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Tatsuo Takeya - One of the best experts on this subject based on the ideXlab platform.
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differential expression of four connexin genes cx 26 cx 30 3 cx 32 and cx 43 in the porcine ovarian follicle
Endocrinology, 1996Co-Authors: Koji Itahana, Y Morikazu, Tatsuo TakeyaAbstract:Connexin genes expressed in porcine ovaries were isolated by reverse transcription-PCR, and the expression of four connexin genes (Cx-43, -32, -30.3, and -26) was detected by in situ hybridization in internal and surrounding compartments of large antral follicles. Cx-43 and Cx-30.3 were expressed in the Theca interna as well as in the granulosa cell compartment. However, two zones were observed in the Theca interna by probing with Cx-43; about a quarter of the region close to the lamina basalis appeared devoid of Cx-43 messenger RNA (mRNA) and protein as well. Cx-30.3, in contrast, seemed to be expressed ubiquitously in these two compartments. Cx-26 and Cx-32 were expressed only in the Thecal cells. Both Cx-43 and -30.3 also gave positive signals in the cumulus cells to the same extent as obtained in the granulosa cells with the respective probes, whereas the expression of Cx-32 and -26 was undetectable. Cx-43 mRNA drastically decreased in the functioning stage of the corpus luteum, whereas Cx-30.3 mRNA increased significantly in the early stage of luteinization in the estrus cycles. These results suggest that Cx-43 is not the only gap junction protein to be expressed in the ovarian follicle; other proteins, such as Cx-32, -30.3, and -26 seem to be expressed, and their expressions are regulated differently.
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differential expression of four connexin genes cx 26 cx 30 3 cx 32 and cx 43 in the porcine ovarian follicle
Endocrinology, 1996Co-Authors: Koji Itahana, Y Morikazu, Tatsuo TakeyaAbstract:Connexin genes expressed in porcine ovaries were isolated by reverse transcription-PCR, and the expression of four connexin genes (Cx-43, -32, -30.3, and -26) was detected by in situ hybridization in internal and surrounding compartments of large antral follicles. Cx-43 and Cx-30.3 were expressed in the Theca interna as well as in the granulosa cell compartment. However, two zones were observed in the Theca interna by probing with Cx-43; about a quarter of the region close to the lamina basalis appeared devoid of Cx-43 messenger RNA (mRNA) and protein as well. Cx-30.3, in contrast, seemed to be expressed ubiquitously in these two compartments. Cx-26 and Cx-32 were expressed only in the Thecal cells. Both Cx-43 and -30.3 also gave positive signals in the cumulus cells to the same extent as obtained in the granulosa cells with the respective probes, whereas the expression of Cx-32 and -26 was undetectable. Cx-43 mRNA drastically decreased in the functioning stage of the corpus luteum, whereas Cx-30.3 mRNA i...
Koji Itahana - One of the best experts on this subject based on the ideXlab platform.
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differential expression of four connexin genes cx 26 cx 30 3 cx 32 and cx 43 in the porcine ovarian follicle
Endocrinology, 1996Co-Authors: Koji Itahana, Y Morikazu, Tatsuo TakeyaAbstract:Connexin genes expressed in porcine ovaries were isolated by reverse transcription-PCR, and the expression of four connexin genes (Cx-43, -32, -30.3, and -26) was detected by in situ hybridization in internal and surrounding compartments of large antral follicles. Cx-43 and Cx-30.3 were expressed in the Theca interna as well as in the granulosa cell compartment. However, two zones were observed in the Theca interna by probing with Cx-43; about a quarter of the region close to the lamina basalis appeared devoid of Cx-43 messenger RNA (mRNA) and protein as well. Cx-30.3, in contrast, seemed to be expressed ubiquitously in these two compartments. Cx-26 and Cx-32 were expressed only in the Thecal cells. Both Cx-43 and -30.3 also gave positive signals in the cumulus cells to the same extent as obtained in the granulosa cells with the respective probes, whereas the expression of Cx-32 and -26 was undetectable. Cx-43 mRNA drastically decreased in the functioning stage of the corpus luteum, whereas Cx-30.3 mRNA increased significantly in the early stage of luteinization in the estrus cycles. These results suggest that Cx-43 is not the only gap junction protein to be expressed in the ovarian follicle; other proteins, such as Cx-32, -30.3, and -26 seem to be expressed, and their expressions are regulated differently.
