Catch-and-release Research Articles

Elusive Protein-Glycosphingolipid Interactions Revealed by Membrane Anchor-Assisted Native Mass Spectrometry.

Interactions between glycan-binding proteins (GBPs) and glycosphingolipids (GSLs) present in cell membranes are implicated in a wide range of biological processes. However, studying GSL binding is hindered by the paucity of purified GSLs and the weak affinities typical of monovalent GBP-GSL interactions. Native mass spectrometry (nMS) performed using soluble model membranes is a promising approach for the discovery of GBP ligands, but the detection of weak interactions remains challenging. The present work introduces MEmbrane ANchor-assisted nMS (MEAN-nMS) for the detection of low-affinity GBP-GSL complexes. The assay utilizes a membrane anchor, produced by covalent cross-linking of the GBP and a lipid in the membrane, to localize the GBP on the surface and promote GSL binding. Ligands are identified by nMS detection of intact GBP-GSL complexes (MEAN-nMS) or using a catch-and-release (CaR) strategy, wherein GSLs are released from GBP-GSL complexes upon collisional activation and detected (MEAN-CaR-nMS). To establish reliability, a library of purified gangliosides incorporated into nanodiscs was screened against human immune lectins, and the results compared with affinities of the corresponding ganglioside oligosaccharides. Without a membrane anchor, nMS analysis yielded predominantly false negatives. In contrast, all ligands were identified by MEAN-(CaR)-nMS, with no false positives. To highlight the potential of MEAN-CaR-nMS for ligand discovery, a natural library of GSLs was incorporated into nanodiscs and screened against human and viral proteins to uncover elusive ligands. Finally, nMS-based detection of GSL ligands directly from cells is demonstrated. This breakthrough paves the way for shotgun glycomics screening using intact cells.

Absolute Affinities from Quantitative Shotgun Glycomics Using Concentration-Independent (COIN) Native Mass Spectrometry.

Native mass spectrometry (nMS) screening of natural glycan libraries against glycan-binding proteins (GBPs) is a powerful tool for ligand discovery. However, as the glycan concentrations are unknown, affinities cannot be measured directly from natural libraries. Here, we introduce Concentration-Independent (COIN)-nMS, which enables quantitative screening of natural glycan libraries by exploiting slow mixing of solutions inside a nanoflow electrospray ionization emitter. The affinities (Kd) of detected GBP-glycan interactions are determined, simultaneously, from nMS analysis of their time-dependent relative abundance changes. We establish the reliability of COIN-nMS using interactions between purified glycans and GBPs with known Kd values. We also demonstrate the implementation of COIN-nMS using the catch-and-release (CaR)-nMS assay for glycosylated GBPs. The COIN-CaR-nMS results obtained for plant, fungal, viral, and human lectins with natural libraries containing hundreds of N-glycans and glycopeptides highlight the assay's versatility for discovering new ligands, precisely measuring their affinities, and uncovering "fine" specificities. Notably, the COIN-CaR-nMS results clarify the sialoglycan binding properties of the SARS-CoV-2 receptor binding domain and establish the recognition of monosialylated hybrid and biantennary N-glycans. Moreover, pharmacological depletion of host complex N-glycans reduces both pseudotyped virions and SARS-CoV-2 cell entry, suggesting that complex N-glycans may serve as attachment factors.

Incorporating estuarine-angler behaviour and delayed blood sampling into the rapid assessment of catch-and release angling on the iconic dusky kob Argyrosomus japonicus

