Female Pairs Research Articles

Does the same refuge signify the same reproductive tactics? Comparing the mating systems of two symbiont alpheid shrimps (Crustacea: Decapoda)

AbstractAnimal populations can present different mating tactics according to the number of mates males or females obtain. The limiting factors for copulation in symbiont crustaceans are the size, structural complexity, and density of refuge, in addition to predation risk outside their shelters. In this study, we aimed to investigate, comparatively, if the occupation of the same refuge leads to the same reproductive tactic in two symbiont species of alpheid shrimps. For this purpose, we described the population distribution of Alpheus estuariensis, a burrowing shrimp, and Salmoneus carvachoi, a tenant species, in an intertidal mudflat in Pernambuco, northeastern Brazil. Alpheus estuariensis experiences sexual dimorphism relative to body and cheliped size, where males present larger body sizes and allocate more resources to cheliped growth than females. However, both males and females presented positive allometric growth in chelipeds. In S. carvachoi, male‐phase individuals reach smaller body sizes than hermaphrodites. Male‐phase shrimps experience positive allometry in cheliped size, while hermaphrodites do not. Both species were found inhabiting burrows as sexual pairs more frequently than expected by chance. Paired females of A. estuariensis were found carrying embryos more frequently than solitary ones. We did not find a statistical difference between the frequency of single and paired ovigerous hermaphrodites in S. carvachoi. Our results indicate that A. estuariensis is social monogamous, while S. carvachoi is promiscuous. We argue that different biological and ecological aspects of these species could explain the distinct tactics adopted by them. Alpheus estuariensis digs its own refuge and is a much larger species, bearing a more robust cheliped than S. carvachoi. Thus, we argue that the burrowing species (A. estuariensis) should monopolize and defend their refuge, and S. carvachoi only takes advantage of this resource.

Exploring the possibility of parents' broad internalizing phenotype acting through passive gene-environment correlations on daughters' disordered eating.

Twin studies demonstrate significant environmental influences and a lack of genetic effects on disordered eating before puberty in girls. However, genetic factors could act indirectly through passive gene-environment correlations (rGE; correlations between parents' genes and an environment shaped by those genes) that inflate environmental (but not genetic) estimates. The only study to explore passive rGE did not find significant effects, but the full range of parental phenotypes (e.g., internalizing symptoms) that could impact daughters' disordered eating was not examined. We addressed this gap by exploring whether parents' internalizing symptoms (e.g., anxiety, depressive symptoms) contribute to daughters' eating pathology through passive rGE. Participants were female twin pairs (aged 8-14 years; M = 10.44) in pre-early puberty and their biological parents (n = 279 families) from the Michigan State University Twin Registry. Nuclear twin family models explored passive rGE for parents' internalizing traits/symptoms and twins' overall eating disorder symptoms. No evidence for passive rGE was found. Instead, environmental factors that create similarities between co-twins (but not with their parents) and unique environmental factors were important. In pre-early puberty, genetic factors do not influence daughters' disordered eating, even indirectly through passive rGE. Future research should explore sibling-specific and unique environmental factors during this critical developmental period.

Effect of formic acid treatment on colostrum quality, and on absorption and function of immunoglobulins: a randomized controlled trial in Holstein dairy calves

