene Family ◽  
Oocyte Maturation ◽  
Tissue Level ◽  
Neurosecretory Cells ◽  
Opsin Gene ◽  
Gamete Release ◽  
Animal Kingdom ◽  
Dark Light ◽  
Induced Spawning ◽  
Environmental Light

AbstractAcross the animal kingdom, environmental light cues are widely involved in regulating gamete release, but the molecular and cellular bases of the photoresponsive mechanisms are poorly understood. In hydrozoan jellyfish, spawning is triggered by dark-light or light-dark transitions acting on the gonad, and is mediated by oocyte maturation-inducing neuropeptide hormones (MIHs) released from the ectoderm. We determined in Clytia hemisphaerica that blue-cyan light triggers spawning in isolated gonads. A candidate opsin (Opsin9) was found co-expressed with MIH within specialised ectodermal cells. Opsin9 knockout jellyfish generated by CRISPR/Cas9 failed to undergo oocyte maturation and spawning, a phenotype reversible by synthetic MIH. Gamete maturation and release in Clytia is thus regulated by gonadal photosensory-neurosecretory cells that secrete MIH in response to light via Opsin9. Similar cells in ancestral eumetazoans may have allowed tissue-level photo-regulation of diverse behaviours, a feature elaborated in cnidarians in parallel with expansion of the opsin gene family.

scholarly journals A gonad-expressed opsin mediates light-induced spawning in the jellyfish Clytia

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Gonzalo Quiroga Artigas ◽  
Pascal Lapébie ◽  
Lucas Leclère ◽  
Noriyo Takeda ◽  
Ryusaku Deguchi ◽  
...  
Keyword(s):  
Gene Family ◽  
Oocyte Maturation ◽  
Tissue Level ◽  
Neurosecretory Cells ◽  
Opsin Gene ◽  
Gamete Release ◽  
Animal Kingdom ◽  
Dark Light ◽  
Induced Spawning ◽  
Environmental Light

Across the animal kingdom, environmental light cues are widely involved in regulating gamete release, but the molecular and cellular bases of the photoresponsive mechanisms are poorly understood. In hydrozoan jellyfish, spawning is triggered by dark-light or light-dark transitions acting on the gonad, and is mediated by oocyte maturation-inducing neuropeptide hormones (MIHs) released from the ectoderm. We determined in Clytia hemisphaerica that blue-cyan light triggers spawning in isolated gonads. A candidate opsin (Opsin9) was found co-expressed with MIH within specialised ectodermal cells. Opsin9 knockout jellyfish generated by CRISPR/Cas9 failed to undergo oocyte maturation and spawning, a phenotype reversible by synthetic MIH. Gamete maturation and release in Clytia is thus regulated by gonadal photosensory-neurosecretory cells that secrete MIH in response to light via Opsin9. Similar cells in ancestral eumetazoans may have allowed tissue-level photo-regulation of diverse behaviours, a feature elaborated in cnidarians in parallel with expansion of the opsin gene family.

scholarly journals Phylogenetic comparison and splice site conservation of eukaryotic U1 snRNP-specific U1-70K gene family

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tao Fan ◽  
Yu-Zhen Zhao ◽  
Jing-Fang Yang ◽  
Qin-Lai Liu ◽  
Yuan Tian ◽  
...  
Keyword(s):  
Gene Family ◽  
Splice Site ◽  
Messenger Rna ◽  
Expression Patterns ◽  
Protein Structures ◽  
Single Copy ◽  
Central Component ◽  
Animal Kingdom ◽  
Functional Studies ◽  
U1 Snrnp

