Resurrecting biodiversity: advanced assisted reproductive technologies and biobanking

Biodiversity is defined as the presence of a variety of living organisms on the Earth that is essential for human survival. However, anthropogenic activities are causing the sixth mass extinction, threatening even our own species. For many animals, dwindling numbers are becoming fragmented populations with low genetic diversity, threatening long-term species viability. With extinction rates 1000–10,000 times greater than natural, ex situ and in situ conservation programmes need additional support to save species. The indefinite storage of cryopreserved (−196°C) viable cells and tissues (cryobanking), followed by assisted or advanced assisted reproductive technology (ART: utilisation of oocytes and spermatozoa to generate offspring; aART: utilisation of somatic cell genetic material to generate offspring), may be the only hope for species’ long-term survival. As such, cryobanking should be considered a necessity for all future conservation strategies. Following cryopreservation, ART/aART can be used to reinstate lost genetics back into a population, resurrecting biodiversity. However, for this to be successful, species-specific protocol optimisation and increased knowledge of basic biology for many taxa are required. Current ART/aART is primarily focused on mammalian taxa; however, this needs to be extended to all, including to some of the most endangered species: amphibians. Gamete, reproductive tissue and somatic cell cryobanking can fill the gap between losing genetic diversity today and future technological developments. This review explores species prioritisation for cryobanking and the successes and challenges of cryopreservation and multiple ARTs/aARTs. We here discuss the value of cryobanking before more species are lost and the potential of advanced reproductive technologies not only to halt but also to reverse biodiversity loss

IL-17RA Signaling Amplifies Antibody-Induced Arthritis

Objective: To investigate the role of IL-17RA signaling in the effector phase of inflammatory arthritis using the K/BxN serumtransfer model. Methods: Wild-type and Il17ra 2/2 mice were injected with serum isolated from arthritic K/BxN mice and their clinical score was recorded daily. Mice were also harvested on days 12 and 21 and ankles were analyzed for cytokine and chemokine mRNA expression by qPCR on day 12 and for bone and cartilage erosions by histology on day 21, respectively. The induction of cytokine and chemokine expression levels by IL-17A in synovial-like fibroblasts was also analyzed using qPCR. Results: Il17ra 2/2 mice were partially protected from clinical signs of arthritis and had markedly fewer cartilage and bone erosions. The expression of several pro-inflammatory mediators, including the chemokines KC/CXCL1, MIP-2/CXCL2, LIX/ CXCL5 MIP-1c/CCL9, MCP-3/CCL7, MIP-3a/CCL20, the cytokines IL-1b, IL-6, RANKL and the matrix metalloproteinases MMP2, MMP3, and MMP13 were decreased in the ankles of Il17ra 2/2 mice compared to wild-type mice. Many of these proinflammatory genes attenuated in the ankles of Il17ra 2/2 mice were shown to be directly induced by IL-17A in synovial fibroblasts in vitro. Conclusions: IL-17RA signaling plays a role as an amplifier of the effector phase of inflammatory arthritis. This effect is likel

Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

BACKGROUND: The alpha-7 nicotinic acetylcholine receptor (alpha7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the alpha7-nAChR, or peptide modulation of receptor expression. METHODOLOGY/PRINCIPAL FINDINGS: This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the alpha7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of alpha7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: The results reported here demonstrate a hitherto unknown relationship between the alpha7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration

Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

BACKGROUND: The alpha-7 nicotinic acetylcholine receptor (alpha7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the alpha7-nAChR, or peptide modulation of receptor expression. METHODOLOGY/PRINCIPAL FINDINGS: This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the alpha7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of alpha7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: The results reported here demonstrate a hitherto unknown relationship between the alpha7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration

Synergistic effect of an ultraviolet feeding cue for an avianrepellent and protection of agricultural crops

