Early-life telomeres are influenced by environments acting at multiple temporal and spatial scales.

An individual's telomere length early in life may reflect or contribute to key life-history processes sensitive to environmental variation. Yet, the relative importance of genetic and environmental factors in shaping early-life telomere length is not well understood as it requires samples collected from multiple generations with known developmental histories. We used a confirmed pedigree and conducted an animal model analysis of telomere lengths obtained from nestling house sparrows (Passer domesticus) sampled over a span of 22 years. We found significant additive genetic variation for early-life telomere length, but it comprised a small proportion (9%) of the total biological variation. Three sources of environmental variation were important: among cohorts, among-breeding attempts within years, and among nestmates. The magnitude of variation among breeding attempts and among nestmates also differed by cohort, suggesting that interactive effects of environmental factors across time or spatial scales were important, yet we were unable to identify the specific causes of these interactions. The mean amount of precipitation during the breeding season positively predicted telomere length, but neither weather during a given breeding attempt nor date in the breeding season contributed to an offspring's telomere length. At the level of individual nestlings, offspring sex, size and mass at 10 days of age also did not predict telomere length. Environmental effects appear especially important in shaping early-life telomere length in some species, and more focus on how environmental factors that interact across scales may help to explain some of the variation observed among studies.

Refutation Text Facilitates Learning: a Meta-Analysis of Between-Subjects Experiments.

Scientific misconceptions are ubiquitous, and in our era of near-instant information exchange, this can be problematic for both public health and the public understanding of scientific topics. Refutation text is one instructional tool for addressing misconceptions and is simple to implement at little cost. We conducted a random-effects meta-analysis to examine the effectiveness of the refutation text structure on learning. Analysis of 44 independent comparisons (n = 3,869) showed that refutation text is associated with a positive, moderate effect (g = 0.41, p < .001) compared to other learning conditions. This effect was consistent and robust across a wide variety of contexts. Our results support the implementation of refutation text to help facilitate scientific understanding in many fields. Supplementary Information: The online version contains supplementary material available at 10.1007/s10648-021-09656-z.

Complications of COVID-19 Pneumonia and Multiple Sclerosis Exacerbation.

Multiple sclerosis (MS) is the most common autoimmune disease in the United States, in which demyelination of the brain and spinal cord disrupts the transmission of signals throughout the body. With an average life expectancy of 30 years from the start of the disease, treatment relies on symptom management through steroids and disease-modifying agents, as there is no cure. While MS patients have not been shown to be at increased risk for coronavirus disease 19 (COVID-19) infection, prolonged hospitalizations and severe COVID-19 sequelae have been linked to various MS subgroups. Limited studies, however, have reported on the role of COVID-19 in precipitating MS exacerbations, as flare-ups often occur during times of stress or immunological insult. Here we present a 45-year-old patient with relapsing-remitting multiple sclerosis whose neurological symptoms worsened sharply in the weeks following an inpatient admission for COVID-19 pneumonia.

Longer telomeres during early life predict higher lifetime reproductive success in females but not males.

The mechanisms that contribute to variation in lifetime reproductive success are not well understood. One possibility is that telomeres, conserved DNA sequences at chromosome ends that often shorten with age and stress exposures, may reflect differences in vital processes or influence fitness. Telomere length often predicts longevity, but longevity is only one component of fitness and little is known about how lifetime reproductive success is related to telomere dynamics in wild populations. We examined the relationships between telomere length beginning in early life, telomere loss into adulthood and lifetime reproductive success in free-living house sparrows (Passer domesticus). We found that females, but not males, with longer telomeres during early life had higher lifetime reproductive success, owing to associations with longevity and not reproduction per year or attempt. Telomeres decreased with age in both sexes, but telomere loss was not associated with lifetime reproductive success. In this species, telomeres may reflect differences in quality or condition rather than the pace of life, but only in females. Sexually discordant selection on telomeres is expected to influence the stability and maintenance of within population variation in telomere dynamics and suggests that any role telomeres play in mediating life-history trade-offs may be sex specific.

TA-65 does not increase telomere length during post-natal development in house sparrow chicks (Passer domesticus).

Telomeres, protective caps at the end of chromosomes, are often positively related to lifespan and are thought to be an important mechanism of organismal aging. To better understand the casual relationships between telomere length and longevity, it is essential to be able to experimentally manipulate telomere dynamics (length and loss rate). Previous studies suggest that exposure to TA-65, an extract from the Chinese root Astragalus membranaceus, activates telomerase, lengthens telomeres, increases the growth of keratin-based structures, and boosts the immune system in adults. However, telomere loss is expected to be greatest during early life but whether TA-65 has similar effects during this life stage is currently unknown. Here, we experimentally exposed free-living house sparrow (Passer domesticus) chicks to TA-65 during post-natal development and examined the effects on telomere length and loss, growth of keratin-based structures, and a measure of cellular immunity. Contrary to expectation, the growth of keratin-based structures was reduced in TA-65 chicks and in the second year of the study, chicks exposed to TA-65 experienced more telomere loss than controls. Thus, the effects of TA-65 on telomeres and keratin-based structures differ across life stages and future research will be necessary to determine the mechanisms underlying these age-specific effects.

Avian Semen Collection by Cloacal Massage and Isolation of DNA from Sperm.

Collection of semen may be useful for a wide range of applications including studies involving sperm quality, sperm telomere dynamics, and epigenetics. Birds are widely used subjects in biological research and are ideal for studies involving repeated sperm samples. However, few resources are currently available for those wishing to learn how to collect and extract DNA from avian sperm. Here we describe cloacal massage, a gentle, non-invasive manual technique for collecting avian sperm. Although this technique is established in the literature, it can be difficult to learn from the available descriptions. We also provide information for extracting DNA from avian semen using a commercial extraction kit with modifications. Cloacal massage can be easily used on any small- to medium-sized male bird in reproductive condition. Following collection, the semen can be used immediately for motility assays, or frozen for DNA extraction following the protocol described herein. This extraction protocol was refined for avian sperm and has been successfully used on samples collected from several passerine species (Passer domesticus, Spizella passerina, Haemorhous mexicanus, and Turdus migratorius) and one columbid (Columba livia).

Repeated immune challenges affect testosterone but not sperm quality.

Mounting an immunological response is energetically demanding and necessarily redirects allocation of resources toward immune system activation and away from other energetically expensive processes, such as reproduction. Lipopolysaccharide (LPS), a major component of the outer membrane of the cell wall of Gram-negative bacteria Escherichia coli, mimics a bacterial infection without producing the cost of replicating the pathogen and is one of the most commonly used agents to induce an acute phase immune response. Here, we ask if a trade-off can be induced between activation of the acute phase immune response and sperm function, a key indicator of sperm competitive ability. Further, we ask whether repeated exposure to this endotoxin in a social species such as the house sparrow (Passer domesticus), where repeated pathogen exposure may be common, may have a more pronounced effect. To address our questions, we exposed individuals to two rounds of LPS treatment or control, to mimic a repeated pathogen exposure in the wild. We predicted that repeated pathogen exposure would have detrimental effects on sperm quality, and therefore, reproductive success. We compared a measure of sperm quality (straight-line velocity) in captive male house sparrows between LPS-treated and control individuals. We found that although LPS treatment impaired circulating testosterone and induced a hypothermic state when compared with controls, it did not affect sperm quality within days or weeks following a single or repeated LPS exposure.