The genomes of a monogenic fly: views of primitive sex chromosomes

Abstract The production of male and female offspring is often determined by the presence of specific sex chromosomes which control sex-specific expression, and sex chromosomes evolve through reduced recombination and specialized gene content. Here we present the genomes of Chrysomya rufifacies, a monogenic blow fly (females produce female or male offspring, exclusively) by separately sequencing and assembling each type of female and the male. The genomes (> 25X coverage) do not appear to have any sex-linked Muller F elements (typical for many Diptera) and exhibit little differentiation between groups supporting the morphological assessments of C. rufifacies homomorphic chromosomes. Males in this species are associated with a unimodal coverage distribution while females exhibit bimodal coverage distributions, suggesting a potential difference in genomic architecture. The presence of the individual-sex draft genomes herein provides new clues regarding the origination and evolution of the diverse sex-determining mechanisms observed within Diptera. Additional genomic analysis of sex chromosomes and sex-determining genes of other blow flies will allow a refined evolutionary understanding of how flies with a typical X/Y heterogametic amphogeny (male and female offspring in similar ratios) sex determination systems evolved into one with a dominant factor that results in single sex progeny in a chromosomally monomorphic system.

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Caution is warranted when using animal space-use and movement to infer behavioral states

Movement Ecology ◽

10.1186/s40462-021-00264-8 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Frances E. Buderman ◽

Tess M. Gingery ◽

Duane R. Diefenbach ◽

Laura C. Gigliotti ◽

Danielle Begley-Miller ◽

...

Keyword(s):

Markov Models ◽

Space Use ◽

Mating Strategies ◽

Movement Behavior ◽

Behavioral State ◽

Validation Data ◽

Male And Female ◽

Location Data ◽

Single Sex ◽

The Individual

Abstract Background Identifying the behavioral state for wild animals that can’t be directly observed is of growing interest to the ecological community. Advances in telemetry technology and statistical methodologies allow researchers to use space-use and movement metrics to infer the underlying, latent, behavioral state of an animal without direct observations. For example, researchers studying ungulate ecology have started using these methods to quantify behaviors related to mating strategies. However, little work has been done to determine if assumed behaviors inferred from movement and space-use patterns correspond to actual behaviors of individuals. Methods Using a dataset with male and female white-tailed deer location data, we evaluated the ability of these two methods to correctly identify male-female interaction events (MFIEs). We identified MFIEs using the proximity of their locations in space as indicators of when mating could have occurred. We then tested the ability of utilization distributions (UDs) and hidden Markov models (HMMs) rendered with single sex location data to identify these events. Results For white-tailed deer, male and female space-use and movement behavior did not vary consistently when with a potential mate. There was no evidence that a probability contour threshold based on UD volume applied to an individual’s UD could be used to identify MFIEs. Additionally, HMMs were unable to identify MFIEs, as single MFIEs were often split across multiple states and the primary state of each MFIE was not consistent across events. Conclusions Caution is warranted when interpreting behavioral insights rendered from statistical models applied to location data, particularly when there is no form of validation data. For these models to detect latent behaviors, the individual needs to exhibit a consistently different type of space-use and movement when engaged in the behavior. Unvalidated assumptions about that relationship may lead to incorrect inference about mating strategies or other behaviors.

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Gendered reasons for leaving a career in the UK TV industry

Media Culture & Society ◽

10.1177/0163443719890533 ◽

2019 ◽

Vol 42 (3) ◽

pp. 414-430

Author(s):

Neil Percival

Keyword(s):

Quantitative Data ◽

Dominant Factor ◽

Structural Barriers ◽

Male And Female ◽

Early Exit ◽

Professional Careers ◽

Using Data ◽

The Individual ◽

The Uk ◽

Equality Of Access

This article concerns gendered sustainability of careers in the UK TV industry. Much academic scrutiny is focused on equality of access and progression, using data secured from those still working in the sector. The research featured here offers a new insight by focusing on career sustainability and exit, reporting on a survey of 80 individuals, both male and female, who left professional careers in the industry to move on to other careers or activities. While quantitative data demonstrate that incompatibility with parenting was the overwhelmingly dominant factor motivating early exit from the sector for women, the qualitative findings also advance discussions of wider structural barriers and gendered inequalities, embedded in working cultures, practices and attitudes. The article explores the wider perception of a lack of care for the sector’s workers, as well as the individual bereavement and identity loss encountered by those who leave.

