Biology subjects

Corona, M.

Publications and source records attributed to Corona, M..

4 recordsLinked to original sources

bioRxiv2024

Nano Colonies: Rearing honey bee queens and their offspring in small laboratory arenas

Honey bees create complex societies of self-organized individuals in intricate colonies. Studies of honey bees are carried out in both the field and the laboratory. However, field research is encumbered by the difficulties of making reliable observations and environmental confounders. Meanwhile, laboratory trials produce data that are not field realistic as they lack key characteristics of a natural colony. Additionally, advances in honey bee research have been hindered without reliable methodology to rear queens in the laboratory. Here we provide a new system to reliably produce queens and worker brood in the laboratory and describe how this system fits with artificial insemination of queens as a step towards a continuous self-contained source of bees. The process creates a bridge between field research and laboratory trials and provides a secure system for contagious or regulated elements while maintaining many of the intrinsic characteristics of a honey bee colony.

zoology↗

bioRxiv2022

LAMC2 marks a tumor-initiating cell population with an aggressive signature in pancreatic cancer

Tumor-initiating cells (TIC), also known as cancer stem cells, are considered a specific subpopulation of cells necessary for cancer initiation and metastasis. Here, we report a LAMC2-positive cell population, which is endowed with enhanced self-renewal capacity, and is sufficient for tumor initiation, differentiation, and driving metastasis. Mechanistically, mRNA profiling of these cells indicate a prominent squamous signature, and differentially activated pathways critical for tumor growth and metastasis, including deregulation of the TGF-{beta} signaling pathway. Treatment with Vactosertib, a new small molecule inhibitor of transforming growth factor-{beta} (TGF-{beta}) type I receptor (activin receptor-like kinase-5, ALK5), completely abrogated the lung metastasis, primarily originating from LAMC2 expressing cells. Our results prompt further study of this TIC population in pancreatic cancer and exploration as a potential therapeutic target and/or biomarker.

cancer biology↗

bioRxiv2020

Africanized honeybees in Colombia exhibit high prevalence but low level of infestation of Varroa mites and low prevalence of pathogenic viruses

The global spread of the ectoparasitic mite Varroa destructor has promoted the spread and virulence of highly infectious honey bee viruses. This phenomenon is considered the leading cause for the increased number of colony losses experienced by the mite-susceptible European honey bee populations in the Northern Hemisphere. Most of the honey bee populations in Central and South America are Africanized honey bees, which are considered more resistant to Varroa compared to European honey bees. However, the relationship between Varroa levels and spread of honey bee viruses in Africanized honey bees remains unknown. In this study, we determined Varroa prevalence and infestation levels as well as the prevalence of seven major honey bee viruses in Africanized honey bees from three regions of Colombia. We found that although Varroa exhibited high prevalence (92%), its infestation levels were low (4.6%) considering that these populations never received acaricide treatments. We also detected four viruses in the three regions analyzed, but all hives were asymptomatic, and virus prevalence was considerably lower than those found in other countries with higher rates of mite-associated colony loss (DWV 19.88%, BQCV 17.39%, SBV 23.4 %, ABPV 10.56%). Our findings indicate that AHBs possess natural resistance to Varroa that does not prevent the spread of this parasite among their population, but restrains mite population growth and suppresses the prevalence and pathogenicity of mite-associated viruses.

pathology↗

bioRxiv2019

Decoupling the effects of nutrition, age and behavioral caste on honey bee physiology and immunity

Nutritional stress, and especially a dearth of pollen, is considered an important factor associated with honey bee colony losses. We used pollen-restricted colonies as a model to study the nutritional stress conditions experienced in colonies within intensively cultivated agricultural areas. This model was complemented by the establishment of an experimental design, which allowed us to uncouple the effect of nutrition, behavior and age in colonies of similar size and demography. We used this system to determine the effect of pollen restriction on workers behavioral development. Then, we analyzed the effect of nutritional stress, behavior and age on the expression of key physiological genes involved in the regulation of division of labor. Finally, we analyzed the effects of these variables on the expression of immune genes and the titers of honey bee viruses. Our results show that pollen restriction led to an increased number of precocious foragers and this behavioral transition was associated with important changes in the expression of nutritionally regulated physiological genes, immunity and viral titers. Vitellogenin (vg) and major royal jelly protein 1 (mrjp1) were the most predictive markers of nutrition and behavior. The expression of immune genes was primarily affected by behavior, with higher levels in foragers. Deformed wing virus (DWV) titers were significantly affected by behavior and nutritional status, with higher titer in foragers and increased levels associated with pollen ingestion. Correlation analyses support the predominant effect of behavior on immunity and susceptibility to viral infection, revealing that both immune genes and DWV exhibited strong negative correlations with genes associated with nursing, but positive correlations with genes associated with foraging. Our results provide valuable insights into the physiological mechanisms by which nutritional stress induce precocious foraging and increased susceptibility to viral infections.

molecular biology↗