scholarly journals Captive breeding of two rare non-migratory galaxiids (Teleostei: Galaxiidae) for species conservation

2020 ◽  
Vol 132 (1) ◽  
pp. 42
Author(s):  
Daniel J. Stoessel ◽  
Tarmo A. Raadik ◽  
Michael D. Nicol ◽  
Peter S. Fairbrother ◽  
Ruby Campbell-Beschorner

Devising effective techniques for breeding and rearing rare non-migratory galaxiids is urgently required for conservation purposes where few animals exist in the wild for translocation or reintroduction. The development of such protocols is particularly pertinent in light of recent intense widespread bushfires and long-term drought in southeastern Australia, which have increased the likelihood of the need for captive maintenance to protect and recover remnant species. In this study, we promoted reproductive maturation via manipulation of day length and temperature, and produced viable offspring from two small, endemic freshwater galaxiids, Galaxias fuscus (Mack 1936) and Galaxias longifundus (Raadik 2014) using in vitro propagation techniques. Propagation trials resulted in 425 oocytes being stripped from four ripe G. fuscus females, and 1527 oocytes from three ripe G. longifundus females. Of these, 342 (80.5%) G. fuscus and 968 (63.4%) G. longifundus eggs hatched into larvae. Newly hatched G. fuscus and G. longifundus larvae were transparent, and 8.4–9.7 mm (mean 9.0 mm TL) and 7.1–8.9 mm (mean 8.3 mm TL) consecutively. Absorption of the yolk sac by G. fuscus larvae (1.5–2.0 mm diameter) was complete 6–7 days after hatching, and for G. longifundus (1.0–1.4 mm diameter) 12–13 days after hatching. One-month-old G. fuscus measured ~16 mm and two-month-old larvae ~22 mm, and one-month-old G. longifundus ~11 mm. Methods and techniques employed may aid broader galaxiid conservation efforts.

2015 ◽  
Vol 37 (2) ◽  
pp. 170 ◽  
Author(s):  
Emily J. Miller ◽  
Mark D. B. Eldridge ◽  
Keith Morris ◽  
Neil Thomas ◽  
Catherine A. Herbert

The endemic Australian greater bilby (Macrotis lagotis) is a vulnerable and iconic species. It has declined significantly due to habitat loss, as well as competition and predation from introduced species. Conservation measures include a National Recovery Plan that incorporates several captive breeding programs. Two of these programs were established within 12 months of one another (1997/98), with the same number and sex ratio of founding individuals, but executed different breeding strategies: (1) unmanipulated mating in semi–free range natural habitat versus (2) minimising mean kinship in large enclosures, with the supplementation of new individuals into both populations. This study evaluates the long-term genetic impact of these programs and examines the congruency between the pedigree studbook estimates of diversity and molecular data. Our data demonstrate that genetic diversity was maintained in both populations, with the supplementation of new individuals contributing to the gene pool. The studbook estimates of diversity and inbreeding are not consistent with the microsatellite data and should not solely be relied upon to evaluate the genetic health of captive populations. Our analyses suggest that captive breeding programs may not require costly and intensive management to effectively maintain long-term genetic diversity in a promiscuous species.


2020 ◽  
Vol 21 (21) ◽  
pp. 8269
Author(s):  
Robert B. Struijk ◽  
Callista L. Mulder ◽  
Saskia K. M. van Daalen ◽  
Cindy M. de Winter-Korver ◽  
Aldo Jongejan ◽  
...  

Autologous spermatogonial stem cell transplantation is an experimental technique aimed at restoring fertility in infertile men. Although effective in animal models, in vitro propagation of human spermatogonia prior to transplantation has proven to be difficult. A major limiting factor is endogenous somatic testicular cell overgrowth during long-term culture. This makes the culture both inefficient and necessitates highly specific cell sorting strategies in order to enrich cultured germ cell fractions prior to transplantation. Here, we employed RNA-Seq to determine cell type composition in sorted integrin alpha-6 (ITGA6+) primary human testicular cells (n = 4 donors) cultured for up to two months, using differential gene expression and cell deconvolution analyses. Our data and analyses reveal that long-term cultured ITGA6+ testicular cells are composed mainly of cells expressing markers of peritubular myoid cells, (progenitor) Leydig cells, fibroblasts and mesenchymal stromal cells and only a limited percentage of spermatogonial cells as compared to their uncultured counterparts. These findings provide valuable insights into the cell type composition of cultured human ITGA6+ testicular cells during in vitro propagation and may serve as a basis for optimizing future cell sorting strategies as well as optimizing the current human testicular cell culture system for clinical use.