Application strategies for avian repellents are needed to maintain efficacious repellentconcentrations throughout the period of needed crop protection. We investigated the repellency of an ultraviolet (UV) feeding cue in the absence of postingestive consequences, thecombination of the UV feeding cue and an UV-absorbent, postingestive repellent (i.e., arepellent that causes negative postingestive consequences), and a non-UV feeding cue com-bined with the UV-absorbent, postingestive repellent in red-winged blackbirds (Agelaiusphoeniceus). In the absence of negative postingestive consequences, 0.2% of the UV feed-ing cue (wt/wt) was not aversive relative to untreated food (i.e., baseline preference test; P = 0.1732). Relative to the repellency of food treated only with the anthraquinone-basedrepellent, synergistic repellency (i.e., 45–115% increase) was observed when 0.2% of the UVfeeding cue was combined with 0.02% or 0.035% anthraquinone (wt/wt). In contrast, \u3c10%repellency was observed for 0.2% of a non-UV feeding cue (red #40 aluminum lake disper-sion) paired with 0.02% anthraquinone. Aversion performance was therefore not attributedto characteristics of either conditioned or unconditioned stimuli but their combinations,and enhanced repellency of anthraquinone plus the UV-absorbent cue was attributed toUV wavelengths. Thus, the addition of an UV feeding cue can enhance avian repellencyat repellent concentrations realized from previous field applications on agricultural crops(e.g., ≤1000 ppm anthraquinone)

Functional significance of ultraviolet feeding cues in wild turkeys

Most birds are able to sense ultraviolet (UV) visual signals. Ultraviolet wavelengths are used for plumage signaling and sexual selection among birds. The aim of our study was to determine if UV cues are also used for the process of food selection in wild turkeys (Meleagris gallopavo). We used avoidance conditioning to test the hypothesis that UV feeding cues can be used functionally for foraging behavior in wild turkeys. Female turkeys exhibited no avoidance of untreated food and 75–98% avoidance of food treated with an UV-absorbent, postingestive repellent (0.5–4% anthraquinone; wt./wt.) during repellent exposure. Male turkeys exhibited 78–99% avoidance of food treated with 0.5–4% anthraquinone. Female and male turkeys that consumed more than 200 mg and 100 mg of anthraquinone, respectively, subsequently avoided food treated only with an UV- absorbent cue. In contrast, unconditioned females consumed 58% more food treated with the UV-absorbent cue than untreated food. Thus, wild turkeys do not prefer foods associated with UV wavelengths regardless of feeding experience. We also observed 1) a weak negative correlation between body condition and intestinal parasite infection and 2) moderate, positive correlations between consumption of food treated with the conditioned UV cue and intestinal parasite infection among male turkeys. The UV feeding cue was used to maintain food avoidance during the four days subsequent to postingestive conditioning. Moreover, the consequences of consuming food treated with the postingestive, UV-absorbent repellent were necessary for conditioned avoidance of the UV-absorbent cue. These findings suggest functional significance of UV feeding cues for avian foraging behavior, the implications of which will enable subsequent investigations regarding the sensory physiology and behavioral ecology of wild birds

The role of starlings in the spread of \u3ci\u3eSalmonella\u3c/i\u3e within concentrated animal feeding operations

1. Characterizing and mitigating the disease risks associated with wildlife use of concentrated animal feeding operations (CAFOs) can reduce the spread of micro-organisms throughout the environment while increasing agricultural productivity. To better understand the disease risks associated with bird use of CAFOs, we assessed the capacity of European starlings Sturnus vulgaris to spread Salmonella enterica to cattle, their feed and water. 2. We sampled starlings, cattle feed, cattle water and cattle faeces from 10 CAFOs in Texas, USA. Samples were screened for Salmonella enterica to investigate: (i) the prevalence of S. enterica in starlings using CAFOs, (ii) whether there was a relationship between cattle infections and starling numbers, and (iii) if S. enterica contamination of cattle feed and water was related to numbers of starlings observed on CAFOs. 3. We used generalized linear mixed logistic regression models to assess the importance of starlings, cattle stocking, facility management and environmental variables in the transmission of S. enterica to cattle, feed troughs and water troughs in CAFOs. 4. Starling gastrointestinal tract samples tested positive for S. enterica (2•5% prevalence; 95% CI = 0•3%, 8•6%) and starlings were retained as model covariates in the best supported logistic regression models for S. enterica contamination within cattle feed, water and faeces. 5. Salmonella enterica contamination of both cattle feed troughs and water troughs is significantly related to numbers of starlings. Contamination in cattle feed increased as more starlings entered feed troughs. Contamination in water troughs increased asymptotically as numbers of starlings on CAFOs increased. Starling variables in the cattle faecal shedding model were not significant. 6. Synthesis and applications. The numbers of European starlings better explained S. enterica contamination of cattle feed and water than other variables including cattle stocking, facility management and environmental variables. This suggests that starlings are a source of S. enterica contamination in CAFOs. Thus, starling management tools such as population control, habitat management, exclusionary devises and bird repellents may be used to reduce the amplification and spread of disease within livestock production systems