Argyrosomus japonicus is arguably South Africa’s most important estuarine recreational and small-scale fishery species. Although juvenile A. japonicus predominate in estuarine environments, where catch-and-release angling is common, limited C&R studies have taken place. The aim of this study was to use angler-behaviour to robustly examine the physiological stress response, reflex impairment and short-term (12–36-hour) survival of A. japonicus following C&R angling. Observations of estuarine recreational angling informed three air exposure treatments based on minimum (10 s), mean (75 s) and maximum (240 s) observed times, for use in a controlled angling experiment. Based on a prior laboratory study, blood sampling was delayed 30–40 min post-capture to allow for peak accumulations of lactate and glucose. Long air exposure (240 s) predicted significantly higher blood glucose concentrations (ANOVA, p = 0.03) than short (10 s) exposure. Similarly, both long (p = 0.01) and moderate (75 s; p = 0.01) air exposure significantly predicted elevated blood lactate concentrations, when compared with short exposure. In terms of physical impairment, long air exposure (240 s) had a significant negative influence on the reflex response (cumulative link model, p = 0.01) of A. japonicus. An observed short-term mortality of 7.7% was primarily attributed to hooking injury. To reduce significant physiological and physical stress, it is proposed that anglers should aim to reduce air exposure times to below the observed mean of 75 s, and ideally to 10 s. For relevant and meaningful future C&R studies, we propound the incorporation of angler behavioural assessments, and the investigation of physiological stress responses, prior to designing field studies.

The influence of catch-and-release on mortality of Salminus brasiliensis (Cuvier, 1816).

Catch-and-release (CR) angling has been used to assist management programs seeking to promote the conservation and recovery of some recreational fish stocks by decreasing mortality from fishing. However, without appropriate fish handling, this activity may cause damage and injuries to individual fish, causing mortality. Therefore, CR should be allowed under some circumstances that ensure higher rates of survival to achieve the goals of the conservation measures. Thus, we experimentally tested the CR effects on dourado (Salminus brasiliensis) by comparing caught-and-released fish (CR fish) with uncaught fish (control fish) in a pond and estimating individual mortality rates related to seven air exposure times (AET: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s and 840 s). We also determined a safe limit for fish handling and investigated the length and weight gain variations. We found that an increase in AET affects fish survival and that the limit of handling time for this species was 546 s; after this threshold, the individual probability of death exceeds 5%. The length and weight gain of CR fish did not differ significantly from the control fish. We believe that CR is efficient for S. brasiliensis because it does not significantly impair their organic growth and causes little or no mortality if handling is performed properly; thus, it could be employed to assist conservation programs.

Multipronged ESI-MS Approach for Studying Glycan-Binding Protein Interactions with Glycoproteins.

A multipronged electrospray ionization mass spectrometry (ESI-MS) approach for investigating glycan-mediated interactions between water-soluble glycan-binding proteins (GBPs) and glycoproteins (GPs) is described. First, the catch-and-release (CaR)-ESI-MS assay, carried with ion mobility separation prior to GBP "release" (i.e., CaRIMS-ESI-MS), is employed to rapidly identify GBP-GP binding in solution. The apparent affinity ( Ka) of the GBP for the GP is then measured using the competitive proxy ligand-ESI-MS binding assay. Finally, N-glycans, enzymatically released as free oligosaccharides from the GP, are screened against the GBP using ESI-MS to identify the glycans that are recognized by the GBP. Measurements performed at multiple GBP concentrations allow for the affinities of released N-glycans (grouped as compositional isomers) to be ranked. Implementation of the approach is illustrated using the known interactions between a C-terminal domain fragment of human galectin-3 (hGal-3C) and three human serum GPs, α-1-acid glycoprotein (AGP), haptoglobin phenotype 1-1 (Hp1-1) and α-2-macroglobulin (α2M). Specific binding of hGal-3C to each GP was successfully detected by CaRIMS-ESI-MS; no binding was detected for a noninteracting reference protein, which served as a negative control. The Ka measured by proxy ligand-ESI-MS for AGP, Hp1-1 and α2M (4 × 105 M-1, 2 × 105 M-1 and 3 × 105 M-1, respectively) are consistent with the reported apparent affinities of hGal-3 for serum GPs and their N-glycans. Screening the N-glycan libraries of each of the GPs against hGal-3C identified ligands corresponding to a total of 20 different saccharide compositions with sialylated bi-, tri-, and tetra-antennary structures. The results of binding measurements performed at two different hGal-3C concentrations revealed that all of the N-glycan ligands exhibit affinities ≥104 M-1.

