Biology subjects

Espinoza, E.

Publications and source records attributed to Espinoza, E..

4 recordsLinked to original sources

bioRxiv2026

In Utero Alcohol Exposure Reprograms Mammary Gland Development and Stem/Progenitor Cell Activity in a Non-Tumorigenic Mouse Model

In utero alcohol exposure (IUE) can alter mammary development and increase mammary tumor susceptibility in experimental models. However, most previous studies have relied on carcinogen-induced or genetically tumor-prone models, leaving it unresolved whether prenatal alcohol exposure produces mammary developmental and molecular changes before the introduction of an oncogenic challenge. Here, we addressed this question using non-tumorigenic C57BL/6 mice. Pregnant dams received a Lieber-DeCarli liquid diet containing 1.7% (v/v) ethanol or an isocaloric control diet from gestational day 11 to 19, and mammary glands from female offspring were examined during puberty (postnatal day 40, PND40) and young adulthood (PND70). At PND40, IUE enhanced mammary ductal morphogenesis, increased terminal end bud numbers, and elevated epithelial proliferation. These developmental alterations persisted at PND70, with increased lateral branching and proliferative activity. IUE also altered mammary epithelial composition, expanding the basal/myoepithelial compartment and the CD24highCD49fhigh mammary repopulating unit/stem cell-enriched population. Mammary epithelial cells from IUE-exposed offspring exhibited increased colony-forming cells (CFCs), mammosphere formation, and 3D Matrigel growth, indicating enhanced stem/progenitor-associated activity. At the molecular level, IUE increased ER; expression and phosphorylation together with Cyclin D1, c-Myc, E2F1, and Bcl-2, and enhanced AKT, ERK, and STAT3 phosphorylation, IL-6 expression, and SOX2 at PND40. Importantly, major components of this signaling phenotype remained altered at PND70, including ER;-associated signaling, AKT/ERK activation, and IL-6/STAT3 signaling, whereas the pubertal increase in SOX2 was not sustained. Together, these findings demonstrate that prenatal alcohol exposure induces profound and persistent histomorphological, cellular, and signaling alterations in the mammary gland in the absence of a carcinogenic challenge or genetically introduced oncogenic driver. These results identify intrinsic developmental reprogramming of normal mammary tissue as a potential basis through which prenatal alcohol exposure may modify subsequent responses to tumor-promoting or other environmental challenges.

developmental biology↗

bioRxiv2023

Diet and chemical defenses of the Sonoran Desert toads

The Sonoran Desert Toad (Incilius alvarius) is the only animal known to secrete the psychedelic compound 5-MeO-DMT as a chemical defense, but the source of 5-MeO-DMT in I. alvarius remains unknown. Some amphibians endogenously produce chemical defenses while others acquire them from specialized diets. In this study we analyzed toxin gland secretions and diet profiles from wild I. alvarius and sympatric anurans from native and urban habitats around Tucson, Arizona to explore possible links between diet and 5-MeO-DMT production. All I. alvarius secreted high concentrations of 5-MeO-DMT, whereas other sympatric toads did not. The diet of I. alvarius was similar to that of sympatric anurans, indicating that I. alvarius does not exhibit relative dietary specialization. Slight dietary differences between I. alvarius in native and urbanized habitats were observed. Taken together, these lines of evidence suggest that diet is not directly linked to 5-MeO-DMT production, and support the alternative hypotheses that Sonoran Desert toads synthesize 5-MeO-DMT endogenously or via a microbial symbiont.

ecology↗

bioRxiv2022

Cannabis sativa oxylipin biosynthesis: Genome-wide characterization of lipoxygenase, allene oxide synthase, allene oxide cyclase, hydroperoxide lyase, and 12-oxo-phytodienoic acid reductase gene families

Cannabis sativa is a global multi-billion-dollar cash crop with numerous industrial uses, including in medicine and recreation where its value is largely owed to the production of pharmacological and psychoactive metabolites known as cannabinoids. Often underappreciated in this role, the lipoxygenase (LOX)-derived green leaf volatiles (GLVs), also known as the scent of cut grass, are the hypothetical origin of hexanoic acid, the initial substrate for cannabinoid biosynthesis. The LOX pathway is best known as the primary source of plant oxylipins, molecules analogous to the eicosanoids from mammalian systems. These molecules are chemically and functionally diverse group of fatty acid-derived signals that govern nearly all biological processes including plant defense and development. The interaction between oxylipin and cannabinoid biosynthetic pathways remains to be explored. Despite their unique importance in this crop, there has not been a comprehensive investigation focusing on the genes responsible for oxylipin biosynthesis in any Cannabis species. This study documents the first genome-wide catalogue of the Cannabis sativa oxylipin biosynthetic genes and identified 21 LOX, five allene oxide synthases (AOS), three allene oxide cyclases (AOC), one hydroperoxide lyase (HPL), and five 12-oxo-phytodienoic acid reductases (OPR). Gene collinearity analysis found chromosomal regions containing several isoforms maintained across Cannabis, Arabidopsis, and tomato. Promoter, expression, weighted co-expression genetic network, and functional enrichment analysis provide evidence of tissue- and cultivar-specific transcription and roles for distinct isoforms in oxylipin and cannabinoid biosynthesis. This knowledge facilitates future targeted approaches towards Cannabis crop improvement and for the manipulation of cannabinoid metabolism.

plant biology↗

bioRxiv2020

Shark movements in the Revillagigedo Archipelago and connectivity with the Eastern Tropical Pacific

Long-distance movements of sharks within and between islands pose substantial challenges for resource managers working with highly migratory species. When no-take zones do not cover the critical areas that sharks use as part of their lifecycle, exposure to fishing activities can be significant. Shark movements between the Marine Protected Areas (MPAs) of the Eastern Tropical Pacific (ETP) have been studied for several years, however little is known about the strength of connectivity between these islands. We analyzed the extensive MigraMar ultrasonic telemetry dataset to assess how Galapagos sharks (Carcharhinus galapagensis) and silky sharks (Carcharhinus falciformis) use different islands as stepping-stones during their migrations within the Revillagigedo National Park and other ETP islands. Of the 66 sharks monitored, 63.5% moved within the same island, 25.4% between two islands or more and only 10.1% across different MPAs. A C. falciformis tagged in Roca Partida Island, Revillagigedo, travelled to Clipperton Atoll and another one tagged in Darwin Island travelled to the atoll on two different years. The largest movement of C. galapagensis was accomplished by a shark tagged at Socorro Island, Revillagigedo, later detected at Clipperton and finally recorded in Darwin Island, Galapagos. This last path was in fact, one of the longest movements ever recorded for the species. Although long-distance dispersion was not common, our results highlight the need for co-operation between different countries to ensure adequate protection for sharks in the form of swimways and other conservation tools in the ETP.

ecology↗