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differential expression of four connexin genes cx 26 cx 30 3 cx 32 and cx 43 in the porcine ovarian follicle
Endocrinology, 1996Co-Authors: Koji Itahana, Y Morikazu, Tatsuo TakeyaAbstract:Connexin genes expressed in porcine ovaries were isolated by reverse transcription-PCR, and the expression of four connexin genes (Cx-43, -32, -30.3, and -26) was detected by in situ hybridization in internal and surrounding compartments of large antral follicles. Cx-43 and Cx-30.3 were expressed in the Theca interna as well as in the granulosa cell compartment. However, two zones were observed in the Theca interna by probing with Cx-43; about a quarter of the region close to the lamina basalis appeared devoid of Cx-43 messenger RNA (mRNA) and protein as well. Cx-30.3, in contrast, seemed to be expressed ubiquitously in these two compartments. Cx-26 and Cx-32 were expressed only in the Thecal cells. Both Cx-43 and -30.3 also gave positive signals in the cumulus cells to the same extent as obtained in the granulosa cells with the respective probes, whereas the expression of Cx-32 and -26 was undetectable. Cx-43 mRNA drastically decreased in the functioning stage of the corpus luteum, whereas Cx-30.3 mRNA i...
Y Morikazu - One of the best experts on this subject based on the ideXlab platform.
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differential expression of four connexin genes cx 26 cx 30 3 cx 32 and cx 43 in the porcine ovarian follicle
Endocrinology, 1996Co-Authors: Koji Itahana, Y Morikazu, Tatsuo TakeyaAbstract:Connexin genes expressed in porcine ovaries were isolated by reverse transcription-PCR, and the expression of four connexin genes (Cx-43, -32, -30.3, and -26) was detected by in situ hybridization in internal and surrounding compartments of large antral follicles. Cx-43 and Cx-30.3 were expressed in the Theca interna as well as in the granulosa cell compartment. However, two zones were observed in the Theca interna by probing with Cx-43; about a quarter of the region close to the lamina basalis appeared devoid of Cx-43 messenger RNA (mRNA) and protein as well. Cx-30.3, in contrast, seemed to be expressed ubiquitously in these two compartments. Cx-26 and Cx-32 were expressed only in the Thecal cells. Both Cx-43 and -30.3 also gave positive signals in the cumulus cells to the same extent as obtained in the granulosa cells with the respective probes, whereas the expression of Cx-32 and -26 was undetectable. Cx-43 mRNA drastically decreased in the functioning stage of the corpus luteum, whereas Cx-30.3 mRNA increased significantly in the early stage of luteinization in the estrus cycles. These results suggest that Cx-43 is not the only gap junction protein to be expressed in the ovarian follicle; other proteins, such as Cx-32, -30.3, and -26 seem to be expressed, and their expressions are regulated differently.
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differential expression of four connexin genes cx 26 cx 30 3 cx 32 and cx 43 in the porcine ovarian follicle
Endocrinology, 1996Co-Authors: Koji Itahana, Y Morikazu, Tatsuo TakeyaAbstract:Connexin genes expressed in porcine ovaries were isolated by reverse transcription-PCR, and the expression of four connexin genes (Cx-43, -32, -30.3, and -26) was detected by in situ hybridization in internal and surrounding compartments of large antral follicles. Cx-43 and Cx-30.3 were expressed in the Theca interna as well as in the granulosa cell compartment. However, two zones were observed in the Theca interna by probing with Cx-43; about a quarter of the region close to the lamina basalis appeared devoid of Cx-43 messenger RNA (mRNA) and protein as well. Cx-30.3, in contrast, seemed to be expressed ubiquitously in these two compartments. Cx-26 and Cx-32 were expressed only in the Thecal cells. Both Cx-43 and -30.3 also gave positive signals in the cumulus cells to the same extent as obtained in the granulosa cells with the respective probes, whereas the expression of Cx-32 and -26 was undetectable. Cx-43 mRNA drastically decreased in the functioning stage of the corpus luteum, whereas Cx-30.3 mRNA i...
Raymond J. Rodgers - One of the best experts on this subject based on the ideXlab platform.
