Evolution of the insulin-like growth factor binding protein (IGFBP) family
2011 (English)In: Endocrinology, ISSN 0013-7227, E-ISSN 1945-7170, Vol. 152, no 6, 2278-2289 p.Article in journal (Refereed) Published
The evolution of the insulin-like growth factor binding protein (IGFBP) gene family has been difficult to resolve. The early discovery of IGFBP gene synteny with the HOX (homeobox) gene clusters suggested that IGFBP was quadrupled along with HOX in the ancestral vertebrate chromosome duplications. However, some recent articles have favored independent serial duplications of the IGFBP genes. By combining sequence-based phylogenies and chromosome information from multiple vertebrate species, we conclude that chromosome duplications did indeed expand the IGFBP repertoire. After the ancestral chordate IGFBP gene had undergone a local gene duplication, resulting in a gene pair adjacent to a HOX cluster, chromosome quadruplication of this pair took place in the two basal vertebrate tetraploidizations (2R). Subsequently one gene was lost from two of the four pairs, leading to six IGFBP genes in the fish-tetrapod ancestor. These six genes are presently found in placental mammals. In teleost fishes the situation is more complex: their third tetraploidization (3R) doubled the IGFBP repertoire from six to twelve members whereupon differential losses have occurred. The five sequenced teleost fish genomes retain 9-11 of IGFBP genes. This scenario is supported by the phylogenies of three adjacent gene families, namely the epidermal growth factor receptors (EGFR) and the Ikaros and distal-less (Dlx) transcription factors, in addition to the HOX clusters. The great ages for the IGFBP genes strongly suggest that they evolved distinct functions early in vertebrate evolution.
Place, publisher, year, edition, pages
2011. Vol. 152, no 6, 2278-2289 p.
IGFBP, IGF, growth regulation, genomics
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-129521DOI: 10.1210/en.2011-0047ISI: 000290788500015PubMedID: 21505050OAI: oai:DiVA.org:uu-129521DiVA: diva2:344172