Biomedical subjects

C Trevino

Publications and source records attributed to C Trevino.

3 recordsLinked to original sources

PubMed1994

Regeneration of HoxD expression domains during pattern regulation in chick wing buds.

The expression domains of genes located at the 5' end of the HoxD (formerly Hox-4) complex appear to correlate with pattern along both the proximal-distal (PrDi) and the anterior-posterior (AP) axes of the developing limb bud, and it has been suggested that the HoxD gene products are involved in the specification of positional information during limb development. The apical ectodermal ridge is required for limb outgrowth and is thought to influence mesodermal cells at the distal end of the limb bud in a region within which patterning events occur. In this paper, we examine the expression of 5' HoxD genes during PrDi pattern regulation in chick wing buds. In limbs undergoing pattern regulation, we demonstrate that the domains of HoxD11 and HoxD13 gene expression are "regenerated" within 24 hr of removal of the distal mesenchyme. In contrast, in limbs which will not form distal structures, HoxD13 expression becomes reduced.

Animals↗

PubMed1993

3T3 cell integration and differentiative potential during limb development in the mouse.

In this study we have investigated the ability of embryonic mouse limb cells to induce the differentiation of 3T3 cells both in vivo and in vitro. Using the exo utero surgical technique we introduced labeled 3T3 cells into the embryonic mouse limb and monitored their subsequent development. We found no indication that the normal pattern of tissue differentiation was perturbed; rather we observed that 3T3 cells were closely associated with a variety of limb mesodermal tissues which include muscle, tendon, and ligament. In very rare instances did we observe 3T3 cells associated with cartilage. To further investigate the differentiative potential of 3T3 cells we cocultured labeled 3T3 cells with limb cells under conditions that favored either cartilage or muscle differentiation. The results from these experiments suggest that 3T3 cells avoid regions of chondrogenesis and rarely participate in myotube formation. We conclude that 3T3 cells are not responding to differentiation signals present in the developing limb, but rather are responding to signals involved in growth and tissue morphogenesis.

3T3 Cells↗

PubMed1992

Position specific growth regulation of 3T3 cells in vivo.

In this study we have investigated the mechanism by which spatial growth is regulated by monitoring 3T3 cells, introduced into the developing mouse limb using exo utero surgery. The 3T3 cells were labeled with a human cell surface glycoprotein, CD8, and injected into stage 7-9 mouse limbs. At 24 and 48 hr after injection embryos were labeled with [3H]thymidine and processed for immunohistochemistry and autoradiography. The labeling index of CD8 positive cells was compared to that of neighboring limb bud cells and also to the position of the injection site within the limb. We find that the labeling index of 3T3 cells is in accord with that of the limb cells that immediately surround them; 3T3 cells display a high labeling index in limb regions of high growth and a low labeling index in limb regions of low growth. In addition, we find that both limb bud cells and injected 3T3 cells display a general proximal (low) to distal (high) gradient of growth at the stages analyzed. We conclude from these results that position-specific regulation of growth occurs in a non-cell autonomous manner and is likely to be mediated by mitogenic signals that are localized within the limb environment. In addition, our results demonstrate the usefulness of utilizing established cell lines as in vivo probes to monitor developmental mechanisms.

3T3 Cells↗