scholarly journals A Hypothesis to Explain Cancers in Confined Colonies of Naked Mole Rats

2016 ◽  
Author(s):  
Michael E. Hochberg ◽  
Robert J. Noble ◽  
Stanton Braude
Keyword(s):  
Molecular Mechanisms ◽  
Cancer Development ◽  
Cancer Resistance ◽  
Virtual Absence ◽  
Captive Populations ◽  
In Captivity ◽  
In The Wild ◽  
Colony Defence ◽  
Low Levels ◽  
Selection For

AbstractNaked mole rats (NMRs) are subterranean eusocial mammals, known for their virtual absence of aging in their first 20 to 30 years of life, and their apparent resistance to cancer development. As such, this species has become an important biological model for investigating the physiological and molecular mechanisms behind cancer resistance. Two recent studies have discovered middle and late-aged worker (that is, non-breeding) NMRs in captive populations exhibiting neoplasms, consistent with cancer development, challenging the claim that NMRs are cancer resistant. These cases are possibly artefacts of inbreeding or certain rearing conditions in captivity, but they are also consistent with evolutionary theory.We present field data showing that worker NMRs live on average for 1 to 2 years. This, together with considerable knowledge about the biology of this species, provides the basis for an evolutionary explanation for why debilitating cancers in NMRs should be rare in captive populations and absent in the wild. Whereas workers are important for maintaining tunnels, colony defence, brood care, and foraging, they are highly vulnerable to predation. However, surviving workers either replace dead breeders, or assume other less active functions whilst preparing for possible dispersal. These countervailing forces (selection resulting in aging due to early-life investments in worker function, and selection for breeder longevity) along with the fact that all breeders derive from the worker morph, can explain the low levels of cancer observed by these recent studies in captive colonies. Because workers in the field typically never reach ages where cancer becomes a risk to performance or mortality, those rare observations of neoplastic growth should be confined to the artificial environments where workers survive to ages rarely if ever occurring in the wild. Thus, we predict that the worker phenotype fortuitously benefits from anti-aging and cancer protection in captive populations.

scholarly journals Somewhat saved: a captive breeding programme for two endemic Christmas Island lizard species, now extinct in the wild

Oryx ◽  
2016 ◽  
Vol 52 (1) ◽  
pp. 171-174 ◽  
Author(s):  
Paul Andrew ◽  
Hal Cogger ◽  
Don Driscoll ◽  
Samantha Flakus ◽  
Peter Harlow ◽  
...  
Keyword(s):  
Native Species ◽  
Captive Breeding ◽  
Biodiversity Loss ◽  
Breeding Programme ◽  
Lizard Species ◽  
Christmas Island ◽  
Captive Populations ◽  
Captive Breeding Programme ◽  
In Captivity ◽  
In The Wild

AbstractAs with many islands, Christmas Island in the Indian Ocean has suffered severe biodiversity loss. Its terrestrial lizard fauna comprised five native species, of which four were endemic. These were abundant until at least the late 1970s, but four species declined rapidly thereafter and were last reported in the wild between 2009 and 2013. In response to the decline, a captive breeding programme was established in August 2009. This attempt came too late for the Christmas Island forest skink Emoia nativitatis, whose last known individual died in captivity in 2014, and for the non-endemic coastal skink Emoia atrocostata. However, two captive populations are now established for Lister's gecko Lepidodactylus listeri and the blue-tailed skink Cryptoblepharus egeriae. The conservation future for these two species is challenging: reintroduction will not be possible until the main threats are identified and controlled.

scholarly journals Firefly Translocation: A Case Study of Genetic and Behavioral Evaluation in Thailand

2021 ◽  
Author(s):  
Anchana Thancharoen
Keyword(s):  
Success Rate ◽  
Captive Breeding ◽  
Large Population ◽  
Metropolitan Region ◽  
Success Rates ◽  
Captive Populations ◽  
In Captivity ◽  
In The Wild ◽  
Threatened Fauna

Conservation translocation is frequently used to conserve the threatened fauna by releasing individuals from the wild or captive populations into a particular area. This approach, however, is not successful in many cases because the translocated populations could not self-sustain in the new habitats. In this chapter, I reviewed the concept of translocation for conservation and the factors associated with the success rate. I used example problems from several cases involving different insect taxa. With its often high potential to mass rear in captivity, captive breeding can be a powerful tool by assuring large population size for insect translocation, which can result in a high success rate. However, genetic consequences from inbreeding and genetic adaptation to captivity can reduce the fitness of the captive population to establish successfully in the wild. Additionally, as the evidence in Japanese fireflies shows, the genetic differences between the translocated and local populations should be considered for a sustainable translocation program. A case study involved genetic and behavioral evaluation of S. aquatilis populations to assess the possibility of including the species for the firefly translocation program in Thailand. Although the results revealed no genetic variation among populations, examination of the variation in flash signals showed that the long-distance population had a longer courtship flash pulse than other populations in the Bangkok Metropolitan Region. With no geographical barrier, the light pollution and urbanization are probably important fragmented barriers causing adaptation of flash communication to increase the fitness. As a consequence, firefly translocation should consider flash variation between populations to prevent this potential pre-mating isolation mechanism from resulting in probable lower translocation success rates.