BackgroundGood quality colostrum is characterized by high immunoglobulin concentration and low pathogen load. Some methods of pathogen reduction can decrease immunoglobulin concentration and potentially affect their function. Objectives were to determine the effect of formic acid treatment on colostral bacterial and immunoglobulin (IgG) levels before feeding, and serum immunoglobulin concentration and neutralizing capabilities after feeding. Fifteen female Holstein calf pairs born < 12 h apart from different dams were randomly assigned to receive four liters of either untreated pooled (both dams) colostrum (MC) or colostrum acidified to pH 4.0–4.5 (AC). Colostrum characteristics estimated; pH, bacterial load, IgG concentration, and neutralization of Infectious Bovine Rhinotracheitis (IBRV/BoHV-1), Bovine Viral Diarrhea (BVDV) Types 1 and 2. Blood samples were collected on days 1, 3 and monthly for 6 months and were analyzed for IgG, and both viral plus leptospiral neutralization, and total protein (day 3 only).ResultsCompared to MC (mean 6.7, SD 0.4; median 6.8, range 6.0–7.3), AC pH was significantly reduced (mean 4.3, SD 0.2; median 4.3, range 4.0–4.5; P < 0.001). Total coliform count (cfu/mL) was also reduced (MC mean 149, SD 444; median 1, range 0–1,700; AC mean 8, SD 31; median 0, range 0–120; P = 0.02). Colostrum IgG concentration was not significantly different between MC (mean 93.3, SD 39.7; median 92.8, range 36.7–164.4 g/L) and AC (mean 101.9, SD 36.7; median 108.3, range 33.8–164.4 g/L; P = 0.54). In calves, serum IgG peaked on day 3 (MC mean 26.1, SD 34.9; median 169.2, range 8.3–151.0 g/L; AC mean 30.2, SD 48.7; median 188.8, range 3.1–204.4 g/L; P = 0.77), and apparent efficiency of IgG absorption was not different between groups (MC mean 24.3, SD 11.4, median 25.3, range 8.6–51.3%; AC mean 22.6, SD 21.7, median 21.6, range 4.1–58.9%; P = 0.65). Thereafter, IgG levels declined but did not differ between groups. MC and AC serum neutralizing titers for IBRV, BVDV Types 1 and 2, or Leptospira interrogans serovars Canicola, and Pomona and L. borgpetersenii serovar Hardjo were not different.ConclusionsColostrum acidification significantly decreased bacterial load fed to newborn calves without affecting colostral IgG concentration or virus neutralization. In addition, acid treatment did not affect serum IgG concentration in calves or its activity against common pathogens.

Heritability of Psychotic Experiences in Adolescents and Interaction With Environmental Risk

Genetic risk factors are known to play a role in the etiology of psychotic experiences in the general population. Little is known about whether these risk factors interact with environmental risks for psychotic experiences. To assess etiological heterogeneity and exposure to environmental risks associated with psychotic experiences in adolescence using the twin design. This twin study, conducted from December 1, 2014, to August 31, 2020, included a UK-based sample of twin pairs aged 16 years. This investigation evaluated the extent to which the genetic variance underlying psychotic experiences and the magnitude of the heritability of psychotic experiences was moderated by exposure to 5 environmental risk factors (bullying, dependent life events, cannabis use, tobacco use, and low birth weight). Psychotic experiences were assessed by 5 self-reported measures and 1 parent-reported measure. Participants' exposure to environmental risks was assessed at birth and age 12 to 16 years. Structural equation models were used to assess differences in the variance in and heritability of psychotic experiences across these exposures, while controlling for gene-environment correlation effects. Analyses were repeated in an independent Swedish sample. Data analyses were performed from September 1, 2018, to August 31, 2020. Primary outcome measures were exposure to environmental factors, as measured by a composite score, and psychotic experiences. A total of 4855 twin pairs (1926 female same-sex pairs, 1397 male same-sex pairs, and 1532 opposite-sex pairs) were included from the Twins Early Development Study (TEDS), and 6435 twin pairs (2358 female same-sex pairs, 1861 male same-sex pairs, and 2216 opposite-sex pairs) were included from the Child and Adolescent Twin Study in Sweden (CATSS). Mean age of twins from TEDS was 16.5 years. Mean age of twins from CATSS was 18.6 years. More exposure to environmental risk factors was associated with having more psychotic experiences. The relative contribution of genetic influences to psychotic experiences was lower with increasing environmental exposure for paranoia (44%; 95% CI, 33%-53% to 38%; 95% CI, 14%-58%), cognitive disorganization (47%; 95% CI, 38%-51% to 32%; 95% CI, 11%-45%), grandiosity (41%; 95% CI, 29%-52% to 32%; 95% CI, 9%-48%), and anhedonia (49%; 95% CI, 42%-53% to 37%; 95% CI, 15%-54%). This pattern was replicated for the measure of psychotic experiences in the independent Swedish replication sample. The heritability of hallucinations and parent-rated negative symptoms remained relatively constant. Findings of this twin study suggest that environmental factors play a greater role in the etiology of psychotic experiences than genetic factors. The relative importance of environmental factors is even higher among individuals exposed to environmental risks for psychotic experiences, highlighting the importance of a diathesis-stress or bioecological framework for understanding adolescent psychotic experiences.

