Effect of myonuclear number and mitochondrial fusion on Drosophila indirect flight muscle organization and size

Journal Article · Tue Oct 15 04:00:00 EDT 2013 · Experimental Cell Research

DOI:https://doi.org/10.1016/J.YEXCR.2013.06.021· OSTI ID:22278174

Rai, Mamta; Nongthomba, Upendra

Mechanisms involved in establishing the organization and numbers of fibres in a muscle are not completely understood. During Drosophila indirect flight muscle (IFM) formation, muscle growth is achieved by both incorporating hundreds of nuclei, and hypertrophy. As a result, IFMs provide a good model with which to understand the mechanisms that govern overall muscle organization and growth. We present a detailed analysis of the organization of dorsal longitudinal muscles (DLMs), a subset of the IFMs. We show that each DLM is similar to a vertebrate fascicle and consists of multiple muscle fibres. However, increased fascicle size does not necessarily change the number of constituent fibres, but does increase the number of myofibrils packed within the fibres. We also find that altering the number of myoblasts available for fusion changes DLM fascicle size and fibres are loosely packed with myofibrils. Additionally, we show that knock down of genes required for mitochondrial fusion causes a severe reduction in the size of DLM fascicles and fibres. Our results establish the organization levels of DLMs and highlight the importance of the appropriate number of nuclei and mitochondrial fusion in determining the overall organization, growth and size of DLMs. - Highlights: • Drosophila dorsal longitudinal muscles are similar to vertebrate skeletal muscles. • A threshold number of myoblasts governs the organization of a fibre and its size. • Mitochondrial fusion defect leads to abnormal fibre growth and organization.

• OSTI ID: 22278174
• Journal Information: Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 17 Vol. 319; ISSN 0014-4827; ISSN ECREAL
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
DROSOPHILA
GROWTH
HYPERTROPHY
MITOCHONDRIA
MYOBLASTS
VERTEBRATES