Temperature effects on the physiological status and reflex impairment in European grayling Thymallus thymallus from catch-and release angling

There is a growing body of research communicating how angler behaviour can be adjusted and optimised to reduce fish injury and impairment resulting from the capture of recreationally angled fishes. However, few studies have focused on how individual and interacting abiotic variables influence the outcomes of catch and release (C&R) angling. A population of European grayling Thymallus thymallus at their upper thermal limit of their geographic distribution provided a model cold-water species that was representative of other fishes sensitive to climate warming impacts and that are subjected to C&R across different seasons. Here, C&R angling for T. thymallus was conducted during summer (>15 °C) and winter (<10 °C), with 97 fish captured (220–490 mm). Measurement of tertiary stress responses (reflex impairment, as time to body equilibrium, an important predictor of post-release mortality) revealed that at >15 °C, fish took significantly longer to regain equilibrium (178 ± 44 s) than at <10 °C (70 ± 40 s). Multivariate testing revealed air exposure had a stronger effect on reflex impairment than fight time. Testing of post-capture, pre-release blood chemistry on sub-samples of captured fish revealed fish had significantly elevated levels of both glucose and lactate at >15 °C versus <10 °C, In entirety, these results suggest that stress responses and post-release mortality risk in cold-water fishes subjected to C&R could be reduced via temperature-informed fishery management practises, and by minimising, or ideally eliminating, air exposure

Size structure suppression and obsolete length regulations in recreational fisheries dominated by catch-and-release

Catch-and-release (CR) rates now approach 100% for some fisheries, which may hamper the ability of harvest-oriented fisheries management tools to positively influence population characteristics. In fisheries where CR practices predominate, mortality associated with CR may comprise the majority of all fishing-related mortality and thus impact population characteristics of management concern such as size and age structure. We evaluated the efficacy of length limits and the effects of CR mortality on population size structure in two impoundments. To do so we estimated total Largemouth Bass Micropterus salmoides catch over two years via angler creel survey and bass tournament monitoring in two Connecticut impoundments. Each year, catch exceeded the population size by 2–3 times. Harvest was rare, representing 0–1.8% of catch events. Using an equilibrium population model, we identified the harvest rate thresholds below which minimum length limits failed to alter size and age structure. Additionally, we evaluated CR mortality rate thresholds above which size structure was suppressed in simulated populations. Our model revealed that harvest rates in our study fisheries were likely too low for the simulated length limits to alter size structure. However, CR mortality was substantial enough that modulation of population size and age structure was possible. Our model assumed relatively low probabilities of death following CR events, yet even these low CR mortality rates ultimately suppressed size structure by compounding over multiple catch events and seasons. Some traditional management tools, such as length limits, may be ineffective in the catch-and-release era, suggesting the need for creative new approaches to manage CR mortality.

Ion mobility-mass spectrometry as a tool to investigate protein-ligand interactions.

Ion mobility-mass spectrometry (IM-MS) is a powerful tool for the simultaneous analysis of mass, charge, size, and shape of ionic species. It allows the characterization of even low-abundant species in complex samples and is therefore particularly suitable for the analysis of proteins and their assemblies. In the last few years even complex and intractable species have been investigated successfully with IM-MS and the number of publications in this field is steadily growing. This trend article highlights recent advances in which IM-MS was used to study protein-ligand complexes and in particular focuses on the catch and release (CaR) strategy and collision-induced unfolding (CIU). Graphical Abstract Native mass spectrometry and ion mobility-mass spectrometry are versatile tools to follow the stoichiometry, energetics, and structural impact of protein-ligand binding.