Breeding biology of captive, reintroduced and wild greater bilbies, Macrotis lagotis (Marsupialia : Peramelidae)

2000 ◽  
Vol 27 (6) ◽  
pp. 621 ◽  
Author(s):  
R. I. Southgate ◽  
P. Christie ◽  
K. Bellchambers
Keyword(s):  
National Park ◽  
Reproductive Output ◽  
Fold Increase ◽  
Breeding Biology ◽  
Captive Populations ◽  
Average Litter Size ◽  
In Captivity ◽  
In The Wild ◽  
Reintroduced Population ◽  
Intensively Managed

The breeding biology and growth of Macrotis lagotis was investigated using captive stock in Alice Springs and Dubbo and a reintroduced population at Watarrka National Park. Individuals of M. lagotis reached sexual maturity at about six months of age and continued growing until about 18 months old. Pouch life and weaning took approximately 90 days and females produced up to four litters per year. Litters comprised 1–3 young. Average litter size at pouch exit ranged from 1.0 to 1.88, depending on whether animals were studied in captivity or under reintroduced free-range conditions. Females commonly continued breeding past the age of four years and longevity extended to 10 years in captivity. In comparison, the most animals caught in the wild were estimated to be less than 12 months old. Animals in the reintroduced population exhibited a greater reproductive output than the captive populations examined. However, survivorship was far greater for animals in captivity. An intensively managed captive population may achieve a three-fold increase in size in a 12-month period.

scholarly journals A macromutation eliminates colour patterning in captive butterflies

2021 ◽  
Author(s):  
Joseph J. Hanly ◽  
Luca Livraghi ◽  
Christa Heryanto ◽  
W. Owen McMillan ◽  
Chris D. Jiggins ◽  
...  
Keyword(s):  
Artificial Selection ◽  
Genetic Basis ◽  
Population Demographics ◽  
Autozygosity Mapping ◽  
Animal Populations ◽  
Captive Populations ◽  
In Captivity ◽  
In The Wild ◽  
Insect Populations ◽  
Mixed Origin

Captive populations often harbor variation that is not present in the wild due to artificial selection. Recent efforts to map this variation have provided insights into the genetic and molecular basis of variation. Heliconius butterflies display a large array of pattern variants in the wild and the genetic basis of these patterns has been well-described. Here we sought to identify the genetic basis of an unusual pattern variant that is instead found in captivity, the ivory mutant, in which all scales on both the wings and body become white or yellow. Using a combination of autozygosity mapping and coverage analysis from 37 captive individuals, we identify a 78kb deletion at the cortex wing patterning locus as the ivory mutation. This deletion is undetected among 458 wild Heliconius genomes samples, and its dosage explains both homozygous and heterozygous ivory phenotypes found in captivity. The deletion spans a large 5' region of the cortex gene that includes a facultative 5' UTR exon detected in larval wing disk transcriptomes. CRISPR mutagenesis of this exon replicates the wing phenotypes from coding knock-outs of cortex, consistent with a functional role of ivory-deleted elements in establishing scale color fate. Population demographics reveal that the stock giving rise to the ivory mutant has a mixed origin from across the wild range of H. melpomene, and supports a scenario where the ivory mutation occurred after the introduction of cortex haplotypes from Ecuador. Homozygotes for the ivory deletion are inviable, joining 40 other examples of allelic variants that provide heterozygous advantage in animal populations under artificial selection by fanciers and breeders. Finally, our results highlight the promise of autozygosity and association mapping for identifying the genetic basis of aberrant mutations in captive insect populations.

scholarly journals Senescence or selective disappearance? Age trajectories of body mass in wild and captive populations of a small-bodied primate

2014 ◽  
Vol 281 (1791) ◽  
pp. 20140830 ◽  
Author(s):  
Anni Hämäläinen ◽  
Melanie Dammhahn ◽  
Fabienne Aujard ◽  
Manfred Eberle ◽  
Isabelle Hardy ◽  
...  
Keyword(s):  
Body Mass ◽  
Evolutionary Process ◽  
Sex Bias ◽  
Extrinsic Mortality ◽  
Captive Populations ◽  
In Captivity ◽  
In The Wild ◽  
Demographic Processes ◽  
High Predation ◽  
Dependent Mortality