Rapid colonization of the post‐burn environment improves egg survival in pyrophilic ground beetles

AbstractMany insects are drawn to the heat, ash, and smoke produced by forest fires and arrive in large numbers at recent burns, often while the fire is still active. Some of these insects are pyrophilic and reproduce exclusively in the immediate aftermath of fire but are rarely, if ever, collected from unburnt habitats. Numerous observations made at active fires note an apparent preference among some pyrophilic insects to oviposit exclusively in the burnt portions of trees, raising broader questions about the adaptive benefits of reproduction in the post‐burn environment. Here, we tested whether the reproductive output of pyrophilic ground beetles (i.e., Sericoda spp.) increased in heat‐sterilized soils. In the first experiment, the eggs of Sericoda quadripunctata were reared in three types of soil collected from burnt forests: recently burnt soil (collected 1–2 weeks after the fire), soil collected 1 year after burn, and soil from an unburnt patch of forest adjacent to the fire. Daily monitoring through a dissecting microscope documented extensive predation of eggs by soil microarthropods (mites, springtails, and nematodes), especially in 1‐year‐old and unburnt soil treatments. This led to a second experiment that included the same three treatments and an additional fourth soil treatment: recently, burnt soil reheated to 100°C for 2 h (i.e., reheated soil). In this experiment, male and female pairs (n = 100) of Sericoda obsoleta were reared for 14 days in jars containing 90 g of soil corresponding to each of the four soil treatments. Reproductive output, measured as the number of larvae produced by each breeding pair, was significantly higher in the reheated soil, suggesting that heat sterilization and removal of soil‐dwelling predators improved egg survival. Our findings suggest that pyrophily in insects may have evolved as a means of increasing reproductive output in the post‐burn environment through access to heat‐sterilized ovipositing substrates. Furthermore, the abrupt disappearance of Sericoda and other pyrophilic insects following fire may be explained by suboptimal reproductive conditions as the burn is colonized by other organisms and by local emigration in favor of other recent burns on the landscape.

Acoustic characteristics of sound produced by males of Bactrocera oleae change in the presence of conspecifics

Males of the olive fruit fly Bactrocera oleae vibrate and stridulate their wings at dusk producing sounds different from flight sounds with no confirmed behavior role. We recorded and performed a temporal-spectral analysis of this sound. Sound produced by male wing vibration/stridulation consists of intermittent pulses of highly variable duration and of fundamental frequency of around 350 Hz. Flight sound has a much lower fundamental frequency of approximately 180 Hz. Males begin to display wing vibration and sound production at the beginning of their sexual maturity at the 5th day of their age. This behavior is more pronounced in the presence of another conspecific male and observed less in male–female pairs or in solitary males. Broadcasts of the recorded sound did not attract flies of either sex. The highest fundamental frequency was found in association with wing vibrations emitted by male–male pairs, followed by those emitted by male–female pairs and then solitary males, which showed the lowest frequency values. The mean pulse duration and interpulse interval were shorter in male–male pairs than in male–female pairs. We assume that the male wing vibration and the produced signal, apart from its possible role in the courtship of the females, could also be associated with male–male interactions for territorial and rival activities, for which further experiments are required.

Increased self-triggered vocalizations in an epidermal growth factor-induced rat model for schizophrenia

Rats elicit two types of ultrasonic vocalizations (USVs), positive (30–80 kHz; high pitch) and negative (10–30 kHz; low pitch) voices. As patients with schizophrenia often exhibit soliloquy-like symptoms, we explored whether an animal model for schizophrenia is similarly characterized by such self-triggered vocalizations. We prepared the animal model by administering an inflammatory cytokine, epidermal growth factor (EGF), to rat neonates, which later develop behavioral and electroencephalographic deficits relevant to schizophrenia. EGF model rats and controls at young (8–10 weeks old) and mature (12–14 weeks old) adult stages were subjected to acclimation, female pairing, and vocalization sessions. In acclimation sessions, low pitch USVs at the mature adult stage were more frequent in EGF model rats than in controls. In the vocalization session, the occurrences of low pitch self-triggered USVs were higher in EGF model rats in both age groups, although this group difference was eliminated by their risperidone treatment. Unlike conventional negative USVs of rats, however, the present low pitch self-triggered USVs had short durations of 10–30 ms. These results suggest the potential that self-triggered vocalization might serve as a translatable pathological trait of schizophrenia to animal models.

