Understanding the thermal sensitivity of reproductive interactions is crucial given global warming. Previous studies have almost exclusively focused on interactions before mating, even though important interactions between the sexes also occur after mating (e.g. gamete interactions), which are likely also affected by temperature. Thus, it remains unknown how temperature affects the influence of female reproductive fluid on sperm performance, thereby altering female control over fertilization (cryptic female choice). This gap limits our understanding of how sexual selection changes with seasonal temperature fluctuations and temperatures outside the range of historical norms. We tested how temperatures relevant to current conditions and climate change projections influence the mechanisms underlying cryptic female choice in a marine fish, Symphodus ocellatus. Under typical, cooler thermal conditions, female reproductive fluid enhances sperm velocity and biases fertilization dynamics to favour preferred, dominant males over sneaker males. We find that warmer temperatures decrease female influence on sperm velocity, especially for dominant males. This results in dominant males having slower sperm than sneaker males at warmer temperatures, reducing the expected paternity of preferred, dominant males. Our results highlight that considering the thermal sensitivity of female-male interactions that occur after mating will be essential for understanding how seasonal variation and climate change can influence fertility, reproduction and sexual selection.Read the free for this article on the Journal blog.

Transgenerational plasticity (TGP) has largely focused on how parental exposure to ecological conditions shapes the phenotypes of future generations. However, organisms acquire information about their ecological environment via social learning, which can also shape TGP in profound ways. We demonstrate that non-parents alter how parents detect and respond to environmental cues in ways that spillover to affect offspring, non-parents influence offspring even without direct physical interactions, and parental cues received by offspring can alter the phenotypes of other juveniles. Because parents can draw on the experiences of a network of non-parents, these socially acquired cues may increase parents’ ability to accurately detect environmental shifts and may explain why TGP is surprisingly ubiquitous despite theory predicting that it should be relatively rare.

Reproduction is often more thermally sensitive than survival. Thus, understanding the thermal sensitivity of reproductive interactions is crucial given global warming. However, it is unknown how temperature influences female control over fertilization after mating ( i.e., cryptic female choice). We tested how temperatures relevant to current conditions and climate change projections influence cryptic female choice in a marine fish, Symphodus ocellatus . Under typical conditions, females bias fertilization dynamics to favor dominant males. We find that warmer temperatures decrease female influence on sperm velocity and reduce the expected paternity of dominant males. Our results demonstrate that temperatures relevant to climate change can shift the balance between mate choice and male-male competition. Thus, climate change may influence sexual selection, leading to evolutionary changes in reproductive traits. ### Competing Interest Statement The authors have declared no competing interest.

Parental care is a critical determinant of offspring fitness. Female presence and male competition affect paternal care, but male-male cooperation during mating may also be an important, yet underappreciated, driver of paternal care. In many systems, males work together to court females or defend territories against male competitors. This male-male cooperation can alter actual or perceived paternity of the parenting male and could, therefore, influence how males invest in care during the postmating period. Here, we measured how reproductive and social dynamics between nesting and satellite males during mating correlate with nesting male paternal care in the ocellated wrasse (Symphodus ocellatus). Although paternal care (fanning rates) was repeatable across days within the same nesting cycle, it was not repeatable across different nesting cycles, suggesting that males plastically alter care in response to the environment. Nesting males provided care for fewer days at nests with the most unstable relationship between the nesting and satellite male: nests with low satellite cooperation and high male-male conflict where the satellite eventually left or was evicted from the nest. Nesting males also parented more intensively, but for fewer days in the warmer year, suggesting that males may adjust care in response to temperature. Collectively, our results suggest that there is no fixed male trait that females can use to predict paternal care behavior. Instead, females may use male-male interactions as a proxy for the quality of care her offspring will receive, suggesting that sexual selection may favor the co-evolution of paternal care with male-male cooperation. Conflict in male reproductive coalitions during the mating period affects how much care fathers provide to their offspring. In the ocellated wrasse Symphodus ocellatus, nesting males provided less care to offspring when they had more conflict with satellite male partners or were paired with less cooperative satellites. This suggests that females use male-male interactions as a proxy for the quality of care her offspring will receive, suggesting that paternal care may co-evolve with male-male cooperation.

