Biology subjects

Morales-Sosa, P.

Publications and source records attributed to Morales-Sosa, P..

4 recordsLinked to original sources

bioRxiv2025

From Development to Regeneration: Insights into Flight Muscle Adaptations from Bat Muscle Cell Lines

Skeletal muscle regeneration depends on muscle stem cells, which give rise to myoblasts that drive muscle growth, repair, and maintenance. In bats--the only mammals capable of powered flight--these processes must also sustain contractile performance under extreme mechanical and metabolic stress. However, the cellular and molecular mechanisms underlying bat muscle physiology remain largely unknown. To enable mechanistic investigation of these traits (Graphical Abstract), we established the first myoblast cell lines from the pectoralis muscle of Pteronotus mesoamericanus, a highly maneuverable aerial insectivore. Using both spontaneous immortalization and exogenous hTERT/CDK4 overexpression, we generated two stable cell lines that retain proliferative capacity and differentiate into contractile myotubes. These cells exhibit frequent spontaneous contractions, suggesting robust functional integrity at the neuromuscular junction. In parallel, we performed transcriptomic and metabolic profiling of native pectoralis tissue to define molecular programs supporting muscle specialization. Gene expression analyses revealed enriched pathways for muscle metabolism, development, and regeneration, highlighting the supporting roles in tissue maintenance and repair. Consistent with this profile, the flight muscle is triglyceride-rich, which serves as an important fuel source for energetically demanding processes, including muscle contraction and cellular recovery. Integration of transcriptomic and metabolic data identified three key metabolic modules--glucose utilization, lipid handling, and nutrient signaling--that likely coordinate ATP production and support metabolic flexibility. Together, these complementary tools and datasets provide the first in vitro platform for investigating bat muscle research, enabling direct exploration of muscle regeneration, metabolic resilience, and evolutionary physiology. Graphical AbstractEstablishment of bat muscle cell cultures from the Mesoamerican mustached bat (P. mesoamericnus) provides an in vitro platform to investigate muscle regeneration and flight muscle biology. The pectoralis major muscle was isolated to generate primary myoblast cultures, which were expanded and immortalized using hTERT/CDK4. The resulting myoblast lines retain proliferative and differentiation capacity. RNA sequencing of native pectoralis muscle tissue revealed molecular signatures of myogenic regulation, stress resilience, and tissue remodeling, supporting the relevance of these in vitro models for studying muscle maintenance and regenerative mechanisms. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=127 SRC="FIGDIR/small/662643v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@490f49org.highwire.dtl.DTLVardef@8ab615org.highwire.dtl.DTLVardef@b840e1org.highwire.dtl.DTLVardef@ab92eb_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Reproductive Adaptation of Astyanax mexicanus Under Nutrient Limitation

Reproduction is a fundamental biological process for the survival and continuity of species. Examining changes in reproductive strategies offers valuable insights into how animals have adapted their life histories to different environments. Since reproduction is one of the most energy-intensive processes in female animals, nutrient scarcity is expected to interfere with the ability to invest in gametes. Lately, a new model to study adaptation to nutrient limitation has emerged; the Mexican tetra Astyanax mexicanus. This fish species exists as two different morphs, a surface river morph and a cave-dwelling morph. The cave-dwelling morph has adapted to the dark, biodiversity, and nutrient-limited cave environment and consequently evolved an impressive starvation resistance. However, how reproductive strategies have adapted to nutrient limitations in this species remains poorly understood. Here, we compared breeding activities and maternal contributions between laboratory-raised surface fish and cavefish. We found that cavefish produce different clutch sizes of eggs with larger yolk compared to surface fish, indicating a greater maternal nutrient deposition in cavefish embryos. To systematically characterize yolk compositions, we used untargeted proteomics and lipidomics approaches to analyze protein and lipid profiles in 2-cell stage embryos and found an increased proportion of sphingolipids in cavefish compared to surface fish. Additionally, we generated transcriptomic profiles of surface fish and cavefish ovaries using a combination of single cell and bulk RNA sequencing to examine differences in maternal contribution. We found that genes essential for hormone regulation were upregulated in cavefish follicular somatic cells compared to surface fish. To evaluate whether these differences contribute to their reproductive abilities under natural-occurring stress, we induced breeding in starved female fish. Remarkably, cavefish maintained their ability to breed under starvation, whereas surface fish largely lost this ability. We identified insulin-like growth factor 1a receptor (igf1ra) as a potential candidate gene mediating the downregulation of ovarian development genes, potentially contributing to the starvation-resistant fertility of cavefish. Taken together, we investigated the female reproductive strategies in Astyanax mexicanus, which will provide fundamental insights into the adaptations of animals to environments with extreme nutrient deficit.