A pilot study for satellite-tracking Gadwalls Mareca strepera wintering in the Lea Valley, UK

ABSTRACT A pilot study monitored four overwintering Gadwalls fitted with satellite trackers in November 2018 at Rye Meads Nature Reserve, Hertfordshire. The research assessed the feasibility of a larger study investigating the range, movement and habitat preference of Gadwall utilising the Greater London wetland areas, and the suitability of fitting trackers using a glue-attachment method. Tracked birds varied in extent of movement. Two male Gadwalls remained largely sedentary, making use of the freshwater gravel lakes in the Lee Valley Regional Park. A pair-bonded male and female moved together, spending a number of weeks in the Lea Valley before moving 20 km to Hatfield Forest, Essex. This represented a change of habitat to a mature woodland with established lakes and ponds. We speculate that differences in movement between the male–female pair and other males may be attributable to mating effort and individual differences in migratory strategy. Considerable variation in the retention of trackers was seen, with one bird believed to have gradually removed the device through preening. Retrap data for one male showed overwinter weight loss that was higher than in any of 14 Gadwalls recorded previously. The cause of weight loss was unknown and we recommend further investigating the energetic costs of having a tracker fitted. Glue attachment may be unreliable for studies that require monitoring of Gadwalls for more than a few weeks, due to a high likelihood of attachment failure.

Who goes where in couples and pairs? Effects of sex and handedness on side preferences in human dyads

ABSTRACT There is increasing evidence that inter-individual interaction among conspecifics can cause population-level lateralization. Male–female and mother–infant dyads of several non-human species show lateralised position preferences, but such preferences have rarely been examined in humans. We observed 430 male–female human pairs and found a significant bias for males to walk on the right side of the pair. A survey measured side preferences in 93 left-handed and 92 right-handed women, and 96 left-handed and 99 right-handed men. When walking, and when sitting on a bench, males showed a significant side preference determined by their handedness, with left-handed men preferring to be on their partner’s left side and right-handed men preferring to be on their partner’s right side. Women did not show significant side preferences. When men are with their partner they show a preference for the side that facilitates the use of their dominant hand. We discuss possible reasons for the side preference, including males prefering to occupy the optimal “fight ready” side, and the influence of sex and handedness on the strength and direction of emotion lateralization.

Social impact of mara pair disruption on the formation of new bonds and reproduction in a multiple mate choice context

Maras, Dolichotis patagonum , combine social monogamy and plural breeding, an unusual mating system for mammals. We tested how maras adapt to the forced separation of pair-bonded partners and how the potential new mates perform over the breeding season and during the process of forming new pairs. Fourteen established pairs from a captive population were randomly assigned to a control (C-group; N = 7) or an experimental (E-group; N = 7) condition. The experiment consisted of replacing seven paired males with seven socially unfamiliar males (new potential mates). Individual behaviour and social interactions were recorded over a 6-month period (spring–summer; i.e. 14 sessions) from 0800 to 1800 hours, totalling 11 hourly sampling points per session. We measured pair behaviours and degree of general behavioural synchrony over sessions 1–7 (early) and over sessions 8–14 (late). We also measured how social disruption affected the social networking of individuals forming new pair bonds as compared to individuals with established mates. We furthermore assessed the level of activity of females exposed to mate switching and the production of offspring over the breeding season. In the E-group, maras showed a reduction in pair behaviours and synchronization of activities. There were also multiple interactions among females with several males, revealing initial mate choice activity during the early time period. The period of mate choice was characterized by instability in social networking and changes in the strength of a pair's fidelity. Although the E-group included five newly established pairs, offspring production was similar to that of the C-group. Our findings show that after presumably stressful experimental social disruption, most maras re-paired in captivity, although with some delay in offspring production, suggesting that this species has the plasticity to cope with male partner loss under semicontrolled environmental conditions. However, the strength of monogamous bonds was affected by this social disruption. • Pair-bonding disruption affected the behaviour of maras, D. patagonum. • Female and male interactions during mate choice caused social instability. • Most female maras were able to re-pair after the loss of their male partner. • Offspring were unaffected by social disruption during the breeding season. • Monogamy level of male–female pairs was affected by social disruption.

