scholarly journals Who is the best surrogate for germ stem cell transplantation in fish?

2021 ◽  
Author(s):  
Roman Franěk ◽  
Yu Cheng ◽  
Michaela Fučíková ◽  
Vojtěch Kašpar ◽  
Xuan Xie ◽  
...  
Keyword(s):  
Germ Cell ◽  
Fish Species ◽  
Reproductive Output ◽  
Large Body ◽  
Gonadal Development ◽  
Transgenic Strain ◽  
Model Species ◽  
Large Body Size ◽  
Dead End ◽  
Late Maturation

Surrogate reproduction technology in fish has potential for aquaculture as well as endangered species preservation and propagation. Species with some unfavourable biological characteristics for culturing such as a late maturation or a large body size are ideal candidates for surrogate reproduction using smaller and faster-maturing host. One of the general prerequisites for the successful surrogacy and the pure donor-derived gamete production is the sterility of the host. Various sterilization methods have been developed and used in fish surrogacy; however, a direct comparison of available methods is missing. Such a knowledge gap hinders choice for the surrogate in various fish species, including those in high commercial demand such as tuna or sturgeons, where is a particular limitation from the point of the live material availability and difficulty to perform a high throughput assessment of different surrogates. Yet, large sturgeons or tuna species are one of the most prominent candidates for surrogacy. Zebrafish was utilized in this study as a model species to answer whether and to which extent different sterilization strategies can affect the surrogacy. Germ cell-depleted recipients (produced using knockdown of dead end gene), triploid recipients, and zebrafish x pearl danio hybrid recipients were tested as they represent the most frequently used types of surrogates. Spermatogonia isolated from vas::EGFP transgenic strain were intraperitoneally transplanted into swim-up 5-day old zebrafish. Transplantation success, survival, gonadal development, and reproductive output of the fish was analyzed. Germ cell-depleted recipients with empty gonads were identified as the most convenient among tested sterilization methods considering surrogacy induction success and reproductive output. The present study stands as significant aid for selecting suitable surrogates in various fish species.

A new species of the subgenus Scheloribates (Topobates) (Acari: Oribatida: Scheloribatidae) from Panama

2020 ◽  
Vol 29 (2) ◽  
pp. 278-283
Author(s):  
S.G. Ermilov
Keyword(s):  
New Species ◽  
Body Size ◽  
Leaf Litter ◽  
Related Species ◽  
Large Body ◽  
Oribatid Mite ◽  
Neotropical Region ◽  
Large Body Size ◽  
First Time ◽  
A New Species

The oribatid mite subgenus Scheloribates (Topobates) Grandjean, 1958, is recorded from the Neotropical region for the first time. A new species of this subgenus is described from the leaf litter collected in Cayo Agua Island, Panama. Scheloribates (Topobates) panamaensis sp. nov. differs from its related species by the very large body size and presence of a strong ventrodistal process on the leg femora II–IV.

scholarly journals Embryonic development of the fire-eye-tetra Moenkhausia oligolepis (Characiformes: Characidae)

Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Raquel Santos dos Santos ◽  
Jeane Rodrigues Rodrigues ◽  
Jhennifer Gomes Cordeiro ◽  
Hadda Tercya ◽  
Marissol Leite ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Germ Cell ◽  
Cell Transplantation ◽  
Species Conservation ◽  
Biotechnological Applications ◽  
Model Species ◽  
Phylogenetic Classification ◽  
Laboratory Conditions ◽  
Adhesive Surface ◽  
Taxonomic Studies

Summary This study describes the embryonic development of Moenkhausia oligolepis in laboratory conditions. After fertilization, the embryos were collected every 10 min up to 2 h, then every 20 min up to 4 h, and afterwards every 30 min until hatching. The fertilized eggs of M. oligolepis measured approximately 0.85 ± 0.5 mm and had an adhesive surface. Embryonic development lasted 14 h at 25ºC through the zygote, cleavage, blastula, gastrula, neurula, and segmentation phases. Hatching occurred in embryos around the 30-somites stage. The present results contribute only the second description of embryonic development to a species from the Moenkhausia genus, being also the first for this species. Such data are of paramount importance considering the current conflicting state of this genus phylogenetic classification and may help taxonomic studies. Understanding the biology of a species that is easily managed in laboratory conditions and has an ornamental appeal may assist studies in its reproduction to both supply the aquarium market and help the species conservation in nature. Moreover, these data enable the use of M. oligolepis as a model species in biotechnological applications, such as the germ cell transplantation approach.

scholarly journals Atmospheric Hypoxia Limits Selection for Large Body Size in Insects

PLoS ONE ◽  
2009 ◽  
Vol 4 (1) ◽  
pp. e3876 ◽  
Author(s):  
C. Jaco Klok ◽  
Jon F. Harrison
Keyword(s):  
Body Size ◽  
Large Body ◽  
Large Body Size ◽  
Selection For

scholarly journals New records of ring nematodes, Bakernema enormese n. sp. and Criconema (Nothocriconemella) graminicola Loof, Wouts & Yeates, 1997 (Nematoda: Criconematidae) from natural forests of Vietnam