Spatial and Temporal Consumption Dynamics of Trout in Catch‐and‐Release Areas in Arkansas Tailwaters

AbstractRestrictive angling regulations in tailwater trout fisheries may be unsuccessful if food availability limits energy for fish to grow. We examined spatial and temporal variation in energy intake and growth in populations of Brown Trout Salmo trutta and Rainbow Trout Oncorhynchus mykiss within three catch‐and‐release (C‐R) areas in Arkansas tailwaters to evaluate food availability compared with consumption. Based on bioenergetic simulations, Rainbow Trout fed at submaintenance levels in both size‐classes (≤400 mm TL, &gt;400 mm TL) throughout most seasons. A particular bottleneck in food availability occurred in the winter for Rainbow Trout when the daily ration was substantially below the minimum required for maintenance, despite reduced metabolic costs associated with lower water temperatures. Rainbow Trout growth rates followed a similar pattern to consumption with negative growth rates during the winter periods. All three size‐classes (&lt;250 mm TL, 250–400 mm TL, &gt;400 mm TL) of Brown Trout experienced high growth rates and limited temporal bottlenecks in food availability. We observed higher mean densities for Rainbow Trout (47–342 fish/ha) than for Brown Trout (3–84 fish/ha) in all C‐R areas. Lower densities of Brown Trout coupled with an ontogenetic shift towards piscivory may have allowed for higher growth rates and sufficient consumption rates to meet energetic demands. Brown Trout at current densities were more effective in maintaining adequate growth rates and larger sizes in C‐R areas than were Rainbow Trout. Bioenergetic simulations suggest that reducing stocking levels of Rainbow Trout in the tailwaters may be necessary in order to achieve increased catch rates of larger trout in the C‐R areas.Received August 31, 2016; accepted January 9, 2017 Published online March 21, 2017

Physiological response of one of South Africa’s premier freshwater sport angling species, the Orange-Vaal smallmouth yellowfish Labeobarbus aeneus, to catch-and-release angling

The practice of catch-and-release fishing has been widely promoted by angling fraternities as a fisheries manage- ment tool. The aim of this investigation was to determine the physiological response of Orange-Vaal smallmouth yellowfish, Labeobarbus aeneus, to catch-and-release angling in the Vaal River, South Africa. Fish were collected using standard fly-fishing techniques, anaesthetised in clove oil and blood was drawn from the caudal vein; thereafter the fish were weighed, measured, revived and released. Blood plasma was analysed for concentra- tions of glucose, cortisol and lactate to determine the effects of angling duration, fish size and water tempera- ture. Larger fish were angled for a longer duration compared with smaller fish. Levels of glucose were affected by water temperature (influenced by time of year). Plasma glucose concentrations decreased with greater angling duration. Few individuals (n = 12) showed increased plasma cortisol concentrations. In extended-capture fish (angled for >1 min), lactate concentrations increased significantly above values for rapid-capture fish (angled for >30 s). These data suggest that catch-and-release causes physiological stress to fish, but nonetheless this practice can be a valuable fisheries management tool to ensure the sustainability of fish populations. Other factors beyond the ‘angling’ time are likely to contribute to physiological disruptions in homeostasis and therefore handling and air exposure of angled fish should be included in future catch-and–release angling studies. In addition, the longer-term impact of angling on fish health should also be determined.

Nanodiscs and electrospray ionization mass spectrometry: a tool for screening glycolipids against proteins.

Electrospray ionization-mass spectrometry (ESI-MS) is extensively employed to detect and quantify protein-carbohydrate interactions in vitro and is increasingly used to screen carbohydrate libraries against target proteins. However, current ESI-MS methods are limited to carbohydrate ligands that are relatively soluble in water and are, therefore, not generally suitable for studying protein interactions with glycolipids, an important class of cellular receptors. Here, we describe a catch-and-release (CaR)-ESI-MS assay, which exploits nanodiscs (NDs) to solubilize glycolipids and mimic their natural cellular environment, suitable for screening libraries of glycosphingolipids (GSL) against proteins to identify specific interactions and to rank their relative affinities. Using the B subunit homopentamers of cholera toxin and heat labile toxin as model GSL-binding proteins, the CaR-ESI-MS was applied to NDs containing mixtures of gangliosides. The results demonstrate that the CaR-ESI-MS assay can simultaneously detect both high and low affinity GSL ligands using either a library of NDs that each contains one GSL or incorporating a mixture of GSLs into a single ND. Moreover, the relative abundances of the released ligands appear to reflect their relative affinities in solution. Application of the CaR-ESI-MS assay using NDs containing gangliosides extracted from porcine brain led to the discovery of a neolacto GSL as a cholera toxin ligand, highlighting the power of the assay for identifying specific protein-glycolipid interactions from biologically relevant mixtures.

