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Transcriptome profiling of the theca interna from bovine ovarian follicles during atresia.

Hatzirodos N, Irving-Rodgers HF, Hummitzsch K, Rodgers RJ - PLoS ONE (2014)

Bottom Line: Further analyses of these genes by Ingenuity Pathway Analysis and Gene Ontology Enrichment Analysis Toolkit software found most of the genes being expressed were related to cytokines, hormones and receptors as well as the cell cycle and DNA replication.In addition to cell cycle regulators, upstream regulators that were predicted to be inhibited included Retinoblastoma 1, E2 transcription factor 1, and hepatocyte growth factor.Our study suggests that during antral atresia of small follicles in the theca interna, arrest of cell cycle and DNA replication occurs rather than up- regulation of apoptosis-associated genes as occurs in granulosa cells.

View Article: PubMed Central - PubMed

Affiliation: Research Centre for Reproductive Health, Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia.

ABSTRACT
The theca interna is a specialized stromal layer that envelops each growing ovarian follicle. It contains capillaries, fibroblasts, immune cells and the steroidogenic cells that synthesize androgens for conversion to estradiol by the neighboring granulosa cells. During reproductive life only a small number of follicles will grow to a sufficient size to ovulate, whereas the majority of follicles will undergo regression/atresia and phagocytosis by macrophages. To identify genes which are differentially regulated in the theca interna during follicular atresia, we undertook transcriptome profiling of the theca interna from healthy (n = 10) and antral atretic (n = 5) bovine follicles at early antral stages (<5 mm). Principal Component Analyses and hierarchical classification of the signal intensity plots for the arrays showed primary clustering into two groups, healthy and atretic. A total of 543 probe sets were differentially expressed between the atretic and healthy theca interna. Further analyses of these genes by Ingenuity Pathway Analysis and Gene Ontology Enrichment Analysis Toolkit software found most of the genes being expressed were related to cytokines, hormones and receptors as well as the cell cycle and DNA replication. Cell cycle genes which encode components of the replicating chromosome complex and mitotic spindle were down-regulated in atretic theca interna, whereas stress response and inflammation-related genes such as TP53, IKBKB and TGFB1 were up-regulated. In addition to cell cycle regulators, upstream regulators that were predicted to be inhibited included Retinoblastoma 1, E2 transcription factor 1, and hepatocyte growth factor. Our study suggests that during antral atresia of small follicles in the theca interna, arrest of cell cycle and DNA replication occurs rather than up- regulation of apoptosis-associated genes as occurs in granulosa cells.

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Related in: MedlinePlus

The most significant network determined in IPA.The network was generated in IPA using triangle connectivity based on focus genes (30 from our differentially regulated data set) and built up according to the number of interactions between a single prospective gene and others in the existing network, and the number of interactions the prospective gene has outside this network with other genes as determined by IPA [43]. Network score = 52, equivalent to −log P value of Fisher's exact t-Test. Interactions between molecules, and the degree and direction of regulation are indicated with up (red) or down regulation (green) and increasing color intensity with degree of fold change.
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pone-0099706-g004: The most significant network determined in IPA.The network was generated in IPA using triangle connectivity based on focus genes (30 from our differentially regulated data set) and built up according to the number of interactions between a single prospective gene and others in the existing network, and the number of interactions the prospective gene has outside this network with other genes as determined by IPA [43]. Network score = 52, equivalent to −log P value of Fisher's exact t-Test. Interactions between molecules, and the degree and direction of regulation are indicated with up (red) or down regulation (green) and increasing color intensity with degree of fold change.

Mentions: The most significant network generated by IPA from the differentially expressed genes is displayed in Fig. 4. This network showed that molecules mostly down regulated in atretic compared with healthy follicles mainly mapped to the nuclear compartment of the cells and were involved with chromosome organization as part of the cell cycle process. Genes which encode components of the condensin-2 complex such as NCAPH, NCAPD3 and NCAPG2 and the mini-chromosome complex which initiates DNA replication [26] such as MCM2, MCM4 and MCM6 were among these. This connection with cell division was further strengthened by the fact that the top canonical pathway in IPA associated with the differentially regulated data set was cell cycle control of chromosomal replication (Fig. S3).