Parental experiences can alter offspring phenotypes via transgenerational plasticity (TGP), which may prime offspring to adaptively respond to novel stressors, including novel predators. However, we know little about the types of sensory cues (e.g. visual, olfactory) that parents use to recognize novel predators and the consequences for offspring. Individuals may respond to novel cues if they mimic historical cues or they may need multiple sensory cues to recognize and respond to novel stimuli. We exposed threespined stickleback (Gasterosteus aculeatus) males to a full factorial of visual and olfactory cues of a novel trout predator prior to fertilization and tested offspring for antipredator behaviour and survival against a live predator. Fathers exposed to visual cues oriented more to and spent time closer to the novel predator post-exposure on the first day. Paternal response to visual cues was echoed in their offspring: offspring of fathers exposed to visual cues were caught faster by a live predator, suggesting that multiple cues are not needed to induce a transgenerational effect. While visual cues elicited responses both within- and transgenerationally, they do not seem to result in adaptive priming in offspring, suggesting the possibility of maladaptive TGP in response to novel cues of predation risk.

Parental care is a critical determinant of offspring fitness, and parents adjust their care in response to ecological challenges, including predation risk. The experiences of both mothers and fathers can influence phenotypes of future generations (transgenerational plasticity). If it is adaptive for parents to alter parental care in response to predation risk, then we expect F-1 and F-2 offspring who receive transgenerational cues of predation risk to shift their parental care behaviour if these ancestral cues reliably predict a similarly risky environment as their F-0 parents. Here, we used three-spined sticklebacks (Gasterosteus aculeatus) to understand how paternal exposure to predation risk prior to mating alters reproductive traits and parental care behaviour in unexposed F-1 sons and F-2 grandsons. Sons of predator-exposed fathers took more attempts to mate than sons of control fathers. F-1 sons and F-2 grandsons with two (maternal and paternal) predator-exposed grandfathers shifted their paternal care (fanning) behaviour in strikingly similar ways: they fanned less initially, but fanned more near egg hatching. This shift in fanning behaviour matches shifts observed in response to direct exposure to predation risk, suggesting a highly conserved response to pre-fertilization predator exposure that persists from the F-0 to the F-1 and F-2 generations.

Parents routinely encounter stress in the ecological environment that can affect offspring development (transgenerational plasticity: TGP); however, parents' interactions with conspecifics may alter how parents respond to ecological stressors. During social buffering, the presence of conspecifics can reduce the response to or increase the speed of recovery from a stressor. This may have cascading effects on offspring if conspecifics can mitigate parental responses to ecological stress in ways that blunt the transmission of stress-induced transgenerational effects. Here, we simultaneously manipulated both paternal social isolation and experience with predation risk prior to fertilisation in threespined stickleback (Gasterosteus aculeatus). We generated offspring via in-vitro fertilisation to allow us to isolate paternal effects mediated via sperm alone (i.e. in the absence of paternal care). If social buffering mitigates TGP induced by paternal exposure to predation risk, then we expect the transgenerational effects of predation exposure to be weaker when a conspecific is present compared to when the father is isolated. Offspring of predator-exposed fathers showed reduced anxiety-like behaviour and tended to be captured faster by the predator. Fathers who were socially isolated also had offspring that were captured faster by a live predator, suggesting that paternal social isolation may have maladaptive effects on how offspring respond to ecological stressors. Despite additive effects of paternal social isolation and paternal predation risk, we found no evidence of an interaction between these paternal treatments, suggesting that the presence of a conspecific did not buffer fathers and/or offspring from the effects of predation risk. Our results suggest that socially induced stress is an important, yet underappreciated, mediator of TGP and can elicit transgenerational effects even in species that do not form permanent social groups. Future studies should therefore consider how the parental social environment can affect both within and trans-generational responses to ecological stressors.