MASKULINITAS DAN PRAKTIK TANGKAP LEPAS DALAM MEMANCING: SEBUAH KAJIAN TERHADAP SPORTFISHING

The absence of legal regulation in fishing activities has brought Indonesian waters to a serious degradation, especially in the population of game fish. The most reasonable solution to this problem is performing Catch and Release (CnR). However, very little has been explored regarding the activity of fishing and CnR in Indonesia. This study aims to identify masculinity traits in sportfishing as a masculine act. Furthermore, the result will hopefully be useful in designing an effective campaign for CnR. This study employs qualitative method to discover how sportfishing is produced and consumed, formulate the meaning of sportfishing to Indonesian anglers, and identify masculinity traits in the enactment and involvement of this activity. The study concludes that sportfishing is the new hegemonic masculinity, replacing the previous conventional fishing. It is a masculine bloc that inherits classic masculine traits and combines them with aspects of femininity, resulting in a new adaptive model of masculinity that sustains the patriarchal dominance toward subordinate masculinity and women.

Evaluation of Catch‐and‐Release Regulations on Brook Trout in Pennsylvania Streams

AbstractIn 2004, the Pennsylvania Fish and Boat Commission implemented catch‐and‐release (CR) regulations on headwater stream systems to determine if eliminating angler harvest would result in an increase in the number of adult (≥100 mm) or large (≥175 mm) Brook Trout Salvelinus fontinalis. Under the CR regulations, angling was permitted on a year‐round basis, no Brook Trout could be harvested at any time, and there were no tackle restrictions. A before‐after–control‐impact design was used to evaluate the experimental regulations. Brook Trout populations were monitored in 16 treatment (CR regulations) and 7 control streams (statewide regulations) using backpack electrofishing gear periodically for up to 15 years (from 1990 to 2003 or 2004) before the implementation of the CR regulations and over a 7–8‐year period (from 2004 or 2005 to 2011) after implementation. We used Poisson mixed models to evaluate whether electrofishing catch per effort (CPE; catch/100 m2) of adult (≥100 mm) or large (≥175 mm) Brook Trout increased in treatment streams as a result of implementing CR regulations. Brook Trout CPE varied among sites and among years, and there was no significant effect (increase or decrease) of CR regulations on the CPE of adult or large Brook Trout. Results of our evaluation suggest that CR regulations were not effective at improving the CPE of adult or large Brook Trout in Pennsylvania streams. Low angler use, high voluntary catch and release, and slow growth rates in infertile headwater streams are likely the primary reasons for the lack of response.Received June 14, 2013; accepted August 28, 2013Published online January 24, 2014

7th International Symposium on Enabling Technologies for Life Sciences (ETP)

7^th International Symposium on Enabling Technologies for Life Sciences (ETP)