Automated radio tracking provides evidence for social pair bonds in an obligate brood parasite

Social monogamy predominates in avian mating systems, but this strategy seems unlikely among brood parasites, where the emancipation from parental care should lead to an increase in numbers of mates for both sexes. Despite this, there is great diversity in mating systems in brood parasitic birds. The Screaming CowbirdMolothrus rufoaxillarisis a brood parasite that specializes almost exclusively on one host, the Greyish BaywingAgelaioides badius. Field observations and a radio telemetry study have indicated that male–female pairs spend a great deal of time together through the day, suggesting that they may be socially monogamous. We tested the hypothesis of social monogamy by radio‐tracking male and female Screaming Cowbirds using an array of automated radiotracking receivers to collect data on spatial behaviour and social mating system. Monogamous pair bonds were recorded through social network analysis. These bonds endured throughout the entire breeding season, with males and females remaining associated throughout the day. In accordance with the hypothesis, paired Screaming Cowbirds spent significantly more time in proximity to their mates than to other conspecifics of the opposite sex, and had similar home‐ranges. Social monogamy in the Screaming Cowbird differed markedly from the social polygyny/promiscuity exhibited by the sympatric congener Shiny CowbirdMolothrus bonariensis, a generalist brood parasite.

Different epilepsy course of a novel AHDC1 mutation in a female monozygotic twin pair

Different epilepsy course of a novel AHDC1 mutation in a female monozygotic twin pair

Different epilepsy course of a novel AHDC1 mutation in a female monozygotic twin pair

PurposeDe novo truncating mutations of AHDC1 gene cause Xia-Gibbs Syndrome (XGS), characterized by developmental delay, hypotonia, speech disturbances, sleep apnea. Seizures have been reported, yet no studies have depicted the epilepsy characteristics and outcome. MethodsWe describe the clinical features of a pair of Caucasian monozygotic female twins affected by severe epilepsy and presenting the same de novo AHDC1 mutation detected by whole exome sequencing. ResultsThey were concordant with respect to seizure onset and type mimicking Lennox-Gastaut syndrome as well as initial EEG features, but differed in terms of epilepsy prognosis (complete seizure freedom on valproate/lamotrigine versus ongoing daily refractory seizures despite multiple drug combinations). ConclusionOur findings suggest that patients with Xia-Gibbs Syndrome may exhibit Lennox-Gastaut-like features and that even the same AHDC1 mutation can be poorly predictive of epilepsy prognosis.

Ventro-Ventral Copulation by an Adult Male-Female Pair of Japanese Macaques at Arashiyama

Ventro-ventral (VV) mountings during copulation are most dominant in humans. In contrast, nonhuman primates have a strong bias toward dorso-ventral mountings, and only apes have been known to show VV mountings during copulation between a pair of mature individuals. Reporting VV mountings during copulation in primates other than apes is critical to discussions regarding why VV mountings have been limited to apes among primates. Here, I report VV mounting in a mature male and female pair of provisioned Japanese macaques (Macaca fuscata). This is the first report of VV mountings during copulation by adult nonhuman primates without disabilities other than apes. The pair of monkeys performed VV mountings 13 times over a week. Following the mounting series, including VV mountings, the presence of a copulatory plug was confirmed around the female’s vagina, indicating that the VV mountings were part of their copulatory behaviors. The male initiated all VV mountings, and the female was often uncooperative during these attempts. In all cases, the female was lying on her back, and the male was on top. The pair were in close contact and did not see each other’s faces during VV mountings. This report suggests that eye contact between mates and morphological characteristics are the primary reasons for the evolution of VV mountings during copulation in apes.

Gender-related presentation, surgical treatment, outcome and failure to rescue after surgery for type A aortic dissection: results from a multicentre registry.

Reports on gender-related differences in perioperative characteristics and the outcome after surgery for type A acute aortic dissection are contradictory. Perioperative characteristics, outcome and overall or itemized failure-to-rescue rates were collected retrospectively and dichotomized by gender in patients operated on at 5 referral institutions. A propensity score matched analysis was performed to compared males and females with similar preoperative risk profiles. Multivariable analysis assessed gender-related predictors of 30-day mortality. A total of 1271 patients were collected. Females (on average, 63 years old) developed type A acute aortic dissection, with differences in clinical presentation (number of intimal tears, thoracic pain at the onset of symptoms). Female-reported characteristics included lower frozen elephant trunk and elephant trunk procedures, higher femoral perfusion, retrograde cerebral perfusion and retrograde cardiopulmonary bypass restart after deep hypothermic circulatory arrest (P < 0.05). The 30-day mortality was 19.8%, without a gender-related difference (P = 0.37). No substantial differences in hospital outcome and in items related to failure to rescue were reported. A total of 256 propensity score matched pairs of males and females were investigated. Previous differences in surgical techniques and strategies were still confirmed; however, a higher incidence of postoperative permanent coma (P = 0.02) was reported in the female population. Different surgical techniques and operative strategies were used on the 2 genders, with a lower complexity in females. However, there were no differences in hospital outcome between genders, except for the higher incidence of coma in female patients.