Glyphosate, a key ingredient in many herbicides, is increasingly present in aquatic systems due to agricultural runoff. High doses of glyphosate cause defects in organisms due to its ability to interfere with physiological processes as an endocrine disruptor. We used the mangrove rivulus fish (Kryptolebias marmoratus) to evaluate the effects of larval exposure to glyphosate on non-target species in aquatic environments. These fish produce genetically identical offspring, allowing us to evaluate phenotypic responses to toxicant exposure while controlling for genetics. We treated newly hatched larvae for 96 h with concentrations of glyphosate on the low and high end of what they would experience in the wild: control (0 mg/L), low (0.01 mg/L), and high (1.1 mg/L), and then measured behavior, morphology, and reproductive traits at 60 and 130 days. We predicted that these amphibious fish exposed to low, environmentally relevant doses would show adaptive emersion behavior to escape poor quality water conditions, and deficits in other traits would be greater with higher glyphosate dosages. We found that low doses (0.01 mg/L) of glyphosate led to lower anxiety (decreased thigmotaxis) and impaired jumping behaviors while high dose exposures to glyphosate resulted in lower activity and lower average egg yield per individual. None of these effects appeared to be adaptive at low or high doses of glyphosate. While deficits in reproductive output scaled with dosage, phenotypic effects were often dosage-specific for each trait. This study demonstrates that even environmentally relevant concentrations of herbicide may be harmful to aquatic organisms and have consequences that persist well into adulthood. Furthermore, given that environmentally relevant concentrations of glyphosate induced deficits in reproductive output, this suggests that glyphosate contamination in natural systems may have population level consequences.

Objective To describe racial inequities in pediatric inflammatory bowel disease care and explore potential drivers. Methods We undertook a single-center, comparative cohort study of newly diagnosed Black and non-Hispanic White patients with inflammatory bowel disease, aged <21 years, from January 2013 through 2020. Primary outcome was corticosteroid-free remission (CSFR) at 1 year. Other longitudinal outcomes included sustained CSFR, time to anti-tumor necrosis factor therapy, and evaluation of health service utilization. Results Among 519 children (89% White, 11% Black), 73% presented with Crohn's disease and 27% with ulcerative colitis. Disease phenotype did not differ by race. More patients from Black families had public insurance (58% vs 30%, P < .001). Black patients were less likely to achieve CSFR 1-year post diagnosis (OR: 0.52, 95% CI:0.3-0.9) and less likely to achieve sustained CSFR (OR: 0.48, 95% CI: 0.25-0.92). When adjusted by insurance type, differences by race to 1-year CSFR were no longer significant (aOR: 0.58; 95% CI: 0.33, 1.04; P = .07). Black patients were more likely to transition from remission to a worsened state, and less likely to transition to remission. We found no differences in biologic therapy utilization or surgical outcomes by race. Black patients had fewer gastroenterology clinic visits and 2-fold increased odds for emergency department visits. Conclusions We observed no differences by race in phenotypic presentation and medication usage. Black patients had half the odds of achieving clinical remission, but a degree of this was mediated by insurance status. Understanding the cause of such differences will require further exploration of social determinants of health.

Background Inflammatory bowel diseases (IBDs) involve an aberrant host response to intestinal microbiota causing mucosal inflammation and gastrointestinal symptoms. Patient-reported outcomes (PROs) are increasingly important in clinical care and research. Our aim was to examine associations between PROs and fecal microbiota in patients 0 to 22 years of age with IBD. Methods A longitudinal, prospective, single-center study tested for associations between microbial community composition via shotgun metagenomics and PROs including stool frequency and rectal bleeding in ulcerative colitis (UC) and abdominal pain and stool frequency in Crohn’s disease (CD). Mucosal inflammation was assessed with fecal calprotectin. A negative binomial mixed-effects model including clinical characteristics and fecal calprotectin tested for differentially abundant species and metabolic pathways by PROs. Results In 70 CD patients with 244 stool samples, abdominal pain correlated with increased relative abundance of Haemophilus and reduced Clostridium spp. There were no differences relative to calprotectin level. In 23 UC patients with 76 samples, both rectal bleeding and increased stool frequency correlated with increased Klebsiella and reduced Bacteroides spp. Conversely, UC patients with lower calprotectin had reduced Klebsiella. Both UC and CD patients with active symptoms exhibited less longitudinal microbial community stability. No differences in metabolic pathways were observed in CD. Increased sulfoglycolysis and ornithine biosynthesis correlated with symptomatic UC. Conclusions Microbial community composition correlated with PROs in both CD and UC. Metabolic pathways differed relative to PROs in UC, but not CD. Data suggest that microbiota may contribute to patient symptoms in IBD, in addition to effects of mucosal inflammation.