Mortality of Palmetto Bass Following Catch‐and‐Release Angling

AbstractPalmetto bass (Striped Bass Morone saxatilis × White Bass M. chrysops) have been stocked into reservoirs in the southeastern USA since the late 1960s and have gained widespread acceptance as a sport fish. These fisheries are growing in popularity and catch‐and‐release (CR) fishing is commonplace; however, there is a dearth of information on CR mortality of palmetto bass. We experimentally angled palmetto bass (n = 56; &gt;373‐mm TL) in a Tennessee reservoir using traditional angling gear in water temperatures ranging from 13°C to 32°C. Ultrasonic transmitters equipped with floats were externally attached to fish, which were released immediately and tracked multiple times within 10 d of release. Mortality was negligible (3.6%) in fall and spring at cool water temperatures but was high (39.3%) in summer when water temperatures exceeded 26°C. The best logistic regression model based on Akaike's information criterion for small sample sizes scores relied on water temperature alone to predict CR mortality of palmetto bass; there was little support for other models that included all possible combinations of the six other predictor variables we tested. Palmetto bass in our study experienced lower CR mortality than Striped Bass in other systems, but CR mortality rates for palmetto bass that approach or exceed 40% during summer are still problematic if the goal is to maintain fishing quality.Received February 20, 2013; accepted June 2, 2013

Relating angling-dependent fish impairment to immediate release mortality of red snapper ( Lutjanus campechanus)

Catch-and-release (CAR) fishing of deep-water physoclistous species can lead to increased stress and impairment often resulting in immediate release mortality. We made use of a condition index (BtR score) to evaluate the relationship between CAR-related impairment and immediate release mortality in the recreational red snapper ( Lutjanus campechanus) fishery. Symptoms of barotrauma and impairment showed positive relationships with capture depth and occurred more frequently during the summer sampling than the fall. Impairment, as measured by BtR score, showed significant logistic relationships with immediate release mortality proxies such as floating and erratic swimming at release. Logistic curves had inflection points at BtR scores of 0.3–0.4 (on a scale of 0–1), above which fish experienced high immediate release mortality regardless of season (60–100%). Mean BtR scores were lower than the inflection point of the logistic curve, resulting in immediate release mortality estimates ranging from 20% to 28%. Recaptured fish showed significantly lower impairment than non-recaptured fish. The BtR score is a proficient method to estimate both impairment and immediate release mortality of red snapper in field settings.

Latitudinal Variation in Physiological and Behavioral Responses of Nest‐Guarding Smallmouth Bass to Common Recreational Angling Practices

AbstractManagement policies related to catch‐and‐release (CR) angling of smallmouth bass Micropterus dolomieu vary widely across the geographic distribution of the species. Some jurisdictions, principally in the northern latitudes, prohibit or limit angling efforts that target nesting male smallmouth bass, whereas angling during the nesting period is generally unregulated in southern jurisdictions. Existing studies of individual‐level angling impacts on nesting smallmouth bass have primarily been conducted in the north; thus, the extent to which these findings are relevant to other regions is unknown. In the current study, we sought to systematically evaluate the rates of nest abandonment by nesting smallmouth bass subjected to common angling practices (CR treatment: Brief angling and no exposure to air; air exposure [AE] treatment: Exhaustive angling and 3 min of AE) and tournament practices (simulated tournament [ST] treatment: Exhaustive angling, 2 h of live‐well retention, and 3 min of AE prior to release) across a latitudinal gradient encompassing virtually the entire south‐north range of smallmouth bass (i.e., southern Missouri [MO], southern Ontario [SON], and northern Ontario [NON]) and compared these treatment groups with nonangled controls. We also quantified the extent to which physiological disturbance associated with angling varied across latitudes (peripheral populations [MO and NON] versus the intermediate‐latitude population [SON]). Whole‐blood lactate and glucose levels were highest in fish subjected to ST conditions, indicating increased stress; this pattern was conserved across all latitudes (although there was some evidence of intraspecific variation in stress response). Additionally, the pattern of brood abandonment was similar among fish at all three latitudes; ST fish exhibited the highest rates of nest abandonment (MO: Control = 9.1%, CR = 0%, AE = 9.1%, ST = 100%; SON: control = 10%, CR = 10%, AE = 10%, ST = 50%; NON: control = 7.7%, CR = 0%, AE = 9.1%, ST = 50%). Interestingly, fish from the most southerly latitude, where regulations are the most liberal, abandoned nests at higher rates than did fish from the other latitudes. Collectively, these data reveal that the reproductive success of individual smallmouth bass can suffer from interaction with anglers, particularly in a tournament context, regardless of the region. Further study is needed to determine the extent to which individual nest success is relevant to recruitment and how this relationship varies across latitudes.

