A specific, nonproliferative role for E2F-5 in choroid plexus function revealed by gene targeting

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• The choroid plexus is responsible for cerebrospinal fluid (CSF) production.
• The role of specific transcription factors in regulating choroid plexus function is not fully understood.

Purpose of the Study:

• To investigate the function of the E2F-5 transcription factor in embryonic development and brain function.
• To determine if E2F-5 plays a role in cell proliferation or secretory activity of neural tissues.

Main Methods:

• Generation of homozygous E2F-5 knockout mice and embryos.
• Analysis of embryonic development and newborn mouse phenotypes.
• Histological and electron microscopy examination of the choroid plexus.
• Assessment of cell cycle kinetics in fibroblasts.

Main Results:

• Homozygous E2F-5 knockout mice exhibited normal embryonic development but developed nonobstructive hydrocephalus postnatally.
• Hydrocephalus was associated with evidence of excessive CSF production.
• The choroid plexus in knockout mice showed abundant electron-lucent epithelial cells, indicating heightened secretory activity.
• E2F-5 expression in normal animals was predominantly localized to the choroid plexus.
• Cell cycle kinetics in knockout fibroblasts were not perturbed, suggesting E2F-5 is not essential for proliferation.

Conclusions:

• E2F-5 plays a critical role in regulating the secretory function of the choroid plexus.
• E2F-5 is not essential for cell proliferation but influences the secretory behavior of differentiated neural tissue.
• Disruption of E2F-5 function leads to excessive CSF production and hydrocephalus.