# DEVELOPMENT OF MAMMALIAN OOCYTE-GRANULOSA CELL COMPLEX

> **NIH NIH R01** · JACKSON LABORATORY · 1994 · $147,660

## Abstract

The overall objective of this project is to determine what role the oocyte
plays in the fundamental organization, differentiation and function of the
ovarian granulosa cells.  Granulosa cells of large antral follicles are
heterogeneous in their expression of specific phenotypic characteristics.
One population of granulosa cells, the mural granulosa cells, is
associated with the basal lamina and the other, the cumulus cells, with
the oocyte. Such microenvironmental associations suggest that the oocyte
and the basal lamina both influence the fate and function of the cells
associated with them. Although many factors originating in the pituitary
gland, the follicular theca or even in the granulosa cells themselves
participate in granulosa cell development and function, the overall goal
of this project is to determine what role the oocyte plays in the
development and function of the granulosa cells. The hypothesis underlying
this work is that the selection of the specific pathway for development,
as functional cumulus cells or as mural granulosa cells, is determined by
the association of the granulosa cells with either the oocyte or the basal
lamina. Furthermore, it is hypothesized that the oocyte is actually the
dominant determinative factor in granulosa cell development. More
specifically, the default program of granulosa cell differentiation is
proposed to yield the mural granulosa cell phenotype, which is augmented
by contact with basal lamina, while paracrine factors from the oocyte
suppress the expression of this phenotype and promote the cumulus cell
phenotype. The following specific aims will address this hypothesis.
First, mRNA species expressed specifically by mural and cumulus granulosa
cells will be identified and cloned.  These will be used as markers of the
cumulus and mural granulosa cell phenotypes.  Specific Aims 2 and 3 will
compare the ability of oocyte secretions and components of basal lamina to
affect these phenotypes.  It will be determined whether the development of
the phenotypic characteristics of mural granulosa cells is suppressed by
paracrine factors from oocytes even when the expression of the mural
granulosa cell phenotype is promoted by components of basal lamina (Aim
2). Then, it will be determined whether microsurgical removal of the
oocyte from oocyte-cumulus cell complexes promotes the expression of the
mural granulosa cell phenotype and the loss of the cumulus cell phenotype.
If so, it will be determined whether paracrine factors from oocytes
maintain the cumulus cell phenotype and suppress the expression of the
mural granulosa cell phenotype even when oocytectomized complexes are
maintained in contact with basal lamina in vitro (Aim 3).

Completion of these aims will further the understanding of how the oocyte
influences the fundamental organization of the follicle. This may be by a
dominant influence of the oocyte in creating the heterogeneity in the
pattern of gene expression and cellular function of granulosa c...

## Key facts

- **NIH application ID:** 2198966
- **Project number:** 2R01HD023839-06A2
- **Recipient organization:** JACKSON LABORATORY
- **SAM.gov UEI:** XR6LMXNKDJJ1
- **Principal Investigator:** JOHN J EPPIG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $147,660
- **Award type:** 2
- **Project period:** 1988-02-03 → 1997-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2198966

## Citation

> US National Institutes of Health, RePORTER application 2198966, DEVELOPMENT OF MAMMALIAN OOCYTE-GRANULOSA CELL COMPLEX (2R01HD023839-06A2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2198966. Licensed CC0.

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