Non-apoptotic cell death in animal development

Cell Death Differ. 2017 Aug;24(8):1326-1336. doi: 10.1038/cdd.2017.20. Epub 2017 Feb 17.

Abstract

Programmed cell death (PCD) is an important process in the development of multicellular organisms. Apoptosis, a form of PCD characterized morphologically by chromatin condensation, membrane blebbing, and cytoplasm compaction, and molecularly by the activation of caspase proteases, has been extensively investigated. Studies in Caenorhabditis elegans, Drosophila, mice, and the developing chick have revealed, however, that developmental PCD also occurs through other mechanisms, morphologically and molecularly distinct from apoptosis. Some non-apoptotic PCD pathways, including those regulating germ cell death in Drosophila, still appear to employ caspases. However, another prominent cell death program, linker cell-type death (LCD), is morphologically conserved, and independent of the key genes that drive apoptosis, functioning, at least in part, through the ubiquitin proteasome system. These non-apoptotic processes may serve as backup programs when caspases are inactivated or unavailable, or, more likely, as freestanding cell culling programs. Non-apoptotic PCD has been documented extensively in the developing nervous system, and during the formation of germline and somatic gonadal structures, suggesting that preservation of these mechanisms is likely under strong selective pressure. Here, we discuss our current understanding of non-apoptotic PCD in animal development, and explore possible roles for LCD and other non-apoptotic developmental pathways in vertebrates. We raise the possibility that during vertebrate development, apoptosis may not be the major PCD mechanism.

Publication types

  • Review

MeSH terms

  • Animals
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans / metabolism
  • Caspases / genetics*
  • Caspases / metabolism
  • Cell Death / genetics*
  • Chick Embryo
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / growth & development
  • Drosophila melanogaster / metabolism
  • Gene Expression Regulation
  • Male
  • Mice
  • Ovum / cytology
  • Ovum / metabolism
  • Proteasome Endopeptidase Complex / metabolism*
  • Signal Transduction
  • Spermatozoa / cytology
  • Spermatozoa / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Ubiquitin / genetics*
  • Ubiquitin / metabolism

Substances

  • Transcription Factors
  • Ubiquitin
  • Caspases
  • Proteasome Endopeptidase Complex