Impact of Different Diets on Adult Tri-Spine Horseshoe Crab, Tachypleus tridentatus.

Effective culture and management of adult tri-spine horseshoe crab, Tachypleus tridentatus can ensure that stock enhancement programs and aquaculture systems are maintained. To explore suitable feed for animals during the breeding season, Pacific oyster (Ostrea gigas) (oyster group; OG) and frozen sharpbelly fish (Hemiculter leucisculus) (frozen fish group; FG) were selected to feed 20 T. tridentatus male and female pairs, respectively. At the end of the experiment, intestinal samples were obtained to measure digestive enzymes activities. The intestinal flora were determined by 16S rDNA sequencing. No eggs were observed in the FG and one T. tridentatus adult died. No animals died in the OG, and 9.7 × 104 eggs were obtained. These results show that oysters are more suitable for the development and reproduction of adult T. tridentatus than frozen fish. Additionally, the digestive enzyme activity analysis revealed that animals in the OG exhibited higher protein digestibility than those in the FG, but no significant differences in lipid and carbohydrate uptake were observed between the groups. Furthermore, the intestinal flora analysis showed that operational taxonomic units (OTUs) and the Chao1 index were significantly higher in the OG than in the FG, but no significant difference was observed in the Shannon or Simpson indices between the groups. Our data indicate that the oyster diet improved the intestinal microbial diversity of T. tridentatus. We hypothesize that nutrients, such as oyster-based taurine, proteins, and highly unsaturated fatty acids, improve protease activity in the T. tridentatus digestive tract, alter the intestinal floral structure, and improve the reproductive performance of T. tridentatus.

Behaviour of Zoo-Housed Red Pandas (Ailurus fulgens): A Case-Study Testing the Behavioural Variety Index

The red panda is listed as “endangered” in the IUCN Red List of Threatened Species, due to the rapid population decline. Improving our knowledge on the red panda biology and ethology is necessary to enhance its husbandry and breeding in zoos. Behavioural variety, intended as the presence of a wide array of species-specific behaviour, has been considered a positive welfare index in zoo-housed animals. The aim of this study was to describe the behaviour of two pairs of zoo-housed red pandas, one of them with an offspring, and to investigate the behavioural variability using the Behavioural Variety Index (BVI). Behavioural data from two zoo-living male–female pairs were collected. A continuous focal animal sampling method was used to collect individual and social behaviours of the two pairs. Forty-eight 30 min sessions per subject were carried out. For the BVI, a list of species-specific behaviours previously reported in the red panda was prepared and compared with the behavioural repertoire of the subjects of the study. First, species-specific behaviours were recorded, and no abnormal behaviour was reported. The percentages of time spent on different activities (e.g., routine behaviours, exploratory/territorial behaviours, consumption behaviours, locomotive behaviours, social behaviours, maternal behaviours) were similar to time budgets reported in the red panda, with routine behaviours (resting, comfort and vigilance) being the most performed in both pairs. Moreover, the BVI suggested that each red panda performed on average 73% of the behaviours described in previous literature on this species. In conclusion, studying the behavioural variety of red pandas in zoos can be a useful tool for assessing their welfare as well as improving our knowledge on the behavioural repertoire of a species that is difficult to observe in the wild.