2019 ◽  
Vol 41 (3) ◽  
Author(s):  
Nguyen Ngoc Chau
Keyword(s):  
New Species ◽  
Body Size ◽  
New Records ◽  
Large Body ◽  
Lateral View ◽  
The Body ◽  
Natural Forests ◽  
Large Body Size ◽  
Stylet Length ◽  
North Vietnam

Bakernema enormese sp. n., collected from rhizosphere of forest wood trees in Muong Phang, Dien Bien Province (north Vietnam) is described and illustrated. The new species is characterized by large body size and stylet. In general, this new species is close to two existing species of the same genus, B. inaequale and B. dauniense by cuticle structure in transparent membranous projections which appear in lateral view as spine-like structures on each annulus. These structure arranged into several rows along the body. In morphology, the new species differs from B. inaequale and B. dauniense  by body and stylet length, i.e. 609–842 µm and 143.5–150 µm vs. 391–578 µm and 59–74 µm for B. inaequale and vs. 391–461 µm and 65–74 µm for B. dauniense. In addition, new species can be distinguished from B. inaequale by the longer membranous projection, 8–12 vs. 6–10 µm and vagina shape, curved vs. sigmoid. From B. dauniense, the new species differs by the much longer membranous projection, 8–12 vs. 1.4–2.2 µm and less number annules between vulva and tail end (RV), 3–4 vs. 7.8 annules. The presence of Criconema (Nothocriconemella) graminicola Loof, Wouts & Yeates, in Vietnam with morphometrics, illustrators and remarks given.

scholarly journals The germ cell marker dead end reveals alternatively spliced transcripts with dissimilar expression

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ana Carina Nogueira Vasconcelos ◽  
Danilo Pedro Streit ◽  
Anna Octavera ◽  
Misako Miwa ◽  
Naoki Kabeya ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Marker ◽  
Dead End ◽  
Alternatively Spliced

scholarly journals New directions in assisted breeding techniques for fish conservation

2020 ◽  
Vol 32 (9) ◽  
pp. 807 ◽  
Author(s):  
Nicola Rivers ◽  
Jonathan Daly ◽  
Peter Temple-Smith
Keyword(s):  
Endangered Species ◽  
Germ Cell ◽  
Cell Transplantation ◽  
Fish Species ◽  
Captive Breeding ◽  
Germ Line ◽  
Management Strategies ◽  
Germ Cell Transplantation ◽  
Spawning Periods ◽  
Breeding Techniques

Fish populations continue to decline globally, signalling the need for new initiatives to conserve endangered species. Over the past two decades, with advances in our understanding of fish germ line biology, new exsitu management strategies for fish genetics and reproduction have focused on the use of germ line cells. The development of germ cell transplantation techniques for the purposes of propagating fish species, most commonly farmed species such as salmonids, has been gaining interest among conservation scientists as a means of regenerating endangered species. Previously, exsitu conservation methods in fish have been restricted to the cryopreservation of gametes or maintaining captive breeding colonies, both of which face significant challenges that have restricted their widespread implementation. However, advances in germ cell transplantation techniques have made its application in endangered species tangible. Using this approach, it is possible to preserve the genetics of fish species at any stage in their reproductive cycle regardless of sexual maturity or the limitations of brief annual spawning periods. Combining cryopreservation and germ cell transplantation will greatly expand our ability to preserve functional genetic samples from threatened species, to secure fish biodiversity and to produce new individuals to enhance or restore native populations.

scholarly journals Cope's Rule and Romer's theory: patterns of diversity and gigantism in eurypterids and Palaeozoic vertebrates

2009 ◽  
Vol 6 (2) ◽  
pp. 265-269 ◽  
Author(s):  
James C. Lamsdell ◽  
Simon J. Braddy
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Feeding Strategy ◽  
Large Body ◽  
Large Body Size ◽  
Causal Mechanisms ◽  
Family Level ◽  
Cope’S Rule ◽  
Abiotic Environmental Factors

Gigantism is widespread among Palaeozoic arthropods, yet causal mechanisms, particularly the role of (abiotic) environmental factors versus (biotic) competition, remain unknown. The eurypterids (Arthropoda: Chelicerata) include the largest arthropods; gigantic predatory pterygotids (Eurypterina) during the Siluro-Devonian and bizarre sweep-feeding hibbertopterids (Stylonurina) from the Carboniferous to end-Permian. Analysis of family-level originations and extinctions among eurypterids and Palaeozoic vertebrates show that the diversity of Eurypterina waned during the Devonian, while the Placodermi radiated, yet Stylonurina remained relatively unaffected; adopting a sweep-feeding strategy they maintained their large body size by avoiding competition, and persisted throughout the Late Palaeozoic while the predatory nektonic Eurypterina (including the giant pterygotids) declined during the Devonian, possibly out-competed by other predators including jawed vertebrates.

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