April 5th, 2025
Version: 3
San Diego State University
systems biology
biorxiv

Uniaxial force modifies the length of the mammary ductal network and the orientation of ducts during pubertal development: Findings from computational modeling and laboratory experiments

The orientation of the epithelium ducts determines the overall shape of the ductal network in the mammary gland, which in turn impacts the efficiency of the delivery of milk through the ducts to breastfeeding infants. However, how the orientations of the ducts are specified is not well understood. Cell-cell and cell-extracellular matrix (ECM) interactions perturb the tissue mechanical environment and influence mechanical signaling, which in turn regulates cell migration, tissue organization, and morphogenesis. This study examined if an applied force that perturbs the tissue mechanical environment can regulate the orientation of the epithelium ducts during puberty, in vivo. Uniaxial forces were applied continuously to the right abdominal number four mouse mammary glands (n=10; TEN) at 5-7 weeks of age, that is, during pubertal formation of the epithelial ductal network. The uniaxial force was applied by pulling and adhering the skin around the nipple of the right abdominal number four mammary gland. This pulling force on the right gland made the left abdominal number four gland also experience a contralateral (CONTRA) force. Mammary glands from litter mates were dissected at 3 weeks, 5 weeks, and 7 weeks of un-manipulated mice to serve as controls. Following dissection, whole mounts were prepared by carmine alum staining and panoramic images were captured under light microscopy. The ductal network in the images were skeletonized and straighten along the longitudinal midline to accurately capture the length of the ductal network without bias from its curvature. Findings from using the Measure tool in ImageJ version 1.54j indicated that the length of the ductal network was increased in the TEN and CONTRA mammary glands compared to control (p<0.05). Analysis of the images using OrientationJ version 16.01.2018, an ImageJ plug-in, indicated that the orientation of ducts in the TEN and CONTRA mammary glands where altered compared to control (p<0.05). Although the ductal network was longer in the TEN and CONTRA glands compared to control, there was no significant difference in the total cross-sectional area. In-silico simulations of the ductal network formation using a branching and annihilating random walk model predicted that the increased length of the ductal network may have resulted from changes in the orientation of the epithelium ducts. Thus it is likely that mechanical forces regulate the orientation of ductal branches in vivo.

