Biology subjects

Jayadev, R.

Publications and source records attributed to Jayadev, R..

5 recordsLinked to original sources

bioRxiv2025

Live visualization of extracellular matrix dynamics during development and regeneration in zebrafish

Extracellular matrix (ECM) plays fundamental roles in animal development, regeneration, and disease. The difficulty of tagging endogenous matrix proteins in vertebrates has limited the understanding of ECM composition and dynamics in complex tissues. To visualize vertebrate ECM components, we tagged zebrafish Laminin, gamma 1 (Lamc1), Collagen, type I, alpha 2 (Col1a2), and Transforming growth factor, beta-induced (Tgfbi) using C-terminus in-fusion genome editing. Analysis of these knock-in lines revealed distinct expression of each protein in various tissues during development and regeneration. Fluorescent recover after photobleaching (FRAP) analysis further indicated that Lamc1 is stable in fin fold matrix but more dynamic in myoseptal matrix of developing zebrafish, while Col1a2 and Tgfbi are stable matrix components in myosepta. Strikingly, we found that Col1a2-mScarlet protein accumulates at the amputation plane during tailfin regeneration, where it remains concentrated for several days and distant from the regeneration blastema. This "foundation" region also displayed a distinct transcriptome suggesting active and dedicated events at the base of the regenerating appendage. Our resource enables live capture of ECM dynamics that can identify new events in developing and regenerating zebrafish. Summary statementExtracellular matrix resources for zebrafish development and tissue regeneration.

developmental biology↗

bioRxiv2023

Reciprocal discoidin domain receptor signaling strengthens integrin adhesion to connect adjacent tissues

Separate tissues connect through adjoining basement membranes to carry out molecular barrier, exchange, and organ support functions. Cell adhesion at these connections must be robust and balanced to withstand independent tissue movement. Yet, how cells achieve synchronized adhesion to connect tissues is unknown. Here, we have investigated this question using the C. elegans utse-seam tissue connection that supports the uterus during egg-laying. Through genetics, quantitative fluorescence, and cell specific molecular disruption, we show that type IV collagen, which fastens the linkage, also activates the collagen receptor discoidin domain receptor 2 (DDR-2) in both the utse and seam. RNAi depletion, genome editing, and photobleaching experiments revealed that DDR-2 signals through LET-60/Ras to coordinately strengthen an integrin adhesion in the utse and seam that stabilizes their connection. These results uncover a synchronizing mechanism for robust adhesion during tissue connection, where collagen both affixes the linkage and signals to both tissues to bolster their adhesion.

developmental biology↗

bioRxiv2021

Hemicentin mediated type IV collagen assembly strengthens juxtaposed basement membrane linkage

Basement membrane (BM) matrices surround and separate most tissues. However, through poorly understood mechanisms, BMs of adjacent tissues can also stably link to support organ structure and function. Using endogenous knock-in fluorescent proteins, conditional RNAi, optogenetics, and quantitative live imaging, we identified matrix proteins mediating a BM linkage (B-LINK) between the uterine utse and epidermal seam cell BMs in Caenorhabditis elegans that supports the uterus during egg-laying. We found that hemicentin is secreted by the utse and promotes fibulin-1 assembly to jointly initiate the B-LINK. During egg-laying, however, both proteins decline in levels and are not required for B-LINK maintenance. Instead, we discovered that hemicentin also promotes type IV collagen assembly, which accumulates to high levels during egg-laying and sustains the B-LINK during the mechanically active egg-laying period. This work reveals mechanisms underlying BM-BM connection maturation and identifies a crucial function for hemicentin and fibulin-1 in initiating attachment and type IV collagen in strengthening this specialized form of tissue linkage. SummaryTissue attachment through linking juxtaposed basement membranes (BMs) is crucial for the structure and function of many organs. Gianakas et al. identify a key role for hemicentin and fibulin-1 in initiating BM-BM attachment and type IV collagen in stabilizing this linkage and allowing it to resist high mechanical loads.

developmental biology↗

bioRxiv2021

A basement membrane discovery pipeline uncovers network complexity, new regulators, and human disease associations

Basement membranes (BMs) are ubiquitous extracellular matrices whose composition remains elusive, limiting our understanding of BM regulation and function. By developing a bioinformatic and in vivo discovery pipeline, we define a network of 222 human proteins localized to BMs. Network analysis and screening in C. elegans and zebrafish identified new BM regulators, including ADAMTS, ROBO, and TGF{beta}. More than 100 BM-network genes associate with human phenotypes and by screening 63,039 genomes from families with rare disorders, we discovered loss-of-function variants in LAMA5, MPZL2, and MATN2, and show they regulate BM composition and function. This cross-disciplinary study establishes the immense complexity and role of BMs in human health.

cell biology↗

bioRxiv2019

α-integrins dictate distinct modes of type IV collagen recruitment to basement membranes

Basement membranes (BMs) are cell-associated extracellular matrices that support tissue integrity, signaling, and barrier properties. Type IV collagen is critical for BM mechanical and signaling functions, yet how it is directed into BMs in vivo is unclear. Through live-cell imaging of endogenous localization, conditional knockdown, and misexpression experiments, we uncovered distinct mechanisms of integrin-mediated collagen recruitment to Caenorhabditis elegans gonadal and pharyngeal BMs. The putative laminin-binding INA-1/{beta}PAT-3 integrin was selectively activated in the gonad and recruited laminin, which directed moderate collagen incorporation. In contrast, the putative Arg-Gly-Asp (RGD)-binding PAT-2/{beta}PAT-3 integrin was activated in the pharynx and recruited high levels of collagen independent of laminin. Through an RNAi screen, we further identified the small GTPase RAP-3 (Rap1) as a pharyngeal-specific PAT-2/PAT-3 activator that modulates collagen levels. Together, these studies demonstrate that tissues can use distinct mechanisms to direct collagen incorporation into BMs to precisely control collagen levels and construct diverse BMs.

cell biology↗