2019 ◽  
Vol 138 (3) ◽  
pp. 467-474 ◽  
Author(s):  
Lidiia Samarina ◽  
Maya Gvasaliya ◽  
Natalia Koninskaya ◽  
Ruslan Rakhmangulov ◽  
Alexander Efremov ◽  
...  

2017 ◽  
Author(s):  
Natalie Emma Calatayud ◽  
Amanda Kathryn Mullen ◽  
Cecilia Jane Langhorne

ABSTRACTLoss of reproductive viability, physiologically and/or behaviorally, can have profound effects on the fitness of a captive population and conservation efforts. The southern rocky mountain (SRM) population of the boreal toad has declined over the past 35 years, making captive breeding necessary to protect and augment the species in the wild. In recent years, a notable reduction in the incidence of amplexus and viable offspring from the captive breeding population has been observed. Hormone treatment protocols to stimulate gamete release in males and females are established in this species and in vitro fertilization has been performed successfully. However, successful hormone stimulation of reproductive behaviors and natural fertilization has not been well documented. During the breeding season of 2012, 24 males and 24 female toads were selected from a population of over 600 captive animals. Both sexes were treated with Human chorionic gonadotropin (hCG) and Gonadotropin Releasing Hormone (GnRH) or phosphate buffered saline (PBS). Females were primed twice with 3.7IU/g hCG and then injected with an ovulatory dose (OvD) of 13.5 IU/ g BW (Body weight) hCG and 0.4 μg/ g BW GnRH. Males were injected a single time with 10 IU/g BW hCG and 0.4 μg/ g BW GnRH, 12 h after females received their OvD. In 2013, knowing the approximate time when females oviposited after hormone treatments, we tested the best time to induce amplexus and spermiation. Males were divided into 4 groups and injected at 4 different times: (a) 12 h before females OvD; (b) at the same time as OvD; (c) 12 h after OvD; (d) control injected with PBS. Results from 2012 indicated that oviposition was solely dependent on females receiving hormone treatments not males. However, in 2013 we found that the duration of amplexus significantly influenced oviposition (P>0.05), and males injected 12 h prior to females spent more time in amplexus than males injected at the same time or 12 h after the females received hormones. Promoting reproductive behaviors and synchronizing gamete deposition continues to be imprecise and may require more than exogenous hormones. The complexity of promoting breeding behaviors may require a closer assessment of the captive environment.


2009 ◽  
Vol 276 (1662) ◽  
pp. 1679-1683 ◽  
Author(s):  
Pierre Bize ◽  
François Criscuolo ◽  
Neil B Metcalfe ◽  
Lubna Nasir ◽  
Pat Monaghan

Despite accumulating evidence from in vitro studies that cellular senescence is linked to telomere dynamics, how this relates to whole-organism senescence and longevity is poorly understood and controversial. Using data on telomere length in red blood cells and long-term survival from wild Alpine swifts of a range of ages, we report that the telomere length and the rate of telomere loss are predictive of life expectancy, and that slow erosion of relatively long telomeres is associated with the highest survival probabilities. Importantly, because telomere dynamics, rather than chronological age, predict life expectancy, our study provides good evidence for a mechanistic link between telomere erosion and reduced organism longevity under natural conditions, chronological age itself possibly not becoming a significant predictor until very old ages beyond those in our sample.


2008 ◽  
Vol 105 (40) ◽  
pp. 15464-15469 ◽  
Author(s):  
Nikos Poulakakis ◽  
Scott Glaberman ◽  
Michael Russello ◽  
Luciano B. Beheregaray ◽  
Claudio Ciofi ◽  
...  