AbstractEukaryotic cells can expand their coding ability by using their splicing machinery, spliceosome, to process precursor mRNA (pre-mRNA) into mature messenger RNA. The mega-macromolecular spliceosome contains multiple subcomplexes, referred to as small nuclear ribonucleoproteins (snRNPs). Among these, U1 snRNP and its central component, U1-70K, are crucial for splice site recognition during early spliceosome assembly. The human U1-70K has been linked to several types of human autoimmune and neurodegenerative diseases. However, its phylogenetic relationship has been seldom reported. To this end, we carried out a systemic analysis of 95 animal U1-70K genes and compare these proteins to their yeast and plant counterparts. Analysis of their gene and protein structures, expression patterns and splicing conservation suggest that animal U1-70Ks are conserved in their molecular function, and may play essential role in cancers and juvenile development. In particular, animal U1-70Ks display unique characteristics of single copy number and a splicing isoform with truncated C-terminal, suggesting the specific role of these U1-70Ks in animal kingdom. In summary, our results provide phylogenetic overview of U1-70K gene family in vertebrates. In silico analyses conducted in this work will act as a reference for future functional studies of this crucial U1 splicing factor in animal kingdom.

scholarly journals Sexual selection after gamete release in broadcast spawning invertebrates

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200069 ◽  
Author(s):  
Jonathan P. Evans ◽  
Rowan A. Lymbery
Keyword(s):  
Sexual Selection ◽  
Mate Choice ◽  
Sperm Competition ◽  
Sexual Conflict ◽  
Gamete Release ◽  
Theme Issue ◽  
Animal Kingdom ◽  
External Fertilization ◽  
Broadcast Spawning ◽  
Males And Females

Broadcast spawning invertebrates offer highly tractable models for evaluating sperm competition, gamete-level mate choice and sexual conflict. By displaying the ancestral mating strategy of external fertilization, where sexual selection is constrained to act after gamete release, broadcast spawners also offer potential evolutionary insights into the cascade of events that led to sexual reproduction in more ‘derived’ groups (including humans). Moreover, the dynamic reproductive conditions faced by these animals mean that the strength and direction of sexual selection on both males and females can vary considerably. These attributes make broadcast spawning invertebrate systems uniquely suited to testing, extending, and sometimes challenging classic and contemporary ideas in sperm competition, many of which were first captured in Parker's seminal papers on the topic. Here, we provide a synthesis outlining progress in these fields, and highlight the burgeoning potential for broadcast spawners to provide both evolutionary and mechanistic understanding into gamete-level sexual selection more broadly across the animal kingdom. This article is part of the theme issue ‘Fifty years of sperm competition’.

scholarly journals Identification of jellyfish neuropeptides that act directly as oocyte maturation inducing hormones

2017 ◽  
Author(s):  
Noriyo Takeda ◽  
Yota Kon ◽  
Gonzalo Quiroga Artigas ◽  
Pascal Lapébie ◽  
Carine Barreau ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Synthetic Peptides ◽  
Meiotic Maturation ◽  
Transcriptome Data ◽  
Dark Light ◽  
Jellyfish Species ◽  
Oocyte Meiotic Maturation ◽  
Critical Process

AbstractOocyte meiotic maturation is a critical process for sexually reproducing animals, and its core cytoplasmic regulators are highly conserved between species. In contrast, the few known Maturation Inducing Hormones (MIHs) that act on oocytes to initiate this process have highly variable molecular natures. Using the hydrozoan jellyfish species Clytia and Cladonema, which undergo oocyte maturation in response to dark-light and light-dark transitions respectively, we deduced from gonad transcriptome data amidated tetrapeptide sequences and found that synthetic peptides could induce maturation of isolated oocytes at nanomolar concentrations. Antibody preabsorption experiments conclusively demonstrated that these W/RPRPamide-related neuropeptides account for endogenous MIH activity produced by isolated gonads. We further showed that the MIH peptides are synthesised by neural-type cells in the gonad, are released following dark-light / light-dark transitions, and probably act on the oocyte surface. They are produced by male as well as female jellyfish and can trigger both sperm and egg release, suggesting a role in spawning coordination. We propose an evolutionary link between hydrozoan MIH and the neuropeptide hormones that regulate reproduction upstream of MIH in bilaterian species.