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Transcriptomal profiling of bovine ovarian granulosa and Theca interna cells in primary culture in comparison with their in vivo counterparts
2017Co-Authors: Nicholas Hatzirodos, Philip G. Knight, Claire Glister, Katja Hummitzsch, Helen F. Irving-rodgers, Raymond J. RodgersAbstract:In vitro culture of ovarian granulosa cells and Theca cells has been very important for our understanding of their function and regulation. One of the most eagerly sought attributes of cell culture is the use of chemically-defined conditions. However, even under such in vitro conditions cell behaviour could differ from the in vivo situation because of differences in oxygen tension, nutrients, adhesion matrix and other factors. To examine this further we compared the transcriptomes of both granulosa cells and cells from the Theca interna that were cultured in what are arguably the best in vitro conditions for maintaining the ‘follicular’ phenotypes of both tissue types, as displayed by their respective freshly-isolated counterparts. The array data analysed are from recently published data and use the same sizes of bovine follicles (small antral 3–6 mm) and the same Affymetrix arrays. We conducted analysis using Partek, Ingenuity Pathway Analysis and GOEAST. Principal Component Analysis (PCA) and hierarchical clustering clearly separated the in vivo from the in vitro groups for both cells types and transcriptomes were more homogeneous upon culture. In both cell cultures behaviours associated with cell adhesion, migration and interaction with matrix or substrate were more abundant. However, the pathways involved generally differed between the two cell types. With the Thecal cultures a gene expression signature of an immune response was more abundant, probably by leukocytes amongst the cells cultured from the Theca interna. These results indicate differences between in vivo and in vitro that should be considered when interpreting in vitro data.
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Transcriptome Profiling of the Theca Interna in Transition from Small to Large Antral Ovarian Follicles
2016Co-Authors: Nicholas Hatzirodos, Katja Hummitzsch, Helen F. Irving-rodgers, Raymond J. RodgersAbstract:The Theca interna layer of the ovarian follicle forms during the antral stage of follicle development and lies adjacent to and directly outside the follicular basal lamina. It supplies androgens and communicates with the granulosa cells and the oocyte by extracellular signaling. To better understand developmental changes in the Theca interna, we undertook transcriptome profiling of the Theca interna from small (3–5 mm, n = 10) and large (9–12 mm, n = 5) healthy antral bovine follicles, representing a calculated.7-fold increase in the amount of Thecal tissue. Principal Component Analysis and hierarchical classification of the signal intensity plots for the arrays showed no clustering of the Theca interna samples into groups depending on follicle size or subcategories of small follicles. From the over 23,000 probe sets analysed, only 76 were differentially expressed between large and small healthy follicles. Some of the differentially expressed genes were associated with processes such as myoblast differentiation, protein ubiquitination, nitric oxide and transforming growth factor b signaling. The most significant pathway affected from our analyses was found to be Wnt signaling, which was suppressed in large follicles via down-regulation of WNT2B and up-regulation of the inhibitor FRZB. These changes in the transcriptional profile could have been due to changes in cellular function or alternatively since the Theca interna is composed of a number of different cell types it could have been due to any systematic change in the volume density of any particular cell type. However, our study suggests that the transcriptional profile of the Theca interna is relatively stabl
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transcriptome comparisons identify new cell markers for Theca interna and granulosa cells from small and large antral ovarian follicles
PLOS ONE, 2015Co-Authors: Nicholas Hatzirodos, Katja Hummitzsch, Helen F Irvingrodgers, Raymond J. RodgersAbstract:In studies using isolated ovarian granulosa and Thecal cells it is important to assess the degree of cross contamination. Marker genes commonly used for granulosa cells include FSHR, CYP19A1 and AMH while CYP17A1 and INSL3 are used for Thecal cells. To increase the number of marker genes available we compared expression microarray data from isolated Theca interna with that from granulosa cells of bovine small (n = 10 for both Theca and granulosa cells; 3-5 mm) and large (n = 4 for both Theca and granulosa cells, > 9 mm) antral follicles. Validation was conducted by qRT-PCR analyses. Known markers such as CYP19A1, FSHR and NR5A2 and another 11 genes (LOC404103, MGARP, GLDC, CHST8, CSN2, GPX3, SLC35G1, CA8, CLGN, FAM78A, SLC16A3) were common to the lists of the 50 most up regulated genes in granulosa cells from both follicle sizes. The expression in Theca interna was more consistent than in granulosa cells between the two follicle sizes. Many genes up regulated in Theca interna were common to both sizes of follicles (MGP, DCN, ASPN, ALDH1A1, COL1A2, FN1, COL3A1, OGN, APOD, COL5A2, IGF2, NID1, LHFP, ACTA2, DUSP12, ACTG2, SPARCL1, FILIP1L, EGFLAM, ADAMDEC1, HPGD, COL12A1, FBLN5, RAMP2, COL15A1, PLK2, COL6A3, LOXL1, RARRES1, FLI1, LAMA2). Many of these were stromal extracellular matrix genes. MGARP, GLDC, CHST8, GPX3 were identified as new potential markers for granulosa cells, while FBLN5, OGN, RAMP2 were significantly elevated in the Theca interna.