Giant tortoises, a prominent symbol of the Galápagos archipelago, illustrate the influence of geological history and natural selection on the diversification of organisms. Because of heavy human exploitation, 4 of the 15 known species (Geochelone spp.) have disappeared. Charles Darwin himself detailed the intense harvesting of one species, G. elephantopus, which once was endemic to the island of Floreana. This species was believed to have been exterminated within 15 years of Darwin's historic visit to the Galápagos in 1835. The application of modern DNA techniques to museum specimens combined with long-term study of a system creates new opportunities for identifying the living remnants of extinct taxa in the wild. Here, we use mitochondrial DNA and microsatellite data obtained from museum specimens to show that the population on Floreana was evolutionarily distinct from all other Galápagos tortoise populations. It was demonstrated that some living individuals on the nearby island of Isabela are genetically distinct from the rest of the island's inhabitants. Surprisingly, we found that these “non-native” tortoises from Isabela are of recent Floreana ancestry and closely match the genetic data provided by the museum specimens. Thus, we show that the genetic line of G. elephantopus has not been completely extinguished and still exists in an intermixed population on Isabela. With enough individuals to commence a serious captive breeding program, this finding may help reestablish a species that was thought to have gone extinct more than a century ago and illustrates the power of long-term genetic analysis and the critical role of museum specimens in conservation biology.


Oryx ◽  
2007 ◽  
Vol 41 (4) ◽  
pp. 488-494 ◽  
Author(s):  
Nicolas Kidjo ◽  
Gérard Feracci ◽  
Eric Bideau ◽  
Georges Gonzalez ◽  
César Mattéi ◽  
...  

AbstractThe Endangered Corsican red deer Cervus elaphus corsicanus was extirpated from Corsica in the early 1970s, at which time the Sardinian population fell to <250 individuals. The Sardinian authorities agreed to protect this subspecies and to secure its reintroduction in Corsica, a natural choice, considering ethological and historical descriptions. Since the beginning of 1985, when the first deer destined for captive breeding and eventual reintroduction arrived in Corsica, the population increased from 13 Sardinian founders to 106 captive animals under constant monitoring in three enclosures (Quenza, Casabianda and Ania di Fium'Orbu). The sites of Quenza, Chisà and Santo Pietro di Venaco were selected by the Regional Nature Park of Corsica for the reintroduction into the wild that began in 1998. Currently the size of the whole Corsican population is c. 250 individuals. These deer are still closely monitored and studied, both in enclosures and in the wild, to secure the long-term conservation of this subspecies. The Corsican and Sardinian populations together now total slightly >1,000, and the subspecies could therefore be downgraded to Near Threatened on the IUCN Red List.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 447E-447
Author(s):  
Kimberly A. Pickens ◽  
Jan Wolf ◽  
James M. Affolter ◽  
Hazel Y. Wetzstein

Many bromeliad species indigenous to the rain forests of Central and South America are threatened because of over-collection and habitat destruction. Studies were conducted to develop propagation protocols for Tillandsia eizii, a rare ornamental bromeliad of ceremonial significance to the Highland Maya communities in Chiapas, Mexico. We anticipate using in vitro propagation for the conservation of this species with the potential of utilizing bromeliads as an alternative and sustainable forest resource. Protocols were developed for the sterilization and germination of axenic seed. Seedling growth in vitro was assessed and outplanting studies were conducted. Media were evaluated to promote adventitious bud production in experiments using the plant growth regulators naphthaleneacetic acid and benzylaminopurine. Pulse time and duration, as well as the stage of seed development, had a marked effect on bud production. The effects of various potting media on plant growth and survival were assessed. A pure pine bark medium elicited over 95 percent survival. Plants exhibited a “tank-like” morphology characteristic of plants in the wild.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1060
Author(s):  
Joo-Hee Wälzlein ◽  
Karla A. Schwenke ◽  
Michael Beekes

There are various existing cell models for the propagation of animal prions. However, in vitro propagation of human prions has been a long-standing challenge. This study presents the establishment of a long-term primary murine glia culture expressing the human prion protein homozygous for methionine at codon 129, which allows in vitro propagation of Creutzfeldt–Jakob disease (CJD) prions (variant CJD (vCJD) and sporadic CJD (sCJD) type MM2). Prion propagation could be detected by Western blotting of pathological proteinase K-resistant prion protein (PrPSc) from 120 days post exposure. The accumulation of PrPSc could be intensified by adding a cationic lipid mixture to the infectious brain homogenate at the time of infection. Stable propagation of human prions in a long-term murine glia cell culture represents a new tool for future drug development and for mechanistic studies in the field of human prion biology. In addition, our cell model can reduce the need for bioassays with human prions and thereby contributes to further implementation of the 3R principles aiming at replacement, reduction and refinement of animal experiments.


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