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1. Eggonomics: Vitrification and bioeconomies of egg donation in the United States and Spain

   https://doi.org/10.1111/maq.12767  

   Tober, Diane; Pavone, Vincenzo; Lafuente‐Funes, Sara; Konvalinka, Nancy (May 2023, Medical Anthropology Quarterly)

   Abstract Regulations governing assisted reproduction control the degree to which gamete donation is legal and how people providing genetic material are selected and compensated. The United States and Spain are both global leaders in fertility treatment with donor oocytes. Yet both countries take different approaches to how egg donation is regulated. The US model reveals a hierarchically organized form of gendered eugenics. In Spain, the eugenic aspects of donor selection are more subtle. Drawing upon fieldwork in the United States and Spain, this article examines (1) how compensated egg donation operates under two regulatory settings, (2) the implications for egg donors as providers of bioproducts, and (3) how advances in oocyte vitrification enhances the commodity quality of human eggs. By comparing these two reproductive bioeconomies we gain insight into how different cultural, medical, and ethical frameworks intersect with egg donor embodied experiences. 

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2. Muscle-directed mechanosensory feedback activates egg-laying circuit activity and behavior in Caenorhabditis elegans

   https://doi.org/10.1016/j.cub.2023.05.008  

   Medrano, Emmanuel; Collins, Kevin M. (June 2023, Current Biology)

   Mechanosensory feedback of the internal reproductive state drives decisions about when and where to reproduce. For instance, stretch in the Drosophila reproductive tract produced by artificial distention or from accumulated eggs regulates the attraction to acetic acid to ensure optimal oviposition. How such mechanosensory feedback modulates neural circuits to coordinate reproductive behaviors is incompletely understood. We previously identified a stretch-dependent homeostat that regulates egg laying in Caenorhabditis elegans. Sterilized animals lacking eggs show reduced Ca2+ transient activity in the presynaptic HSN command motoneurons that drive egg-laying behavior, while animals forced to accumulate extra eggs show dramatically increased circuit activity that restores egg laying. Interestingly, genetic ablation or electrical silencing of the HSNs delays, but does not abolish, the onset of egg laying, with animals recovering vulval muscle Ca2+ transient activity upon egg accumulation. Using an acute gonad microinjection technique to mimic changes in pressure and stretch resulting from germline activity and egg accumulation, we find that injection rapidly stimulates Ca2+ activity in both neurons and muscles of the egg-laying circuit. Injection-induced vulval muscle Ca2+ activity requires L-type Ca2+ channels but is independent of presynaptic input. Conversely, injection-induced neural activity is disrupted in mutants lacking the vulval muscles, suggesting "bottom-up" feedback from muscles to neurons. Direct mechanical prodding activates the vulval muscles, suggesting that they are the proximal targets of the stretch-dependent stimulus. Our results show that egg-laying behavior in C. elegans is regulated by a stretch-dependent homeostat that scales postsynaptic muscle responses with egg accumulation in the uterus. 

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3. Transnational Affective Circuitry: Public Information Campaigns, Affective Governmentality, and Border Enforcement

   https://doi.org/10.1080/24694452.2023.2226193  

   Williams, Jill M; Coddington, Kate (November 2023, Annals of the American Association of Geographers)

   Geographers have been central to identifying and exploring the shifting spatialities of border enforcement and how different enforcement strategies alter the geography of state sovereignty. Migration-related public information campaigns (PICs) are one strategy that has received increasing attention from geographers and social scientists more broadly in recent years. While existing research examines the sites and spaces where PICs are distributed, as well as the affective content of their messaging, little research has examined the development of campaigns and the transnational connections that enable their deployment. This article draws on work in the fields of carceral circuitry and transnational enforcement networks in order to expand our understanding of affective governmentality as a transnational strategy of border governance. Based on data collected as part of a large-scale comparative study of the use of PICs by the US and Australian governments, we argue that this form of affective governmentality relies upon transnational circuits through which people, money, and knowledge move to enable the development and circulation of affective messaging. In doing so, we develop the concept of transnational affective circuitry to refer to the often contingent, temporary relations and connections that enable PICs to operate as a form of transnational affective governmentality aimed at hindering unauthorized migration. Our analysis illustrates the transnational connections that enable increasingly expansive and creative forms of border enforcement to emerge while also expanding the scope of examinations of affective governmentality to attend to the relations that undergird and enable this form of transnational governance. 

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4. Maternal genetic variants in kinesin motor domains prematurely increase egg aneuploidy

   https://doi.org/10.1073/pnas.2414963121  

   Biswas, Leelabati; Tyc, Katarzyna M; Aboelenain, Mansour; Sun, Siqi; Dundović, Iva; Vukušić, Kruno; Liu, Jason; Guo, Vanessa; Xu, Min; Scott, Richard T; et al (November 2024, Proceedings of the National Academy of Sciences)

   The female reproductive lifespan is highly dependent on egg quality, especially the presence of a normal number of chromosomes in an egg, known as euploidy. Mistakes in meiosis leading to egg aneuploidy are frequent in humans. Yet, knowledge of the precise genetic landscape that causes egg aneuploidy in women is limited, as phenotypic data on the frequency of human egg aneuploidy are difficult to obtain and therefore absent in public genetic datasets. Here, we identify genetic determinants of reproductive aging via egg aneuploidy in women using a biobank of individual maternal exomes linked with maternal age and embryonic aneuploidy data. Using the exome data, we identified 404 genes bearing variants enriched in individuals with pathologically elevated egg aneuploidy rates. Analysis of the gene ontology and protein–protein interaction network implicated genes encoding the kinesin protein family in egg aneuploidy. We interrogate the causal relationship of the human variants within candidate kinesin genes via experimental perturbations and demonstrate that motor domain variants increase aneuploidy in mouse oocytes. Finally, using a knock-in mouse model, we validate that a specific variant in kinesin KIF18A accelerates reproductive aging and diminishes fertility. These findings reveal additional functional mechanisms of reproductive aging and shed light on how genetic variation underlies individual heterogeneity in the female reproductive lifespan, which might be leveraged to predict reproductive longevity. Together, these results lay the groundwork for the noninvasive biomarkers for egg quality, a first step toward personalized fertility medicine. 

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5. Hybridization, reinforcement selection, and sex-dependent reproductive character displacement of sperm and egg recognition proteins

   https://doi.org/10.1093/evolut/qpaf092  

   Levitan, Don_R; Hao, Yueling; Kronforst, ed., Marcus; Connallon, ed., Tim (May 2025, Evolution)

   Abstract The establishment of reproductive isolation between species via gametic incompatibility initially requires within-species variation in reproductive compatibility. We investigate how within-species variation in sperm and egg recognition proteins, potentially generated via sexual conflict, influences reproductive isolation between two partially sympatric sea urchin species; the North American west coast Mesocentrotus franciscanus and the circumpolar Strongylocentrotus droebachiensis. Barriers to hybridization are stronger when eggs are given a choice of conspecific versus heterospecific sperm and the variation in hybridization among crosses can be explained by whether the sperm or egg protein variant is ancestral or derived. Derived proteins can be recognized as different and prevent hybridization. Examination of the allele frequencies of these proteins in M. franciscanus in and out of sympatry with S. droebachiensis along the west coast of North America reveals evidence of reinforcement selection and reproductive character displacement in eggs but not sperm, which likely reflects the differential cost of hybridization for males and females. 

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