Several predictions of sperm competition theory are not well supported empirically. One potential reason is that most current theory and empirical research ignore how the social environment influence the temporal dynamics of mating. We propose that understanding these dynamics is key to understanding sexual selection and improving the predictive power of theory. To demonstrate the importance of these dynamics, we quantify how males' social role, interactions among males, and current social environment influence the timing of mating in Symphodus ocellatus, a species with three alternative male reproductive tactics. Nesting males spawn synchronously with females; sneakers and satellites sneak-spawn with some time delay. Satellites also cooperate with nesting males. We found that satellites have shorter sneak-spawning delays than sneakers, a benefit of their cooperation with nesting males. Sneak-spawning delays decreased with increasing nest activity for sneakers but not for satellites, suggesting that sneakers may benefit from increased sperm competition intensity. Current sperm competition models ignore this potential benefit, which may be why the prediction that males should decrease investment when sperm competition involves more than two males is not well supported. Our study provides insight into mechanisms that drive variation in the timing of spawning, which could explain mismatches between theoretical and empirical results.

There is growing evidence that offspring receive information about their environment vertically, i.e. from their parents (environmental parental effects or transgenerational plasticity). For example, parents exposed to predation risk may produce offspring with heightened antipredator defences. At the same time, organisms can gain information about the environment horizontally, from conspecifics. In this study, we provide some of the first evidence that horizontally acquired social information can be transmitted vertically across generations. Three-spined stickleback (Gasterosteus aculeatus) fathers produced larval offspring with altered antipredator behaviour when fathers received visual and olfactory cues from predator-chased neighbours. Although fathers did not personally witness their neighbours being chased (i.e. they never saw the predator), changes in offspring traits were similar to those induced by direct paternal exposure to predation risk. These findings suggest that two different non-genetic pathways (horizontal transfer of social information, vertical transfer via sperm-mediated paternal effects) can combine to affect offspring phenotypes. The implications of simultaneous horizontal and vertical transmission are widely appreciated in the context of disease and culture; our results suggest that they could be equally important for the maintenance of phenotypic variation and could have profound consequences for the rate at which information flows within and across generations.

Background & Aims:The truncating mutations in tight junction protein 2 (TJP2) cause progressive cholestasis, liver failure, and hepatocyte carcinogenesis. Due to the lack of effective model systems, there are no targeted medications for the liver pathology with TJP2 deficiency. We leveraged the technologies of patient-specific induced pluripotent stem cells (iPSC) and CRISPR genome-editing, and we aim to establish a disease model which recapitulates phenotypes of patients with TJP2 deficiency. Methods:We differentiated iPSC to hepatocyte-like cells (iHep) on the Transwell membrane in a polarized monolayer. Immunofluorescent staining of polarity markers was detected by a confocal microscope. The epithelial barrier function and bile acid transport of bile canaliculi were quantified between the two chambers of Transwell. The morphology of bile canaliculi was measured in iHep cultured in the Matrigel sandwich system using a fluorescent probe and live-confocal imaging. Results:The iHep differentiated from iPSC with TJP2 mutations exhibited intracellular inclusions of disrupted apical membrane structures, distorted canalicular networks, altered distribution of apical and basolateral markers/transporters. The directional bile acid transport of bile canaliculi was compromised in the mutant hepatocytes, resembling the disease phenotypes observed in the liver of patients. Conclusions:Our iPSC-derived in vitro hepatocyte system revealed canalicular membrane disruption in TJP2 deficient hepatocytes and demonstrated the ability to model cholestatic disease with TJP2 deficiency to serve as a platform for further pathophysiologic study and drug discovery. Lay summary:We investigated a genetic liver disease, progressive familial intrahepatic cholestasis (PFIC), which causes severe liver disease in newborns and infants due to a lack of gene called TJP2. By using cutting-edge stem cell technology and genome editing methods, we established a novel disease modeling system in cell culture experiments. Our experiments demonstrated that the lack of TJP2 induced abnormal cell polarity and disrupted bile acid transport. These findings will lead to the subsequent investigation to further understand disease mechanisms and develop an effective treatment.