Similar Papers

biorxiv
Sat Apr 12 2025
Cadmium-induced gut dysbiosis precedes the onset of hippocampus-dependent learning and memory deficits in mice
Background: Cadmium (Cd) is a heavy metal recognized as a neurotoxicant. However, the mechanisms underlying its neurotoxicity remain poorly understood. The gut-brain axis, a bidirectional communication pathway between the central nervous system and the gut microbiome, has been linked to various neurological disorders. Because the gut microbiome is a known target of Cd, it is important to investiga...
Wang, H.
Lim, J. J.
Gu, H.
Xia, Z.
Cui, J. Y. Y.
biorxiv
Sat Apr 12 2025
CoDIAC: A comprehensive approach for interaction analysis reveals novel insights into SH2 domain function and regulation
Protein domains are conserved structural and functional units that serve as building blocks of proteins. Through evolutionary expansion, domain families are represented by multiple members in diverse configurations with other domains, evolving new specificities for their interacting partners. Here, we develop a structure-based interface analysis to comprehensively map domain interfaces from experi...
Kandoor, A.
Martinez, G.
Hitchcock, J. M.
Angel, S.
...
Naegle, K. M.
biorxiv
Fri Apr 11 2025
Transfer Learning and Permutation-Invariance improving Predicting Genome-wide, Cell-Specific and Directional Interventions Effects of Complex Systems
With the advent of precision medicine, single-drug treatments may not fully satisfy the pursuit of precision medicine. However, single-drug treatments have accumulated a large amount of data and a considerable number of deep learning models. In this context, using transfer learning to effectively leverage the existing vast amount of single-compound intervention effect data to build models that can...
Wang, B.
Pan, B.
Zhang, T.
Liu, Q.
Li, S.
biorxiv
Fri Apr 11 2025
Genome-wide consensus transcriptional signatures identify synaptic pruning linking Alzheimer's disease and epilepsy
Alzheimer's disease (AD) and epilepsy (EP) share a complex bidirectional relationship, yet the molecular mechanisms underlying their comorbidity remain insufficiently explored. To identify potential consensus transcriptional programs across animal models and human patients with AD and EP, we conducted comprehensive genome-wide transcriptomic analyses of multiple datasets. Our investigation include...
Li, H.
Xie, Z.
Tian, Y.
Yang, Y.
...
Ji, X.
biorxiv
Thu Apr 10 2025
Identification of Monotonically Classifying Pairs of Genes for Ordinal Disease Outcomes
In this study, we extend an existing classification method for identifying pairs of genes whose joint expression is associated with binary outcomes to ordinal multi-class outcomes, such as overall survival or disease progression. Our approach is motivated by the need for interpretable classifiers that can provide insights into the underlying biological mechanisms. It can be easily adapted to diffe...
Fourquet, O.
Afenteva, D.
Zhang, K.
Hautaniemi, S.
...
Schwikowski, B.
biorxiv
Thu Apr 10 2025
High-content microscopy and machine learning characterize a cell morphology signature of NF1 genotype in Schwann cells
Neurofibromatosis type 1 (NF1) is a multi-system, autosomal dominant genetic disorder driven by the systemic loss of the NF1 protein neurofibromin. Loss of neurofibromin in Schwann cells is particularly detrimental, as the acquisition of a second-hit (e.g., complete loss of NF1) can lead to the development of plexiform neurofibromas (pNF). pNFs are painful, disfiguring tumors with an approximately...
Tomkinson, J.
Mattson, C.
Mattson-Hoss, M.
Sarnoff, H.
...
Way, G. P.
biorxiv
Thu Apr 10 2025
Gene regulatory network determinants of rapid recall in human memory CD4+ T cells
Rapid recall is the hallmark of memory T cells. While naive T cells require days to mount an effector response to a new threat, antigen-experienced memory T cells can produce cytokines within hours of the repeat encounter. The establishment of memory and control of rapid recall across lifespan is poorly understood, yet the mechanisms are fundamental to pathogen defense and immunological diseases. ...
Katko, A.
Korinfskaya, S.
Bejjani, A. T.
Owoeye, S. M.
...
Miraldi, E. R.
biorxiv
Thu Apr 10 2025
Reduced glutathione levels in Enterococcus faecalis trigger metabolic and transcriptional compensatory adjustments during iron exposure.
Enterococcus faecalis, a facultative anaerobic pathogen and common constituent of the gastrointestinal microbiota, must navigate varying iron levels within the host. This study explores its response to iron supplementation in a glutathione-deficient mutant strain ({Delta}gsh). We examined the transcriptomic and metabolic responses of a glutathione synthetase mutant strain ({Delta}gsh) exposed to i...
Aliaga-Tobar, V. M.
Torres, J.
Mendoza, S.
Galvez, G.
...
Latorre, M. A.
biorxiv
Thu Apr 10 2025
Ribosome demand links transcriptional bursts to protein expression noise
Stochastic variation in protein expression generates phenotypic heterogeneity in a cell population and has an important role in antibiotic persistence, mutation penetrance, tumor growth and therapy resistance. Studies investigating molecular origins of noise have predominantly focused on the transcription process. However, the noise generated in the transcription process is further modulated by tr...
Pal, S.
Ray, U.
Dhar, R.
biorxiv
Wed Apr 09 2025
Implementing N-terminomics and machine learning to probe in vivo Nt-arginylation
N-terminal arginylation (Nt-arginylation) serves as a protein degradation signal in both the ubiquitin-proteasome system and the autophagy-lysosomal pathway. However, the scarcity of arginylated proteins in cells and limitations in current identification methods have hindered progress in this field. In this study, we developed a novel integrated approach that combines N-terminomics (N-terminomic e...
Ju, S.
Nawale, L.
Lee, S.
Kim, J. G.
...
Lee, C.