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226 expression of matrix metalloproteinases in bovine Thecal cells
Reproduction Fertility and Development, 2005Co-Authors: L Harland, Helen F Irvingrodgers, Stephanie E Morris, Raymond J. RodgersAbstract:As follicles grow the Thecal layers expand. It is likely that extracellular matrix is remodelled in this process and possibly by matrix metalloproteinases (MMPs). A promising candidate to regulate MMPs is insulin-like factor 3 (INSL3). It is produced by Thecal cells, its receptor, LGR8, is expressed in the Theca interna (unpublished) and a related molecule, relaxin, regulates turnover of matrix in a number of tissues. For this reason we sort to examine the role of INSL3 in matrix turnover. However, in all Thecal cell culture systems examined LGR8 receptors appear to be down regulated within 24 h. We therefore examined the effects of second messenger pathway activators. Thecal and granulosa cells were isolated and cultured and the levels of RNA for MMP2 and 9 quantitated by RT-PCR. MMP2 mRNA levels in Thecal tissues were >10 fold higher than in granulosa cells (n = 19 follicles >10 mm). MMP2 levels were substantially greater than MMP9. At 12 h phorbol ester (100 nM phorbol 12,13-didecanoate) increased Thecal expression of MMP 9 mRNA levels 11.5 fold (P < 0.001) and at 48 h MMP2 mRNA was increased 5 fold (P < 0.01). Pieces of whole follicle wall [follicles <5 mm in diameter, classified as healthy (n = 12) or atretic (n = 6)] were cultured in serum free media. Expression of the steroidogenic enzymes 17β HSD and P450scc but not 3β HSD were detected by immunohistochemistry even after 10 days. MMP activity on day 2 was analysed by gelatin zymography. Treatment with phorbol ester increased active MMP9 19 fold (P < 0.001). Treatment of Thecal cells or follicle walls with 1 mM dibutyryl cAMP induced additional MMP activities at sizes of 110 and 122kDa. No effects on MMP2 activity were observed. In conclusion whilst we do not know the ligand inducers of the synthesis and activator of MMPs in Thecal cells they can be regulated. Hence MMPs are candidates for remodelling the extracellular matrix of Thecal layers.
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dynamic changes in the expression of relaxin like factor insl3 cholesterol side chain cleavage cytochrome p450 and 3β hydroxysteroid dehydrogenase in bovine ovarian follicles during growth and atresia
Biology of Reproduction, 2002Co-Authors: Helen F Irvingrodgers, Ross A D Bathgate, Raymond J. Rodgers, Roger DomagalskiAbstract:Relaxin-like factor (RLF) is a new member of the insulin-relaxin gene family known to be expressed in the ovarian follicular Thecal cells of ruminants. To investigate the pattern of RLF expression in development and atresia of bovine follicles, antisera were raised in rats and rabbits to recombinantly expressed bovine pro-RLF and to chemically synthesized ovine RLF B chain, respectively. On dot blotting analysis, the rat antiserum bound to pro-RLF and less strongly to a synthetic mature ovine RLF lacking the C-domain, whereas the rabbit antiserum bound the mature form of ovine RLF. These antisera were used to immunostain bovine ovarian follicles of differing sizes and stages of health and atresia. 3beta-Hydroxysteroid dehydrogenase was colocalized with pro-RLF (n = 86 follicles), and cholesterol side-chain cleavage cytochrome P450 was localized in another section of many of the same follicles (n = 66). Not all follicles expressed pro-RLF in the Theca interna, so the results are presented as the proportion of follicles expressing pro-RLF. Both mature and pro-RLF were immunolocalized to steroidogenic Thecal cells of healthy follicles. As follicles enlarged to >5 mm, the proportion expressing pro-RLF declined (19/19 for 6 mm). Atresia was divided into antral (antral granulosa cells dying first) or basal (basal cells dying first) and further divided into early, middle, and late. For antral atresia of small follicles (2-5 mm), no decline in the proportion expressing pro-RLF was observed (early 6/6, middle 2/2) until the late stages (1/4). For basal atresia, which only occurs in small follicles (2-5 mm), the proportion expressing pro-RLF declined in the middle (2/5) and late (0/8) stages. In larger follicles (>6 to <10 mm), the proportion expressing pro-RLF also declined with atresia (1/13). These declines in RLF expression with atresia or increasing size were not accompanied by a decline in the expression of steroidogenic enzymes in the Theca interna. A significant (P < 0.001) inverse relationship in the expression of pro-RLF and 3beta-hydroxysteroid dehydrogenase in the membrana granulosa was observed. We conclude that the expression of pro-RLF in the Theca interna is switched off as follicles enlarge or enter atresia, whereas the expression of steroidogenic enzymes is maintained in the Theca interna.