Classic theories of ageing consider extrinsic mortality (EM) a major factor in shaping longevity and ageing, yet most studies of functional ageing focus on species with low EM. This bias may cause overestimation of the influence of senescent declines in performance over condition-dependent mortality on demographic processes across taxa. To simultaneously investigate the roles of functional senescence (FS) and intrinsic, extrinsic and condition-dependent mortality in a species with a high predation risk in nature, we compared age trajectories of body mass (BM) in wild and captive grey mouse lemurs ( Microcebus murinus ) using longitudinal data (853 individuals followed through adulthood). We found evidence of non-random mortality in both settings. In captivity, the oldest animals showed senescence in their ability to regain lost BM, whereas no evidence of FS was found in the wild. Overall, captive animals lived longer, but a reversed sex bias in lifespan was observed between wild and captive populations. We suggest that even moderately condition-dependent EM may lead to negligible FS in the wild. While high EM may act to reduce the average lifespan, this evolutionary process may be counteracted by the increased fitness of the long-lived, high-quality individuals.

scholarly journals Transcriptomic analysis identifies genes and pathways related to myrmecophagy in the Malayan pangolin (Manis javanica)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4140 ◽  
Author(s):  
Jing-E Ma ◽  
Lin-Miao Li ◽  
Hai-Ying Jiang ◽  
Xiu-Juan Zhang ◽  
Juan Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Molecular Mechanisms ◽  
Digestive Enzyme ◽  
Sugar Metabolism ◽  
Gene Families ◽  
Amino Sugar ◽  
New Genes ◽  
In Captivity ◽  
Manis Javanica ◽  
In The Wild

The Malayan pangolin (Manis javanica) is an unusual, scale-covered, toothless mammal that specializes in myrmecophagy. Due to their threatened status and continuing decline in the wild, concerted efforts have been made to conserve and rescue this species in captivity in China. Maintaining this species in captivity is a significant challenge, partly because little is known of the molecular mechanisms of its digestive system. Here, the first large-scale sequencing analyses of the salivary gland, liver and small intestine transcriptomes of an adult M. javanica genome were performed, and the results were compared with published liver transcriptome profiles for a pregnant M. javanica female. A total of 24,452 transcripts were obtained, among which 22,538 were annotated on the basis of seven databases. In addition, 3,373 new genes were predicted, of which 1,459 were annotated. Several pathways were found to be involved in myrmecophagy, including olfactory transduction, amino sugar and nucleotide sugar metabolism, lipid metabolism, and terpenoid and polyketide metabolism pathways. Many of the annotated transcripts were involved in digestive functions: 997 transcripts were related to sensory perception, 129 were related to digestive enzyme gene families, and 199 were related to molecular transporters. One transcript for an acidic mammalian chitinase was found in the annotated data, and this might be closely related to the unique digestive function of pangolins. These pathways and transcripts are involved in specialization processes related to myrmecophagy (a form of insectivory) and carbohydrate, protein and lipid digestive pathways, probably reflecting adaptations to myrmecophagy. Our study is the first to investigate the molecular mechanisms underlying myrmecophagy in M. javanica, and we hope that our results may play a role in the conservation of this species.

scholarly journals Genetic Diversity and Population Structure of Two Endangered Neotropical Parrots Inform In Situ and Ex Situ Conservation Strategies

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 386
Author(s):  
Carlos I. Campos ◽  
Melinda A. Martinez ◽  
Daniel Acosta ◽  
Jose A. Diaz-Luque ◽  
Igor Berkunsky ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Management Strategies ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Genetic Management ◽  
Captive Populations ◽  
In Captivity ◽  
In The Wild ◽  
Genetic Signatures

A key aspect in the conservation of endangered populations is understanding patterns of genetic variation and structure, which can provide managers with critical information to support evidence-based status assessments and management strategies. This is especially important for species with small wild and larger captive populations, as found in many endangered parrots. We used genotypic data to assess genetic variation and structure in wild and captive populations of two endangered parrots, the blue-throated macaw, Ara glaucogularis, of Bolivia, and the thick-billed parrot, Rhynchopsitta pachyrhyncha, of Mexico. In the blue-throated macaw, we found evidence of weak genetic differentiation between wild northern and southern subpopulations, and between wild and captive populations. In the thick-billed parrot we found no signal of differentiation between the Madera and Tutuaca breeding colonies or between wild and captive populations. Similar levels of genetic diversity were detected in the wild and captive populations of both species, with private alleles detected in captivity in both, and in the wild in the thick-billed parrot. We found genetic signatures of a bottleneck in the northern blue-throated macaw subpopulation, but no such signal was identified in any other subpopulation of either species. Our results suggest both species could potentially benefit from reintroduction of genetic variation found in captivity, and emphasize the need for genetic management of captive populations.