Transcriptome profiling of the theca interna from bovine ovarian follicles during atresia.

Hatzirodos N, Irving-Rodgers HF, Hummitzsch K, Rodgers RJ - PLoS ONE (2014)

The most significant network determined in IPA.The network was generated in IPA using triangle connectivity based on focus genes (30 from our differentially regulated data set) and built up according to the number of interactions between a single prospective gene and others in the existing network, and the number of interactions the prospective gene has outside this network with other genes as determined by IPA [43]. Network score = 52, equivalent to −log P value of Fisher's exact t-Test. Interactions between molecules, and the degree and direction of regulation are indicated with up (red) or down regulation (green) and increasing color intensity with degree of fold change.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4067288&req=5

pone-0099706-g004: The most significant network determined in IPA.The network was generated in IPA using triangle connectivity based on focus genes (30 from our differentially regulated data set) and built up according to the number of interactions between a single prospective gene and others in the existing network, and the number of interactions the prospective gene has outside this network with other genes as determined by IPA [43]. Network score = 52, equivalent to −log P value of Fisher's exact t-Test. Interactions between molecules, and the degree and direction of regulation are indicated with up (red) or down regulation (green) and increasing color intensity with degree of fold change.
Mentions: The most significant network generated by IPA from the differentially expressed genes is displayed in Fig. 4. This network showed that molecules mostly down regulated in atretic compared with healthy follicles mainly mapped to the nuclear compartment of the cells and were involved with chromosome organization as part of the cell cycle process. Genes which encode components of the condensin-2 complex such as NCAPH, NCAPD3 and NCAPG2 and the mini-chromosome complex which initiates DNA replication [26] such as MCM2, MCM4 and MCM6 were among these. This connection with cell division was further strengthened by the fact that the top canonical pathway in IPA associated with the differentially regulated data set was cell cycle control of chromosomal replication (Fig. S3).

Bottom Line: Further analyses of these genes by Ingenuity Pathway Analysis and Gene Ontology Enrichment Analysis Toolkit software found most of the genes being expressed were related to cytokines, hormones and receptors as well as the cell cycle and DNA replication.In addition to cell cycle regulators, upstream regulators that were predicted to be inhibited included Retinoblastoma 1, E2 transcription factor 1, and hepatocyte growth factor.Our study suggests that during antral atresia of small follicles in the theca interna, arrest of cell cycle and DNA replication occurs rather than up- regulation of apoptosis-associated genes as occurs in granulosa cells.

View Article: PubMed Central - PubMed

Affiliation: Research Centre for Reproductive Health, Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia.

ABSTRACT
The theca interna is a specialized stromal layer that envelops each growing ovarian follicle. It contains capillaries, fibroblasts, immune cells and the steroidogenic cells that synthesize androgens for conversion to estradiol by the neighboring granulosa cells. During reproductive life only a small number of follicles will grow to a sufficient size to ovulate, whereas the majority of follicles will undergo regression/atresia and phagocytosis by macrophages. To identify genes which are differentially regulated in the theca interna during follicular atresia, we undertook transcriptome profiling of the theca interna from healthy (n = 10) and antral atretic (n = 5) bovine follicles at early antral stages (<5 mm). Principal Component Analyses and hierarchical classification of the signal intensity plots for the arrays showed primary clustering into two groups, healthy and atretic. A total of 543 probe sets were differentially expressed between the atretic and healthy theca interna. Further analyses of these genes by Ingenuity Pathway Analysis and Gene Ontology Enrichment Analysis Toolkit software found most of the genes being expressed were related to cytokines, hormones and receptors as well as the cell cycle and DNA replication. Cell cycle genes which encode components of the replicating chromosome complex and mitotic spindle were down-regulated in atretic theca interna, whereas stress response and inflammation-related genes such as TP53, IKBKB and TGFB1 were up-regulated. In addition to cell cycle regulators, upstream regulators that were predicted to be inhibited included Retinoblastoma 1, E2 transcription factor 1, and hepatocyte growth factor. Our study suggests that during antral atresia of small follicles in the theca interna, arrest of cell cycle and DNA replication occurs rather than up- regulation of apoptosis-associated genes as occurs in granulosa cells.

Show MeSH
Related in: MedlinePlus