Analysis of Opsin Gene Family of Crimson Snapper (Lutjanus erythropterus)

Gene ◽  
2021 ◽  
pp. 145960
Author(s):  
Qiulu Liang ◽  
Gyamfua Afriyie ◽  
Zizhao Chen ◽  
Zhenmin Xu ◽  
Zhongdian Dong ◽  
...  
Keyword(s):  
Gene Family ◽  
Opsin Gene

scholarly journals The last common ancestor of most bilaterian animals possessed at least 9 opsins

2016 ◽  
Author(s):  
MD Ramirez ◽  
AN Pairett ◽  
MS Pankey ◽  
JM Serb ◽  
DI Speiser ◽  
...  
Keyword(s):  
Gene Family ◽  
Complex Traits ◽  
Common Ancestor ◽  
Opsin Gene ◽  
Last Common Ancestor ◽  
Phylogenetic Information ◽  
Animal Evolution ◽  
Animal Phyla ◽  
Evolution Understanding

AbstractThe opsin gene family encodes key proteins animals use to sense light and has expanded dramatically since it originated early in animal evolution. Understanding the origins of opsin diversity can offer clues to how separate lineages of animals have repurposed different opsin paralogs for different light-detecting functions. However, the more we look for opsins outside of eyes and from additional animal phyla, the more opsins we uncover, suggesting we still do not know the true extent of opsin diversity, nor the ancestry of opsin diversity in animals. To estimate the number of opsin paralogs present in both the last common ancestor of the Nephrozoa (bilaterians excluding Xenoacoelomorpha), and the ancestor of Cnidaria + Bilateria, we reconstructed a reconciled opsin phylogeny using sequences from 14 animal phyla, especially the traditionally poorly-sampled echinoderms and molluscs. Our analysis strongly supports a repertoire of at least nine opsin paralogs in the bilaterian ancestor and at least four opsin paralogs in the last common ancestor of Cnidaria + Bilateria. Thus, the kernels of extant opsin diversity arose much earlier in animal history than previously known. Further, opsins likely duplicated and were lost many times, with different lineages of animals maintaining different repertoires of opsin paralogs. This phylogenetic information can inform hypotheses about the functions of different opsin paralogs and be used to understand how and when opsins were incorporated into complex traits like eyes and extraocular sensors.

scholarly journals Central Nervous System Associated With Light Perception and Physiological Responses of Birds

2021 ◽  
Vol 12 ◽  
Author(s):  
Seong W. Kang
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Physiological Responses ◽  
Reproductive Function ◽  
Neurosecretory Cells ◽  
Raphe Nucleus ◽  
Light Perception ◽  
Environmental Light ◽  
Serotonin Neurons ◽  
Deep Brain Photoreceptors

Environmental light that animal receives (i.e., photoperiod and light intensity) has recently been shown that it affects avian central nervous system for the physiological responses to the environment by up or downregulation of dopamine and serotonin activities, and this, in turn, affects the reproductive function and stress-related behavior of birds. In this study, the author speculated on the intriguing possibility that one of the proposed avian deep-brain photoreceptors (DBPs), i.e., melanopsin (Opn4), may play roles in the dual sensory-neurosecretory cells in the hypothalamus, midbrain, and brain stem for the behavior and physiological responses of birds by light. Specifically, the author has shown that the direct light perception of premammillary nucleus dopamine-melatonin (PMM DA-Mel) neurons is associated with the reproductive activation in birds. Although further research is required to establish the functional role of Opn4 in the ventral tegmental area (VTA), dorsal raphe nucleus, and caudal raphe nucleus in the light perception and physiological responses of birds, it is an exciting prospect because the previous results in birds support this hypothesis that Opn4 in the midbrain DA and serotonin neurons may play significant roles on the light-induced welfare of birds.

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