scholarly journals MicroRNAs and Stem-like Properties: The Complex Regulation Underlying Stemness Maintenance and Cancer Development

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1074
Author(s):  
Giuseppina Divisato ◽  
Silvia Piscitelli ◽  
Mariantonietta Elia ◽  
Emanuela Cascone ◽  
Silvia Parisi
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Embryonic Stem ◽  
Cell Types ◽  
Cancer Development ◽  
Special Focus ◽  
Self Renewal ◽  
Mesenchymal Transition ◽  
Different Cell Types

Embryonic stem cells (ESCs) have the extraordinary properties to indefinitely proliferate and self-renew in culture to produce different cell progeny through differentiation. This latter process recapitulates embryonic development and requires rounds of the epithelial–mesenchymal transition (EMT). EMT is characterized by the loss of the epithelial features and the acquisition of the typical phenotype of the mesenchymal cells. In pathological conditions, EMT can confer stemness or stem-like phenotypes, playing a role in the tumorigenic process. Cancer stem cells (CSCs) represent a subpopulation, found in the tumor tissues, with stem-like properties such as uncontrolled proliferation, self-renewal, and ability to differentiate into different cell types. ESCs and CSCs share numerous features (pluripotency, self-renewal, expression of stemness genes, and acquisition of epithelial–mesenchymal features), and most of them are under the control of microRNAs (miRNAs). These small molecules have relevant roles during both embryogenesis and cancer development. The aim of this review was to recapitulate molecular mechanisms shared by ESCs and CSCs, with a special focus on the recently identified classes of microRNAs (noncanonical miRNAs, mirtrons, isomiRs, and competitive endogenous miRNAs) and their complex functions during embryogenesis and cancer development.

scholarly journals Introgression of the sesquiterpene biosynthesis from Solanum habrochaites to cultivated tomato offers insights into trichome morphology and arthropod resistance

Planta ◽  
2021 ◽  
Vol 254 (1) ◽  
Author(s):  
Rodrigo Therezan ◽  
Ruy Kortbeek ◽  
Eloisa Vendemiatti ◽  
Saioa Legarrea ◽  
Severino M. de Alencar ◽  
...  
Keyword(s):  
Glandular Trichomes ◽  
Pest Resistance ◽  
Chromosome 8 ◽  
Cavity Size ◽  
Solanum Habrochaites ◽  
Genetic Components ◽  
Internal Storage ◽  
In The Wild ◽  
Low Levels ◽  
Trichome Morphology

Abstract Main conclusion Cultivated tomatoes harboring the plastid-derived sesquiterpenes from S. habrochaites have altered type-VI trichome morphology and unveil additional genetic components necessary for piercing-sucking pest resistance. Abstract Arthropod resistance in the tomato wild relative Solanum habrochaites LA1777 is linked to specific sesquiterpene biosynthesis. The Sesquiterpene synthase 2 (SsT2) gene cluster on LA1777 chromosome 8 controls plastid-derived sesquiterpene synthesis. The main genes at SsT2 are Z-prenyltransferase (zFPS) and Santalene and Bergamotene Synthase (SBS), which produce α-santalene, β-bergamotene, and α-bergamotene in LA1777 round-shaped type-VI glandular trichomes. Cultivated tomatoes have mushroom-shaped type-VI trichomes with much smaller glands that contain low levels of monoterpenes and cytosolic-derived sesquiterpenes, not presenting the same pest resistance as in LA1777. We successfully transferred zFPS and SBS from LA1777 to cultivated tomato (cv. Micro-Tom, MT) by a backcrossing approach. The trichomes of the MT-Sst2 introgressed line produced high levels of the plastid-derived sesquiterpenes. The type-VI trichome internal storage-cavity size increased in MT-Sst2, probably as an effect of the increased amount of sesquiterpenes, although it was not enough to mimic the round-shaped LA1777 trichomes. The presence of high amounts of plastid-derived sesquiterpenes was also not sufficient to confer resistance to various tomato piercing-sucking pests, indicating that the effect of the sesquiterpenes found in the wild S. habrochaites can be insect specific. Our results provide for a better understanding of the morphology of S. habrochaites type-VI trichomes and paves the way to obtain insect-resistant tomatoes.

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