Denis A Magoffin - One of the best experts on this subject based on the ideXlab platform.
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overexpression of Theca cell messenger rna in polycystic ovary syndrome does not correlate with polymorphisms in the cholesterol side chain cleavage and 17α hydroxylase c17 20 lyase promoters
Fertility and Sterility, 2002Co-Authors: Said Daneshmand, Stacy R Weitsman, Artur J Jakimiuk, Alireza Navab, Denis A MagoffinAbstract:Abstract Objective: To determine whether overexpression of CYP17 or CYP11A messenger (m)RNA in Theca cells from polycystic ovaries is related to polymorphic regions in the gene promoters that may increase transcription. Design: Case-control study. Setting: Research institute. Patient(s): Fifty-one women with PCOS and 280 regularly cycling controls underwent genotyping. Thecal cells were obtained from 23 women with PCOS and 51 controls. Main Outcome Measure(s): Ovarian tissue was obtained from women with PCOS undergoing wedge resection for treatment of their infertility and from controls undergoing ovariectomy for indications unrelated to the study. Expression of mRNA in Theca cells was measured by using competitive reverse transcriptase polymerase chain reaction. Genotype analysis for polymorphisms in the CYP11A and CYP17 promoters was performed by using polymerase chain reaction. Result(s): Although expression of CYP11A and CYP17 mRNA was higher in women with PCOS, no significant dose effects of CYP11A or CYP17 alleles were observed with respect to serum testosterone; follicular fluid androstenedione, estradiol, and androstenedione-to-estradiol ratio; or CYP11A or CYP17 mRNA expression. Conclusion(s): Overexpression of CYP17 and CYP11A mRNA in Theca cells from polycystic ovaries is explained by polymorphic differences in the gene promoters.
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luteinizing hormone receptor steroidogenesis acute regulatory protein and steroidogenic enzyme messenger ribonucleic acids are overexpressed in Thecal and granulosa cells from polycystic ovaries
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Artur J Jakimiuk, Stacy R Weitsman, Alireza Navab, Denis A MagoffinAbstract:Recent data suggest that steroidogenic enzyme messenger ribonucleic acids (mRNAs) may be overexpressed in Thecal cells, and LH receptors may be prematurely expressed in granulosa cells in women with polycystic ovaries. The purpose of this study was to determine whether there is abnormal gene expression in Thecal and granulosa cells from polycystic ovaries. Ovarian tissue specimens were obtained from 12 women with PCOS and 24 regularly cycling control women. The granulosa cells and the Theca interna were microdissected from individual follicles. LH receptor, steroidogenesis acute regulatory protein (StAR), cholesterol side-chain cleavage cytochrome P450 (CYP11A), and 17α-hydroxylase/C17–20 lyase cytochrome P450 (CYP17) mRNAs were measured by RT-PCR. There was no difference between 3- to 7-mm control follicles and dominant follicles with respect to LH receptor mRNA expression in either Thecal or granulosa cells. CYP11A and CYP17 mRNAs were higher in Thecal cells from 3- to 7-mm follicles than in dominant fo...