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Placental treatment improves cardiac tolerance to ischemia/reperfusion insult in adult male and female offspring exposed to prenatal hypoxia

Pharmacological Research ◽

10.1016/j.phrs.2021.105461 ◽

2021 ◽

Vol 165 ◽

pp. 105461

Author(s):

Nataliia Hula ◽

Floor Spaans ◽

Jennie Vu ◽

Anita Quon ◽

Raven Kirschenman ◽

...

Keyword(s):

Adult Male ◽

Ischemia Reperfusion ◽

Female Offspring ◽

Prenatal Hypoxia ◽

Male And Female

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The maintenance of polygenic sex determination depends on the dominance of fitness effects which are predictive of the role of sexual antagonism

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkab149 ◽

2021 ◽

Author(s):

Richard P Meisel

Keyword(s):

Sex Determination ◽

Sex Chromosomes ◽

House Fly ◽

Sexual Antagonism ◽

Antagonistic Effects ◽

Fitness Effects ◽

Y Chromosomes ◽

Sexually Antagonistic Selection ◽

The Individual ◽

Polygenic Sex Determination

Abstract In species with polygenic sex determination, multiple male- and female-determining loci on different proto-sex chromosomes segregate as polymorphisms within populations. The extent to which these polymorphisms are at stable equilibria is not yet resolved. Previous work demonstrated that polygenic sex determination is most likely to be maintained as a stable polymorphism when the proto-sex chromosomes have opposite (sexually antagonistic) fitness effects in males and females. However, these models usually consider polygenic sex determination systems with only two proto-sex chromosomes, or they do not broadly consider the dominance of the alleles under selection. To address these shortcomings, I used forward population genetic simulations to identify selection pressures that can maintain polygenic sex determination under different dominance scenarios in a system with more than two proto-sex chromosomes (modeled after the house fly). I found that overdominant fitness effects of male-determining proto-Y chromosomes are more likely to maintain polygenic sex determination than dominant, recessive, or additive fitness effects. The overdominant fitness effects that maintain polygenic sex determination tend to have proto-Y chromosomes with sexually antagonistic effects (male-beneficial and female-detrimental). In contrast, dominant fitness effects that maintain polygenic sex determination tend to have sexually antagonistic multi-chromosomal genotypes, but the individual proto-sex chromosomes do not have sexually antagonistic effects. These results demonstrate that sexual antagonism can be an emergent property of the multi-chromosome genotype without individual sexually antagonistic chromosomes. My results further illustrate how the dominance of fitness effects has consequences for both the likelihood that polygenic sex determination will be maintained as well as the role sexually antagonistic selection is expected to play in maintaining the polymorphism.

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Perinatal SSRIs, maternal stress, and their effects on social behaviors in male and female offspring

Toxicology Letters ◽

10.1016/j.toxlet.2017.07.185 ◽

2017 ◽

Vol 280 ◽

pp. S72

Author(s):

Jodi Pawluski

Keyword(s):

Maternal Stress ◽

Social Behaviors ◽

Female Offspring ◽

Male And Female

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PRE-MATERNAL ISOLATION EFFECTS ON BEHAVIOUR AND ENDOCRINE FUNCTION OF OFFSPRING

Acta Endocrinologica ◽

10.1530/acta.0.0620367 ◽

1969 ◽

Vol 62 (2) ◽

pp. 367-384 ◽

Cited By ~ 2

Author(s):