evolutionary biology↗

bioRxiv2024

Cave Adaptation Favors Aging Resilience in the Mexican Tetra

All animals age, but the rate at which some species age varies widely. What environmental pressures and what molecular factors underlie the remarkable diversity in aging and lifespan across species remains largely enigmatic. The Mexican tetra, Astyanax mexicanus, serves as an intriguing new model to study how adaptations to different environments can change aging. This species exists as two morphotypes: the river-dwelling surface fish, which inhabits environments rich in food and light, and the blind cave-adapted cavefish, that thrive in dark, nutrient-limited but predator free environments. Nutrient limitation and lack of predation are known to impact lifespan, however, how adaption to such environments changes the aging trajectory in this species remains unknown. Here, we compared aging markers between surface and cavefish populations, focusing on morphological and behavioral changes, as well as molecular signatures, and found that aging markers are pronounced and evident in surface fish, whereas these signatures are less distinct in aged cavefish. Using zebrafish, we explored the contribution of the cavefish insulin receptor mutation to longevity. Although the insulin receptor mutation is sufficient to increase lifespan in fish, our findings suggest its impact is limited. Instead, our data indicate that metabolic shifts, particularly those related to mitochondrial function, may be key contributors to the extended longevity observed in cavefish.

evolutionary biology↗

bioRxiv2024

Establishing Primary and Stable Cell Lines from Frozen Wing Biopsies for Cellular, Physiological, and Genetic Studies in Bats

Bats stand out among mammalian species for their exceptional traits, including the capacity to navigate through flight and echolocation, conserve energy through torpor/hibernation, harbor a multitude of viruses, exhibit resistance to disease, survive harsh environmental conditions, and demonstrate exceptional longevity compared to other mammals of similar size. In vivo studies of bats can be challenging for several reasons such as ability to locate and capture them in their natural environments, limited accessibility, low sample size, environmental variation, long lifespans, slow reproductive rates, zoonotic disease risks, species protection, and ethical concerns. Thus, establishing alternative laboratory models is crucial for investigating the diverse physiological adaptations observed in bats. Obtaining quality cells from tissues is a critical first step for successful primary cell derivation. However, it is often impractical to collect fresh tissue and process the samples immediately for cell culture due to the resources required for isolating and expanding cells. As a result, frozen tissue is typically the starting resource for bat primary cell derivation. Yet, cells in frozen tissue are usually damaged and represent low integrity and viability. As a result, isolating primary cells from frozen tissues poses a significant challenge. Herein, we present a successfully developed protocol for isolating primary dermal fibroblasts from frozen bat wing biopsies. This protocol marks a significant milestone, as this the first protocol specially focused on fibroblasts isolation from bat frozen tissue. We also describe methods for primary cell characterization, genetic manipulation of primary cells through lentivirus transduction, and the development of stable cell lines. Basic Protocol 1: Bat wing biopsy collection and preservation Support Protocol 1: Blood collection from bat-venipuncture Basic Protocol 2: Isolation of primary fibroblasts from adult bat frozen wing biopsy Support Protocol 2: Maintenance of primary fibroblasts Support Protocol 3: Cell banking and thawing of primary fibroblasts Support Protocol 4: Growth curve and doubling time Support Protocol 5: Lentiviral transduction of bat primary fibroblasts Basic Protocol 3: Bat stable fibroblasts cell lines development Support Protocol 6: Bat fibroblasts validation by immunofluorescence staining Support Protocol 7: Chromosome counting

cell biology↗