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ontogeny of steroidogenic enzyme gene expression in ovarian Theca interstitial cells in the rat regulation by a paracrine Theca differentiating factor prior to achieving luteinizing hormone responsiveness
Biology of Reproduction, 1997Co-Authors: Timothy J Gelety, Denis A MagoffinAbstract:The Theca cells (TC) first become identifiable in preantral follicles after the granulosa cells (GC) begin to divide. It remains unknown when the TC first respond to LH and acquire the capacity to produce androgens. The signal initiating TC differentiation is also unknown since pre-Theca cells do not contain LH receptors. Since the first wave of follicle development in the rat occurs postnatally, we correlated the function of dispersed ovarian cells from 4-, 5-, 6-, 7-, and 10-day-old rats with the morphological differentiation of TC. The largest follicles in ovaries from 4-day-old rats were primary follicles without associated TC. These cells were unable to produce cAMP or steroids in vitro in response to hCG. At 5 days, the first Theca were associated with follicles containing 2-3 layers of GC. These cells were responsive to hCG, producing cAMP, progesterone, androstenedione, and androsterone. Responses to hCG increased progressively through 10 days of age. Cholesterol side-chain cleavage (P450scc), 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), and 17 alpha-hydroxylase/C17-20 lyase (P450(17 alpha)) enzymes were localized exclusively to the Theca interna. Messenger RNAs for LH receptor, P450scc, 3 beta-HSD, and P450(17 alpha) were expressed prior to the time the TC become responsive to LH or morphologically differentiated. To determine the source of the signal regulating TC differentiation, dispersed cells from 4-day-old rat ovaries that were unresponsive to LH were treated with preantral follicle-conditioned medium containing Thecal differentiating factor (TDF) activity. The TDF activity stimulated androgen production and expression of LH receptor, P450scc, 3 beta-HSD, and P450(17 alpha) mRNAs. These data demonstrate that a paracrine signal from the preantral follicle can initiate TC differentiation prior to expression of LH receptors. TC become responsive to LH and capable of producing androgens coincident with morphological differentiation.
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developmental and hormonal regulation of rat Theca cell differentiation factor secretion in ovarian follicles
Biology of Reproduction, 1996Co-Authors: Paul C Magarelli, Rob J Zachow, Denis A MagoffinAbstract:We have recently presented data demonstrating that preantral follicles secrete a peptide (or family of peptides) that stimulates ovarian Theca-interstitial cell (TIC) androgen production by an LH-independent mechanism. The purpose of the study reported here was to study the gonadotropin and developmental regulation of this Thecal differentiating factor(s) (TDF) and to determine whether follicle-conditioned medium (FCM) containing TDF bioactivity could stimulate LH receptor and steroidogenic enzyme mRNA expression in TIC. Preantral follicles devoid of Theca were obtained by limited enzymatic dispersal of 26-day-old rat ovaries. Follicles were cultured (5 follicles/well) in 96-well plates containing serum-free medium to generate FCM containing bioactive TDF. To bioassay for TDF activity, isolated TIC were cultured (2 days) with 50% FCM; then androsterone production was measured by RIA. Recombinant FSH (rFSH, 0.3-100 mlU/ml) increased TDF bioactivity in a dose-dependent fashion, stimulating maximum androsterone production (20 ng/ml) at 30 mlU/ml. To determine the time course of the production of TDF bioactivity, FCM was collected from follicle cultures treated with and without rFSH at 1, 6, 12, 18, 24, 30, 36, 42, and 48 h. FCM from follicles cultured without rFSH caused a progressive increase in androsterone production to a peak (8 ng/ml) at 18 h followed by a decline to baseline by 48 h. A similar time course was observed for the first 18 h with the rFSH-treated FCM, but androsterone production continued to increase to a level twice that of the untreated FCM (18 ng/ml) at 36 h of culture. In the presence of 100 mlU/ml of rFSH, TDF bioactivity was produced by preantral follicles with > or = 2 layers of granulosa cells but not by small antral follicles, preovulatory follicles, or corpora lutea, demonstrating that production of TDF bioactivity is developmentally regulated. To determine whether FCM could stimulate mRNA expression in TIC, LH receptor, cholesterol side-chain cleavage (P450scc), 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), and 17 alpha-hydroxylase (P450(17) alpha) mRNAs were measured by reverse transcription polymerase chain reaction assays. FCM stimulated LH-receptor, P450scc, 3 beta-HSD, and P450(17) alpha mRNAs above controls. Our data demonstrate that the production of TDF bioactivity is increased by FSH during a specific stage in follicular development when the Theca interna is rapidly differentiating, but its production stops when the follicle develops an antrum. Treatment of TIC with FCM stimulates the expression of the mRNAs coding for LH receptors and the steroidogenic enzymes P450scc, 3 beta-HSD, and P450(17) alpha, mimicking the events that occur during normal Thecal differentiation. Thus, it seems likely that TDF is involved in the regulation of initial Thecal differentiation in preantral follicles.