A. M. Sackler ◽

A. S. Weltman ◽

R. Schwartz ◽

P. Steinglass

Keyword(s):

Locomotor Activity ◽

Growth Rates ◽

Female Offspring ◽

The Body ◽

Endocrine Function ◽

Male And Female ◽

Isolation Stress ◽

Developmental Growth ◽

Body Weights ◽

And Control

ABSTRACT This report was designed to determine combined effects of maternal endocrine imbalances and abnormal behaviour due to prolonged isolation stress of female mice on the behaviour, developmental growth rate and endocrine function of their offspring. Sixty female albino mice averaging 19 g were divided equally into isolated and control groups. The isolated females were housed singly; control females were maintained in groups of 2 mice per cage. After observation of behavioural and physiological effects characteristic of isolation stress in the test mice, all isolated and control mice were mated after a 6½ month experimental, isolation period. No differences were observed in fertility and fecundity of the two groups of mothers. Analyses of developmental growth rates of the litters of the isolated versus control mothers showed significantly lower body weights in the test offspring at 3 and 4 weeks of age. The body weights of the female offspring remained significantly lower from the 4th to 11th weeks. The effects on the body weights of the male offspring declined and were no longer statistically significant at the 5th to 11 weeks. Locomotor activity at 4½ and 8 weeks of age was markedly or significantly higher in the male and female mice from isolated mothers. Tail-blood samples taken prior to autopsy at 5 and 11 weeks of age revealed significant decreases in the total leukocyte and eosinophil counts of both sexes. At the two ages, the absolute and relative spleen and thymus weights of the male and female offspring were markedly and/or significantly lower than the values observed in counterpart young from control females. Significant decreases were also observed in the absolute gonadal organ weights of both sexes at 11 weeks of age. The various data indicated inhibited growth rates, heightened locomotor activity and evasiveness, as well as evidence of increased adrenocortical function in the offspring from test mothers. The gonadal weight decreases suggested retarded gonadal development. Further studies using split-litter techniques are required to differentiate the effects of prenatal endocrine imbalances versus postnatal maternal influence (i. e., nursing care) on the offspring.

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Differences in recombination frequencies during female and male meioses of the sex chromosomes of the medaka, Oryzias latipes

Genetics Research ◽

10.1017/s0016672301005109 ◽

2001 ◽

Vol 78 (1) ◽

pp. 23-30 ◽

Cited By ~ 65

Author(s):

MARIKO KONDO ◽

ERIKO NAGAO ◽

HIROSHI MITANI ◽

AKIHIRO SHIMA

Keyword(s):

Genetic Map ◽

Sex Chromosomes ◽

Sex Chromosome ◽

Oryzias Latipes ◽

Male Recombination ◽

Male And Female ◽

Y Chromosomes ◽

Genetic Length ◽

Expressed Sequence ◽

Group 1

In the medaka, Oryzias latipes, sex is determined chromosomally. The sex chromosomes differ from those of mammals in that the X and Y chromosomes are highly homologous. Using backcross panels for linkage analysis, we mapped 21 sequence tagged site (STS) markers on the sex chromosomes (linkage group 1). The genetic map of the sex chromosome was established using male and female meioses. The genetic length of the sex chromosome was shorter in male than in female meioses. The region where male recombination is suppressed is the region close to the sex-determining gene y, while female recombination was suppressed in both the telomeric regions. The restriction in recombination does not occur uniformly on the sex chromosome, as the genetic map distances of the markers are not proportional in male and female recombination. Thus, this observation seems to support the hypothesis that the heterogeneous sex chromosomes were derived from suppression of recombination between autosomal chromosomes. In two of the markers, Yc-2 and Casp6, which were expressed sequence-tagged (EST) sites, polymorphisms of both X and Y chromosomes were detected. The alleles of the X and Y chromosomes were also detected in O. curvinotus, a species related to the medaka. These markers could be used for genotyping the sex chromosomes in the medaka and other species, and could be used in other studies on sex chromosomes.

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