Related Experiment Videos
Transforming growth factor-beta isoforms in the developing chicken intestine and spleen: increase in transforming
S B Jakowlew1, A Mathias, H S Lillehoj
1National Cancer Institute, Biomarkers and Prevention Research Branch, Rockville, MD 20850, USA.
Abstract:
Expression of transforming growth factor-betas 2, 3 and 4 (TGF-beta) in the developing chicken intestine and spleen was investigated using specific cDNA probes and antibodies for the different TGF-beta isoforms. Coordinate expression of the mRNAs for TGF-beta s 2, 3 and 4 was detected in the embryonic intestine by 8 days, with maximal expression of the mRNAs for TGF-beta s 2 and 4 occurring at 12 and 19 days, respectively, while expression of TGF-beta 3 mRNA remained constant during this time. While specific antibodies for TGF-beta s 2, 3 and 4 could detect only weak immunohistochemical staining of the intestinal epithelium in 4-, 12- and 16-day-old embryos, intense staining for TGF-beta s 2, 3 and 4 was detected in the tips of the intestinal villi of 19-day-old embryos. In the spleen, expression of the mRNAs for TGF-beta s 2 and 3 increased in the newly hatched chick compared with the embryo and then decreased in the adult to levels that were lower than in the embryo; expression of TGF-beta 4 mRNA increased progressively with developmental age, with expression in the adult spleen being significantly higher than in the embryonic and hatchling spleen. Immunohistochemical staining of spleens showed a selective increase in the level of reactive TGF-beta 4 with increasing developmental age, while staining for TGF-beta s 2 and 3 was constant during development. After infection of 1-month-old chickens with coccidian parasite, expression of TGF-beta 4 mRNAs increased 5-8-fold in intestinal intra-epithelial lymphocytes and 2.5-fold in spleen cells, while expression of the mRNAs for TGF-beta s 2 and 3 remained constant in these cells. The results of this study suggest that TGF-beta may play a role in development of the intestine and spleen in the chicken and that TGF-beta 4 in particular increases after infection of coccidia in the chicken.
Insights
Transforming growth factor-betas (TGF-betas) 2, 3, and 4 are expressed in developing chicken intestines and spleens. TGF-beta 4 specifically increases in these tissues after coccidian parasite infection.
Area of Science:
- Immunology
- Developmental Biology
- Molecular Biology
Background:
- Transforming growth factor-betas (TGF-betas) are crucial signaling molecules involved in various biological processes.
- Understanding the expression patterns of different TGF-beta isoforms during development is essential for elucidating their roles.
Purpose of the Study:
- To investigate the expression of TGF-beta 2, 3, and 4 isoforms in the developing chicken intestine and spleen.
- To determine the changes in TGF-beta expression following coccidian parasite infection.
Main Methods:
- Quantitative analysis of TGF-beta mRNA expression using cDNA probes.
- Immunohistochemical detection of TGF-beta protein localization using specific antibodies.
- Analysis of gene expression changes in response to coccidian infection.
Main Results:
- Coordinate expression of TGF-beta 2, 3, and 4 mRNAs was observed in the embryonic intestine, with isoform-specific temporal patterns.
- Intense TGF-beta staining was localized to the tips of intestinal villi in late-stage embryos.
- TGF-beta 4 mRNA and protein levels increased progressively in the spleen with developmental age.
- Coccidian infection led to a significant upregulation of TGF-beta 4 mRNA in intestinal lymphocytes and spleen cells.
Conclusions:
- TGF-betas play a role in the development of the chicken intestine and spleen.
- TGF-beta 4 is particularly upregulated in response to coccidian infection, suggesting a role in host defense or immune response.