CRISPR/Cas-9 induced knockout of myostatin gene improves growth and disease resistance in channel catfish (Ictalurus punctatus)

Channel catfish, Ictalurus punctatus, is the most produced aquaculture species in the United States, although production levels have decreased since their peak in 2003. Myostatin (mstn) regulates skeletal muscle growth and has been identified as an important gene for increasing body weight in aquaculture species. In this study, the effects of CRISPR/Cas9 knockout of the mstn gene in channel catfish were investigated. Three sgRNAs targeting exon 1 of the channel catfish myostatin gene were microinjected with Cas9 protein in embryos. A total of 209 fish survived to 6 mph after microinjection of Cas9 and sgRNA targeting exon 1 of the mstn gene over the 3 yr experiment (2017–2019) with an average mutation rate of 58%. Successful generation of myostatin knockout (MSTN KO) F1 heterozygotes was achieved in 2019 by individually mating two pairs of control females with MSTN homozygous KO males. The offspring of both families inherited the mutation at a mean rate of 88%. Growth was generally higher in MSTN mutants than controls at all life stages and environments. P1 MSTN mutants were 88% larger than controls at the stocker stage (100 to 200 g) and 27% larger than controls at market size. Heterozygous F1 mutants were 218% larger than controls at the stocker stage. MSTN mutants had reduced overall expression levels of mstn compared to controls. When challenged with Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish, MSTN mutants performed equally or better than controls. With a high mutation rate and inheritance as well as improved growth and disease resistance, using MSTN gene-edited channel catfish could greatly benefit commercial farms.

Diverse grouping and mating strategies in the Critically Endangered Hainan gibbon (Nomascus hainanus)

Understanding flexibility in the social structure and mating strategies of the world’s last remaining population (35 individuals) of wild Hainan gibbons (Nomascus hainanus) is critical for developing effective management plans to aid in their population recovery. Three of the five remaining Hainan gibbon groups (A, B, and C) currently live in a social unit characterized by two or three adult males, two reproducing adult females, and offspring. A fourth group (D) contains one adult male, two adult females, and offspring, and Group E contains a single adult male–adult female pair with a young infant. In this study, we describe observations of copulations between multiple resident males and one of the two resident females in Group C. Group C is best described as a small multi-male/multi-female group. We found that this breeding female (F2) solicited copulations from two resident adult males (M1 and M2) on the same day, and also mated with each of these two males on different days. Resident males were not observed to interrupt the mating pair. Although factors such as a biased adult sex ratio, severe population disruption, and habitat degradation can help explain variation in group composition and mating strategies in Hainan gibbons, we argue that there exists considerable mating system variability across gibbon species, and that this variability offers important insights into male and female Hainan gibbon group structure and reproductive strategies.

Familial Aspects of Mammographic Density Measures Associated with Breast Cancer Risk.

Simple SummaryCumulus, Cumulus-percent, Altocumulus, Cirrocumulus, and Cumulus-white are mammogram risk scores (MRSs) that predict a woman’s risk of breast cancer based on mammographically dense areas when defined by different levels of brightness. We measured these MRS for 593 monozygotic (MZ) and 326 dizygotic (DZ) female twin pairs and 1592 of their sisters. We estimated how much these MRSs were correlated in relatives (ρ), how much of the differences between women were due to genetic factors (heritability), and how much these MRS explained why breast cancer runs in families. The ρ estimates ranged from: 0.41 to 0.60 for MZ pairs, 0.16 to 0.26 for DZ pairs, and 0.19 to 0.29 sister pairs, respectively. Heritability estimates were 36% to 69%. Genetic factors explain most of why twins and sisters are similar in their MRS, and these genetic factors explain one-quarter to one-half as much breast cancer risk as to the current best genetic risk score.Cumulus, Cumulus-percent, Altocumulus, Cirrocumulus, and Cumulus-white are mammogram risk scores (MRSs) for breast cancer based on mammographic density defined in effect by different levels of pixel brightness and adjusted for age and body mass index. We measured these MRS from digitized film mammograms for 593 monozygotic (MZ) and 326 dizygotic (DZ) female twin pairs and 1592 of their sisters. We estimated the correlations in relatives (r) and the proportion of variance due to genetic factors (heritability) using the software FISHER and predicted the familial risk ratio (FRR) associated with each MRS. The ρ estimates ranged from: 0.41 to 0.60 (standard error [SE] 0.02) for MZ pairs, 0.16 to 0.26 (SE 0.05) for DZ pairs, and 0.19 to 0.29 (SE 0.02) for sister pairs (including pairs of a twin and her non-twin sister), respectively. Heritability estimates were 39% to 69% under the classic twin model and 36% to 56% when allowing for shared non-genetic factors specific to MZ pairs. The FRRs were 1.08 to 1.17. These MRSs are substantially familial, due mostly to genetic factors that explain one-quarter to one-half as much of the familial aggregation of breast cancer that is explained by the current best polygenic risk score.