Bull Trout Population Responses to Reductions in Angler Effort and Retention Limits

AbstractWe compared historical (1977–1980) and recent (1997–2001) abundance, catch‐per‐unit‐effort (CPUE), and growth data to assess whether the implementation of restrictive sportfishing regulatory regimes in the 1990s led to changes in abundance and population structure of bull trout Salvelinus confluentus in two small Rocky Mountain lakes in Alberta, Canada. For remote Harrison Lake, we used changes in gill‐net CPUE to infer a fivefold increase in bull trout abundance after closure of an access road and implementation of catch‐and‐release (CR) regulations. Bull trout growth rates decreased as their abundance increased. All large (fork length &gt; 420 mm), old (age &gt;12) bull trout were eliminated after regulatory changes were imposed. Reductions in prey abundance and size as bull trout abundance increased probably contributed to the demise of the large bull trout. For road‐accessible Osprey Lake, no change in bull trout mark–recapture abundance estimates or growth rates were observed despite implementation of CR regulations and, later, closure of the lake to angling. We speculate that illegal angling and migration of bull trout between Osprey Lake and its tributary streams limited abundance responses at this site. A variety of site‐specific factors, including ease of access, angler noncompliance with regulations, and local metapopulation structure of bull trout, led to variable bull trout population responses to the implementation of restrictive angling regulations. Active advertisement and enforcement of regulations may be required to achieve increased bull trout abundance at small, easily accessible waterbodies.

The design and analysis of field studies to estimate catch‐and‐release mortality

Abstract The practice of catch and release (CR) as a fisheries management tool to reduce fishing mortality is widely applied in both freshwater and marine fisheries, whether from shifts in angler attitudes related to harvest or from the increasing use of harvest restrictions such as closed seasons or length limits. This approach assumes that for CR fishing policies to benefit the stock, CR will result in much lower mortality than would otherwise occur. There are many challenges in the design of CR studies to assess mortality, and in many practical settings it is difficult to obtain accurate and precise estimates. The focus of this article is on the design and quantitative aspects of estimating CR mortality, the need for a comprehensive approach that explicitly states all components of CR mortality, and the assumptions behind these methods. A general conceptual model for CR mortality that is applicable to containment and tagging‐based studies with a slight modification is presented. This article reviews the design and analysis of containment and tagging studies to estimate CR mortality over both the short and long term and then compares these two approaches. Additionally, the potential population‐level impacts of CR mortality are discussed. A recurring theme is the difficulty of designing studies to estimate CR mortality comprehensively and the need for additional research into both statistical model development and field study design.

Catch-and-Release Reagents for Broadscale Quantitative Proteomics Analyses

The relative quantification of protein expression levels in different cell samples through the utilization of stable isotope dilution has become a standard method in the field of proteomics. We describe here the development of a new reductively cleavable reagent which facilitates the relative quantification of thousands of proteins from only tens of micrograms of starting protein. The ligand features a novel disulfide moiety that links biotin and a thiol-reactive entity. The disulfide is stable to reductive conditions employed during sample labeling but is readily cleaved under mild conditions using tris-(2-carboxyethyl) phosphine (TCEP). This unique chemical property allows for the facile use of immobilized avidin in a manner equivalent to the use of conventional reversible-binding affinity resins. Target peptides are bound to avidin resin, washed rigorously, then cleaved directly from the resin, resulting in simplified sample handling procedures and reduced nonspecific interactions. Here we demonstrate the stability of the linker under two different reducing conditions and show how this "catch-and-release (CAR)" reagent can be used to quantitatively compare protein abundances from two distinct cellular lysates. Starting with only 40 microg protein from each sample, 1840 individual proteins were identified in a single experiment. Using in-house software for automated peak integration, 1620 of these proteins were quantified for differential expression.