NEWS In embryonic studies, Umeå University researchers have found that bone morphogenetic protein (BMP) signals both trigger and regulate the formation of sensory cells for smell, hearing and vision. In addition, BMP activity plays a crucial role for the early development of the lens and the retina, two important structures of the eye. This is according to a doctoral dissertation at Umeå University.
“Understanding how the different cell types of the sensory organs are generated during the course of embryonic development is important to understand how we develop our senses needed to perceive the world,” says Vijay Kumar Jidigam, doctoral student at the Umeå Centre for Molecular Medicine (UCMM).
“We have identified a BMP-regulated mechanism for sensory placode invagination, which is a morphological process where flat cell sheets transform into three-dimensional structures.”
The nervous system is composed of two separate parts, the peripheral nervous system (PNS) and the central nervous system (CNS). The PNS includes olfactory (smell), otic (hearing) and lens (vision) sensory cells which transmit sensory information to the brain.
Together with his research colleagues at UCMM, Vijay Kumar Jidigam has studied the formation of sensory organs. The researcher has studied olfactory, otic and lens placodes, which develop from the region that gives rise to the PNS during early embryonic development. The sensory organs are initially visible as a thickened region of the head ectoderm called placode. Shortly after thickening, the placodes bend inwards to form three-dimensional cup-like structures (pictured). This crucial step for the development of sensory organs is a process known as placode invagination.
“We have studied the signals involved in placode invagination to see if there is a common regulatory molecular mechanism for all sensory placode invaginations, or if the process is controlled by different mechanisms for each individual placode,” explains Vijay Kumar Jidigam. “Using a combination of in vitro and in vivo assays, we discovered that BMP signals were required for placode invagination during the formation of all three sensory organs, namely olfactory, otic and lens.”
Other important questions that Vijay has examined are how lens and retina cells are generated, and how the lens and retina interact with each other during eye development. Prior to the lens placode stage, BMP signals are essential for acquisition of lens identity whereas after the lens placode stage, the primary lens fibre cells become independent of BMP signals. In addition, BMP signals from the lens ectoderm are required for promoting retina character in part by suppressing forebrain identity.
“Interestingly, we found that in the absence of BMP activity, cultured lens cells developed olfactory characteristics. This emphasizes the importance of correct signaling information during embryonic development in order to generate cells with proper sensory identity,” says Vijay Kumar Jidigam.
Vijay Kumar Jidigam is from India. In addition Vijay is a doctoral student at Umeå Centre for Molecular Medicine (UCMM). Vijay Kumar has an educational background in Master in Biotechnology and Masters in Molecular Biology.
Read a summary of the doctoral dissertation
On Friday May 20, Vijay Kumar Jidigam, Umeå Centre for Molecular Medicine (UCMM), is publicly defending his dissertation with the title BMP - a key signaling molecule in specification and morphogenesis of sensory structures. Faculty opponent: Professor Richard Lang, Visual Systems Groups, UC Department of pediatric, Cincinnati children's hospital. Principal supervisor: Professor Lena Gunhaga.
The public dissertation defense takes place at 9:00 in Hall B, Unod T9 (9th floor), Norrlands University Hospital (NUS).
Vijay Kumar Jidigam, Umeå Centre for Molecular Medicine (UCMM), Umeå UniversityPhone: 076-909 4579
Email: vijay.kumar.jidigam@umu.se
Editor: Daniel Harju